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swiftshader/SwiftShader/104f72dbb79fc2faf28fa544c048cc65c52286c8/./third_party/llvm-16.0/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
blob: a93a82153165de54fd97a5cc7c63219eff781ef1 [file]
//===- OpenMPIRBuilder.cpp - Builder for LLVM-IR for OpenMP directives ----===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
/// \file
///
/// This file implements the OpenMPIRBuilder class, which is used as a
/// convenient way to create LLVM instructions for OpenMP directives.
///
//===----------------------------------------------------------------------===//
#include "llvm/Frontend/OpenMP/OMPIRBuilder.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/CodeMetrics.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/OptimizationRemarkEmitter.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/IR/CFG.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/MDBuilder.h"
#include "llvm/IR/PassManager.h"
#include "llvm/IR/Value.h"
#include "llvm/MC/TargetRegistry.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/Transforms/Utils/CodeExtractor.h"
#include "llvm/Transforms/Utils/LoopPeel.h"
#include "llvm/Transforms/Utils/UnrollLoop.h"
#include <cstdint>
#include <optional>
#define DEBUG_TYPE "openmp-ir-builder"
using namespace llvm;
using namespace omp;
static cl::opt<bool>
OptimisticAttributes("openmp-ir-builder-optimistic-attributes", cl::Hidden,
cl::desc("Use optimistic attributes describing "
"'as-if' properties of runtime calls."),
cl::init(false));
static cl::opt<double> UnrollThresholdFactor(
"openmp-ir-builder-unroll-threshold-factor", cl::Hidden,
cl::desc("Factor for the unroll threshold to account for code "
"simplifications still taking place"),
cl::init(1.5));
#ifndef NDEBUG
/// Return whether IP1 and IP2 are ambiguous, i.e. that inserting instructions
/// at position IP1 may change the meaning of IP2 or vice-versa. This is because
/// an InsertPoint stores the instruction before something is inserted. For
/// instance, if both point to the same instruction, two IRBuilders alternating
/// creating instruction will cause the instructions to be interleaved.
static bool isConflictIP(IRBuilder<>::InsertPoint IP1,
IRBuilder<>::InsertPoint IP2) {
if (!IP1.isSet() || !IP2.isSet())
return false;
return IP1.getBlock() == IP2.getBlock() && IP1.getPoint() == IP2.getPoint();
}
static bool isValidWorkshareLoopScheduleType(OMPScheduleType SchedType) {
// Valid ordered/unordered and base algorithm combinations.
switch (SchedType & ~OMPScheduleType::MonotonicityMask) {
case OMPScheduleType::UnorderedStaticChunked:
case OMPScheduleType::UnorderedStatic:
case OMPScheduleType::UnorderedDynamicChunked:
case OMPScheduleType::UnorderedGuidedChunked:
case OMPScheduleType::UnorderedRuntime:
case OMPScheduleType::UnorderedAuto:
case OMPScheduleType::UnorderedTrapezoidal:
case OMPScheduleType::UnorderedGreedy:
case OMPScheduleType::UnorderedBalanced:
case OMPScheduleType::UnorderedGuidedIterativeChunked:
case OMPScheduleType::UnorderedGuidedAnalyticalChunked:
case OMPScheduleType::UnorderedSteal:
case OMPScheduleType::UnorderedStaticBalancedChunked:
case OMPScheduleType::UnorderedGuidedSimd:
case OMPScheduleType::UnorderedRuntimeSimd:
case OMPScheduleType::OrderedStaticChunked:
case OMPScheduleType::OrderedStatic:
case OMPScheduleType::OrderedDynamicChunked:
case OMPScheduleType::OrderedGuidedChunked:
case OMPScheduleType::OrderedRuntime:
case OMPScheduleType::OrderedAuto:
case OMPScheduleType::OrderdTrapezoidal:
case OMPScheduleType::NomergeUnorderedStaticChunked:
case OMPScheduleType::NomergeUnorderedStatic:
case OMPScheduleType::NomergeUnorderedDynamicChunked:
case OMPScheduleType::NomergeUnorderedGuidedChunked:
case OMPScheduleType::NomergeUnorderedRuntime:
case OMPScheduleType::NomergeUnorderedAuto:
case OMPScheduleType::NomergeUnorderedTrapezoidal:
case OMPScheduleType::NomergeUnorderedGreedy:
case OMPScheduleType::NomergeUnorderedBalanced:
case OMPScheduleType::NomergeUnorderedGuidedIterativeChunked:
case OMPScheduleType::NomergeUnorderedGuidedAnalyticalChunked:
case OMPScheduleType::NomergeUnorderedSteal:
case OMPScheduleType::NomergeOrderedStaticChunked:
case OMPScheduleType::NomergeOrderedStatic:
case OMPScheduleType::NomergeOrderedDynamicChunked:
case OMPScheduleType::NomergeOrderedGuidedChunked:
case OMPScheduleType::NomergeOrderedRuntime:
case OMPScheduleType::NomergeOrderedAuto:
case OMPScheduleType::NomergeOrderedTrapezoidal:
break;
default:
return false;
}
// Must not set both monotonicity modifiers at the same time.
OMPScheduleType MonotonicityFlags =
SchedType & OMPScheduleType::MonotonicityMask;
if (MonotonicityFlags == OMPScheduleType::MonotonicityMask)
return false;
return true;
}
#endif
/// Determine which scheduling algorithm to use, determined from schedule clause
/// arguments.
static OMPScheduleType
getOpenMPBaseScheduleType(llvm::omp::ScheduleKind ClauseKind, bool HasChunks,
bool HasSimdModifier) {
// Currently, the default schedule it static.
switch (ClauseKind) {
case OMP_SCHEDULE_Default:
case OMP_SCHEDULE_Static:
return HasChunks ? OMPScheduleType::BaseStaticChunked
: OMPScheduleType::BaseStatic;
case OMP_SCHEDULE_Dynamic:
return OMPScheduleType::BaseDynamicChunked;
case OMP_SCHEDULE_Guided:
return HasSimdModifier ? OMPScheduleType::BaseGuidedSimd
: OMPScheduleType::BaseGuidedChunked;
case OMP_SCHEDULE_Auto:
return llvm::omp::OMPScheduleType::BaseAuto;
case OMP_SCHEDULE_Runtime:
return HasSimdModifier ? OMPScheduleType::BaseRuntimeSimd
: OMPScheduleType::BaseRuntime;
}
llvm_unreachable("unhandled schedule clause argument");
}
/// Adds ordering modifier flags to schedule type.
static OMPScheduleType
getOpenMPOrderingScheduleType(OMPScheduleType BaseScheduleType,
bool HasOrderedClause) {
assert((BaseScheduleType & OMPScheduleType::ModifierMask) ==
OMPScheduleType::None &&
"Must not have ordering nor monotonicity flags already set");
OMPScheduleType OrderingModifier = HasOrderedClause
? OMPScheduleType::ModifierOrdered
: OMPScheduleType::ModifierUnordered;
OMPScheduleType OrderingScheduleType = BaseScheduleType | OrderingModifier;
// Unsupported combinations
if (OrderingScheduleType ==
(OMPScheduleType::BaseGuidedSimd | OMPScheduleType::ModifierOrdered))
return OMPScheduleType::OrderedGuidedChunked;
else if (OrderingScheduleType == (OMPScheduleType::BaseRuntimeSimd |
OMPScheduleType::ModifierOrdered))
return OMPScheduleType::OrderedRuntime;
return OrderingScheduleType;
}
/// Adds monotonicity modifier flags to schedule type.
static OMPScheduleType
getOpenMPMonotonicityScheduleType(OMPScheduleType ScheduleType,
bool HasSimdModifier, bool HasMonotonic,
bool HasNonmonotonic, bool HasOrderedClause) {
assert((ScheduleType & OMPScheduleType::MonotonicityMask) ==
OMPScheduleType::None &&
"Must not have monotonicity flags already set");
assert((!HasMonotonic || !HasNonmonotonic) &&
"Monotonic and Nonmonotonic are contradicting each other");
if (HasMonotonic) {
return ScheduleType | OMPScheduleType::ModifierMonotonic;
} else if (HasNonmonotonic) {
return ScheduleType | OMPScheduleType::ModifierNonmonotonic;
} else {
// OpenMP 5.1, 2.11.4 Worksharing-Loop Construct, Description.
// If the static schedule kind is specified or if the ordered clause is
// specified, and if the nonmonotonic modifier is not specified, the
// effect is as if the monotonic modifier is specified. Otherwise, unless
// the monotonic modifier is specified, the effect is as if the
// nonmonotonic modifier is specified.
OMPScheduleType BaseScheduleType =
ScheduleType & ~OMPScheduleType::ModifierMask;
if ((BaseScheduleType == OMPScheduleType::BaseStatic) ||
(BaseScheduleType == OMPScheduleType::BaseStaticChunked) ||
HasOrderedClause) {
// The monotonic is used by default in openmp runtime library, so no need
// to set it.
return ScheduleType;
} else {
return ScheduleType | OMPScheduleType::ModifierNonmonotonic;
}
}
}
/// Determine the schedule type using schedule and ordering clause arguments.
static OMPScheduleType
computeOpenMPScheduleType(ScheduleKind ClauseKind, bool HasChunks,
bool HasSimdModifier, bool HasMonotonicModifier,
bool HasNonmonotonicModifier, bool HasOrderedClause) {
OMPScheduleType BaseSchedule =
getOpenMPBaseScheduleType(ClauseKind, HasChunks, HasSimdModifier);
OMPScheduleType OrderedSchedule =
getOpenMPOrderingScheduleType(BaseSchedule, HasOrderedClause);
OMPScheduleType Result = getOpenMPMonotonicityScheduleType(
OrderedSchedule, HasSimdModifier, HasMonotonicModifier,
HasNonmonotonicModifier, HasOrderedClause);
assert(isValidWorkshareLoopScheduleType(Result));
return Result;
}
/// Make \p Source branch to \p Target.
///
/// Handles two situations:
/// * \p Source already has an unconditional branch.
/// * \p Source is a degenerate block (no terminator because the BB is
/// the current head of the IR construction).
static void redirectTo(BasicBlock *Source, BasicBlock *Target, DebugLoc DL) {
if (Instruction *Term = Source->getTerminator()) {
auto *Br = cast<BranchInst>(Term);
assert(!Br->isConditional() &&
"BB's terminator must be an unconditional branch (or degenerate)");
BasicBlock *Succ = Br->getSuccessor(0);
Succ->removePredecessor(Source, /*KeepOneInputPHIs=*/true);
Br->setSuccessor(0, Target);
return;
}
auto *NewBr = BranchInst::Create(Target, Source);
NewBr->setDebugLoc(DL);
}
void llvm::spliceBB(IRBuilderBase::InsertPoint IP, BasicBlock *New,
bool CreateBranch) {
assert(New->getFirstInsertionPt() == New->begin() &&
"Target BB must not have PHI nodes");
// Move instructions to new block.
BasicBlock *Old = IP.getBlock();
New->splice(New->begin(), Old, IP.getPoint(), Old->end());
if (CreateBranch)
BranchInst::Create(New, Old);
}
void llvm::spliceBB(IRBuilder<> &Builder, BasicBlock *New, bool CreateBranch) {
DebugLoc DebugLoc = Builder.getCurrentDebugLocation();
BasicBlock *Old = Builder.GetInsertBlock();
spliceBB(Builder.saveIP(), New, CreateBranch);
if (CreateBranch)
Builder.SetInsertPoint(Old->getTerminator());
else
Builder.SetInsertPoint(Old);
// SetInsertPoint also updates the Builder's debug location, but we want to
// keep the one the Builder was configured to use.
Builder.SetCurrentDebugLocation(DebugLoc);
}
BasicBlock *llvm::splitBB(IRBuilderBase::InsertPoint IP, bool CreateBranch,
llvm::Twine Name) {
BasicBlock *Old = IP.getBlock();
BasicBlock *New = BasicBlock::Create(
Old->getContext(), Name.isTriviallyEmpty() ? Old->getName() : Name,
Old->getParent(), Old->getNextNode());
spliceBB(IP, New, CreateBranch);
New->replaceSuccessorsPhiUsesWith(Old, New);
return New;
}
BasicBlock *llvm::splitBB(IRBuilderBase &Builder, bool CreateBranch,
llvm::Twine Name) {
DebugLoc DebugLoc = Builder.getCurrentDebugLocation();
BasicBlock *New = splitBB(Builder.saveIP(), CreateBranch, Name);
if (CreateBranch)
Builder.SetInsertPoint(Builder.GetInsertBlock()->getTerminator());
else
Builder.SetInsertPoint(Builder.GetInsertBlock());
// SetInsertPoint also updates the Builder's debug location, but we want to
// keep the one the Builder was configured to use.
Builder.SetCurrentDebugLocation(DebugLoc);
return New;
}
BasicBlock *llvm::splitBB(IRBuilder<> &Builder, bool CreateBranch,
llvm::Twine Name) {
DebugLoc DebugLoc = Builder.getCurrentDebugLocation();
BasicBlock *New = splitBB(Builder.saveIP(), CreateBranch, Name);
if (CreateBranch)
Builder.SetInsertPoint(Builder.GetInsertBlock()->getTerminator());
else
Builder.SetInsertPoint(Builder.GetInsertBlock());
// SetInsertPoint also updates the Builder's debug location, but we want to
// keep the one the Builder was configured to use.
Builder.SetCurrentDebugLocation(DebugLoc);
return New;
}
BasicBlock *llvm::splitBBWithSuffix(IRBuilderBase &Builder, bool CreateBranch,
llvm::Twine Suffix) {
BasicBlock *Old = Builder.GetInsertBlock();
return splitBB(Builder, CreateBranch, Old->getName() + Suffix);
}
void OpenMPIRBuilder::addAttributes(omp::RuntimeFunction FnID, Function &Fn) {
LLVMContext &Ctx = Fn.getContext();
Triple T(M.getTargetTriple());
// Get the function's current attributes.
auto Attrs = Fn.getAttributes();
auto FnAttrs = Attrs.getFnAttrs();
auto RetAttrs = Attrs.getRetAttrs();
SmallVector<AttributeSet, 4> ArgAttrs;
for (size_t ArgNo = 0; ArgNo < Fn.arg_size(); ++ArgNo)
ArgAttrs.emplace_back(Attrs.getParamAttrs(ArgNo));
// Add AS to FnAS while taking special care with integer extensions.
auto addAttrSet = [&](AttributeSet &FnAS, const AttributeSet &AS,
bool Param = true) -> void {
bool HasSignExt = AS.hasAttribute(Attribute::SExt);
bool HasZeroExt = AS.hasAttribute(Attribute::ZExt);
if (HasSignExt || HasZeroExt) {
assert(AS.getNumAttributes() == 1 &&
"Currently not handling extension attr combined with others.");
if (Param) {
if (auto AK = TargetLibraryInfo::getExtAttrForI32Param(T, HasSignExt))
FnAS = FnAS.addAttribute(Ctx, AK);
} else
if (auto AK = TargetLibraryInfo::getExtAttrForI32Return(T, HasSignExt))
FnAS = FnAS.addAttribute(Ctx, AK);
} else {
FnAS = FnAS.addAttributes(Ctx, AS);
}
};
#define OMP_ATTRS_SET(VarName, AttrSet) AttributeSet VarName = AttrSet;
#include "llvm/Frontend/OpenMP/OMPKinds.def"
// Add attributes to the function declaration.
switch (FnID) {
#define OMP_RTL_ATTRS(Enum, FnAttrSet, RetAttrSet, ArgAttrSets) \
case Enum: \
FnAttrs = FnAttrs.addAttributes(Ctx, FnAttrSet); \
addAttrSet(RetAttrs, RetAttrSet, /*Param*/false); \
for (size_t ArgNo = 0; ArgNo < ArgAttrSets.size(); ++ArgNo) \
addAttrSet(ArgAttrs[ArgNo], ArgAttrSets[ArgNo]); \
Fn.setAttributes(AttributeList::get(Ctx, FnAttrs, RetAttrs, ArgAttrs)); \
break;
#include "llvm/Frontend/OpenMP/OMPKinds.def"
default:
// Attributes are optional.
break;
}
}
FunctionCallee
OpenMPIRBuilder::getOrCreateRuntimeFunction(Module &M, RuntimeFunction FnID) {
FunctionType *FnTy = nullptr;
Function *Fn = nullptr;
// Try to find the declation in the module first.
switch (FnID) {
#define OMP_RTL(Enum, Str, IsVarArg, ReturnType, ...) \
case Enum: \
FnTy = FunctionType::get(ReturnType, ArrayRef<Type *>{__VA_ARGS__}, \
IsVarArg); \
Fn = M.getFunction(Str); \
break;
#include "llvm/Frontend/OpenMP/OMPKinds.def"
}
if (!Fn) {
// Create a new declaration if we need one.
switch (FnID) {
#define OMP_RTL(Enum, Str, ...) \
case Enum: \
Fn = Function::Create(FnTy, GlobalValue::ExternalLinkage, Str, M); \
break;
#include "llvm/Frontend/OpenMP/OMPKinds.def"
}
// Add information if the runtime function takes a callback function
if (FnID == OMPRTL___kmpc_fork_call || FnID == OMPRTL___kmpc_fork_teams) {
if (!Fn->hasMetadata(LLVMContext::MD_callback)) {
LLVMContext &Ctx = Fn->getContext();
MDBuilder MDB(Ctx);
// Annotate the callback behavior of the runtime function:
// - The callback callee is argument number 2 (microtask).
// - The first two arguments of the callback callee are unknown (-1).
// - All variadic arguments to the runtime function are passed to the
// callback callee.
Fn->addMetadata(
LLVMContext::MD_callback,
*MDNode::get(Ctx, {MDB.createCallbackEncoding(
2, {-1, -1}, /* VarArgsArePassed */ true)}));
}
}
LLVM_DEBUG(dbgs() << "Created OpenMP runtime function " << Fn->getName()
<< " with type " << *Fn->getFunctionType() << "\n");
addAttributes(FnID, *Fn);
} else {
LLVM_DEBUG(dbgs() << "Found OpenMP runtime function " << Fn->getName()
<< " with type " << *Fn->getFunctionType() << "\n");
}
assert(Fn && "Failed to create OpenMP runtime function");
// Cast the function to the expected type if necessary
Constant *C = ConstantExpr::getBitCast(Fn, FnTy->getPointerTo());
return {FnTy, C};
}
Function *OpenMPIRBuilder::getOrCreateRuntimeFunctionPtr(RuntimeFunction FnID) {
FunctionCallee RTLFn = getOrCreateRuntimeFunction(M, FnID);
auto *Fn = dyn_cast<llvm::Function>(RTLFn.getCallee());
assert(Fn && "Failed to create OpenMP runtime function pointer");
return Fn;
}
void OpenMPIRBuilder::initialize() { initializeTypes(M); }
void OpenMPIRBuilder::finalize(Function *Fn) {
SmallPtrSet<BasicBlock *, 32> ParallelRegionBlockSet;
SmallVector<BasicBlock *, 32> Blocks;
SmallVector<OutlineInfo, 16> DeferredOutlines;
for (OutlineInfo &OI : OutlineInfos) {
// Skip functions that have not finalized yet; may happen with nested
// function generation.
if (Fn && OI.getFunction() != Fn) {
DeferredOutlines.push_back(OI);
continue;
}
ParallelRegionBlockSet.clear();
Blocks.clear();
OI.collectBlocks(ParallelRegionBlockSet, Blocks);
Function *OuterFn = OI.getFunction();
CodeExtractorAnalysisCache CEAC(*OuterFn);
CodeExtractor Extractor(Blocks, /* DominatorTree */ nullptr,
/* AggregateArgs */ true,
/* BlockFrequencyInfo */ nullptr,
/* BranchProbabilityInfo */ nullptr,
/* AssumptionCache */ nullptr,
/* AllowVarArgs */ true,
/* AllowAlloca */ true,
/* AllocaBlock*/ OI.OuterAllocaBB,
/* Suffix */ ".omp_par");
LLVM_DEBUG(dbgs() << "Before outlining: " << *OuterFn << "\n");
LLVM_DEBUG(dbgs() << "Entry " << OI.EntryBB->getName()
<< " Exit: " << OI.ExitBB->getName() << "\n");
assert(Extractor.isEligible() &&
"Expected OpenMP outlining to be possible!");
for (auto *V : OI.ExcludeArgsFromAggregate)
Extractor.excludeArgFromAggregate(V);
Function *OutlinedFn = Extractor.extractCodeRegion(CEAC);
LLVM_DEBUG(dbgs() << "After outlining: " << *OuterFn << "\n");
LLVM_DEBUG(dbgs() << " Outlined function: " << *OutlinedFn << "\n");
assert(OutlinedFn->getReturnType()->isVoidTy() &&
"OpenMP outlined functions should not return a value!");
// For compability with the clang CG we move the outlined function after the
// one with the parallel region.
OutlinedFn->removeFromParent();
M.getFunctionList().insertAfter(OuterFn->getIterator(), OutlinedFn);
// Remove the artificial entry introduced by the extractor right away, we
// made our own entry block after all.
{
BasicBlock &ArtificialEntry = OutlinedFn->getEntryBlock();
assert(ArtificialEntry.getUniqueSuccessor() == OI.EntryBB);
assert(OI.EntryBB->getUniquePredecessor() == &ArtificialEntry);
// Move instructions from the to-be-deleted ArtificialEntry to the entry
// basic block of the parallel region. CodeExtractor generates
// instructions to unwrap the aggregate argument and may sink
// allocas/bitcasts for values that are solely used in the outlined region
// and do not escape.
assert(!ArtificialEntry.empty() &&
"Expected instructions to add in the outlined region entry");
for (BasicBlock::reverse_iterator It = ArtificialEntry.rbegin(),
End = ArtificialEntry.rend();
It != End;) {
Instruction &I = *It;
It++;
if (I.isTerminator())
continue;
I.moveBefore(*OI.EntryBB, OI.EntryBB->getFirstInsertionPt());
}
OI.EntryBB->moveBefore(&ArtificialEntry);
ArtificialEntry.eraseFromParent();
}
assert(&OutlinedFn->getEntryBlock() == OI.EntryBB);
assert(OutlinedFn && OutlinedFn->getNumUses() == 1);
// Run a user callback, e.g. to add attributes.
if (OI.PostOutlineCB)
OI.PostOutlineCB(*OutlinedFn);
}
// Remove work items that have been completed.
OutlineInfos = std::move(DeferredOutlines);
}
OpenMPIRBuilder::~OpenMPIRBuilder() {
assert(OutlineInfos.empty() && "There must be no outstanding outlinings");
}
GlobalValue *OpenMPIRBuilder::createGlobalFlag(unsigned Value, StringRef Name) {
IntegerType *I32Ty = Type::getInt32Ty(M.getContext());
auto *GV =
new GlobalVariable(M, I32Ty,
/* isConstant = */ true, GlobalValue::WeakODRLinkage,
ConstantInt::get(I32Ty, Value), Name);
GV->setVisibility(GlobalValue::HiddenVisibility);
return GV;
}
Constant *OpenMPIRBuilder::getOrCreateIdent(Constant *SrcLocStr,
uint32_t SrcLocStrSize,
IdentFlag LocFlags,
unsigned Reserve2Flags) {
// Enable "C-mode".
LocFlags |= OMP_IDENT_FLAG_KMPC;
Constant *&Ident =
IdentMap[{SrcLocStr, uint64_t(LocFlags) << 31 | Reserve2Flags}];
if (!Ident) {
Constant *I32Null = ConstantInt::getNullValue(Int32);
Constant *IdentData[] = {I32Null,
ConstantInt::get(Int32, uint32_t(LocFlags)),
ConstantInt::get(Int32, Reserve2Flags),
ConstantInt::get(Int32, SrcLocStrSize), SrcLocStr};
Constant *Initializer =
ConstantStruct::get(OpenMPIRBuilder::Ident, IdentData);
// Look for existing encoding of the location + flags, not needed but
// minimizes the difference to the existing solution while we transition.
for (GlobalVariable &GV : M.getGlobalList())
if (GV.getValueType() == OpenMPIRBuilder::Ident && GV.hasInitializer())
if (GV.getInitializer() == Initializer)
Ident = &GV;
if (!Ident) {
auto *GV = new GlobalVariable(
M, OpenMPIRBuilder::Ident,
/* isConstant = */ true, GlobalValue::PrivateLinkage, Initializer, "",
nullptr, GlobalValue::NotThreadLocal,
M.getDataLayout().getDefaultGlobalsAddressSpace());
GV->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
GV->setAlignment(Align(8));
Ident = GV;
}
}
return ConstantExpr::getPointerBitCastOrAddrSpaceCast(Ident, IdentPtr);
}
Constant *OpenMPIRBuilder::getOrCreateSrcLocStr(StringRef LocStr,
uint32_t &SrcLocStrSize) {
SrcLocStrSize = LocStr.size();
Constant *&SrcLocStr = SrcLocStrMap[LocStr];
if (!SrcLocStr) {
Constant *Initializer =
ConstantDataArray::getString(M.getContext(), LocStr);
// Look for existing encoding of the location, not needed but minimizes the
// difference to the existing solution while we transition.
for (GlobalVariable &GV : M.getGlobalList())
if (GV.isConstant() && GV.hasInitializer() &&
GV.getInitializer() == Initializer)
return SrcLocStr = ConstantExpr::getPointerCast(&GV, Int8Ptr);
SrcLocStr = Builder.CreateGlobalStringPtr(LocStr, /* Name */ "",
/* AddressSpace */ 0, &M);
}
return SrcLocStr;
}
Constant *OpenMPIRBuilder::getOrCreateSrcLocStr(StringRef FunctionName,
StringRef FileName,
unsigned Line, unsigned Column,
uint32_t &SrcLocStrSize) {
SmallString<128> Buffer;
Buffer.push_back(';');
Buffer.append(FileName);
Buffer.push_back(';');
Buffer.append(FunctionName);
Buffer.push_back(';');
Buffer.append(std::to_string(Line));
Buffer.push_back(';');
Buffer.append(std::to_string(Column));
Buffer.push_back(';');
Buffer.push_back(';');
return getOrCreateSrcLocStr(Buffer.str(), SrcLocStrSize);
}
Constant *
OpenMPIRBuilder::getOrCreateDefaultSrcLocStr(uint32_t &SrcLocStrSize) {
StringRef UnknownLoc = ";unknown;unknown;0;0;;";
return getOrCreateSrcLocStr(UnknownLoc, SrcLocStrSize);
}
Constant *OpenMPIRBuilder::getOrCreateSrcLocStr(DebugLoc DL,
uint32_t &SrcLocStrSize,
Function *F) {
DILocation *DIL = DL.get();
if (!DIL)
return getOrCreateDefaultSrcLocStr(SrcLocStrSize);
StringRef FileName = M.getName();
if (DIFile *DIF = DIL->getFile())
if (std::optional<StringRef> Source = DIF->getSource())
FileName = *Source;
StringRef Function = DIL->getScope()->getSubprogram()->getName();
if (Function.empty() && F)
Function = F->getName();
return getOrCreateSrcLocStr(Function, FileName, DIL->getLine(),
DIL->getColumn(), SrcLocStrSize);
}
Constant *OpenMPIRBuilder::getOrCreateSrcLocStr(const LocationDescription &Loc,
uint32_t &SrcLocStrSize) {
return getOrCreateSrcLocStr(Loc.DL, SrcLocStrSize,
Loc.IP.getBlock()->getParent());
}
Value *OpenMPIRBuilder::getOrCreateThreadID(Value *Ident) {
return Builder.CreateCall(
getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_global_thread_num), Ident,
"omp_global_thread_num");
}
OpenMPIRBuilder::InsertPointTy
OpenMPIRBuilder::createBarrier(const LocationDescription &Loc, Directive DK,
bool ForceSimpleCall, bool CheckCancelFlag) {
if (!updateToLocation(Loc))
return Loc.IP;
return emitBarrierImpl(Loc, DK, ForceSimpleCall, CheckCancelFlag);
}
OpenMPIRBuilder::InsertPointTy
OpenMPIRBuilder::emitBarrierImpl(const LocationDescription &Loc, Directive Kind,
bool ForceSimpleCall, bool CheckCancelFlag) {
// Build call __kmpc_cancel_barrier(loc, thread_id) or
// __kmpc_barrier(loc, thread_id);
IdentFlag BarrierLocFlags;
switch (Kind) {
case OMPD_for:
BarrierLocFlags = OMP_IDENT_FLAG_BARRIER_IMPL_FOR;
break;
case OMPD_sections:
BarrierLocFlags = OMP_IDENT_FLAG_BARRIER_IMPL_SECTIONS;
break;
case OMPD_single:
BarrierLocFlags = OMP_IDENT_FLAG_BARRIER_IMPL_SINGLE;
break;
case OMPD_barrier:
BarrierLocFlags = OMP_IDENT_FLAG_BARRIER_EXPL;
break;
default:
BarrierLocFlags = OMP_IDENT_FLAG_BARRIER_IMPL;
break;
}
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Args[] = {
getOrCreateIdent(SrcLocStr, SrcLocStrSize, BarrierLocFlags),
getOrCreateThreadID(getOrCreateIdent(SrcLocStr, SrcLocStrSize))};
// If we are in a cancellable parallel region, barriers are cancellation
// points.
// TODO: Check why we would force simple calls or to ignore the cancel flag.
bool UseCancelBarrier =
!ForceSimpleCall && isLastFinalizationInfoCancellable(OMPD_parallel);
Value *Result =
Builder.CreateCall(getOrCreateRuntimeFunctionPtr(
UseCancelBarrier ? OMPRTL___kmpc_cancel_barrier
: OMPRTL___kmpc_barrier),
Args);
if (UseCancelBarrier && CheckCancelFlag)
emitCancelationCheckImpl(Result, OMPD_parallel);
return Builder.saveIP();
}
OpenMPIRBuilder::InsertPointTy
OpenMPIRBuilder::createCancel(const LocationDescription &Loc,
Value *IfCondition,
omp::Directive CanceledDirective) {
if (!updateToLocation(Loc))
return Loc.IP;
// LLVM utilities like blocks with terminators.
auto *UI = Builder.CreateUnreachable();
Instruction *ThenTI = UI, *ElseTI = nullptr;
if (IfCondition)
SplitBlockAndInsertIfThenElse(IfCondition, UI, &ThenTI, &ElseTI);
Builder.SetInsertPoint(ThenTI);
Value *CancelKind = nullptr;
switch (CanceledDirective) {
#define OMP_CANCEL_KIND(Enum, Str, DirectiveEnum, Value) \
case DirectiveEnum: \
CancelKind = Builder.getInt32(Value); \
break;
#include "llvm/Frontend/OpenMP/OMPKinds.def"
default:
llvm_unreachable("Unknown cancel kind!");
}
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Value *Args[] = {Ident, getOrCreateThreadID(Ident), CancelKind};
Value *Result = Builder.CreateCall(
getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_cancel), Args);
auto ExitCB = [this, CanceledDirective, Loc](InsertPointTy IP) {
if (CanceledDirective == OMPD_parallel) {
IRBuilder<>::InsertPointGuard IPG(Builder);
Builder.restoreIP(IP);
createBarrier(LocationDescription(Builder.saveIP(), Loc.DL),
omp::Directive::OMPD_unknown, /* ForceSimpleCall */ false,
/* CheckCancelFlag */ false);
}
};
// The actual cancel logic is shared with others, e.g., cancel_barriers.
emitCancelationCheckImpl(Result, CanceledDirective, ExitCB);
// Update the insertion point and remove the terminator we introduced.
Builder.SetInsertPoint(UI->getParent());
UI->eraseFromParent();
return Builder.saveIP();
}
void OpenMPIRBuilder::emitOffloadingEntry(Constant *Addr, StringRef Name,
uint64_t Size, int32_t Flags,
StringRef SectionName) {
Type *Int8PtrTy = Type::getInt8PtrTy(M.getContext());
Type *Int32Ty = Type::getInt32Ty(M.getContext());
Type *SizeTy = M.getDataLayout().getIntPtrType(M.getContext());
Constant *AddrName = ConstantDataArray::getString(M.getContext(), Name);
// Create the constant string used to look up the symbol in the device.
auto *Str =
new llvm::GlobalVariable(M, AddrName->getType(), /*isConstant=*/true,
llvm::GlobalValue::InternalLinkage, AddrName,
".omp_offloading.entry_name");
Str->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
// Construct the offloading entry.
Constant *EntryData[] = {
ConstantExpr::getPointerBitCastOrAddrSpaceCast(Addr, Int8PtrTy),
ConstantExpr::getPointerBitCastOrAddrSpaceCast(Str, Int8PtrTy),
ConstantInt::get(SizeTy, Size),
ConstantInt::get(Int32Ty, Flags),
ConstantInt::get(Int32Ty, 0),
};
Constant *EntryInitializer =
ConstantStruct::get(OpenMPIRBuilder::OffloadEntry, EntryData);
auto *Entry = new GlobalVariable(
M, OpenMPIRBuilder::OffloadEntry,
/* isConstant = */ true, GlobalValue::WeakAnyLinkage, EntryInitializer,
".omp_offloading.entry." + Name, nullptr, GlobalValue::NotThreadLocal,
M.getDataLayout().getDefaultGlobalsAddressSpace());
// The entry has to be created in the section the linker expects it to be.
Entry->setSection(SectionName);
Entry->setAlignment(Align(1));
}
OpenMPIRBuilder::InsertPointTy OpenMPIRBuilder::emitTargetKernel(
const LocationDescription &Loc, Value *&Return, Value *Ident,
Value *DeviceID, Value *NumTeams, Value *NumThreads, Value *HostPtr,
ArrayRef<Value *> KernelArgs) {
if (!updateToLocation(Loc))
return Loc.IP;
auto *KernelArgsPtr =
Builder.CreateAlloca(OpenMPIRBuilder::KernelArgs, nullptr, "kernel_args");
for (unsigned I = 0, Size = KernelArgs.size(); I != Size; ++I) {
llvm::Value *Arg =
Builder.CreateStructGEP(OpenMPIRBuilder::KernelArgs, KernelArgsPtr, I);
Builder.CreateAlignedStore(
KernelArgs[I], Arg,
M.getDataLayout().getPrefTypeAlign(KernelArgs[I]->getType()));
}
SmallVector<Value *> OffloadingArgs{Ident, DeviceID, NumTeams,
NumThreads, HostPtr, KernelArgsPtr};
Return = Builder.CreateCall(
getOrCreateRuntimeFunction(M, OMPRTL___tgt_target_kernel),
OffloadingArgs);
return Builder.saveIP();
}
void OpenMPIRBuilder::emitCancelationCheckImpl(Value *CancelFlag,
omp::Directive CanceledDirective,
FinalizeCallbackTy ExitCB) {
assert(isLastFinalizationInfoCancellable(CanceledDirective) &&
"Unexpected cancellation!");
// For a cancel barrier we create two new blocks.
BasicBlock *BB = Builder.GetInsertBlock();
BasicBlock *NonCancellationBlock;
if (Builder.GetInsertPoint() == BB->end()) {
// TODO: This branch will not be needed once we moved to the
// OpenMPIRBuilder codegen completely.
NonCancellationBlock = BasicBlock::Create(
BB->getContext(), BB->getName() + ".cont", BB->getParent());
} else {
NonCancellationBlock = SplitBlock(BB, &*Builder.GetInsertPoint());
BB->getTerminator()->eraseFromParent();
Builder.SetInsertPoint(BB);
}
BasicBlock *CancellationBlock = BasicBlock::Create(
BB->getContext(), BB->getName() + ".cncl", BB->getParent());
// Jump to them based on the return value.
Value *Cmp = Builder.CreateIsNull(CancelFlag);
Builder.CreateCondBr(Cmp, NonCancellationBlock, CancellationBlock,
/* TODO weight */ nullptr, nullptr);
// From the cancellation block we finalize all variables and go to the
// post finalization block that is known to the FiniCB callback.
Builder.SetInsertPoint(CancellationBlock);
if (ExitCB)
ExitCB(Builder.saveIP());
auto &FI = FinalizationStack.back();
FI.FiniCB(Builder.saveIP());
// The continuation block is where code generation continues.
Builder.SetInsertPoint(NonCancellationBlock, NonCancellationBlock->begin());
}
IRBuilder<>::InsertPoint OpenMPIRBuilder::createParallel(
const LocationDescription &Loc, InsertPointTy OuterAllocaIP,
BodyGenCallbackTy BodyGenCB, PrivatizeCallbackTy PrivCB,
FinalizeCallbackTy FiniCB, Value *IfCondition, Value *NumThreads,
omp::ProcBindKind ProcBind, bool IsCancellable) {
assert(!isConflictIP(Loc.IP, OuterAllocaIP) && "IPs must not be ambiguous");
if (!updateToLocation(Loc))
return Loc.IP;
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Value *ThreadID = getOrCreateThreadID(Ident);
if (NumThreads) {
// Build call __kmpc_push_num_threads(&Ident, global_tid, num_threads)
Value *Args[] = {
Ident, ThreadID,
Builder.CreateIntCast(NumThreads, Int32, /*isSigned*/ false)};
Builder.CreateCall(
getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_push_num_threads), Args);
}
if (ProcBind != OMP_PROC_BIND_default) {
// Build call __kmpc_push_proc_bind(&Ident, global_tid, proc_bind)
Value *Args[] = {
Ident, ThreadID,
ConstantInt::get(Int32, unsigned(ProcBind), /*isSigned=*/true)};
Builder.CreateCall(
getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_push_proc_bind), Args);
}
BasicBlock *InsertBB = Builder.GetInsertBlock();
Function *OuterFn = InsertBB->getParent();
// Save the outer alloca block because the insertion iterator may get
// invalidated and we still need this later.
BasicBlock *OuterAllocaBlock = OuterAllocaIP.getBlock();
// Vector to remember instructions we used only during the modeling but which
// we want to delete at the end.
SmallVector<Instruction *, 4> ToBeDeleted;
// Change the location to the outer alloca insertion point to create and
// initialize the allocas we pass into the parallel region.
Builder.restoreIP(OuterAllocaIP);
AllocaInst *TIDAddr = Builder.CreateAlloca(Int32, nullptr, "tid.addr");
AllocaInst *ZeroAddr = Builder.CreateAlloca(Int32, nullptr, "zero.addr");
// We only need TIDAddr and ZeroAddr for modeling purposes to get the
// associated arguments in the outlined function, so we delete them later.
ToBeDeleted.push_back(TIDAddr);
ToBeDeleted.push_back(ZeroAddr);
// Create an artificial insertion point that will also ensure the blocks we
// are about to split are not degenerated.
auto *UI = new UnreachableInst(Builder.getContext(), InsertBB);
BasicBlock *EntryBB = UI->getParent();
BasicBlock *PRegEntryBB = EntryBB->splitBasicBlock(UI, "omp.par.entry");
BasicBlock *PRegBodyBB = PRegEntryBB->splitBasicBlock(UI, "omp.par.region");
BasicBlock *PRegPreFiniBB =
PRegBodyBB->splitBasicBlock(UI, "omp.par.pre_finalize");
BasicBlock *PRegExitBB = PRegPreFiniBB->splitBasicBlock(UI, "omp.par.exit");
auto FiniCBWrapper = [&](InsertPointTy IP) {
// Hide "open-ended" blocks from the given FiniCB by setting the right jump
// target to the region exit block.
if (IP.getBlock()->end() == IP.getPoint()) {
IRBuilder<>::InsertPointGuard IPG(Builder);
Builder.restoreIP(IP);
Instruction *I = Builder.CreateBr(PRegExitBB);
IP = InsertPointTy(I->getParent(), I->getIterator());
}
assert(IP.getBlock()->getTerminator()->getNumSuccessors() == 1 &&
IP.getBlock()->getTerminator()->getSuccessor(0) == PRegExitBB &&
"Unexpected insertion point for finalization call!");
return FiniCB(IP);
};
FinalizationStack.push_back({FiniCBWrapper, OMPD_parallel, IsCancellable});
// Generate the privatization allocas in the block that will become the entry
// of the outlined function.
Builder.SetInsertPoint(PRegEntryBB->getTerminator());
InsertPointTy InnerAllocaIP = Builder.saveIP();
AllocaInst *PrivTIDAddr =
Builder.CreateAlloca(Int32, nullptr, "tid.addr.local");
Instruction *PrivTID = Builder.CreateLoad(Int32, PrivTIDAddr, "tid");
// Add some fake uses for OpenMP provided arguments.
ToBeDeleted.push_back(Builder.CreateLoad(Int32, TIDAddr, "tid.addr.use"));
Instruction *ZeroAddrUse =
Builder.CreateLoad(Int32, ZeroAddr, "zero.addr.use");
ToBeDeleted.push_back(ZeroAddrUse);
// EntryBB
// |
// V
// PRegionEntryBB <- Privatization allocas are placed here.
// |
// V
// PRegionBodyBB <- BodeGen is invoked here.
// |
// V
// PRegPreFiniBB <- The block we will start finalization from.
// |
// V
// PRegionExitBB <- A common exit to simplify block collection.
//
LLVM_DEBUG(dbgs() << "Before body codegen: " << *OuterFn << "\n");
// Let the caller create the body.
assert(BodyGenCB && "Expected body generation callback!");
InsertPointTy CodeGenIP(PRegBodyBB, PRegBodyBB->begin());
BodyGenCB(InnerAllocaIP, CodeGenIP);
LLVM_DEBUG(dbgs() << "After body codegen: " << *OuterFn << "\n");
FunctionCallee RTLFn;
if (IfCondition)
RTLFn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_fork_call_if);
else
RTLFn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_fork_call);
if (auto *F = dyn_cast<llvm::Function>(RTLFn.getCallee())) {
if (!F->hasMetadata(llvm::LLVMContext::MD_callback)) {
llvm::LLVMContext &Ctx = F->getContext();
MDBuilder MDB(Ctx);
// Annotate the callback behavior of the __kmpc_fork_call:
// - The callback callee is argument number 2 (microtask).
// - The first two arguments of the callback callee are unknown (-1).
// - All variadic arguments to the __kmpc_fork_call are passed to the
// callback callee.
F->addMetadata(
llvm::LLVMContext::MD_callback,
*llvm::MDNode::get(
Ctx, {MDB.createCallbackEncoding(2, {-1, -1},
/* VarArgsArePassed */ true)}));
}
}
OutlineInfo OI;
OI.PostOutlineCB = [=, this](Function &OutlinedFn) {
// Add some known attributes.
OutlinedFn.addParamAttr(0, Attribute::NoAlias);
OutlinedFn.addParamAttr(1, Attribute::NoAlias);
OutlinedFn.addFnAttr(Attribute::NoUnwind);
OutlinedFn.addFnAttr(Attribute::NoRecurse);
assert(OutlinedFn.arg_size() >= 2 &&
"Expected at least tid and bounded tid as arguments");
unsigned NumCapturedVars =
OutlinedFn.arg_size() - /* tid & bounded tid */ 2;
CallInst *CI = cast<CallInst>(OutlinedFn.user_back());
CI->getParent()->setName("omp_parallel");
Builder.SetInsertPoint(CI);
// Build call __kmpc_fork_call[_if](Ident, n, microtask, var1, .., varn);
Value *ForkCallArgs[] = {
Ident, Builder.getInt32(NumCapturedVars),
Builder.CreateBitCast(&OutlinedFn, ParallelTaskPtr)};
SmallVector<Value *, 16> RealArgs;
RealArgs.append(std::begin(ForkCallArgs), std::end(ForkCallArgs));
if (IfCondition) {
Value *Cond = Builder.CreateSExtOrTrunc(IfCondition,
Type::getInt32Ty(M.getContext()));
RealArgs.push_back(Cond);
}
RealArgs.append(CI->arg_begin() + /* tid & bound tid */ 2, CI->arg_end());
// __kmpc_fork_call_if always expects a void ptr as the last argument
// If there are no arguments, pass a null pointer.
auto PtrTy = Type::getInt8PtrTy(M.getContext());
if (IfCondition && NumCapturedVars == 0) {
llvm::Value *Void = ConstantPointerNull::get(PtrTy);
RealArgs.push_back(Void);
}
if (IfCondition && RealArgs.back()->getType() != PtrTy)
RealArgs.back() = Builder.CreateBitCast(RealArgs.back(), PtrTy);
Builder.CreateCall(RTLFn, RealArgs);
LLVM_DEBUG(dbgs() << "With fork_call placed: "
<< *Builder.GetInsertBlock()->getParent() << "\n");
InsertPointTy ExitIP(PRegExitBB, PRegExitBB->end());
// Initialize the local TID stack location with the argument value.
Builder.SetInsertPoint(PrivTID);
Function::arg_iterator OutlinedAI = OutlinedFn.arg_begin();
Builder.CreateStore(Builder.CreateLoad(Int32, OutlinedAI), PrivTIDAddr);
CI->eraseFromParent();
for (Instruction *I : ToBeDeleted)
I->eraseFromParent();
};
// Adjust the finalization stack, verify the adjustment, and call the
// finalize function a last time to finalize values between the pre-fini
// block and the exit block if we left the parallel "the normal way".
auto FiniInfo = FinalizationStack.pop_back_val();
(void)FiniInfo;
assert(FiniInfo.DK == OMPD_parallel &&
"Unexpected finalization stack state!");
Instruction *PRegPreFiniTI = PRegPreFiniBB->getTerminator();
InsertPointTy PreFiniIP(PRegPreFiniBB, PRegPreFiniTI->getIterator());
FiniCB(PreFiniIP);
OI.OuterAllocaBB = OuterAllocaBlock;
OI.EntryBB = PRegEntryBB;
OI.ExitBB = PRegExitBB;
SmallPtrSet<BasicBlock *, 32> ParallelRegionBlockSet;
SmallVector<BasicBlock *, 32> Blocks;
OI.collectBlocks(ParallelRegionBlockSet, Blocks);
// Ensure a single exit node for the outlined region by creating one.
// We might have multiple incoming edges to the exit now due to finalizations,
// e.g., cancel calls that cause the control flow to leave the region.
BasicBlock *PRegOutlinedExitBB = PRegExitBB;
PRegExitBB = SplitBlock(PRegExitBB, &*PRegExitBB->getFirstInsertionPt());
PRegOutlinedExitBB->setName("omp.par.outlined.exit");
Blocks.push_back(PRegOutlinedExitBB);
CodeExtractorAnalysisCache CEAC(*OuterFn);
CodeExtractor Extractor(Blocks, /* DominatorTree */ nullptr,
/* AggregateArgs */ false,
/* BlockFrequencyInfo */ nullptr,
/* BranchProbabilityInfo */ nullptr,
/* AssumptionCache */ nullptr,
/* AllowVarArgs */ true,
/* AllowAlloca */ true,
/* AllocationBlock */ OuterAllocaBlock,
/* Suffix */ ".omp_par");
// Find inputs to, outputs from the code region.
BasicBlock *CommonExit = nullptr;
SetVector<Value *> Inputs, Outputs, SinkingCands, HoistingCands;
Extractor.findAllocas(CEAC, SinkingCands, HoistingCands, CommonExit);
Extractor.findInputsOutputs(Inputs, Outputs, SinkingCands);
LLVM_DEBUG(dbgs() << "Before privatization: " << *OuterFn << "\n");
FunctionCallee TIDRTLFn =
getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_global_thread_num);
auto PrivHelper = [&](Value &V) {
if (&V == TIDAddr || &V == ZeroAddr) {
OI.ExcludeArgsFromAggregate.push_back(&V);
return;
}
SetVector<Use *> Uses;
for (Use &U : V.uses())
if (auto *UserI = dyn_cast<Instruction>(U.getUser()))
if (ParallelRegionBlockSet.count(UserI->getParent()))
Uses.insert(&U);
// __kmpc_fork_call expects extra arguments as pointers. If the input
// already has a pointer type, everything is fine. Otherwise, store the
// value onto stack and load it back inside the to-be-outlined region. This
// will ensure only the pointer will be passed to the function.
// FIXME: if there are more than 15 trailing arguments, they must be
// additionally packed in a struct.
Value *Inner = &V;
if (!V.getType()->isPointerTy()) {
IRBuilder<>::InsertPointGuard Guard(Builder);
LLVM_DEBUG(llvm::dbgs() << "Forwarding input as pointer: " << V << "\n");
Builder.restoreIP(OuterAllocaIP);
Value *Ptr =
Builder.CreateAlloca(V.getType(), nullptr, V.getName() + ".reloaded");
// Store to stack at end of the block that currently branches to the entry
// block of the to-be-outlined region.
Builder.SetInsertPoint(InsertBB,
InsertBB->getTerminator()->getIterator());
Builder.CreateStore(&V, Ptr);
// Load back next to allocations in the to-be-outlined region.
Builder.restoreIP(InnerAllocaIP);
Inner = Builder.CreateLoad(V.getType(), Ptr);
}
Value *ReplacementValue = nullptr;
CallInst *CI = dyn_cast<CallInst>(&V);
if (CI && CI->getCalledFunction() == TIDRTLFn.getCallee()) {
ReplacementValue = PrivTID;
} else {
Builder.restoreIP(
PrivCB(InnerAllocaIP, Builder.saveIP(), V, *Inner, ReplacementValue));
assert(ReplacementValue &&
"Expected copy/create callback to set replacement value!");
if (ReplacementValue == &V)
return;
}
for (Use *UPtr : Uses)
UPtr->set(ReplacementValue);
};
// Reset the inner alloca insertion as it will be used for loading the values
// wrapped into pointers before passing them into the to-be-outlined region.
// Configure it to insert immediately after the fake use of zero address so
// that they are available in the generated body and so that the
// OpenMP-related values (thread ID and zero address pointers) remain leading
// in the argument list.
InnerAllocaIP = IRBuilder<>::InsertPoint(
ZeroAddrUse->getParent(), ZeroAddrUse->getNextNode()->getIterator());
// Reset the outer alloca insertion point to the entry of the relevant block
// in case it was invalidated.
OuterAllocaIP = IRBuilder<>::InsertPoint(
OuterAllocaBlock, OuterAllocaBlock->getFirstInsertionPt());
for (Value *Input : Inputs) {
LLVM_DEBUG(dbgs() << "Captured input: " << *Input << "\n");
PrivHelper(*Input);
}
LLVM_DEBUG({
for (Value *Output : Outputs)
LLVM_DEBUG(dbgs() << "Captured output: " << *Output << "\n");
});
assert(Outputs.empty() &&
"OpenMP outlining should not produce live-out values!");
LLVM_DEBUG(dbgs() << "After privatization: " << *OuterFn << "\n");
LLVM_DEBUG({
for (auto *BB : Blocks)
dbgs() << " PBR: " << BB->getName() << "\n";
});
// Register the outlined info.
addOutlineInfo(std::move(OI));
InsertPointTy AfterIP(UI->getParent(), UI->getParent()->end());
UI->eraseFromParent();
return AfterIP;
}
void OpenMPIRBuilder::emitFlush(const LocationDescription &Loc) {
// Build call void __kmpc_flush(ident_t *loc)
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Args[] = {getOrCreateIdent(SrcLocStr, SrcLocStrSize)};
Builder.CreateCall(getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_flush), Args);
}
void OpenMPIRBuilder::createFlush(const LocationDescription &Loc) {
if (!updateToLocation(Loc))
return;
emitFlush(Loc);
}
void OpenMPIRBuilder::emitTaskwaitImpl(const LocationDescription &Loc) {
// Build call kmp_int32 __kmpc_omp_taskwait(ident_t *loc, kmp_int32
// global_tid);
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Value *Args[] = {Ident, getOrCreateThreadID(Ident)};
// Ignore return result until untied tasks are supported.
Builder.CreateCall(getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_omp_taskwait),
Args);
}
void OpenMPIRBuilder::createTaskwait(const LocationDescription &Loc) {
if (!updateToLocation(Loc))
return;
emitTaskwaitImpl(Loc);
}
void OpenMPIRBuilder::emitTaskyieldImpl(const LocationDescription &Loc) {
// Build call __kmpc_omp_taskyield(loc, thread_id, 0);
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Constant *I32Null = ConstantInt::getNullValue(Int32);
Value *Args[] = {Ident, getOrCreateThreadID(Ident), I32Null};
Builder.CreateCall(getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_omp_taskyield),
Args);
}
void OpenMPIRBuilder::createTaskyield(const LocationDescription &Loc) {
if (!updateToLocation(Loc))
return;
emitTaskyieldImpl(Loc);
}
OpenMPIRBuilder::InsertPointTy
OpenMPIRBuilder::createTask(const LocationDescription &Loc,
InsertPointTy AllocaIP, BodyGenCallbackTy BodyGenCB,
bool Tied, Value *Final, Value *IfCondition,
SmallVector<DependData> Dependencies) {
if (!updateToLocation(Loc))
return InsertPointTy();
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
// The current basic block is split into four basic blocks. After outlining,
// they will be mapped as follows:
// ```
// def current_fn() {
// current_basic_block:
// br label %task.exit
// task.exit:
// ; instructions after task
// }
// def outlined_fn() {
// task.alloca:
// br label %task.body
// task.body:
// ret void
// }
// ```
BasicBlock *TaskExitBB = splitBB(Builder, /*CreateBranch=*/true, "task.exit");
BasicBlock *TaskBodyBB = splitBB(Builder, /*CreateBranch=*/true, "task.body");
BasicBlock *TaskAllocaBB =
splitBB(Builder, /*CreateBranch=*/true, "task.alloca");
OutlineInfo OI;
OI.EntryBB = TaskAllocaBB;
OI.OuterAllocaBB = AllocaIP.getBlock();
OI.ExitBB = TaskExitBB;
OI.PostOutlineCB = [this, Ident, Tied, Final, IfCondition,
Dependencies](Function &OutlinedFn) {
// The input IR here looks like the following-
// ```
// func @current_fn() {
// outlined_fn(%args)
// }
// func @outlined_fn(%args) { ... }
// ```
//
// This is changed to the following-
//
// ```
// func @current_fn() {
// runtime_call(..., wrapper_fn, ...)
// }
// func @wrapper_fn(..., %args) {
// outlined_fn(%args)
// }
// func @outlined_fn(%args) { ... }
// ```
// The stale call instruction will be replaced with a new call instruction
// for runtime call with a wrapper function.
assert(OutlinedFn.getNumUses() == 1 &&
"there must be a single user for the outlined function");
CallInst *StaleCI = cast<CallInst>(OutlinedFn.user_back());
// HasTaskData is true if any variables are captured in the outlined region,
// false otherwise.
bool HasTaskData = StaleCI->arg_size() > 0;
Builder.SetInsertPoint(StaleCI);
// Gather the arguments for emitting the runtime call for
// @__kmpc_omp_task_alloc
Function *TaskAllocFn =
getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_omp_task_alloc);
// Arguments - `loc_ref` (Ident) and `gtid` (ThreadID)
// call.
Value *ThreadID = getOrCreateThreadID(Ident);
// Argument - `flags`
// Task is tied iff (Flags & 1) == 1.
// Task is untied iff (Flags & 1) == 0.
// Task is final iff (Flags & 2) == 2.
// Task is not final iff (Flags & 2) == 0.
// TODO: Handle the other flags.
Value *Flags = Builder.getInt32(Tied);
if (Final) {
Value *FinalFlag =
Builder.CreateSelect(Final, Builder.getInt32(2), Builder.getInt32(0));
Flags = Builder.CreateOr(FinalFlag, Flags);
}
// Argument - `sizeof_kmp_task_t` (TaskSize)
// Tasksize refers to the size in bytes of kmp_task_t data structure
// including private vars accessed in task.
Value *TaskSize = Builder.getInt64(0);
if (HasTaskData) {
AllocaInst *ArgStructAlloca =
dyn_cast<AllocaInst>(StaleCI->getArgOperand(0));
assert(ArgStructAlloca &&
"Unable to find the alloca instruction corresponding to arguments "
"for extracted function");
StructType *ArgStructType =
dyn_cast<StructType>(ArgStructAlloca->getAllocatedType());
assert(ArgStructType && "Unable to find struct type corresponding to "
"arguments for extracted function");
TaskSize =
Builder.getInt64(M.getDataLayout().getTypeStoreSize(ArgStructType));
}
// TODO: Argument - sizeof_shareds
// Argument - task_entry (the wrapper function)
// If the outlined function has some captured variables (i.e. HasTaskData is
// true), then the wrapper function will have an additional argument (the
// struct containing captured variables). Otherwise, no such argument will
// be present.
SmallVector<Type *> WrapperArgTys{Builder.getInt32Ty()};
if (HasTaskData)
WrapperArgTys.push_back(OutlinedFn.getArg(0)->getType());
FunctionCallee WrapperFuncVal = M.getOrInsertFunction(
(Twine(OutlinedFn.getName()) + ".wrapper").str(),
FunctionType::get(Builder.getInt32Ty(), WrapperArgTys, false));
Function *WrapperFunc = dyn_cast<Function>(WrapperFuncVal.getCallee());
PointerType *WrapperFuncBitcastType =
FunctionType::get(Builder.getInt32Ty(),
{Builder.getInt32Ty(), Builder.getInt8PtrTy()}, false)
->getPointerTo();
Value *WrapperFuncBitcast =
ConstantExpr::getBitCast(WrapperFunc, WrapperFuncBitcastType);
// Emit the @__kmpc_omp_task_alloc runtime call
// The runtime call returns a pointer to an area where the task captured
// variables must be copied before the task is run (NewTaskData)
CallInst *NewTaskData = Builder.CreateCall(
TaskAllocFn,
{/*loc_ref=*/Ident, /*gtid=*/ThreadID, /*flags=*/Flags,
/*sizeof_task=*/TaskSize, /*sizeof_shared=*/Builder.getInt64(0),
/*task_func=*/WrapperFuncBitcast});
// Copy the arguments for outlined function
if (HasTaskData) {
Value *TaskData = StaleCI->getArgOperand(0);
Align Alignment = TaskData->getPointerAlignment(M.getDataLayout());
Builder.CreateMemCpy(NewTaskData, Alignment, TaskData, Alignment,
TaskSize);
}
Value *DepArrayPtr = nullptr;
if (Dependencies.size()) {
InsertPointTy OldIP = Builder.saveIP();
Builder.SetInsertPoint(
&OldIP.getBlock()->getParent()->getEntryBlock().back());
Type *DepArrayTy = ArrayType::get(DependInfo, Dependencies.size());
Value *DepArray =
Builder.CreateAlloca(DepArrayTy, nullptr, ".dep.arr.addr");
unsigned P = 0;
for (const DependData &Dep : Dependencies) {
Value *Base =
Builder.CreateConstInBoundsGEP2_64(DepArrayTy, DepArray, 0, P);
// Store the pointer to the variable
Value *Addr = Builder.CreateStructGEP(
DependInfo, Base,
static_cast<unsigned int>(RTLDependInfoFields::BaseAddr));
Value *DepValPtr =
Builder.CreatePtrToInt(Dep.DepVal, Builder.getInt64Ty());
Builder.CreateStore(DepValPtr, Addr);
// Store the size of the variable
Value *Size = Builder.CreateStructGEP(
DependInfo, Base,
static_cast<unsigned int>(RTLDependInfoFields::Len));
Builder.CreateStore(Builder.getInt64(M.getDataLayout().getTypeStoreSize(
Dep.DepValueType)),
Size);
// Store the dependency kind
Value *Flags = Builder.CreateStructGEP(
DependInfo, Base,
static_cast<unsigned int>(RTLDependInfoFields::Flags));
Builder.CreateStore(
ConstantInt::get(Builder.getInt8Ty(),
static_cast<unsigned int>(Dep.DepKind)),
Flags);
++P;
}
DepArrayPtr = Builder.CreateBitCast(DepArray, Builder.getInt8PtrTy());
Builder.restoreIP(OldIP);
}
// In the presence of the `if` clause, the following IR is generated:
// ...
// %data = call @__kmpc_omp_task_alloc(...)
// br i1 %if_condition, label %then, label %else
// then:
// call @__kmpc_omp_task(...)
// br label %exit
// else:
// call @__kmpc_omp_task_begin_if0(...)
// call @wrapper_fn(...)
// call @__kmpc_omp_task_complete_if0(...)
// br label %exit
// exit:
// ...
if (IfCondition) {
// `SplitBlockAndInsertIfThenElse` requires the block to have a
// terminator.
BasicBlock *NewBasicBlock =
splitBB(Builder, /*CreateBranch=*/true, "if.end");
Instruction *IfTerminator =
NewBasicBlock->getSinglePredecessor()->getTerminator();
Instruction *ThenTI = IfTerminator, *ElseTI = nullptr;
Builder.SetInsertPoint(IfTerminator);
SplitBlockAndInsertIfThenElse(IfCondition, IfTerminator, &ThenTI,
&ElseTI);
Builder.SetInsertPoint(ElseTI);
Function *TaskBeginFn =
getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_omp_task_begin_if0);
Function *TaskCompleteFn =
getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_omp_task_complete_if0);
Builder.CreateCall(TaskBeginFn, {Ident, ThreadID, NewTaskData});
if (HasTaskData)
Builder.CreateCall(WrapperFunc, {ThreadID, NewTaskData});
else
Builder.CreateCall(WrapperFunc, {ThreadID});
Builder.CreateCall(TaskCompleteFn, {Ident, ThreadID, NewTaskData});
Builder.SetInsertPoint(ThenTI);
}
if (Dependencies.size()) {
Function *TaskFn =
getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_omp_task_with_deps);
Builder.CreateCall(
TaskFn,
{Ident, ThreadID, NewTaskData, Builder.getInt32(Dependencies.size()),
DepArrayPtr, ConstantInt::get(Builder.getInt32Ty(), 0),
ConstantPointerNull::get(Type::getInt8PtrTy(M.getContext()))});
} else {
// Emit the @__kmpc_omp_task runtime call to spawn the task
Function *TaskFn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_omp_task);
Builder.CreateCall(TaskFn, {Ident, ThreadID, NewTaskData});
}
StaleCI->eraseFromParent();
// Emit the body for wrapper function
BasicBlock *WrapperEntryBB =
BasicBlock::Create(M.getContext(), "", WrapperFunc);
Builder.SetInsertPoint(WrapperEntryBB);
if (HasTaskData)
Builder.CreateCall(&OutlinedFn, {WrapperFunc->getArg(1)});
else
Builder.CreateCall(&OutlinedFn);
Builder.CreateRet(Builder.getInt32(0));
};
addOutlineInfo(std::move(OI));
InsertPointTy TaskAllocaIP =
InsertPointTy(TaskAllocaBB, TaskAllocaBB->begin());
InsertPointTy TaskBodyIP = InsertPointTy(TaskBodyBB, TaskBodyBB->begin());
BodyGenCB(TaskAllocaIP, TaskBodyIP);
Builder.SetInsertPoint(TaskExitBB, TaskExitBB->begin());
return Builder.saveIP();
}
OpenMPIRBuilder::InsertPointTy
OpenMPIRBuilder::createTaskgroup(const LocationDescription &Loc,
InsertPointTy AllocaIP,
BodyGenCallbackTy BodyGenCB) {
if (!updateToLocation(Loc))
return InsertPointTy();
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Value *ThreadID = getOrCreateThreadID(Ident);
// Emit the @__kmpc_taskgroup runtime call to start the taskgroup
Function *TaskgroupFn =
getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_taskgroup);
Builder.CreateCall(TaskgroupFn, {Ident, ThreadID});
BasicBlock *TaskgroupExitBB = splitBB(Builder, true, "taskgroup.exit");
BodyGenCB(AllocaIP, Builder.saveIP());
Builder.SetInsertPoint(TaskgroupExitBB);
// Emit the @__kmpc_end_taskgroup runtime call to end the taskgroup
Function *EndTaskgroupFn =
getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_end_taskgroup);
Builder.CreateCall(EndTaskgroupFn, {Ident, ThreadID});
return Builder.saveIP();
}
OpenMPIRBuilder::InsertPointTy OpenMPIRBuilder::createSections(
const LocationDescription &Loc, InsertPointTy AllocaIP,
ArrayRef<StorableBodyGenCallbackTy> SectionCBs, PrivatizeCallbackTy PrivCB,
FinalizeCallbackTy FiniCB, bool IsCancellable, bool IsNowait) {
assert(!isConflictIP(AllocaIP, Loc.IP) && "Dedicated IP allocas required");
if (!updateToLocation(Loc))
return Loc.IP;
auto FiniCBWrapper = [&](InsertPointTy IP) {
if (IP.getBlock()->end() != IP.getPoint())
return FiniCB(IP);
// This must be done otherwise any nested constructs using FinalizeOMPRegion
// will fail because that function requires the Finalization Basic Block to
// have a terminator, which is already removed by EmitOMPRegionBody.
// IP is currently at cancelation block.
// We need to backtrack to the condition block to fetch
// the exit block and create a branch from cancelation
// to exit block.
IRBuilder<>::InsertPointGuard IPG(Builder);
Builder.restoreIP(IP);
auto *CaseBB = IP.getBlock()->getSinglePredecessor();
auto *CondBB = CaseBB->getSinglePredecessor()->getSinglePredecessor();
auto *ExitBB = CondBB->getTerminator()->getSuccessor(1);
Instruction *I = Builder.CreateBr(ExitBB);
IP = InsertPointTy(I->getParent(), I->getIterator());
return FiniCB(IP);
};
FinalizationStack.push_back({FiniCBWrapper, OMPD_sections, IsCancellable});
// Each section is emitted as a switch case
// Each finalization callback is handled from clang.EmitOMPSectionDirective()
// -> OMP.createSection() which generates the IR for each section
// Iterate through all sections and emit a switch construct:
// switch (IV) {
// case 0:
// <SectionStmt[0]>;
// break;
// ...
// case <NumSection> - 1:
// <SectionStmt[<NumSection> - 1]>;
// break;
// }
// ...
// section_loop.after:
// <FiniCB>;
auto LoopBodyGenCB = [&](InsertPointTy CodeGenIP, Value *IndVar) {
Builder.restoreIP(CodeGenIP);
BasicBlock *Continue =
splitBBWithSuffix(Builder, /*CreateBranch=*/false, ".sections.after");
Function *CurFn = Continue->getParent();
SwitchInst *SwitchStmt = Builder.CreateSwitch(IndVar, Continue);
unsigned CaseNumber = 0;
for (auto SectionCB : SectionCBs) {
BasicBlock *CaseBB = BasicBlock::Create(
M.getContext(), "omp_section_loop.body.case", CurFn, Continue);
SwitchStmt->addCase(Builder.getInt32(CaseNumber), CaseBB);
Builder.SetInsertPoint(CaseBB);
BranchInst *CaseEndBr = Builder.CreateBr(Continue);
SectionCB(InsertPointTy(),
{CaseEndBr->getParent(), CaseEndBr->getIterator()});
CaseNumber++;
}
// remove the existing terminator from body BB since there can be no
// terminators after switch/case
};
// Loop body ends here
// LowerBound, UpperBound, and STride for createCanonicalLoop
Type *I32Ty = Type::getInt32Ty(M.getContext());
Value *LB = ConstantInt::get(I32Ty, 0);
Value *UB = ConstantInt::get(I32Ty, SectionCBs.size());
Value *ST = ConstantInt::get(I32Ty, 1);
llvm::CanonicalLoopInfo *LoopInfo = createCanonicalLoop(
Loc, LoopBodyGenCB, LB, UB, ST, true, false, AllocaIP, "section_loop");
InsertPointTy AfterIP =
applyStaticWorkshareLoop(Loc.DL, LoopInfo, AllocaIP, !IsNowait);
// Apply the finalization callback in LoopAfterBB
auto FiniInfo = FinalizationStack.pop_back_val();
assert(FiniInfo.DK == OMPD_sections &&
"Unexpected finalization stack state!");
if (FinalizeCallbackTy &CB = FiniInfo.FiniCB) {
Builder.restoreIP(AfterIP);
BasicBlock *FiniBB =
splitBBWithSuffix(Builder, /*CreateBranch=*/true, "sections.fini");
CB(Builder.saveIP());
AfterIP = {FiniBB, FiniBB->begin()};
}
return AfterIP;
}
OpenMPIRBuilder::InsertPointTy
OpenMPIRBuilder::createSection(const LocationDescription &Loc,
BodyGenCallbackTy BodyGenCB,
FinalizeCallbackTy FiniCB) {
if (!updateToLocation(Loc))
return Loc.IP;
auto FiniCBWrapper = [&](InsertPointTy IP) {
if (IP.getBlock()->end() != IP.getPoint())
return FiniCB(IP);
// This must be done otherwise any nested constructs using FinalizeOMPRegion
// will fail because that function requires the Finalization Basic Block to
// have a terminator, which is already removed by EmitOMPRegionBody.
// IP is currently at cancelation block.
// We need to backtrack to the condition block to fetch
// the exit block and create a branch from cancelation
// to exit block.
IRBuilder<>::InsertPointGuard IPG(Builder);
Builder.restoreIP(IP);
auto *CaseBB = Loc.IP.getBlock();
auto *CondBB = CaseBB->getSinglePredecessor()->getSinglePredecessor();
auto *ExitBB = CondBB->getTerminator()->getSuccessor(1);
Instruction *I = Builder.CreateBr(ExitBB);
IP = InsertPointTy(I->getParent(), I->getIterator());
return FiniCB(IP);
};
Directive OMPD = Directive::OMPD_sections;
// Since we are using Finalization Callback here, HasFinalize
// and IsCancellable have to be true
return EmitOMPInlinedRegion(OMPD, nullptr, nullptr, BodyGenCB, FiniCBWrapper,
/*Conditional*/ false, /*hasFinalize*/ true,
/*IsCancellable*/ true);
}
/// Create a function with a unique name and a "void (i8*, i8*)" signature in
/// the given module and return it.
Function *getFreshReductionFunc(Module &M) {
Type *VoidTy = Type::getVoidTy(M.getContext());
Type *Int8PtrTy = Type::getInt8PtrTy(M.getContext());
auto *FuncTy =
FunctionType::get(VoidTy, {Int8PtrTy, Int8PtrTy}, /* IsVarArg */ false);
return Function::Create(FuncTy, GlobalVariable::InternalLinkage,
M.getDataLayout().getDefaultGlobalsAddressSpace(),
".omp.reduction.func", &M);
}
OpenMPIRBuilder::InsertPointTy OpenMPIRBuilder::createReductions(
const LocationDescription &Loc, InsertPointTy AllocaIP,
ArrayRef<ReductionInfo> ReductionInfos, bool IsNoWait) {
for (const ReductionInfo &RI : ReductionInfos) {
(void)RI;
assert(RI.Variable && "expected non-null variable");
assert(RI.PrivateVariable && "expected non-null private variable");
assert(RI.ReductionGen && "expected non-null reduction generator callback");
assert(RI.Variable->getType() == RI.PrivateVariable->getType() &&
"expected variables and their private equivalents to have the same "
"type");
assert(RI.Variable->getType()->isPointerTy() &&
"expected variables to be pointers");
}
if (!updateToLocation(Loc))
return InsertPointTy();
BasicBlock *InsertBlock = Loc.IP.getBlock();
BasicBlock *ContinuationBlock =
InsertBlock->splitBasicBlock(Loc.IP.getPoint(), "reduce.finalize");
InsertBlock->getTerminator()->eraseFromParent();
// Create and populate array of type-erased pointers to private reduction
// values.
unsigned NumReductions = ReductionInfos.size();
Type *RedArrayTy = ArrayType::get(Builder.getInt8PtrTy(), NumReductions);
Builder.restoreIP(AllocaIP);
Value *RedArray = Builder.CreateAlloca(RedArrayTy, nullptr, "red.array");
Builder.SetInsertPoint(InsertBlock, InsertBlock->end());
for (auto En : enumerate(ReductionInfos)) {
unsigned Index = En.index();
const ReductionInfo &RI = En.value();
Value *RedArrayElemPtr = Builder.CreateConstInBoundsGEP2_64(
RedArrayTy, RedArray, 0, Index, "red.array.elem." + Twine(Index));
Value *Casted =
Builder.CreateBitCast(RI.PrivateVariable, Builder.getInt8PtrTy(),
"private.red.var." + Twine(Index) + ".casted");
Builder.CreateStore(Casted, RedArrayElemPtr);
}
// Emit a call to the runtime function that orchestrates the reduction.
// Declare the reduction function in the process.
Function *Func = Builder.GetInsertBlock()->getParent();
Module *Module = Func->getParent();
Value *RedArrayPtr =
Builder.CreateBitCast(RedArray, Builder.getInt8PtrTy(), "red.array.ptr");
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
bool CanGenerateAtomic =
llvm::all_of(ReductionInfos, [](const ReductionInfo &RI) {
return RI.AtomicReductionGen;
});
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize,
CanGenerateAtomic
? IdentFlag::OMP_IDENT_FLAG_ATOMIC_REDUCE
: IdentFlag(0));
Value *ThreadId = getOrCreateThreadID(Ident);
Constant *NumVariables = Builder.getInt32(NumReductions);
const DataLayout &DL = Module->getDataLayout();
unsigned RedArrayByteSize = DL.getTypeStoreSize(RedArrayTy);
Constant *RedArraySize = Builder.getInt64(RedArrayByteSize);
Function *ReductionFunc = getFreshReductionFunc(*Module);
Value *Lock = getOMPCriticalRegionLock(".reduction");
Function *ReduceFunc = getOrCreateRuntimeFunctionPtr(
IsNoWait ? RuntimeFunction::OMPRTL___kmpc_reduce_nowait
: RuntimeFunction::OMPRTL___kmpc_reduce);
CallInst *ReduceCall =
Builder.CreateCall(ReduceFunc,
{Ident, ThreadId, NumVariables, RedArraySize,
RedArrayPtr, ReductionFunc, Lock},
"reduce");
// Create final reduction entry blocks for the atomic and non-atomic case.
// Emit IR that dispatches control flow to one of the blocks based on the
// reduction supporting the atomic mode.
BasicBlock *NonAtomicRedBlock =
BasicBlock::Create(Module->getContext(), "reduce.switch.nonatomic", Func);
BasicBlock *AtomicRedBlock =
BasicBlock::Create(Module->getContext(), "reduce.switch.atomic", Func);
SwitchInst *Switch =
Builder.CreateSwitch(ReduceCall, ContinuationBlock, /* NumCases */ 2);
Switch->addCase(Builder.getInt32(1), NonAtomicRedBlock);
Switch->addCase(Builder.getInt32(2), AtomicRedBlock);
// Populate the non-atomic reduction using the elementwise reduction function.
// This loads the elements from the global and private variables and reduces
// them before storing back the result to the global variable.
Builder.SetInsertPoint(NonAtomicRedBlock);
for (auto En : enumerate(ReductionInfos)) {
const ReductionInfo &RI = En.value();
Type *ValueType = RI.ElementType;
Value *RedValue = Builder.CreateLoad(ValueType, RI.Variable,
"red.value." + Twine(En.index()));
Value *PrivateRedValue =
Builder.CreateLoad(ValueType, RI.PrivateVariable,
"red.private.value." + Twine(En.index()));
Value *Reduced;
Builder.restoreIP(
RI.ReductionGen(Builder.saveIP(), RedValue, PrivateRedValue, Reduced));
if (!Builder.GetInsertBlock())
return InsertPointTy();
Builder.CreateStore(Reduced, RI.Variable);
}
Function *EndReduceFunc = getOrCreateRuntimeFunctionPtr(
IsNoWait ? RuntimeFunction::OMPRTL___kmpc_end_reduce_nowait
: RuntimeFunction::OMPRTL___kmpc_end_reduce);
Builder.CreateCall(EndReduceFunc, {Ident, ThreadId, Lock});
Builder.CreateBr(ContinuationBlock);
// Populate the atomic reduction using the atomic elementwise reduction
// function. There are no loads/stores here because they will be happening
// inside the atomic elementwise reduction.
Builder.SetInsertPoint(AtomicRedBlock);
if (CanGenerateAtomic) {
for (const ReductionInfo &RI : ReductionInfos) {
Builder.restoreIP(RI.AtomicReductionGen(Builder.saveIP(), RI.ElementType,
RI.Variable, RI.PrivateVariable));
if (!Builder.GetInsertBlock())
return InsertPointTy();
}
Builder.CreateBr(ContinuationBlock);
} else {
Builder.CreateUnreachable();
}
// Populate the outlined reduction function using the elementwise reduction
// function. Partial values are extracted from the type-erased array of
// pointers to private variables.
BasicBlock *ReductionFuncBlock =
BasicBlock::Create(Module->getContext(), "", ReductionFunc);
Builder.SetInsertPoint(ReductionFuncBlock);
Value *LHSArrayPtr = Builder.CreateBitCast(ReductionFunc->getArg(0),
RedArrayTy->getPointerTo());
Value *RHSArrayPtr = Builder.CreateBitCast(ReductionFunc->getArg(1),
RedArrayTy->getPointerTo());
for (auto En : enumerate(ReductionInfos)) {
const ReductionInfo &RI = En.value();
Value *LHSI8PtrPtr = Builder.CreateConstInBoundsGEP2_64(
RedArrayTy, LHSArrayPtr, 0, En.index());
Value *LHSI8Ptr = Builder.CreateLoad(Builder.getInt8PtrTy(), LHSI8PtrPtr);
Value *LHSPtr = Builder.CreateBitCast(LHSI8Ptr, RI.Variable->getType());
Value *LHS = Builder.CreateLoad(RI.ElementType, LHSPtr);
Value *RHSI8PtrPtr = Builder.CreateConstInBoundsGEP2_64(
RedArrayTy, RHSArrayPtr, 0, En.index());
Value *RHSI8Ptr = Builder.CreateLoad(Builder.getInt8PtrTy(), RHSI8PtrPtr);
Value *RHSPtr =
Builder.CreateBitCast(RHSI8Ptr, RI.PrivateVariable->getType());
Value *RHS = Builder.CreateLoad(RI.ElementType, RHSPtr);
Value *Reduced;
Builder.restoreIP(RI.ReductionGen(Builder.saveIP(), LHS, RHS, Reduced));
if (!Builder.GetInsertBlock())
return InsertPointTy();
Builder.CreateStore(Reduced, LHSPtr);
}
Builder.CreateRetVoid();
Builder.SetInsertPoint(ContinuationBlock);
return Builder.saveIP();
}
OpenMPIRBuilder::InsertPointTy
OpenMPIRBuilder::createMaster(const LocationDescription &Loc,
BodyGenCallbackTy BodyGenCB,
FinalizeCallbackTy FiniCB) {
if (!updateToLocation(Loc))
return Loc.IP;
Directive OMPD = Directive::OMPD_master;
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Value *ThreadId = getOrCreateThreadID(Ident);
Value *Args[] = {Ident, ThreadId};
Function *EntryRTLFn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_master);
Instruction *EntryCall = Builder.CreateCall(EntryRTLFn, Args);
Function *ExitRTLFn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_end_master);
Instruction *ExitCall = Builder.CreateCall(ExitRTLFn, Args);
return EmitOMPInlinedRegion(OMPD, EntryCall, ExitCall, BodyGenCB, FiniCB,
/*Conditional*/ true, /*hasFinalize*/ true);
}
OpenMPIRBuilder::InsertPointTy
OpenMPIRBuilder::createMasked(const LocationDescription &Loc,
BodyGenCallbackTy BodyGenCB,
FinalizeCallbackTy FiniCB, Value *Filter) {
if (!updateToLocation(Loc))
return Loc.IP;
Directive OMPD = Directive::OMPD_masked;
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Value *ThreadId = getOrCreateThreadID(Ident);
Value *Args[] = {Ident, ThreadId, Filter};
Value *ArgsEnd[] = {Ident, ThreadId};
Function *EntryRTLFn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_masked);
Instruction *EntryCall = Builder.CreateCall(EntryRTLFn, Args);
Function *ExitRTLFn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_end_masked);
Instruction *ExitCall = Builder.CreateCall(ExitRTLFn, ArgsEnd);
return EmitOMPInlinedRegion(OMPD, EntryCall, ExitCall, BodyGenCB, FiniCB,
/*Conditional*/ true, /*hasFinalize*/ true);
}
CanonicalLoopInfo *OpenMPIRBuilder::createLoopSkeleton(
DebugLoc DL, Value *TripCount, Function *F, BasicBlock *PreInsertBefore,
BasicBlock *PostInsertBefore, const Twine &Name) {
Module *M = F->getParent();
LLVMContext &Ctx = M->getContext();
Type *IndVarTy = TripCount->getType();
// Create the basic block structure.
BasicBlock *Preheader =
BasicBlock::Create(Ctx, "omp_" + Name + ".preheader", F, PreInsertBefore);
BasicBlock *Header =
BasicBlock::Create(Ctx, "omp_" + Name + ".header", F, PreInsertBefore);
BasicBlock *Cond =
BasicBlock::Create(Ctx, "omp_" + Name + ".cond", F, PreInsertBefore);
BasicBlock *Body =
BasicBlock::Create(Ctx, "omp_" + Name + ".body", F, PreInsertBefore);
BasicBlock *Latch =
BasicBlock::Create(Ctx, "omp_" + Name + ".inc", F, PostInsertBefore);
BasicBlock *Exit =
BasicBlock::Create(Ctx, "omp_" + Name + ".exit", F, PostInsertBefore);
BasicBlock *After =
BasicBlock::Create(Ctx, "omp_" + Name + ".after", F, PostInsertBefore);
// Use specified DebugLoc for new instructions.
Builder.SetCurrentDebugLocation(DL);
Builder.SetInsertPoint(Preheader);
Builder.CreateBr(Header);
Builder.SetInsertPoint(Header);
PHINode *IndVarPHI = Builder.CreatePHI(IndVarTy, 2, "omp_" + Name + ".iv");
IndVarPHI->addIncoming(ConstantInt::get(IndVarTy, 0), Preheader);
Builder.CreateBr(Cond);
Builder.SetInsertPoint(Cond);
Value *Cmp =
Builder.CreateICmpULT(IndVarPHI, TripCount, "omp_" + Name + ".cmp");
Builder.CreateCondBr(Cmp, Body, Exit);
Builder.SetInsertPoint(Body);
Builder.CreateBr(Latch);
Builder.SetInsertPoint(Latch);
Value *Next = Builder.CreateAdd(IndVarPHI, ConstantInt::get(IndVarTy, 1),
"omp_" + Name + ".next", /*HasNUW=*/true);
Builder.CreateBr(Header);
IndVarPHI->addIncoming(Next, Latch);
Builder.SetInsertPoint(Exit);
Builder.CreateBr(After);
// Remember and return the canonical control flow.
LoopInfos.emplace_front();
CanonicalLoopInfo *CL = &LoopInfos.front();
CL->Header = Header;
CL->Cond = Cond;
CL->Latch = Latch;
CL->Exit = Exit;
#ifndef NDEBUG
CL->assertOK();
#endif
return CL;
}
CanonicalLoopInfo *
OpenMPIRBuilder::createCanonicalLoop(const LocationDescription &Loc,
LoopBodyGenCallbackTy BodyGenCB,
Value *TripCount, const Twine &Name) {
BasicBlock *BB = Loc.IP.getBlock();
BasicBlock *NextBB = BB->getNextNode();
CanonicalLoopInfo *CL = createLoopSkeleton(Loc.DL, TripCount, BB->getParent(),
NextBB, NextBB, Name);
BasicBlock *After = CL->getAfter();
// If location is not set, don't connect the loop.
if (updateToLocation(Loc)) {
// Split the loop at the insertion point: Branch to the preheader and move
// every following instruction to after the loop (the After BB). Also, the
// new successor is the loop's after block.
spliceBB(Builder, After, /*CreateBranch=*/false);
Builder.CreateBr(CL->getPreheader());
}
// Emit the body content. We do it after connecting the loop to the CFG to
// avoid that the callback encounters degenerate BBs.
BodyGenCB(CL->getBodyIP(), CL->getIndVar());
#ifndef NDEBUG
CL->assertOK();
#endif
return CL;
}
CanonicalLoopInfo *OpenMPIRBuilder::createCanonicalLoop(
const LocationDescription &Loc, LoopBodyGenCallbackTy BodyGenCB,
Value *Start, Value *Stop, Value *Step, bool IsSigned, bool InclusiveStop,
InsertPointTy ComputeIP, const Twine &Name) {
// Consider the following difficulties (assuming 8-bit signed integers):
// * Adding \p Step to the loop counter which passes \p Stop may overflow:
// DO I = 1, 100, 50
/// * A \p Step of INT_MIN cannot not be normalized to a positive direction:
// DO I = 100, 0, -128
// Start, Stop and Step must be of the same integer type.
auto *IndVarTy = cast<IntegerType>(Start->getType());
assert(IndVarTy == Stop->getType() && "Stop type mismatch");
assert(IndVarTy == Step->getType() && "Step type mismatch");
LocationDescription ComputeLoc =
ComputeIP.isSet() ? LocationDescription(ComputeIP, Loc.DL) : Loc;
updateToLocation(ComputeLoc);
ConstantInt *Zero = ConstantInt::get(IndVarTy, 0);
ConstantInt *One = ConstantInt::get(IndVarTy, 1);
// Like Step, but always positive.
Value *Incr = Step;
// Distance between Start and Stop; always positive.
Value *Span;
// Condition whether there are no iterations are executed at all, e.g. because
// UB < LB.
Value *ZeroCmp;
if (IsSigned) {
// Ensure that increment is positive. If not, negate and invert LB and UB.
Value *IsNeg = Builder.CreateICmpSLT(Step, Zero);
Incr = Builder.CreateSelect(IsNeg, Builder.CreateNeg(Step), Step);
Value *LB = Builder.CreateSelect(IsNeg, Stop, Start);
Value *UB = Builder.CreateSelect(IsNeg, Start, Stop);
Span = Builder.CreateSub(UB, LB, "", false, true);
ZeroCmp = Builder.CreateICmp(
InclusiveStop ? CmpInst::ICMP_SLT : CmpInst::ICMP_SLE, UB, LB);
} else {
Span = Builder.CreateSub(Stop, Start, "", true);
ZeroCmp = Builder.CreateICmp(
InclusiveStop ? CmpInst::ICMP_ULT : CmpInst::ICMP_ULE, Stop, Start);
}
Value *CountIfLooping;
if (InclusiveStop) {
CountIfLooping = Builder.CreateAdd(Builder.CreateUDiv(Span, Incr), One);
} else {
// Avoid incrementing past stop since it could overflow.
Value *CountIfTwo = Builder.CreateAdd(
Builder.CreateUDiv(Builder.CreateSub(Span, One), Incr), One);
Value *OneCmp = Builder.CreateICmp(
InclusiveStop ? CmpInst::ICMP_ULT : CmpInst::ICMP_ULE, Span, Incr);
CountIfLooping = Builder.CreateSelect(OneCmp, One, CountIfTwo);
}
Value *TripCount = Builder.CreateSelect(ZeroCmp, Zero, CountIfLooping,
"omp_" + Name + ".tripcount");
auto BodyGen = [=, this](InsertPointTy CodeGenIP, Value *IV) {
Builder.restoreIP(CodeGenIP);
Value *Span = Builder.CreateMul(IV, Step);
Value *IndVar = Builder.CreateAdd(Span, Start);
BodyGenCB(Builder.saveIP(), IndVar);
};
LocationDescription LoopLoc = ComputeIP.isSet() ? Loc.IP : Builder.saveIP();
return createCanonicalLoop(LoopLoc, BodyGen, TripCount, Name);
}
// Returns an LLVM function to call for initializing loop bounds using OpenMP
// static scheduling depending on `type`. Only i32 and i64 are supported by the
// runtime. Always interpret integers as unsigned similarly to
// CanonicalLoopInfo.
static FunctionCallee getKmpcForStaticInitForType(Type *Ty, Module &M,
OpenMPIRBuilder &OMPBuilder) {
unsigned Bitwidth = Ty->getIntegerBitWidth();
if (Bitwidth == 32)
return OMPBuilder.getOrCreateRuntimeFunction(
M, omp::RuntimeFunction::OMPRTL___kmpc_for_static_init_4u);
if (Bitwidth == 64)
return OMPBuilder.getOrCreateRuntimeFunction(
M, omp::RuntimeFunction::OMPRTL___kmpc_for_static_init_8u);
llvm_unreachable("unknown OpenMP loop iterator bitwidth");
}
OpenMPIRBuilder::InsertPointTy
OpenMPIRBuilder::applyStaticWorkshareLoop(DebugLoc DL, CanonicalLoopInfo *CLI,
InsertPointTy AllocaIP,
bool NeedsBarrier) {
assert(CLI->isValid() && "Requires a valid canonical loop");
assert(!isConflictIP(AllocaIP, CLI->getPreheaderIP()) &&
"Require dedicated allocate IP");
// Set up the source location value for OpenMP runtime.
Builder.restoreIP(CLI->getPreheaderIP());
Builder.SetCurrentDebugLocation(DL);
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(DL, SrcLocStrSize);
Value *SrcLoc = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
// Declare useful OpenMP runtime functions.
Value *IV = CLI->getIndVar();
Type *IVTy = IV->getType();
FunctionCallee StaticInit = getKmpcForStaticInitForType(IVTy, M, *this);
FunctionCallee StaticFini =
getOrCreateRuntimeFunction(M, omp::OMPRTL___kmpc_for_static_fini);
// Allocate space for computed loop bounds as expected by the "init" function.
Builder.restoreIP(AllocaIP);
Type *I32Type = Type::getInt32Ty(M.getContext());
Value *PLastIter = Builder.CreateAlloca(I32Type, nullptr, "p.lastiter");
Value *PLowerBound = Builder.CreateAlloca(IVTy, nullptr, "p.lowerbound");
Value *PUpperBound = Builder.CreateAlloca(IVTy, nullptr, "p.upperbound");
Value *PStride = Builder.CreateAlloca(IVTy, nullptr, "p.stride");
// At the end of the preheader, prepare for calling the "init" function by
// storing the current loop bounds into the allocated space. A canonical loop
// always iterates from 0 to trip-count with step 1. Note that "init" expects
// and produces an inclusive upper bound.
Builder.SetInsertPoint(CLI->getPreheader()->getTerminator());
Constant *Zero = ConstantInt::get(IVTy, 0);
Constant *One = ConstantInt::get(IVTy, 1);
Builder.CreateStore(Zero, PLowerBound);
Value *UpperBound = Builder.CreateSub(CLI->getTripCount(), One);
Builder.CreateStore(UpperBound, PUpperBound);
Builder.CreateStore(One, PStride);
Value *ThreadNum = getOrCreateThreadID(SrcLoc);
Constant *SchedulingType = ConstantInt::get(
I32Type, static_cast<int>(OMPScheduleType::UnorderedStatic));
// Call the "init" function and update the trip count of the loop with the
// value it produced.
Builder.CreateCall(StaticInit,
{SrcLoc, ThreadNum, SchedulingType, PLastIter, PLowerBound,
PUpperBound, PStride, One, Zero});
Value *LowerBound = Builder.CreateLoad(IVTy, PLowerBound);
Value *InclusiveUpperBound = Builder.CreateLoad(IVTy, PUpperBound);
Value *TripCountMinusOne = Builder.CreateSub(InclusiveUpperBound, LowerBound);
Value *TripCount = Builder.CreateAdd(TripCountMinusOne, One);
CLI->setTripCount(TripCount);
// Update all uses of the induction variable except the one in the condition
// block that compares it with the actual upper bound, and the increment in
// the latch block.
CLI->mapIndVar([&](Instruction *OldIV) -> Value * {
Builder.SetInsertPoint(CLI->getBody(),
CLI->getBody()->getFirstInsertionPt());
Builder.SetCurrentDebugLocation(DL);
return Builder.CreateAdd(OldIV, LowerBound);
});
// In the "exit" block, call the "fini" function.
Builder.SetInsertPoint(CLI->getExit(),
CLI->getExit()->getTerminator()->getIterator());
Builder.CreateCall(StaticFini, {SrcLoc, ThreadNum});
// Add the barrier if requested.
if (NeedsBarrier)
createBarrier(LocationDescription(Builder.saveIP(), DL),
omp::Directive::OMPD_for, /* ForceSimpleCall */ false,
/* CheckCancelFlag */ false);
InsertPointTy AfterIP = CLI->getAfterIP();
CLI->invalidate();
return AfterIP;
}
OpenMPIRBuilder::InsertPointTy OpenMPIRBuilder::applyStaticChunkedWorkshareLoop(
DebugLoc DL, CanonicalLoopInfo *CLI, InsertPointTy AllocaIP,
bool NeedsBarrier, Value *ChunkSize) {
assert(CLI->isValid() && "Requires a valid canonical loop");
assert(ChunkSize && "Chunk size is required");
LLVMContext &Ctx = CLI->getFunction()->getContext();
Value *IV = CLI->getIndVar();
Value *OrigTripCount = CLI->getTripCount();
Type *IVTy = IV->getType();
assert(IVTy->getIntegerBitWidth() <= 64 &&
"Max supported tripcount bitwidth is 64 bits");
Type *InternalIVTy = IVTy->getIntegerBitWidth() <= 32 ? Type::getInt32Ty(Ctx)
: Type::getInt64Ty(Ctx);
Type *I32Type = Type::getInt32Ty(M.getContext());
Constant *Zero = ConstantInt::get(InternalIVTy, 0);
Constant *One = ConstantInt::get(InternalIVTy, 1);
// Declare useful OpenMP runtime functions.
FunctionCallee StaticInit =
getKmpcForStaticInitForType(InternalIVTy, M, *this);
FunctionCallee StaticFini =
getOrCreateRuntimeFunction(M, omp::OMPRTL___kmpc_for_static_fini);
// Allocate space for computed loop bounds as expected by the "init" function.
Builder.restoreIP(AllocaIP);
Builder.SetCurrentDebugLocation(DL);
Value *PLastIter = Builder.CreateAlloca(I32Type, nullptr, "p.lastiter");
Value *PLowerBound =
Builder.CreateAlloca(InternalIVTy, nullptr, "p.lowerbound");
Value *PUpperBound =
Builder.CreateAlloca(InternalIVTy, nullptr, "p.upperbound");
Value *PStride = Builder.CreateAlloca(InternalIVTy, nullptr, "p.stride");
// Set up the source location value for the OpenMP runtime.
Builder.restoreIP(CLI->getPreheaderIP());
Builder.SetCurrentDebugLocation(DL);
// TODO: Detect overflow in ubsan or max-out with current tripcount.
Value *CastedChunkSize =
Builder.CreateZExtOrTrunc(ChunkSize, InternalIVTy, "chunksize");
Value *CastedTripCount =
Builder.CreateZExt(OrigTripCount, InternalIVTy, "tripcount");
Constant *SchedulingType = ConstantInt::get(
I32Type, static_cast<int>(OMPScheduleType::UnorderedStaticChunked));
Builder.CreateStore(Zero, PLowerBound);
Value *OrigUpperBound = Builder.CreateSub(CastedTripCount, One);
Builder.CreateStore(OrigUpperBound, PUpperBound);
Builder.CreateStore(One, PStride);
// Call the "init" function and update the trip count of the loop with the
// value it produced.
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(DL, SrcLocStrSize);
Value *SrcLoc = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Value *ThreadNum = getOrCreateThreadID(SrcLoc);
Builder.CreateCall(StaticInit,
{/*loc=*/SrcLoc, /*global_tid=*/ThreadNum,
/*schedtype=*/SchedulingType, /*plastiter=*/PLastIter,
/*plower=*/PLowerBound, /*pupper=*/PUpperBound,
/*pstride=*/PStride, /*incr=*/One,
/*chunk=*/CastedChunkSize});
// Load values written by the "init" function.
Value *FirstChunkStart =
Builder.CreateLoad(InternalIVTy, PLowerBound, "omp_firstchunk.lb");
Value *FirstChunkStop =
Builder.CreateLoad(InternalIVTy, PUpperBound, "omp_firstchunk.ub");
Value *FirstChunkEnd = Builder.CreateAdd(FirstChunkStop, One);
Value *ChunkRange =
Builder.CreateSub(FirstChunkEnd, FirstChunkStart, "omp_chunk.range");
Value *NextChunkStride =
Builder.CreateLoad(InternalIVTy, PStride, "omp_dispatch.stride");
// Create outer "dispatch" loop for enumerating the chunks.
BasicBlock *DispatchEnter = splitBB(Builder, true);
Value *DispatchCounter;
CanonicalLoopInfo *DispatchCLI = createCanonicalLoop(
{Builder.saveIP(), DL},
[&](InsertPointTy BodyIP, Value *Counter) { DispatchCounter = Counter; },
FirstChunkStart, CastedTripCount, NextChunkStride,
/*IsSigned=*/false, /*InclusiveStop=*/false, /*ComputeIP=*/{},
"dispatch");
// Remember the BasicBlocks of the dispatch loop we need, then invalidate to
// not have to preserve the canonical invariant.
BasicBlock *DispatchBody = DispatchCLI->getBody();
BasicBlock *DispatchLatch = DispatchCLI->getLatch();
BasicBlock *DispatchExit = DispatchCLI->getExit();
BasicBlock *DispatchAfter = DispatchCLI->getAfter();
DispatchCLI->invalidate();
// Rewire the original loop to become the chunk loop inside the dispatch loop.
redirectTo(DispatchAfter, CLI->getAfter(), DL);
redirectTo(CLI->getExit(), DispatchLatch, DL);
redirectTo(DispatchBody, DispatchEnter, DL);
// Prepare the prolog of the chunk loop.
Builder.restoreIP(CLI->getPreheaderIP());
Builder.SetCurrentDebugLocation(DL);
// Compute the number of iterations of the chunk loop.
Builder.SetInsertPoint(CLI->getPreheader()->getTerminator());
Value *ChunkEnd = Builder.CreateAdd(DispatchCounter, ChunkRange);
Value *IsLastChunk =
Builder.CreateICmpUGE(ChunkEnd, CastedTripCount, "omp_chunk.is_last");
Value *CountUntilOrigTripCount =
Builder.CreateSub(CastedTripCount, DispatchCounter);
Value *ChunkTripCount = Builder.CreateSelect(
IsLastChunk, CountUntilOrigTripCount, ChunkRange, "omp_chunk.tripcount");
Value *BackcastedChunkTC =
Builder.CreateTrunc(ChunkTripCount, IVTy, "omp_chunk.tripcount.trunc");
CLI->setTripCount(BackcastedChunkTC);
// Update all uses of the induction variable except the one in the condition
// block that compares it with the actual upper bound, and the increment in
// the latch block.
Value *BackcastedDispatchCounter =
Builder.CreateTrunc(DispatchCounter, IVTy, "omp_dispatch.iv.trunc");
CLI->mapIndVar([&](Instruction *) -> Value * {
Builder.restoreIP(CLI->getBodyIP());
return Builder.CreateAdd(IV, BackcastedDispatchCounter);
});
// In the "exit" block, call the "fini" function.
Builder.SetInsertPoint(DispatchExit, DispatchExit->getFirstInsertionPt());
Builder.CreateCall(StaticFini, {SrcLoc, ThreadNum});
// Add the barrier if requested.
if (NeedsBarrier)
createBarrier(LocationDescription(Builder.saveIP(), DL), OMPD_for,
/*ForceSimpleCall=*/false, /*CheckCancelFlag=*/false);
#ifndef NDEBUG
// Even though we currently do not support applying additional methods to it,
// the chunk loop should remain a canonical loop.
CLI->assertOK();
#endif
return {DispatchAfter, DispatchAfter->getFirstInsertionPt()};
}
OpenMPIRBuilder::InsertPointTy OpenMPIRBuilder::applyWorkshareLoop(
DebugLoc DL, CanonicalLoopInfo *CLI, InsertPointTy AllocaIP,
bool NeedsBarrier, llvm::omp::ScheduleKind SchedKind,
llvm::Value *ChunkSize, bool HasSimdModifier, bool HasMonotonicModifier,
bool HasNonmonotonicModifier, bool HasOrderedClause) {
OMPScheduleType EffectiveScheduleType = computeOpenMPScheduleType(
SchedKind, ChunkSize, HasSimdModifier, HasMonotonicModifier,
HasNonmonotonicModifier, HasOrderedClause);
bool IsOrdered = (EffectiveScheduleType & OMPScheduleType::ModifierOrdered) ==
OMPScheduleType::ModifierOrdered;
switch (EffectiveScheduleType & ~OMPScheduleType::ModifierMask) {
case OMPScheduleType::BaseStatic:
assert(!ChunkSize && "No chunk size with static-chunked schedule");
if (IsOrdered)
return applyDynamicWorkshareLoop(DL, CLI, AllocaIP, EffectiveScheduleType,
NeedsBarrier, ChunkSize);
// FIXME: Monotonicity ignored?
return applyStaticWorkshareLoop(DL, CLI, AllocaIP, NeedsBarrier);
case OMPScheduleType::BaseStaticChunked:
if (IsOrdered)
return applyDynamicWorkshareLoop(DL, CLI, AllocaIP, EffectiveScheduleType,
NeedsBarrier, ChunkSize);
// FIXME: Monotonicity ignored?
return applyStaticChunkedWorkshareLoop(DL, CLI, AllocaIP, NeedsBarrier,
ChunkSize);
case OMPScheduleType::BaseRuntime:
case OMPScheduleType::BaseAuto:
case OMPScheduleType::BaseGreedy:
case OMPScheduleType::BaseBalanced:
case OMPScheduleType::BaseSteal:
case OMPScheduleType::BaseGuidedSimd:
case OMPScheduleType::BaseRuntimeSimd:
assert(!ChunkSize &&
"schedule type does not support user-defined chunk sizes");
LLVM_FALLTHROUGH;
case OMPScheduleType::BaseDynamicChunked:
case OMPScheduleType::BaseGuidedChunked:
case OMPScheduleType::BaseGuidedIterativeChunked:
case OMPScheduleType::BaseGuidedAnalyticalChunked:
case OMPScheduleType::BaseStaticBalancedChunked:
return applyDynamicWorkshareLoop(DL, CLI, AllocaIP, EffectiveScheduleType,
NeedsBarrier, ChunkSize);
default:
llvm_unreachable("Unknown/unimplemented schedule kind");
}
}
/// Returns an LLVM function to call for initializing loop bounds using OpenMP
/// dynamic scheduling depending on `type`. Only i32 and i64 are supported by
/// the runtime. Always interpret integers as unsigned similarly to
/// CanonicalLoopInfo.
static FunctionCallee
getKmpcForDynamicInitForType(Type *Ty, Module &M, OpenMPIRBuilder &OMPBuilder) {
unsigned Bitwidth = Ty->getIntegerBitWidth();
if (Bitwidth == 32)
return OMPBuilder.getOrCreateRuntimeFunction(
M, omp::RuntimeFunction::OMPRTL___kmpc_dispatch_init_4u);
if (Bitwidth == 64)
return OMPBuilder.getOrCreateRuntimeFunction(
M, omp::RuntimeFunction::OMPRTL___kmpc_dispatch_init_8u);
llvm_unreachable("unknown OpenMP loop iterator bitwidth");
}
/// Returns an LLVM function to call for updating the next loop using OpenMP
/// dynamic scheduling depending on `type`. Only i32 and i64 are supported by
/// the runtime. Always interpret integers as unsigned similarly to
/// CanonicalLoopInfo.
static FunctionCallee
getKmpcForDynamicNextForType(Type *Ty, Module &M, OpenMPIRBuilder &OMPBuilder) {
unsigned Bitwidth = Ty->getIntegerBitWidth();
if (Bitwidth == 32)
return OMPBuilder.getOrCreateRuntimeFunction(
M, omp::RuntimeFunction::OMPRTL___kmpc_dispatch_next_4u);
if (Bitwidth == 64)
return OMPBuilder.getOrCreateRuntimeFunction(
M, omp::RuntimeFunction::OMPRTL___kmpc_dispatch_next_8u);
llvm_unreachable("unknown OpenMP loop iterator bitwidth");
}
/// Returns an LLVM function to call for finalizing the dynamic loop using
/// depending on `type`. Only i32 and i64 are supported by the runtime. Always
/// interpret integers as unsigned similarly to CanonicalLoopInfo.
static FunctionCallee
getKmpcForDynamicFiniForType(Type *Ty, Module &M, OpenMPIRBuilder &OMPBuilder) {
unsigned Bitwidth = Ty->getIntegerBitWidth();
if (Bitwidth == 32)
return OMPBuilder.getOrCreateRuntimeFunction(
M, omp::RuntimeFunction::OMPRTL___kmpc_dispatch_fini_4u);
if (Bitwidth == 64)
return OMPBuilder.getOrCreateRuntimeFunction(
M, omp::RuntimeFunction::OMPRTL___kmpc_dispatch_fini_8u);
llvm_unreachable("unknown OpenMP loop iterator bitwidth");
}
OpenMPIRBuilder::InsertPointTy OpenMPIRBuilder::applyDynamicWorkshareLoop(
DebugLoc DL, CanonicalLoopInfo *CLI, InsertPointTy AllocaIP,
OMPScheduleType SchedType, bool NeedsBarrier, Value *Chunk) {
assert(CLI->isValid() && "Requires a valid canonical loop");
assert(!isConflictIP(AllocaIP, CLI->getPreheaderIP()) &&
"Require dedicated allocate IP");
assert(isValidWorkshareLoopScheduleType(SchedType) &&
"Require valid schedule type");
bool Ordered = (SchedType & OMPScheduleType::ModifierOrdered) ==
OMPScheduleType::ModifierOrdered;
// Set up the source location value for OpenMP runtime.
Builder.SetCurrentDebugLocation(DL);
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(DL, SrcLocStrSize);
Value *SrcLoc = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
// Declare useful OpenMP runtime functions.
Value *IV = CLI->getIndVar();
Type *IVTy = IV->getType();
FunctionCallee DynamicInit = getKmpcForDynamicInitForType(IVTy, M, *this);
FunctionCallee DynamicNext = getKmpcForDynamicNextForType(IVTy, M, *this);
// Allocate space for computed loop bounds as expected by the "init" function.
Builder.restoreIP(AllocaIP);
Type *I32Type = Type::getInt32Ty(M.getContext());
Value *PLastIter = Builder.CreateAlloca(I32Type, nullptr, "p.lastiter");
Value *PLowerBound = Builder.CreateAlloca(IVTy, nullptr, "p.lowerbound");
Value *PUpperBound = Builder.CreateAlloca(IVTy, nullptr, "p.upperbound");
Value *PStride = Builder.CreateAlloca(IVTy, nullptr, "p.stride");
// At the end of the preheader, prepare for calling the "init" function by
// storing the current loop bounds into the allocated space. A canonical loop
// always iterates from 0 to trip-count with step 1. Note that "init" expects
// and produces an inclusive upper bound.
BasicBlock *PreHeader = CLI->getPreheader();
Builder.SetInsertPoint(PreHeader->getTerminator());
Constant *One = ConstantInt::get(IVTy, 1);
Builder.CreateStore(One, PLowerBound);
Value *UpperBound = CLI->getTripCount();
Builder.CreateStore(UpperBound, PUpperBound);
Builder.CreateStore(One, PStride);
BasicBlock *Header = CLI->getHeader();
BasicBlock *Exit = CLI->getExit();
BasicBlock *Cond = CLI->getCond();
BasicBlock *Latch = CLI->getLatch();
InsertPointTy AfterIP = CLI->getAfterIP();
// The CLI will be "broken" in the code below, as the loop is no longer
// a valid canonical loop.
if (!Chunk)
Chunk = One;
Value *ThreadNum = getOrCreateThreadID(SrcLoc);
Constant *SchedulingType =
ConstantInt::get(I32Type, static_cast<int>(SchedType));
// Call the "init" function.
Builder.CreateCall(DynamicInit,
{SrcLoc, ThreadNum, SchedulingType, /* LowerBound */ One,
UpperBound, /* step */ One, Chunk});
// An outer loop around the existing one.
BasicBlock *OuterCond = BasicBlock::Create(
PreHeader->getContext(), Twine(PreHeader->getName()) + ".outer.cond",
PreHeader->getParent());
// This needs to be 32-bit always, so can't use the IVTy Zero above.
Builder.SetInsertPoint(OuterCond, OuterCond->getFirstInsertionPt());
Value *Res =
Builder.CreateCall(DynamicNext, {SrcLoc, ThreadNum, PLastIter,
PLowerBound, PUpperBound, PStride});
Constant *Zero32 = ConstantInt::get(I32Type, 0);
Value *MoreWork = Builder.CreateCmp(CmpInst::ICMP_NE, Res, Zero32);
Value *LowerBound =
Builder.CreateSub(Builder.CreateLoad(IVTy, PLowerBound), One, "lb");
Builder.CreateCondBr(MoreWork, Header, Exit);
// Change PHI-node in loop header to use outer cond rather than preheader,
// and set IV to the LowerBound.
Instruction *Phi = &Header->front();
auto *PI = cast<PHINode>(Phi);
PI->setIncomingBlock(0, OuterCond);
PI->setIncomingValue(0, LowerBound);
// Then set the pre-header to jump to the OuterCond
Instruction *Term = PreHeader->getTerminator();
auto *Br = cast<BranchInst>(Term);
Br->setSuccessor(0, OuterCond);
// Modify the inner condition:
// * Use the UpperBound returned from the DynamicNext call.
// * jump to the loop outer loop when done with one of the inner loops.
Builder.SetInsertPoint(Cond, Cond->getFirstInsertionPt());
UpperBound = Builder.CreateLoad(IVTy, PUpperBound, "ub");
Instruction *Comp = &*Builder.GetInsertPoint();
auto *CI = cast<CmpInst>(Comp);
CI->setOperand(1, UpperBound);
// Redirect the inner exit to branch to outer condition.
Instruction *Branch = &Cond->back();
auto *BI = cast<BranchInst>(Branch);
assert(BI->getSuccessor(1) == Exit);
BI->setSuccessor(1, OuterCond);
// Call the "fini" function if "ordered" is present in wsloop directive.
if (Ordered) {
Builder.SetInsertPoint(&Latch->back());
FunctionCallee DynamicFini = getKmpcForDynamicFiniForType(IVTy, M, *this);
Builder.CreateCall(DynamicFini, {SrcLoc, ThreadNum});
}
// Add the barrier if requested.
if (NeedsBarrier) {
Builder.SetInsertPoint(&Exit->back());
createBarrier(LocationDescription(Builder.saveIP(), DL),
omp::Directive::OMPD_for, /* ForceSimpleCall */ false,
/* CheckCancelFlag */ false);
}
CLI->invalidate();
return AfterIP;
}
/// Redirect all edges that branch to \p OldTarget to \p NewTarget. That is,
/// after this \p OldTarget will be orphaned.
static void redirectAllPredecessorsTo(BasicBlock *OldTarget,
BasicBlock *NewTarget, DebugLoc DL) {
for (BasicBlock *Pred : make_early_inc_range(predecessors(OldTarget)))
redirectTo(Pred, NewTarget, DL);
}
/// Determine which blocks in \p BBs are reachable from outside and remove the
/// ones that are not reachable from the function.
static void removeUnusedBlocksFromParent(ArrayRef<BasicBlock *> BBs) {
SmallPtrSet<BasicBlock *, 6> BBsToErase{BBs.begin(), BBs.end()};
auto HasRemainingUses = [&BBsToErase](BasicBlock *BB) {
for (Use &U : BB->uses()) {
auto *UseInst = dyn_cast<Instruction>(U.getUser());
if (!UseInst)
continue;
if (BBsToErase.count(UseInst->getParent()))
continue;
return true;
}
return false;
};
while (true) {
bool Changed = false;
for (BasicBlock *BB : make_early_inc_range(BBsToErase)) {
if (HasRemainingUses(BB)) {
BBsToErase.erase(BB);
Changed = true;
}
}
if (!Changed)
break;
}
SmallVector<BasicBlock *, 7> BBVec(BBsToErase.begin(), BBsToErase.end());
DeleteDeadBlocks(BBVec);
}
CanonicalLoopInfo *
OpenMPIRBuilder::collapseLoops(DebugLoc DL, ArrayRef<CanonicalLoopInfo *> Loops,
InsertPointTy ComputeIP) {
assert(Loops.size() >= 1 && "At least one loop required");
size_t NumLoops = Loops.size();
// Nothing to do if there is already just one loop.
if (NumLoops == 1)
return Loops.front();
CanonicalLoopInfo *Outermost = Loops.front();
CanonicalLoopInfo *Innermost = Loops.back();
BasicBlock *OrigPreheader = Outermost->getPreheader();
BasicBlock *OrigAfter = Outermost->getAfter();
Function *F = OrigPreheader->getParent();
// Loop control blocks that may become orphaned later.
SmallVector<BasicBlock *, 12> OldControlBBs;
OldControlBBs.reserve(6 * Loops.size());
for (CanonicalLoopInfo *Loop : Loops)
Loop->collectControlBlocks(OldControlBBs);
// Setup the IRBuilder for inserting the trip count computation.
Builder.SetCurrentDebugLocation(DL);
if (ComputeIP.isSet())
Builder.restoreIP(ComputeIP);
else
Builder.restoreIP(Outermost->getPreheaderIP());
// Derive the collapsed' loop trip count.
// TODO: Find common/largest indvar type.
Value *CollapsedTripCount = nullptr;
for (CanonicalLoopInfo *L : Loops) {
assert(L->isValid() &&
"All loops to collapse must be valid canonical loops");
Value *OrigTripCount = L->getTripCount();
if (!CollapsedTripCount) {
CollapsedTripCount = OrigTripCount;
continue;
}
// TODO: Enable UndefinedSanitizer to diagnose an overflow here.
CollapsedTripCount = Builder.CreateMul(CollapsedTripCount, OrigTripCount,
{}, /*HasNUW=*/true);
}
// Create the collapsed loop control flow.
CanonicalLoopInfo *Result =
createLoopSkeleton(DL, CollapsedTripCount, F,
OrigPreheader->getNextNode(), OrigAfter, "collapsed");
// Build the collapsed loop body code.
// Start with deriving the input loop induction variables from the collapsed
// one, using a divmod scheme. To preserve the original loops' order, the
// innermost loop use the least significant bits.
Builder.restoreIP(Result->getBodyIP());
Value *Leftover = Result->getIndVar();
SmallVector<Value *> NewIndVars;
NewIndVars.resize(NumLoops);
for (int i = NumLoops - 1; i >= 1; --i) {
Value *OrigTripCount = Loops[i]->getTripCount();
Value *NewIndVar = Builder.CreateURem(Leftover, OrigTripCount);
NewIndVars[i] = NewIndVar;
Leftover = Builder.CreateUDiv(Leftover, OrigTripCount);
}
// Outermost loop gets all the remaining bits.
NewIndVars[0] = Leftover;
// Construct the loop body control flow.
// We progressively construct the branch structure following in direction of
// the control flow, from the leading in-between code, the loop nest body, the
// trailing in-between code, and rejoining the collapsed loop's latch.
// ContinueBlock and ContinuePred keep track of the source(s) of next edge. If
// the ContinueBlock is set, continue with that block. If ContinuePred, use
// its predecessors as sources.
BasicBlock *ContinueBlock = Result->getBody();
BasicBlock *ContinuePred = nullptr;
auto ContinueWith = [&ContinueBlock, &ContinuePred, DL](BasicBlock *Dest,
BasicBlock *NextSrc) {
if (ContinueBlock)
redirectTo(ContinueBlock, Dest, DL);
else
redirectAllPredecessorsTo(ContinuePred, Dest, DL);
ContinueBlock = nullptr;
ContinuePred = NextSrc;
};
// The code before the nested loop of each level.
// Because we are sinking it into the nest, it will be executed more often
// that the original loop. More sophisticated schemes could keep track of what
// the in-between code is and instantiate it only once per thread.
for (size_t i = 0; i < NumLoops - 1; ++i)
ContinueWith(Loops[i]->getBody(), Loops[i + 1]->getHeader());
// Connect the loop nest body.
ContinueWith(Innermost->getBody(), Innermost->getLatch());
// The code after the nested loop at each level.
for (size_t i = NumLoops - 1; i > 0; --i)
ContinueWith(Loops[i]->getAfter(), Loops[i - 1]->getLatch());
// Connect the finished loop to the collapsed loop latch.
ContinueWith(Result->getLatch(), nullptr);
// Replace the input loops with the new collapsed loop.
redirectTo(Outermost->getPreheader(), Result->getPreheader(), DL);
redirectTo(Result->getAfter(), Outermost->getAfter(), DL);
// Replace the input loop indvars with the derived ones.
for (size_t i = 0; i < NumLoops; ++i)
Loops[i]->getIndVar()->replaceAllUsesWith(NewIndVars[i]);
// Remove unused parts of the input loops.
removeUnusedBlocksFromParent(OldControlBBs);
for (CanonicalLoopInfo *L : Loops)
L->invalidate();
#ifndef NDEBUG
Result->assertOK();
#endif
return Result;
}
std::vector<CanonicalLoopInfo *>
OpenMPIRBuilder::tileLoops(DebugLoc DL, ArrayRef<CanonicalLoopInfo *> Loops,
ArrayRef<Value *> TileSizes) {
assert(TileSizes.size() == Loops.size() &&
"Must pass as many tile sizes as there are loops");
int NumLoops = Loops.size();
assert(NumLoops >= 1 && "At least one loop to tile required");
CanonicalLoopInfo *OutermostLoop = Loops.front();
CanonicalLoopInfo *InnermostLoop = Loops.back();
Function *F = OutermostLoop->getBody()->getParent();
BasicBlock *InnerEnter = InnermostLoop->getBody();
BasicBlock *InnerLatch = InnermostLoop->getLatch();
// Loop control blocks that may become orphaned later.
SmallVector<BasicBlock *, 12> OldControlBBs;
OldControlBBs.reserve(6 * Loops.size());
for (CanonicalLoopInfo *Loop : Loops)
Loop->collectControlBlocks(OldControlBBs);
// Collect original trip counts and induction variable to be accessible by
// index. Also, the structure of the original loops is not preserved during
// the construction of the tiled loops, so do it before we scavenge the BBs of
// any original CanonicalLoopInfo.
SmallVector<Value *, 4> OrigTripCounts, OrigIndVars;
for (CanonicalLoopInfo *L : Loops) {
assert(L->isValid() && "All input loops must be valid canonical loops");
OrigTripCounts.push_back(L->getTripCount());
OrigIndVars.push_back(L->getIndVar());
}
// Collect the code between loop headers. These may contain SSA definitions
// that are used in the loop nest body. To be usable with in the innermost
// body, these BasicBlocks will be sunk into the loop nest body. That is,
// these instructions may be executed more often than before the tiling.
// TODO: It would be sufficient to only sink them into body of the
// corresponding tile loop.
SmallVector<std::pair<BasicBlock *, BasicBlock *>, 4> InbetweenCode;
for (int i = 0; i < NumLoops - 1; ++i) {
CanonicalLoopInfo *Surrounding = Loops[i];
CanonicalLoopInfo *Nested = Loops[i + 1];
BasicBlock *EnterBB = Surrounding->getBody();
BasicBlock *ExitBB = Nested->getHeader();
InbetweenCode.emplace_back(EnterBB, ExitBB);
}
// Compute the trip counts of the floor loops.
Builder.SetCurrentDebugLocation(DL);
Builder.restoreIP(OutermostLoop->getPreheaderIP());
SmallVector<Value *, 4> FloorCount, FloorRems;
for (int i = 0; i < NumLoops; ++i) {
Value *TileSize = TileSizes[i];
Value *OrigTripCount = OrigTripCounts[i];
Type *IVType = OrigTripCount->getType();
Value *FloorTripCount = Builder.CreateUDiv(OrigTripCount, TileSize);
Value *FloorTripRem = Builder.CreateURem(OrigTripCount, TileSize);
// 0 if tripcount divides the tilesize, 1 otherwise.
// 1 means we need an additional iteration for a partial tile.
//
// Unfortunately we cannot just use the roundup-formula
// (tripcount + tilesize - 1)/tilesize
// because the summation might overflow. We do not want introduce undefined
// behavior when the untiled loop nest did not.
Value *FloorTripOverflow =
Builder.CreateICmpNE(FloorTripRem, ConstantInt::get(IVType, 0));
FloorTripOverflow = Builder.CreateZExt(FloorTripOverflow, IVType);
FloorTripCount =
Builder.CreateAdd(FloorTripCount, FloorTripOverflow,
"omp_floor" + Twine(i) + ".tripcount", true);
// Remember some values for later use.
FloorCount.push_back(FloorTripCount);
FloorRems.push_back(FloorTripRem);
}
// Generate the new loop nest, from the outermost to the innermost.
std::vector<CanonicalLoopInfo *> Result;
Result.reserve(NumLoops * 2);
// The basic block of the surrounding loop that enters the nest generated
// loop.
BasicBlock *Enter = OutermostLoop->getPreheader();
// The basic block of the surrounding loop where the inner code should
// continue.
BasicBlock *Continue = OutermostLoop->getAfter();
// Where the next loop basic block should be inserted.
BasicBlock *OutroInsertBefore = InnermostLoop->getExit();
auto EmbeddNewLoop =
[this, DL, F, InnerEnter, &Enter, &Continue, &OutroInsertBefore](
Value *TripCount, const Twine &Name) -> CanonicalLoopInfo * {
CanonicalLoopInfo *EmbeddedLoop = createLoopSkeleton(
DL, TripCount, F, InnerEnter, OutroInsertBefore, Name);
redirectTo(Enter, EmbeddedLoop->getPreheader(), DL);
redirectTo(EmbeddedLoop->getAfter(), Continue, DL);
// Setup the position where the next embedded loop connects to this loop.
Enter = EmbeddedLoop->getBody();
Continue = EmbeddedLoop->getLatch();
OutroInsertBefore = EmbeddedLoop->getLatch();
return EmbeddedLoop;
};
auto EmbeddNewLoops = [&Result, &EmbeddNewLoop](ArrayRef<Value *> TripCounts,
const Twine &NameBase) {
for (auto P : enumerate(TripCounts)) {
CanonicalLoopInfo *EmbeddedLoop =
EmbeddNewLoop(P.value(), NameBase + Twine(P.index()));
Result.push_back(EmbeddedLoop);
}
};
EmbeddNewLoops(FloorCount, "floor");
// Within the innermost floor loop, emit the code that computes the tile
// sizes.
Builder.SetInsertPoint(Enter->getTerminator());
SmallVector<Value *, 4> TileCounts;
for (int i = 0; i < NumLoops; ++i) {
CanonicalLoopInfo *FloorLoop = Result[i];
Value *TileSize = TileSizes[i];
Value *FloorIsEpilogue =
Builder.CreateICmpEQ(FloorLoop->getIndVar(), FloorCount[i]);
Value *TileTripCount =
Builder.CreateSelect(FloorIsEpilogue, FloorRems[i], TileSize);
TileCounts.push_back(TileTripCount);
}
// Create the tile loops.
EmbeddNewLoops(TileCounts, "tile");
// Insert the inbetween code into the body.
BasicBlock *BodyEnter = Enter;
BasicBlock *BodyEntered = nullptr;
for (std::pair<BasicBlock *, BasicBlock *> P : InbetweenCode) {
BasicBlock *EnterBB = P.first;
BasicBlock *ExitBB = P.second;
if (BodyEnter)
redirectTo(BodyEnter, EnterBB, DL);
else
redirectAllPredecessorsTo(BodyEntered, EnterBB, DL);
BodyEnter = nullptr;
BodyEntered = ExitBB;
}
// Append the original loop nest body into the generated loop nest body.
if (BodyEnter)
redirectTo(BodyEnter, InnerEnter, DL);
else
redirectAllPredecessorsTo(BodyEntered, InnerEnter, DL);
redirectAllPredecessorsTo(InnerLatch, Continue, DL);
// Replace the original induction variable with an induction variable computed
// from the tile and floor induction variables.
Builder.restoreIP(Result.back()->getBodyIP());
for (int i = 0; i < NumLoops; ++i) {
CanonicalLoopInfo *FloorLoop = Result[i];
CanonicalLoopInfo *TileLoop = Result[NumLoops + i];
Value *OrigIndVar = OrigIndVars[i];
Value *Size = TileSizes[i];
Value *Scale =
Builder.CreateMul(Size, FloorLoop->getIndVar(), {}, /*HasNUW=*/true);
Value *Shift =
Builder.CreateAdd(Scale, TileLoop->getIndVar(), {}, /*HasNUW=*/true);
OrigIndVar->replaceAllUsesWith(Shift);
}
// Remove unused parts of the original loops.
removeUnusedBlocksFromParent(OldControlBBs);
for (CanonicalLoopInfo *L : Loops)
L->invalidate();
#ifndef NDEBUG
for (CanonicalLoopInfo *GenL : Result)
GenL->assertOK();
#endif
return Result;
}
/// Attach metadata \p Properties to the basic block described by \p BB. If the
/// basic block already has metadata, the basic block properties are appended.
static void addBasicBlockMetadata(BasicBlock *BB,
ArrayRef<Metadata *> Properties) {
// Nothing to do if no property to attach.
if (Properties.empty())
return;
LLVMContext &Ctx = BB->getContext();
SmallVector<Metadata *> NewProperties;
NewProperties.push_back(nullptr);
// If the basic block already has metadata, prepend it to the new metadata.
MDNode *Existing = BB->getTerminator()->getMetadata(LLVMContext::MD_loop);
if (Existing)
append_range(NewProperties, drop_begin(Existing->operands(), 1));
append_range(NewProperties, Properties);
MDNode *BasicBlockID = MDNode::getDistinct(Ctx, NewProperties);
BasicBlockID->replaceOperandWith(0, BasicBlockID);
BB->getTerminator()->setMetadata(LLVMContext::MD_loop, BasicBlockID);
}
/// Attach loop metadata \p Properties to the loop described by \p Loop. If the
/// loop already has metadata, the loop properties are appended.
static void addLoopMetadata(CanonicalLoopInfo *Loop,
ArrayRef<Metadata *> Properties) {
assert(Loop->isValid() && "Expecting a valid CanonicalLoopInfo");
// Attach metadata to the loop's latch
BasicBlock *Latch = Loop->getLatch();
assert(Latch && "A valid CanonicalLoopInfo must have a unique latch");
addBasicBlockMetadata(Latch, Properties);
}
/// Attach llvm.access.group metadata to the memref instructions of \p Block
static void addSimdMetadata(BasicBlock *Block, MDNode *AccessGroup,
LoopInfo &LI) {
for (Instruction &I : *Block) {
if (I.mayReadOrWriteMemory()) {
// TODO: This instruction may already have access group from
// other pragmas e.g. #pragma clang loop vectorize. Append
// so that the existing metadata is not overwritten.
I.setMetadata(LLVMContext::MD_access_group, AccessGroup);
}
}
}
void OpenMPIRBuilder::unrollLoopFull(DebugLoc, CanonicalLoopInfo *Loop) {
LLVMContext &Ctx = Builder.getContext();
addLoopMetadata(
Loop, {MDNode::get(Ctx, MDString::get(Ctx, "llvm.loop.unroll.enable")),
MDNode::get(Ctx, MDString::get(Ctx, "llvm.loop.unroll.full"))});
}
void OpenMPIRBuilder::unrollLoopHeuristic(DebugLoc, CanonicalLoopInfo *Loop) {
LLVMContext &Ctx = Builder.getContext();
addLoopMetadata(
Loop, {
MDNode::get(Ctx, MDString::get(Ctx, "llvm.loop.unroll.enable")),
});
}
void OpenMPIRBuilder::createIfVersion(CanonicalLoopInfo *CanonicalLoop,
Value *IfCond, ValueToValueMapTy &VMap,
const Twine &NamePrefix) {
Function *F = CanonicalLoop->getFunction();
// Define where if branch should be inserted
Instruction *SplitBefore;
if (Instruction::classof(IfCond)) {
SplitBefore = dyn_cast<Instruction>(IfCond);
} else {
SplitBefore = CanonicalLoop->getPreheader()->getTerminator();
}
// TODO: We should not rely on pass manager. Currently we use pass manager
// only for getting llvm::Loop which corresponds to given CanonicalLoopInfo
// object. We should have a method which returns all blocks between
// CanonicalLoopInfo::getHeader() and CanonicalLoopInfo::getAfter()
FunctionAnalysisManager FAM;
FAM.registerPass([]() { return DominatorTreeAnalysis(); });
FAM.registerPass([]() { return LoopAnalysis(); });
FAM.registerPass([]() { return PassInstrumentationAnalysis(); });
// Get the loop which needs to be cloned
LoopAnalysis LIA;
LoopInfo &&LI = LIA.run(*F, FAM);
Loop *L = LI.getLoopFor(CanonicalLoop->getHeader());
// Create additional blocks for the if statement
BasicBlock *Head = SplitBefore->getParent();
Instruction *HeadOldTerm = Head->getTerminator();
llvm::LLVMContext &C = Head->getContext();
llvm::BasicBlock *ThenBlock = llvm::BasicBlock::Create(
C, NamePrefix + ".if.then", Head->getParent(), Head->getNextNode());
llvm::BasicBlock *ElseBlock = llvm::BasicBlock::Create(
C, NamePrefix + ".if.else", Head->getParent(), CanonicalLoop->getExit());
// Create if condition branch.
Builder.SetInsertPoint(HeadOldTerm);
Instruction *BrInstr =
Builder.CreateCondBr(IfCond, ThenBlock, /*ifFalse*/ ElseBlock);
InsertPointTy IP{BrInstr->getParent(), ++BrInstr->getIterator()};
// Then block contains branch to omp loop which needs to be vectorized
spliceBB(IP, ThenBlock, false);
ThenBlock->replaceSuccessorsPhiUsesWith(Head, ThenBlock);
Builder.SetInsertPoint(ElseBlock);
// Clone loop for the else branch
SmallVector<BasicBlock *, 8> NewBlocks;
VMap[CanonicalLoop->getPreheader()] = ElseBlock;
for (BasicBlock *Block : L->getBlocks()) {
BasicBlock *NewBB = CloneBasicBlock(Block, VMap, "", F);
NewBB->moveBefore(CanonicalLoop->getExit());
VMap[Block] = NewBB;
NewBlocks.push_back(NewBB);
}
remapInstructionsInBlocks(NewBlocks, VMap);
Builder.CreateBr(NewBlocks.front());
}
void OpenMPIRBuilder::applySimd(CanonicalLoopInfo *CanonicalLoop,
MapVector<Value *, Value *> AlignedVars,
Value *IfCond, OrderKind Order,
ConstantInt *Simdlen, ConstantInt *Safelen) {
LLVMContext &Ctx = Builder.getContext();
Function *F = CanonicalLoop->getFunction();
// TODO: We should not rely on pass manager. Currently we use pass manager
// only for getting llvm::Loop which corresponds to given CanonicalLoopInfo
// object. We should have a method which returns all blocks between
// CanonicalLoopInfo::getHeader() and CanonicalLoopInfo::getAfter()
FunctionAnalysisManager FAM;
FAM.registerPass([]() { return DominatorTreeAnalysis(); });
FAM.registerPass([]() { return LoopAnalysis(); });
FAM.registerPass([]() { return PassInstrumentationAnalysis(); });
LoopAnalysis LIA;
LoopInfo &&LI = LIA.run(*F, FAM);
Loop *L = LI.getLoopFor(CanonicalLoop->getHeader());
if (AlignedVars.size()) {
InsertPointTy IP = Builder.saveIP();
Builder.SetInsertPoint(CanonicalLoop->getPreheader()->getTerminator());
for (auto &AlignedItem : AlignedVars) {
Value *AlignedPtr = AlignedItem.first;
Value *Alignment = AlignedItem.second;
Builder.CreateAlignmentAssumption(F->getParent()->getDataLayout(),
AlignedPtr, Alignment);
}
Builder.restoreIP(IP);
}
if (IfCond) {
ValueToValueMapTy VMap;
createIfVersion(CanonicalLoop, IfCond, VMap, "simd");
// Add metadata to the cloned loop which disables vectorization
Value *MappedLatch = VMap.lookup(CanonicalLoop->getLatch());
assert(MappedLatch &&
"Cannot find value which corresponds to original loop latch");
assert(isa<BasicBlock>(MappedLatch) &&
"Cannot cast mapped latch block value to BasicBlock");
BasicBlock *NewLatchBlock = dyn_cast<BasicBlock>(MappedLatch);
ConstantAsMetadata *BoolConst =
ConstantAsMetadata::get(ConstantInt::getFalse(Type::getInt1Ty(Ctx)));
addBasicBlockMetadata(
NewLatchBlock,
{MDNode::get(Ctx, {MDString::get(Ctx, "llvm.loop.vectorize.enable"),
BoolConst})});
}
SmallSet<BasicBlock *, 8> Reachable;
// Get the basic blocks from the loop in which memref instructions
// can be found.
// TODO: Generalize getting all blocks inside a CanonicalizeLoopInfo,
// preferably without running any passes.
for (BasicBlock *Block : L->getBlocks()) {
if (Block == CanonicalLoop->getCond() ||
Block == CanonicalLoop->getHeader())
continue;
Reachable.insert(Block);
}
SmallVector<Metadata *> LoopMDList;
// In presence of finite 'safelen', it may be unsafe to mark all
// the memory instructions parallel, because loop-carried
// dependences of 'safelen' iterations are possible.
// If clause order(concurrent) is specified then the memory instructions
// are marked parallel even if 'safelen' is finite.
if ((Safelen == nullptr) || (Order == OrderKind::OMP_ORDER_concurrent)) {
// Add access group metadata to memory-access instructions.
MDNode *AccessGroup = MDNode::getDistinct(Ctx, {});
for (BasicBlock *BB : Reachable)
addSimdMetadata(BB, AccessGroup, LI);
// TODO: If the loop has existing parallel access metadata, have
// to combine two lists.
LoopMDList.push_back(MDNode::get(
Ctx, {MDString::get(Ctx, "llvm.loop.parallel_accesses"), AccessGroup}));
}
// Use the above access group metadata to create loop level
// metadata, which should be distinct for each loop.
ConstantAsMetadata *BoolConst =
ConstantAsMetadata::get(ConstantInt::getTrue(Type::getInt1Ty(Ctx)));
LoopMDList.push_back(MDNode::get(
Ctx, {MDString::get(Ctx, "llvm.loop.vectorize.enable"), BoolConst}));
if (Simdlen || Safelen) {
// If both simdlen and safelen clauses are specified, the value of the
// simdlen parameter must be less than or equal to the value of the safelen
// parameter. Therefore, use safelen only in the absence of simdlen.
ConstantInt *VectorizeWidth = Simdlen == nullptr ? Safelen : Simdlen;
LoopMDList.push_back(
MDNode::get(Ctx, {MDString::get(Ctx, "llvm.loop.vectorize.width"),
ConstantAsMetadata::get(VectorizeWidth)}));
}
addLoopMetadata(CanonicalLoop, LoopMDList);
}
/// Create the TargetMachine object to query the backend for optimization
/// preferences.
///
/// Ideally, this would be passed from the front-end to the OpenMPBuilder, but
/// e.g. Clang does not pass it to its CodeGen layer and creates it only when
/// needed for the LLVM pass pipline. We use some default options to avoid
/// having to pass too many settings from the frontend that probably do not
/// matter.
///
/// Currently, TargetMachine is only used sometimes by the unrollLoopPartial
/// method. If we are going to use TargetMachine for more purposes, especially
/// those that are sensitive to TargetOptions, RelocModel and CodeModel, it
/// might become be worth requiring front-ends to pass on their TargetMachine,
/// or at least cache it between methods. Note that while fontends such as Clang
/// have just a single main TargetMachine per translation unit, "target-cpu" and
/// "target-features" that determine the TargetMachine are per-function and can
/// be overrided using __attribute__((target("OPTIONS"))).
static std::unique_ptr<TargetMachine>
createTargetMachine(Function *F, CodeGenOpt::Level OptLevel) {
Module *M = F->getParent();
StringRef CPU = F->getFnAttribute("target-cpu").getValueAsString();
StringRef Features = F->getFnAttribute("target-features").getValueAsString();
const std::string &Triple = M->getTargetTriple();
std::string Error;
const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error);
if (!TheTarget)
return {};
llvm::TargetOptions Options;
return std::unique_ptr<TargetMachine>(TheTarget->createTargetMachine(
Triple, CPU, Features, Options, /*RelocModel=*/std::nullopt,
/*CodeModel=*/std::nullopt, OptLevel));
}
/// Heuristically determine the best-performant unroll factor for \p CLI. This
/// depends on the target processor. We are re-using the same heuristics as the
/// LoopUnrollPass.
static int32_t computeHeuristicUnrollFactor(CanonicalLoopInfo *CLI) {
Function *F = CLI->getFunction();
// Assume the user requests the most aggressive unrolling, even if the rest of
// the code is optimized using a lower setting.
CodeGenOpt::Level OptLevel = CodeGenOpt::Aggressive;
std::unique_ptr<TargetMachine> TM = createTargetMachine(F, OptLevel);
FunctionAnalysisManager FAM;
FAM.registerPass([]() { return TargetLibraryAnalysis(); });
FAM.registerPass([]() { return AssumptionAnalysis(); });
FAM.registerPass([]() { return DominatorTreeAnalysis(); });
FAM.registerPass([]() { return LoopAnalysis(); });
FAM.registerPass([]() { return ScalarEvolutionAnalysis(); });
FAM.registerPass([]() { return PassInstrumentationAnalysis(); });
TargetIRAnalysis TIRA;
if (TM)
TIRA = TargetIRAnalysis(
[&](const Function &F) { return TM->getTargetTransformInfo(F); });
FAM.registerPass([&]() { return TIRA; });
TargetIRAnalysis::Result &&TTI = TIRA.run(*F, FAM);
ScalarEvolutionAnalysis SEA;
ScalarEvolution &&SE = SEA.run(*F, FAM);
DominatorTreeAnalysis DTA;
DominatorTree &&DT = DTA.run(*F, FAM);
LoopAnalysis LIA;
LoopInfo &&LI = LIA.run(*F, FAM);
AssumptionAnalysis ACT;
AssumptionCache &&AC = ACT.run(*F, FAM);
OptimizationRemarkEmitter ORE{F};
Loop *L = LI.getLoopFor(CLI->getHeader());
assert(L && "Expecting CanonicalLoopInfo to be recognized as a loop");
TargetTransformInfo::UnrollingPreferences UP =
gatherUnrollingPreferences(L, SE, TTI,
/*BlockFrequencyInfo=*/nullptr,
/*ProfileSummaryInfo=*/nullptr, ORE, OptLevel,
/*UserThreshold=*/std::nullopt,
/*UserCount=*/std::nullopt,
/*UserAllowPartial=*/true,
/*UserAllowRuntime=*/true,
/*UserUpperBound=*/std::nullopt,
/*UserFullUnrollMaxCount=*/std::nullopt);
UP.Force = true;
// Account for additional optimizations taking place before the LoopUnrollPass
// would unroll the loop.
UP.Threshold *= UnrollThresholdFactor;
UP.PartialThreshold *= UnrollThresholdFactor;
// Use normal unroll factors even if the rest of the code is optimized for
// size.
UP.OptSizeThreshold = UP.Threshold;
UP.PartialOptSizeThreshold = UP.PartialThreshold;
LLVM_DEBUG(dbgs() << "Unroll heuristic thresholds:\n"
<< " Threshold=" << UP.Threshold << "\n"
<< " PartialThreshold=" << UP.PartialThreshold << "\n"
<< " OptSizeThreshold=" << UP.OptSizeThreshold << "\n"
<< " PartialOptSizeThreshold="
<< UP.PartialOptSizeThreshold << "\n");
// Disable peeling.
TargetTransformInfo::PeelingPreferences PP =
gatherPeelingPreferences(L, SE, TTI,
/*UserAllowPeeling=*/false,
/*UserAllowProfileBasedPeeling=*/false,
/*UnrollingSpecficValues=*/false);
SmallPtrSet<const Value *, 32> EphValues;
CodeMetrics::collectEphemeralValues(L, &AC, EphValues);
// Assume that reads and writes to stack variables can be eliminated by
// Mem2Reg, SROA or LICM. That is, don't count them towards the loop body's
// size.
for (BasicBlock *BB : L->blocks()) {
for (Instruction &I : *BB) {
Value *Ptr;
if (auto *Load = dyn_cast<LoadInst>(&I)) {
Ptr = Load->getPointerOperand();
} else if (auto *Store = dyn_cast<StoreInst>(&I)) {
Ptr = Store->getPointerOperand();
} else
continue;
Ptr = Ptr->stripPointerCasts();
if (auto *Alloca = dyn_cast<AllocaInst>(Ptr)) {
if (Alloca->getParent() == &F->getEntryBlock())
EphValues.insert(&I);
}
}
}
unsigned NumInlineCandidates;
bool NotDuplicatable;
bool Convergent;
InstructionCost LoopSizeIC =
ApproximateLoopSize(L, NumInlineCandidates, NotDuplicatable, Convergent,
TTI, EphValues, UP.BEInsns);
LLVM_DEBUG(dbgs() << "Estimated loop size is " << LoopSizeIC << "\n");
// Loop is not unrollable if the loop contains certain instructions.
if (NotDuplicatable || Convergent || !LoopSizeIC.isValid()) {
LLVM_DEBUG(dbgs() << "Loop not considered unrollable\n");
return 1;
}
unsigned LoopSize = *LoopSizeIC.getValue();
// TODO: Determine trip count of \p CLI if constant, computeUnrollCount might
// be able to use it.
int TripCount = 0;
int MaxTripCount = 0;
bool MaxOrZero = false;
unsigned TripMultiple = 0;
bool UseUpperBound = false;
computeUnrollCount(L, TTI, DT, &LI, &AC, SE, EphValues, &ORE, TripCount,
MaxTripCount, MaxOrZero, TripMultiple, LoopSize, UP, PP,
UseUpperBound);
unsigned Factor = UP.Count;
LLVM_DEBUG(dbgs() << "Suggesting unroll factor of " << Factor << "\n");
// This function returns 1 to signal to not unroll a loop.
if (Factor == 0)
return 1;
return Factor;
}
void OpenMPIRBuilder::unrollLoopPartial(DebugLoc DL, CanonicalLoopInfo *Loop,
int32_t Factor,
CanonicalLoopInfo **UnrolledCLI) {
assert(Factor >= 0 && "Unroll factor must not be negative");
Function *F = Loop->getFunction();
LLVMContext &Ctx = F->getContext();
// If the unrolled loop is not used for another loop-associated directive, it
// is sufficient to add metadata for the LoopUnrollPass.
if (!UnrolledCLI) {
SmallVector<Metadata *, 2> LoopMetadata;
LoopMetadata.push_back(
MDNode::get(Ctx, MDString::get(Ctx, "llvm.loop.unroll.enable")));
if (Factor >= 1) {
ConstantAsMetadata *FactorConst = ConstantAsMetadata::get(
ConstantInt::get(Type::getInt32Ty(Ctx), APInt(32, Factor)));
LoopMetadata.push_back(MDNode::get(
Ctx, {MDString::get(Ctx, "llvm.loop.unroll.count"), FactorConst}));
}
addLoopMetadata(Loop, LoopMetadata);
return;
}
// Heuristically determine the unroll factor.
if (Factor == 0)
Factor = computeHeuristicUnrollFactor(Loop);
// No change required with unroll factor 1.
if (Factor == 1) {
*UnrolledCLI = Loop;
return;
}
assert(Factor >= 2 &&
"unrolling only makes sense with a factor of 2 or larger");
Type *IndVarTy = Loop->getIndVarType();
// Apply partial unrolling by tiling the loop by the unroll-factor, then fully
// unroll the inner loop.
Value *FactorVal =
ConstantInt::get(IndVarTy, APInt(IndVarTy->getIntegerBitWidth(), Factor,
/*isSigned=*/false));
std::vector<CanonicalLoopInfo *> LoopNest =
tileLoops(DL, {Loop}, {FactorVal});
assert(LoopNest.size() == 2 && "Expect 2 loops after tiling");
*UnrolledCLI = LoopNest[0];
CanonicalLoopInfo *InnerLoop = LoopNest[1];
// LoopUnrollPass can only fully unroll loops with constant trip count.
// Unroll by the unroll factor with a fallback epilog for the remainder
// iterations if necessary.
ConstantAsMetadata *FactorConst = ConstantAsMetadata::get(
ConstantInt::get(Type::getInt32Ty(Ctx), APInt(32, Factor)));
addLoopMetadata(
InnerLoop,
{MDNode::get(Ctx, MDString::get(Ctx, "llvm.loop.unroll.enable")),
MDNode::get(
Ctx, {MDString::get(Ctx, "llvm.loop.unroll.count"), FactorConst})});
#ifndef NDEBUG
(*UnrolledCLI)->assertOK();
#endif
}
OpenMPIRBuilder::InsertPointTy
OpenMPIRBuilder::createCopyPrivate(const LocationDescription &Loc,
llvm::Value *BufSize, llvm::Value *CpyBuf,
llvm::Value *CpyFn, llvm::Value *DidIt) {
if (!updateToLocation(Loc))
return Loc.IP;
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Value *ThreadId = getOrCreateThreadID(Ident);
llvm::Value *DidItLD = Builder.CreateLoad(Builder.getInt32Ty(), DidIt);
Value *Args[] = {Ident, ThreadId, BufSize, CpyBuf, CpyFn, DidItLD};
Function *Fn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_copyprivate);
Builder.CreateCall(Fn, Args);
return Builder.saveIP();
}
OpenMPIRBuilder::InsertPointTy OpenMPIRBuilder::createSingle(
const LocationDescription &Loc, BodyGenCallbackTy BodyGenCB,
FinalizeCallbackTy FiniCB, bool IsNowait, llvm::Value *DidIt) {
if (!updateToLocation(Loc))
return Loc.IP;
// If needed (i.e. not null), initialize `DidIt` with 0
if (DidIt) {
Builder.CreateStore(Builder.getInt32(0), DidIt);
}
Directive OMPD = Directive::OMPD_single;
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Value *ThreadId = getOrCreateThreadID(Ident);
Value *Args[] = {Ident, ThreadId};
Function *EntryRTLFn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_single);
Instruction *EntryCall = Builder.CreateCall(EntryRTLFn, Args);
Function *ExitRTLFn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_end_single);
Instruction *ExitCall = Builder.CreateCall(ExitRTLFn, Args);
// generates the following:
// if (__kmpc_single()) {
// .... single region ...
// __kmpc_end_single
// }
// __kmpc_barrier
EmitOMPInlinedRegion(OMPD, EntryCall, ExitCall, BodyGenCB, FiniCB,
/*Conditional*/ true,
/*hasFinalize*/ true);
if (!IsNowait)
createBarrier(LocationDescription(Builder.saveIP(), Loc.DL),
omp::Directive::OMPD_unknown, /* ForceSimpleCall */ false,
/* CheckCancelFlag */ false);
return Builder.saveIP();
}
OpenMPIRBuilder::InsertPointTy OpenMPIRBuilder::createCritical(
const LocationDescription &Loc, BodyGenCallbackTy BodyGenCB,
FinalizeCallbackTy FiniCB, StringRef CriticalName, Value *HintInst) {
if (!updateToLocation(Loc))
return Loc.IP;
Directive OMPD = Directive::OMPD_critical;
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Value *ThreadId = getOrCreateThreadID(Ident);
Value *LockVar = getOMPCriticalRegionLock(CriticalName);
Value *Args[] = {Ident, ThreadId, LockVar};
SmallVector<llvm::Value *, 4> EnterArgs(std::begin(Args), std::end(Args));
Function *RTFn = nullptr;
if (HintInst) {
// Add Hint to entry Args and create call
EnterArgs.push_back(HintInst);
RTFn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_critical_with_hint);
} else {
RTFn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_critical);
}
Instruction *EntryCall = Builder.CreateCall(RTFn, EnterArgs);
Function *ExitRTLFn =
getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_end_critical);
Instruction *ExitCall = Builder.CreateCall(ExitRTLFn, Args);
return EmitOMPInlinedRegion(OMPD, EntryCall, ExitCall, BodyGenCB, FiniCB,
/*Conditional*/ false, /*hasFinalize*/ true);
}
OpenMPIRBuilder::InsertPointTy
OpenMPIRBuilder::createOrderedDepend(const LocationDescription &Loc,
InsertPointTy AllocaIP, unsigned NumLoops,
ArrayRef<llvm::Value *> StoreValues,
const Twine &Name, bool IsDependSource) {
assert(
llvm::all_of(StoreValues,
[](Value *SV) { return SV->getType()->isIntegerTy(64); }) &&
"OpenMP runtime requires depend vec with i64 type");
if (!updateToLocation(Loc))
return Loc.IP;
// Allocate space for vector and generate alloc instruction.
auto *ArrI64Ty = ArrayType::get(Int64, NumLoops);
Builder.restoreIP(AllocaIP);
AllocaInst *ArgsBase = Builder.CreateAlloca(ArrI64Ty, nullptr, Name);
ArgsBase->setAlignment(Align(8));
Builder.restoreIP(Loc.IP);
// Store the index value with offset in depend vector.
for (unsigned I = 0; I < NumLoops; ++I) {
Value *DependAddrGEPIter = Builder.CreateInBoundsGEP(
ArrI64Ty, ArgsBase, {Builder.getInt64(0), Builder.getInt64(I)});
StoreInst *STInst = Builder.CreateStore(StoreValues[I], DependAddrGEPIter);
STInst->setAlignment(Align(8));
}
Value *DependBaseAddrGEP = Builder.CreateInBoundsGEP(
ArrI64Ty, ArgsBase, {Builder.getInt64(0), Builder.getInt64(0)});
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Value *ThreadId = getOrCreateThreadID(Ident);
Value *Args[] = {Ident, ThreadId, DependBaseAddrGEP};
Function *RTLFn = nullptr;
if (IsDependSource)
RTLFn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_doacross_post);
else
RTLFn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_doacross_wait);
Builder.CreateCall(RTLFn, Args);
return Builder.saveIP();
}
OpenMPIRBuilder::InsertPointTy OpenMPIRBuilder::createOrderedThreadsSimd(
const LocationDescription &Loc, BodyGenCallbackTy BodyGenCB,
FinalizeCallbackTy FiniCB, bool IsThreads) {
if (!updateToLocation(Loc))
return Loc.IP;
Directive OMPD = Directive::OMPD_ordered;
Instruction *EntryCall = nullptr;
Instruction *ExitCall = nullptr;
if (IsThreads) {
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Value *ThreadId = getOrCreateThreadID(Ident);
Value *Args[] = {Ident, ThreadId};
Function *EntryRTLFn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_ordered);
EntryCall = Builder.CreateCall(EntryRTLFn, Args);
Function *ExitRTLFn =
getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_end_ordered);
ExitCall = Builder.CreateCall(ExitRTLFn, Args);
}
return EmitOMPInlinedRegion(OMPD, EntryCall, ExitCall, BodyGenCB, FiniCB,
/*Conditional*/ false, /*hasFinalize*/ true);
}
OpenMPIRBuilder::InsertPointTy OpenMPIRBuilder::EmitOMPInlinedRegion(
Directive OMPD, Instruction *EntryCall, Instruction *ExitCall,
BodyGenCallbackTy BodyGenCB, FinalizeCallbackTy FiniCB, bool Conditional,
bool HasFinalize, bool IsCancellable) {
if (HasFinalize)
FinalizationStack.push_back({FiniCB, OMPD, IsCancellable});
// Create inlined region's entry and body blocks, in preparation
// for conditional creation
BasicBlock *EntryBB = Builder.GetInsertBlock();
Instruction *SplitPos = EntryBB->getTerminator();
if (!isa_and_nonnull<BranchInst>(SplitPos))
SplitPos = new UnreachableInst(Builder.getContext(), EntryBB);
BasicBlock *ExitBB = EntryBB->splitBasicBlock(SplitPos, "omp_region.end");
BasicBlock *FiniBB =
EntryBB->splitBasicBlock(EntryBB->getTerminator(), "omp_region.finalize");
Builder.SetInsertPoint(EntryBB->getTerminator());
emitCommonDirectiveEntry(OMPD, EntryCall, ExitBB, Conditional);
// generate body
BodyGenCB(/* AllocaIP */ InsertPointTy(),
/* CodeGenIP */ Builder.saveIP());
// emit exit call and do any needed finalization.
auto FinIP = InsertPointTy(FiniBB, FiniBB->getFirstInsertionPt());
assert(FiniBB->getTerminator()->getNumSuccessors() == 1 &&
FiniBB->getTerminator()->getSuccessor(0) == ExitBB &&
"Unexpected control flow graph state!!");
emitCommonDirectiveExit(OMPD, FinIP, ExitCall, HasFinalize);
assert(FiniBB->getUniquePredecessor()->getUniqueSuccessor() == FiniBB &&
"Unexpected Control Flow State!");
MergeBlockIntoPredecessor(FiniBB);
// If we are skipping the region of a non conditional, remove the exit
// block, and clear the builder's insertion point.
assert(SplitPos->getParent() == ExitBB &&
"Unexpected Insertion point location!");
auto merged = MergeBlockIntoPredecessor(ExitBB);
BasicBlock *ExitPredBB = SplitPos->getParent();
auto InsertBB = merged ? ExitPredBB : ExitBB;
if (!isa_and_nonnull<BranchInst>(SplitPos))
SplitPos->eraseFromParent();
Builder.SetInsertPoint(InsertBB);
return Builder.saveIP();
}
OpenMPIRBuilder::InsertPointTy OpenMPIRBuilder::emitCommonDirectiveEntry(
Directive OMPD, Value *EntryCall, BasicBlock *ExitBB, bool Conditional) {
// if nothing to do, Return current insertion point.
if (!Conditional || !EntryCall)
return Builder.saveIP();
BasicBlock *EntryBB = Builder.GetInsertBlock();
Value *CallBool = Builder.CreateIsNotNull(EntryCall);
auto *ThenBB = BasicBlock::Create(M.getContext(), "omp_region.body");
auto *UI = new UnreachableInst(Builder.getContext(), ThenBB);
// Emit thenBB and set the Builder's insertion point there for
// body generation next. Place the block after the current block.
Function *CurFn = EntryBB->getParent();
CurFn->insert(std::next(EntryBB->getIterator()), ThenBB);
// Move Entry branch to end of ThenBB, and replace with conditional
// branch (If-stmt)
Instruction *EntryBBTI = EntryBB->getTerminator();
Builder.CreateCondBr(CallBool, ThenBB, ExitBB);
EntryBBTI->removeFromParent();
Builder.SetInsertPoint(UI);
Builder.Insert(EntryBBTI);
UI->eraseFromParent();
Builder.SetInsertPoint(ThenBB->getTerminator());
// return an insertion point to ExitBB.
return IRBuilder<>::InsertPoint(ExitBB, ExitBB->getFirstInsertionPt());
}
OpenMPIRBuilder::InsertPointTy OpenMPIRBuilder::emitCommonDirectiveExit(
omp::Directive OMPD, InsertPointTy FinIP, Instruction *ExitCall,
bool HasFinalize) {
Builder.restoreIP(FinIP);
// If there is finalization to do, emit it before the exit call
if (HasFinalize) {
assert(!FinalizationStack.empty() &&
"Unexpected finalization stack state!");
FinalizationInfo Fi = FinalizationStack.pop_back_val();
assert(Fi.DK == OMPD && "Unexpected Directive for Finalization call!");
Fi.FiniCB(FinIP);
BasicBlock *FiniBB = FinIP.getBlock();
Instruction *FiniBBTI = FiniBB->getTerminator();
// set Builder IP for call creation
Builder.SetInsertPoint(FiniBBTI);
}
if (!ExitCall)
return Builder.saveIP();
// place the Exitcall as last instruction before Finalization block terminator
ExitCall->removeFromParent();
Builder.Insert(ExitCall);
return IRBuilder<>::InsertPoint(ExitCall->getParent(),
ExitCall->getIterator());
}
OpenMPIRBuilder::InsertPointTy OpenMPIRBuilder::createCopyinClauseBlocks(
InsertPointTy IP, Value *MasterAddr, Value *PrivateAddr,
llvm::IntegerType *IntPtrTy, bool BranchtoEnd) {
if (!IP.isSet())
return IP;
IRBuilder<>::InsertPointGuard IPG(Builder);
// creates the following CFG structure
// OMP_Entry : (MasterAddr != PrivateAddr)?
// F T
// | \
// | copin.not.master
// | /
// v /
// copyin.not.master.end
// |
// v
// OMP.Entry.Next
BasicBlock *OMP_Entry = IP.getBlock();
Function *CurFn = OMP_Entry->getParent();
BasicBlock *CopyBegin =
BasicBlock::Create(M.getContext(), "copyin.not.master", CurFn);
BasicBlock *CopyEnd = nullptr;
// If entry block is terminated, split to preserve the branch to following
// basic block (i.e. OMP.Entry.Next), otherwise, leave everything as is.
if (isa_and_nonnull<BranchInst>(OMP_Entry->getTerminator())) {
CopyEnd = OMP_Entry->splitBasicBlock(OMP_Entry->getTerminator(),
"copyin.not.master.end");
OMP_Entry->getTerminator()->eraseFromParent();
} else {
CopyEnd =
BasicBlock::Create(M.getContext(), "copyin.not.master.end", CurFn);
}
Builder.SetInsertPoint(OMP_Entry);
Value *MasterPtr = Builder.CreatePtrToInt(MasterAddr, IntPtrTy);
Value *PrivatePtr = Builder.CreatePtrToInt(PrivateAddr, IntPtrTy);
Value *cmp = Builder.CreateICmpNE(MasterPtr, PrivatePtr);
Builder.CreateCondBr(cmp, CopyBegin, CopyEnd);
Builder.SetInsertPoint(CopyBegin);
if (BranchtoEnd)
Builder.SetInsertPoint(Builder.CreateBr(CopyEnd));
return Builder.saveIP();
}
CallInst *OpenMPIRBuilder::createOMPAlloc(const LocationDescription &Loc,
Value *Size, Value *Allocator,
std::string Name) {
IRBuilder<>::InsertPointGuard IPG(Builder);
Builder.restoreIP(Loc.IP);
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Value *ThreadId = getOrCreateThreadID(Ident);
Value *Args[] = {ThreadId, Size, Allocator};
Function *Fn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_alloc);
return Builder.CreateCall(Fn, Args, Name);
}
CallInst *OpenMPIRBuilder::createOMPFree(const LocationDescription &Loc,
Value *Addr, Value *Allocator,
std::string Name) {
IRBuilder<>::InsertPointGuard IPG(Builder);
Builder.restoreIP(Loc.IP);
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Value *ThreadId = getOrCreateThreadID(Ident);
Value *Args[] = {ThreadId, Addr, Allocator};
Function *Fn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_free);
return Builder.CreateCall(Fn, Args, Name);
}
CallInst *OpenMPIRBuilder::createOMPInteropInit(
const LocationDescription &Loc, Value *InteropVar,
omp::OMPInteropType InteropType, Value *Device, Value *NumDependences,
Value *DependenceAddress, bool HaveNowaitClause) {
IRBuilder<>::InsertPointGuard IPG(Builder);
Builder.restoreIP(Loc.IP);
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Value *ThreadId = getOrCreateThreadID(Ident);
if (Device == nullptr)
Device = ConstantInt::get(Int32, -1);
Constant *InteropTypeVal = ConstantInt::get(Int32, (int)InteropType);
if (NumDependences == nullptr) {
NumDependences = ConstantInt::get(Int64, 0);
PointerType *PointerTypeVar = Type::getInt8PtrTy(M.getContext());
DependenceAddress = ConstantPointerNull::get(PointerTypeVar);
}
Value *HaveNowaitClauseVal = ConstantInt::get(Int32, HaveNowaitClause);
Value *Args[] = {
Ident, ThreadId, InteropVar, InteropTypeVal,
Device, NumDependences, DependenceAddress, HaveNowaitClauseVal};
Function *Fn = getOrCreateRuntimeFunctionPtr(OMPRTL___tgt_interop_init);
return Builder.CreateCall(Fn, Args);
}
CallInst *OpenMPIRBuilder::createOMPInteropDestroy(
const LocationDescription &Loc, Value *InteropVar, Value *Device,
Value *NumDependences, Value *DependenceAddress, bool HaveNowaitClause) {
IRBuilder<>::InsertPointGuard IPG(Builder);
Builder.restoreIP(Loc.IP);
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Value *ThreadId = getOrCreateThreadID(Ident);
if (Device == nullptr)
Device = ConstantInt::get(Int32, -1);
if (NumDependences == nullptr) {
NumDependences = ConstantInt::get(Int32, 0);
PointerType *PointerTypeVar = Type::getInt8PtrTy(M.getContext());
DependenceAddress = ConstantPointerNull::get(PointerTypeVar);
}
Value *HaveNowaitClauseVal = ConstantInt::get(Int32, HaveNowaitClause);
Value *Args[] = {
Ident, ThreadId, InteropVar, Device,
NumDependences, DependenceAddress, HaveNowaitClauseVal};
Function *Fn = getOrCreateRuntimeFunctionPtr(OMPRTL___tgt_interop_destroy);
return Builder.CreateCall(Fn, Args);
}
CallInst *OpenMPIRBuilder::createOMPInteropUse(const LocationDescription &Loc,
Value *InteropVar, Value *Device,
Value *NumDependences,
Value *DependenceAddress,
bool HaveNowaitClause) {
IRBuilder<>::InsertPointGuard IPG(Builder);
Builder.restoreIP(Loc.IP);
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Value *ThreadId = getOrCreateThreadID(Ident);
if (Device == nullptr)
Device = ConstantInt::get(Int32, -1);
if (NumDependences == nullptr) {
NumDependences = ConstantInt::get(Int32, 0);
PointerType *PointerTypeVar = Type::getInt8PtrTy(M.getContext());
DependenceAddress = ConstantPointerNull::get(PointerTypeVar);
}
Value *HaveNowaitClauseVal = ConstantInt::get(Int32, HaveNowaitClause);
Value *Args[] = {
Ident, ThreadId, InteropVar, Device,
NumDependences, DependenceAddress, HaveNowaitClauseVal};
Function *Fn = getOrCreateRuntimeFunctionPtr(OMPRTL___tgt_interop_use);
return Builder.CreateCall(Fn, Args);
}
CallInst *OpenMPIRBuilder::createCachedThreadPrivate(
const LocationDescription &Loc, llvm::Value *Pointer,
llvm::ConstantInt *Size, const llvm::Twine &Name) {
IRBuilder<>::InsertPointGuard IPG(Builder);
Builder.restoreIP(Loc.IP);
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
Value *ThreadId = getOrCreateThreadID(Ident);
Constant *ThreadPrivateCache =
getOrCreateInternalVariable(Int8PtrPtr, Name.str());
llvm::Value *Args[] = {Ident, ThreadId, Pointer, Size, ThreadPrivateCache};
Function *Fn =
getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_threadprivate_cached);
return Builder.CreateCall(Fn, Args);
}
OpenMPIRBuilder::InsertPointTy
OpenMPIRBuilder::createTargetInit(const LocationDescription &Loc, bool IsSPMD) {
if (!updateToLocation(Loc))
return Loc.IP;
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Constant *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
ConstantInt *IsSPMDVal = ConstantInt::getSigned(
IntegerType::getInt8Ty(Int8->getContext()),
IsSPMD ? OMP_TGT_EXEC_MODE_SPMD : OMP_TGT_EXEC_MODE_GENERIC);
ConstantInt *UseGenericStateMachine =
ConstantInt::getBool(Int32->getContext(), !IsSPMD);
Function *Fn = getOrCreateRuntimeFunctionPtr(
omp::RuntimeFunction::OMPRTL___kmpc_target_init);
CallInst *ThreadKind = Builder.CreateCall(
Fn, {Ident, IsSPMDVal, UseGenericStateMachine});
Value *ExecUserCode = Builder.CreateICmpEQ(
ThreadKind, ConstantInt::get(ThreadKind->getType(), -1),
"exec_user_code");
// ThreadKind = __kmpc_target_init(...)
// if (ThreadKind == -1)
// user_code
// else
// return;
auto *UI = Builder.CreateUnreachable();
BasicBlock *CheckBB = UI->getParent();
BasicBlock *UserCodeEntryBB = CheckBB->splitBasicBlock(UI, "user_code.entry");
BasicBlock *WorkerExitBB = BasicBlock::Create(
CheckBB->getContext(), "worker.exit", CheckBB->getParent());
Builder.SetInsertPoint(WorkerExitBB);
Builder.CreateRetVoid();
auto *CheckBBTI = CheckBB->getTerminator();
Builder.SetInsertPoint(CheckBBTI);
Builder.CreateCondBr(ExecUserCode, UI->getParent(), WorkerExitBB);
CheckBBTI->eraseFromParent();
UI->eraseFromParent();
// Continue in the "user_code" block, see diagram above and in
// openmp/libomptarget/deviceRTLs/common/include/target.h .
return InsertPointTy(UserCodeEntryBB, UserCodeEntryBB->getFirstInsertionPt());
}
void OpenMPIRBuilder::createTargetDeinit(const LocationDescription &Loc,
bool IsSPMD) {
if (!updateToLocation(Loc))
return;
uint32_t SrcLocStrSize;
Constant *SrcLocStr = getOrCreateSrcLocStr(Loc, SrcLocStrSize);
Value *Ident = getOrCreateIdent(SrcLocStr, SrcLocStrSize);
ConstantInt *IsSPMDVal = ConstantInt::getSigned(
IntegerType::getInt8Ty(Int8->getContext()),
IsSPMD ? OMP_TGT_EXEC_MODE_SPMD : OMP_TGT_EXEC_MODE_GENERIC);
Function *Fn = getOrCreateRuntimeFunctionPtr(
omp::RuntimeFunction::OMPRTL___kmpc_target_deinit);
Builder.CreateCall(Fn, {Ident, IsSPMDVal});
}
void OpenMPIRBuilder::setOutlinedTargetRegionFunctionAttributes(
Function *OutlinedFn, int32_t NumTeams, int32_t NumThreads) {
if (Config.isEmbedded()) {
OutlinedFn->setLinkage(GlobalValue::WeakODRLinkage);
// TODO: Determine if DSO local can be set to true.
OutlinedFn->setDSOLocal(false);
OutlinedFn->setVisibility(GlobalValue::ProtectedVisibility);
if (Triple(M.getTargetTriple()).isAMDGCN())
OutlinedFn->setCallingConv(CallingConv::AMDGPU_KERNEL);
}
if (NumTeams > 0)
OutlinedFn->addFnAttr("omp_target_num_teams", std::to_string(NumTeams));
if (NumThreads > 0)
OutlinedFn->addFnAttr("omp_target_thread_limit",
std::to_string(NumThreads));
}
Constant *OpenMPIRBuilder::createOutlinedFunctionID(Function *OutlinedFn,
StringRef EntryFnIDName) {
if (Config.isEmbedded()) {
assert(OutlinedFn && "The outlined function must exist if embedded");
return ConstantExpr::getBitCast(OutlinedFn, Builder.getInt8PtrTy());
}
return new GlobalVariable(
M, Builder.getInt8Ty(), /*isConstant=*/true, GlobalValue::WeakAnyLinkage,
Constant::getNullValue(Builder.getInt8Ty()), EntryFnIDName);
}
Constant *OpenMPIRBuilder::createTargetRegionEntryAddr(Function *OutlinedFn,
StringRef EntryFnName) {
if (OutlinedFn)
return OutlinedFn;
assert(!M.getGlobalVariable(EntryFnName, true) &&
"Named kernel already exists?");
return new GlobalVariable(
M, Builder.getInt8Ty(), /*isConstant=*/true, GlobalValue::InternalLinkage,
Constant::getNullValue(Builder.getInt8Ty()), EntryFnName);
}
void OpenMPIRBuilder::emitTargetRegionFunction(
OffloadEntriesInfoManager &InfoManager, TargetRegionEntryInfo &EntryInfo,
FunctionGenCallback &GenerateFunctionCallback, int32_t NumTeams,
int32_t NumThreads, bool IsOffloadEntry, Function *&OutlinedFn,
Constant *&OutlinedFnID) {
SmallString<64> EntryFnName;
InfoManager.getTargetRegionEntryFnName(EntryFnName, EntryInfo);
OutlinedFn = Config.isEmbedded() || !Config.openMPOffloadMandatory()
? GenerateFunctionCallback(EntryFnName)
: nullptr;
// If this target outline function is not an offload entry, we don't need to
// register it. This may be in the case of a false if clause, or if there are
// no OpenMP targets.
if (!IsOffloadEntry)
return;
std::string EntryFnIDName =
Config.isEmbedded()
? std::string(EntryFnName)
: createPlatformSpecificName({EntryFnName, "region_id"});
OutlinedFnID = registerTargetRegionFunction(
InfoManager, EntryInfo, OutlinedFn, EntryFnName, EntryFnIDName, NumTeams,
NumThreads);
}
Constant *OpenMPIRBuilder::registerTargetRegionFunction(
OffloadEntriesInfoManager &InfoManager, TargetRegionEntryInfo &EntryInfo,
Function *OutlinedFn, StringRef EntryFnName, StringRef EntryFnIDName,
int32_t NumTeams, int32_t NumThreads) {
if (OutlinedFn)
setOutlinedTargetRegionFunctionAttributes(OutlinedFn, NumTeams, NumThreads);
auto OutlinedFnID = createOutlinedFunctionID(OutlinedFn, EntryFnIDName);
auto EntryAddr = createTargetRegionEntryAddr(OutlinedFn, EntryFnName);
InfoManager.registerTargetRegionEntryInfo(
EntryInfo, EntryAddr, OutlinedFnID,
OffloadEntriesInfoManager::OMPTargetRegionEntryTargetRegion);
return OutlinedFnID;
}
std::string OpenMPIRBuilder::getNameWithSeparators(ArrayRef<StringRef> Parts,
StringRef FirstSeparator,
StringRef Separator) {
SmallString<128> Buffer;
llvm::raw_svector_ostream OS(Buffer);
StringRef Sep = FirstSeparator;
for (StringRef Part : Parts) {
OS << Sep << Part;
Sep = Separator;
}
return OS.str().str();
}
std::string
OpenMPIRBuilder::createPlatformSpecificName(ArrayRef<StringRef> Parts) const {
return OpenMPIRBuilder::getNameWithSeparators(Parts, Config.firstSeparator(),
Config.separator());
}
GlobalVariable *
OpenMPIRBuilder::getOrCreateInternalVariable(Type *Ty, const StringRef &Name,
unsigned AddressSpace) {
auto &Elem = *InternalVars.try_emplace(Name, nullptr).first;
if (Elem.second) {
assert(cast<PointerType>(Elem.second->getType())
->isOpaqueOrPointeeTypeMatches(Ty) &&
"OMP internal variable has different type than requested");
} else {
// TODO: investigate the appropriate linkage type used for the global
// variable for possibly changing that to internal or private, or maybe
// create different versions of the function for different OMP internal
// variables.
Elem.second = new GlobalVariable(
M, Ty, /*IsConstant=*/false, GlobalValue::CommonLinkage,
Constant::getNullValue(Ty), Elem.first(),
/*InsertBefore=*/nullptr, GlobalValue::NotThreadLocal, AddressSpace);
}
return cast<GlobalVariable>(&*Elem.second);
}
Value *OpenMPIRBuilder::getOMPCriticalRegionLock(StringRef CriticalName) {
std::string Prefix = Twine("gomp_critical_user_", CriticalName).str();
std::string Name = getNameWithSeparators({Prefix, "var"}, ".", ".");
return getOrCreateInternalVariable(KmpCriticalNameTy, Name);
}
GlobalVariable *
OpenMPIRBuilder::createOffloadMaptypes(SmallVectorImpl<uint64_t> &Mappings,
std::string VarName) {
llvm::Constant *MaptypesArrayInit =
llvm::ConstantDataArray::get(M.getContext(), Mappings);
auto *MaptypesArrayGlobal = new llvm::GlobalVariable(
M, MaptypesArrayInit->getType(),
/*isConstant=*/true, llvm::GlobalValue::PrivateLinkage, MaptypesArrayInit,
VarName);
MaptypesArrayGlobal->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
return MaptypesArrayGlobal;
}
void OpenMPIRBuilder::createMapperAllocas(const LocationDescription &Loc,
InsertPointTy AllocaIP,
unsigned NumOperands,
struct MapperAllocas &MapperAllocas) {
if (!updateToLocation(Loc))
return;
auto *ArrI8PtrTy = ArrayType::get(Int8Ptr, NumOperands);
auto *ArrI64Ty = ArrayType::get(Int64, NumOperands);
Builder.restoreIP(AllocaIP);
AllocaInst *ArgsBase = Builder.CreateAlloca(ArrI8PtrTy);
AllocaInst *Args = Builder.CreateAlloca(ArrI8PtrTy);
AllocaInst *ArgSizes = Builder.CreateAlloca(ArrI64Ty);
Builder.restoreIP(Loc.IP);
MapperAllocas.ArgsBase = ArgsBase;
MapperAllocas.Args = Args;
MapperAllocas.ArgSizes = ArgSizes;
}
void OpenMPIRBuilder::emitMapperCall(const LocationDescription &Loc,
Function *MapperFunc, Value *SrcLocInfo,
Value *MaptypesArg, Value *MapnamesArg,
struct MapperAllocas &MapperAllocas,
int64_t DeviceID, unsigned NumOperands) {
if (!updateToLocation(Loc))
return;
auto *ArrI8PtrTy = ArrayType::get(Int8Ptr, NumOperands);
auto *ArrI64Ty = ArrayType::get(Int64, NumOperands);
Value *ArgsBaseGEP =
Builder.CreateInBoundsGEP(ArrI8PtrTy, MapperAllocas.ArgsBase,
{Builder.getInt32(0), Builder.getInt32(0)});
Value *ArgsGEP =
Builder.CreateInBoundsGEP(ArrI8PtrTy, MapperAllocas.Args,
{Builder.getInt32(0), Builder.getInt32(0)});
Value *ArgSizesGEP =
Builder.CreateInBoundsGEP(ArrI64Ty, MapperAllocas.ArgSizes,
{Builder.getInt32(0), Builder.getInt32(0)});
Value *NullPtr = Constant::getNullValue(Int8Ptr->getPointerTo());
Builder.CreateCall(MapperFunc,
{SrcLocInfo, Builder.getInt64(DeviceID),
Builder.getInt32(NumOperands), ArgsBaseGEP, ArgsGEP,
ArgSizesGEP, MaptypesArg, MapnamesArg, NullPtr});
}
void OpenMPIRBuilder::emitOffloadingArraysArgument(IRBuilderBase &Builder,
TargetDataRTArgs &RTArgs,
TargetDataInfo &Info,
bool EmitDebug,
bool ForEndCall) {
assert((!ForEndCall || Info.separateBeginEndCalls()) &&
"expected region end call to runtime only when end call is separate");
auto VoidPtrTy = Type::getInt8PtrTy(M.getContext());
auto VoidPtrPtrTy = VoidPtrTy->getPointerTo(0);
auto Int64Ty = Type::getInt64Ty(M.getContext());
auto Int64PtrTy = Type::getInt64PtrTy(M.getContext());
if (!Info.NumberOfPtrs) {
RTArgs.BasePointersArray = ConstantPointerNull::get(VoidPtrPtrTy);
RTArgs.PointersArray = ConstantPointerNull::get(VoidPtrPtrTy);
RTArgs.SizesArray = ConstantPointerNull::get(Int64PtrTy);
RTArgs.MapTypesArray = ConstantPointerNull::get(Int64PtrTy);
RTArgs.MapNamesArray = ConstantPointerNull::get(VoidPtrPtrTy);
RTArgs.MappersArray = ConstantPointerNull::get(VoidPtrPtrTy);
return;
}
RTArgs.BasePointersArray = Builder.CreateConstInBoundsGEP2_32(
ArrayType::get(VoidPtrTy, Info.NumberOfPtrs),
Info.RTArgs.BasePointersArray,
/*Idx0=*/0, /*Idx1=*/0);
RTArgs.PointersArray = Builder.CreateConstInBoundsGEP2_32(
ArrayType::get(VoidPtrTy, Info.NumberOfPtrs), Info.RTArgs.PointersArray,
/*Idx0=*/0,
/*Idx1=*/0);
RTArgs.SizesArray = Builder.CreateConstInBoundsGEP2_32(
ArrayType::get(Int64Ty, Info.NumberOfPtrs), Info.RTArgs.SizesArray,
/*Idx0=*/0, /*Idx1=*/0);
RTArgs.MapTypesArray = Builder.CreateConstInBoundsGEP2_32(
ArrayType::get(Int64Ty, Info.NumberOfPtrs),
ForEndCall && Info.RTArgs.MapTypesArrayEnd ? Info.RTArgs.MapTypesArrayEnd
: Info.RTArgs.MapTypesArray,
/*Idx0=*/0,
/*Idx1=*/0);
// Only emit the mapper information arrays if debug information is
// requested.
if (!EmitDebug)
RTArgs.MapNamesArray = ConstantPointerNull::get(VoidPtrPtrTy);
else
RTArgs.MapNamesArray = Builder.CreateConstInBoundsGEP2_32(
ArrayType::get(VoidPtrTy, Info.NumberOfPtrs), Info.RTArgs.MapNamesArray,
/*Idx0=*/0,
/*Idx1=*/0);
// If there is no user-defined mapper, set the mapper array to nullptr to
// avoid an unnecessary data privatization
if (!Info.HasMapper)
RTArgs.MappersArray = ConstantPointerNull::get(VoidPtrPtrTy);
else
RTArgs.MappersArray =
Builder.CreatePointerCast(Info.RTArgs.MappersArray, VoidPtrPtrTy);
}
bool OpenMPIRBuilder::checkAndEmitFlushAfterAtomic(
const LocationDescription &Loc, llvm::AtomicOrdering AO, AtomicKind AK) {
assert(!(AO == AtomicOrdering::NotAtomic ||
AO == llvm::AtomicOrdering::Unordered) &&
"Unexpected Atomic Ordering.");
bool Flush = false;
llvm::AtomicOrdering FlushAO = AtomicOrdering::Monotonic;
switch (AK) {
case Read:
if (AO == AtomicOrdering::Acquire || AO == AtomicOrdering::AcquireRelease ||
AO == AtomicOrdering::SequentiallyConsistent) {
FlushAO = AtomicOrdering::Acquire;
Flush = true;
}
break;
case Write:
case Compare:
case Update:
if (AO == AtomicOrdering::Release || AO == AtomicOrdering::AcquireRelease ||
AO == AtomicOrdering::SequentiallyConsistent) {
FlushAO = AtomicOrdering::Release;
Flush = true;
}
break;
case Capture:
switch (AO) {
case AtomicOrdering::Acquire:
FlushAO = AtomicOrdering::Acquire;
Flush = true;
break;
case AtomicOrdering::Release:
FlushAO = AtomicOrdering::Release;
Flush = true;
break;
case AtomicOrdering::AcquireRelease:
case AtomicOrdering::SequentiallyConsistent:
FlushAO = AtomicOrdering::AcquireRelease;
Flush = true;
break;
default:
// do nothing - leave silently.
break;
}
}
if (Flush) {
// Currently Flush RT call still doesn't take memory_ordering, so for when
// that happens, this tries to do the resolution of which atomic ordering
// to use with but issue the flush call
// TODO: pass `FlushAO` after memory ordering support is added
(void)FlushAO;
emitFlush(Loc);
}
// for AO == AtomicOrdering::Monotonic and all other case combinations
// do nothing
return Flush;
}
OpenMPIRBuilder::InsertPointTy
OpenMPIRBuilder::createAtomicRead(const LocationDescription &Loc,
AtomicOpValue &X, AtomicOpValue &V,
AtomicOrdering AO) {
if (!updateToLocation(Loc))
return Loc.IP;
Type *XTy = X.Var->getType();
assert(XTy->isPointerTy() && "OMP Atomic expects a pointer to target memory");
Type *XElemTy = X.ElemTy;
assert((XElemTy->isFloatingPointTy() || XElemTy->isIntegerTy() ||
XElemTy->isPointerTy()) &&
"OMP atomic read expected a scalar type");
Value *XRead = nullptr;
if (XElemTy->isIntegerTy()) {
LoadInst *XLD =
Builder.CreateLoad(XElemTy, X.Var, X.IsVolatile, "omp.atomic.read");
XLD->setAtomic(AO);
XRead = cast<Value>(XLD);
} else {
// We need to bitcast and perform atomic op as integer
unsigned Addrspace = cast<PointerType>(XTy)->getAddressSpace();
IntegerType *IntCastTy =
IntegerType::get(M.getContext(), XElemTy->getScalarSizeInBits());
Value *XBCast = Builder.CreateBitCast(
X.Var, IntCastTy->getPointerTo(Addrspace), "atomic.src.int.cast");
LoadInst *XLoad =
Builder.CreateLoad(IntCastTy, XBCast, X.IsVolatile, "omp.atomic.load");
XLoad->setAtomic(AO);
if (XElemTy->isFloatingPointTy()) {
XRead = Builder.CreateBitCast(XLoad, XElemTy, "atomic.flt.cast");
} else {
XRead = Builder.CreateIntToPtr(XLoad, XElemTy, "atomic.ptr.cast");
}
}
checkAndEmitFlushAfterAtomic(Loc, AO, AtomicKind::Read);
Builder.CreateStore(XRead, V.Var, V.IsVolatile);
return Builder.saveIP();
}
OpenMPIRBuilder::InsertPointTy
OpenMPIRBuilder::createAtomicWrite(const LocationDescription &Loc,
AtomicOpValue &X, Value *Expr,
AtomicOrdering AO) {
if (!updateToLocation(Loc))
return Loc.IP;
Type *XTy = X.Var->getType();
assert(XTy->isPointerTy() && "OMP Atomic expects a pointer to target memory");
Type *XElemTy = X.ElemTy;
assert((XElemTy->isFloatingPointTy() || XElemTy->isIntegerTy() ||
XElemTy->isPointerTy()) &&
"OMP atomic write expected a scalar type");
if (XElemTy->isIntegerTy()) {
StoreInst *XSt = Builder.CreateStore(Expr, X.Var, X.IsVolatile);
XSt->setAtomic(AO);
} else {
// We need to bitcast and perform atomic op as integers
unsigned Addrspace = cast<PointerType>(XTy)->getAddressSpace();
IntegerType *IntCastTy =
IntegerType::get(M.getContext(), XElemTy->getScalarSizeInBits());
Value *XBCast = Builder.CreateBitCast(
X.Var, IntCastTy->getPointerTo(Addrspace), "atomic.dst.int.cast");
Value *ExprCast =
Builder.CreateBitCast(Expr, IntCastTy, "atomic.src.int.cast");
StoreInst *XSt = Builder.CreateStore(ExprCast, XBCast, X.IsVolatile);
XSt->setAtomic(AO);
}
checkAndEmitFlushAfterAtomic(Loc, AO, AtomicKind::Write);
return Builder.saveIP();
}
OpenMPIRBuilder::InsertPointTy OpenMPIRBuilder::createAtomicUpdate(
const LocationDescription &Loc, InsertPointTy AllocaIP, AtomicOpValue &X,
Value *Expr, AtomicOrdering AO, AtomicRMWInst::BinOp RMWOp,
AtomicUpdateCallbackTy &UpdateOp, bool IsXBinopExpr) {
assert(!isConflictIP(Loc.IP, AllocaIP) && "IPs must not be ambiguous");
if (!updateToLocation(Loc))
return Loc.IP;
LLVM_DEBUG({
Type *XTy = X.Var->getType();
assert(XTy->isPointerTy() &&
"OMP Atomic expects a pointer to target memory");
Type *XElemTy = X.ElemTy;
assert((XElemTy->isFloatingPointTy() || XElemTy->isIntegerTy() ||
XElemTy->isPointerTy()) &&
"OMP atomic update expected a scalar type");
assert((RMWOp != AtomicRMWInst::Max) && (RMWOp != AtomicRMWInst::Min) &&
(RMWOp != AtomicRMWInst::UMax) && (RMWOp != AtomicRMWInst::UMin) &&
"OpenMP atomic does not support LT or GT operations");
});
emitAtomicUpdate(AllocaIP, X.Var, X.ElemTy, Expr, AO, RMWOp, UpdateOp,
X.IsVolatile, IsXBinopExpr);
checkAndEmitFlushAfterAtomic(Loc, AO, AtomicKind::Update);
return Builder.saveIP();
}
// FIXME: Duplicating AtomicExpand
Value *OpenMPIRBuilder::emitRMWOpAsInstruction(Value *Src1, Value *Src2,
AtomicRMWInst::BinOp RMWOp) {
switch (RMWOp) {
case AtomicRMWInst::Add:
return Builder.CreateAdd(Src1, Src2);
case AtomicRMWInst::Sub:
return Builder.CreateSub(Src1, Src2);
case AtomicRMWInst::And:
return Builder.CreateAnd(Src1, Src2);
case AtomicRMWInst::Nand:
return Builder.CreateNeg(Builder.CreateAnd(Src1, Src2));
case AtomicRMWInst::Or:
return Builder.CreateOr(Src1, Src2);
case AtomicRMWInst::Xor:
return Builder.CreateXor(Src1, Src2);
case AtomicRMWInst::Xchg:
case AtomicRMWInst::FAdd:
case AtomicRMWInst::FSub:
case AtomicRMWInst::BAD_BINOP:
case AtomicRMWInst::Max:
case AtomicRMWInst::Min:
case AtomicRMWInst::UMax:
case AtomicRMWInst::UMin:
case AtomicRMWInst::FMax:
case AtomicRMWInst::FMin:
case AtomicRMWInst::UIncWrap:
case AtomicRMWInst::UDecWrap:
llvm_unreachable("Unsupported atomic update operation");
}
llvm_unreachable("Unsupported atomic update operation");
}
std::pair<Value *, Value *> OpenMPIRBuilder::emitAtomicUpdate(
InsertPointTy AllocaIP, Value *X, Type *XElemTy, Value *Expr,
AtomicOrdering AO, AtomicRMWInst::BinOp RMWOp,
AtomicUpdateCallbackTy &UpdateOp, bool VolatileX, bool IsXBinopExpr) {
// TODO: handle the case where XElemTy is not byte-sized or not a power of 2
// or a complex datatype.
bool emitRMWOp = false;
switch (RMWOp) {
case AtomicRMWInst::Add:
case AtomicRMWInst::And:
case AtomicRMWInst::Nand:
case AtomicRMWInst::Or:
case AtomicRMWInst::Xor:
case AtomicRMWInst::Xchg:
emitRMWOp = XElemTy;
break;
case AtomicRMWInst::Sub:
emitRMWOp = (IsXBinopExpr && XElemTy);
break;
default:
emitRMWOp = false;
}
emitRMWOp &= XElemTy->isIntegerTy();
std::pair<Value *, Value *> Res;
if (emitRMWOp) {
Res.first = Builder.CreateAtomicRMW(RMWOp, X, Expr, llvm::MaybeAlign(), AO);
// not needed except in case of postfix captures. Generate anyway for
// consistency with the else part. Will be removed with any DCE pass.
// AtomicRMWInst::Xchg does not have a coressponding instruction.
if (RMWOp == AtomicRMWInst::Xchg)
Res.second = Res.first;
else
Res.second = emitRMWOpAsInstruction(Res.first, Expr, RMWOp);
} else {
unsigned Addrspace = cast<PointerType>(X->getType())->getAddressSpace();
IntegerType *IntCastTy =
IntegerType::get(M.getContext(), XElemTy->getScalarSizeInBits());
Value *XBCast =
Builder.CreateBitCast(X, IntCastTy->getPointerTo(Addrspace));
LoadInst *OldVal =
Builder.CreateLoad(IntCastTy, XBCast, X->getName() + ".atomic.load");
OldVal->setAtomic(AO);
// CurBB
// | /---\
// ContBB |
// | \---/
// ExitBB
BasicBlock *CurBB = Builder.GetInsertBlock();
Instruction *CurBBTI = CurBB->getTerminator();
CurBBTI = CurBBTI ? CurBBTI : Builder.CreateUnreachable();
BasicBlock *ExitBB =
CurBB->splitBasicBlock(CurBBTI, X->getName() + ".atomic.exit");
BasicBlock *ContBB = CurBB->splitBasicBlock(CurBB->getTerminator(),
X->getName() + ".atomic.cont");
ContBB->getTerminator()->eraseFromParent();
Builder.restoreIP(AllocaIP);
AllocaInst *NewAtomicAddr = Builder.CreateAlloca(XElemTy);
NewAtomicAddr->setName(X->getName() + "x.new.val");
Builder.SetInsertPoint(ContBB);
llvm::PHINode *PHI = Builder.CreatePHI(OldVal->getType(), 2);
PHI->addIncoming(OldVal, CurBB);
IntegerType *NewAtomicCastTy =
IntegerType::get(M.getContext(), XElemTy->getScalarSizeInBits());
bool IsIntTy = XElemTy->isIntegerTy();
Value *NewAtomicIntAddr =
(IsIntTy)
? NewAtomicAddr
: Builder.CreateBitCast(NewAtomicAddr,
NewAtomicCastTy->getPointerTo(Addrspace));
Value *OldExprVal = PHI;
if (!IsIntTy) {
if (XElemTy->isFloatingPointTy()) {
OldExprVal = Builder.CreateBitCast(PHI, XElemTy,
X->getName() + ".atomic.fltCast");
} else {
OldExprVal = Builder.CreateIntToPtr(PHI, XElemTy,
X->getName() + ".atomic.ptrCast");
}
}
Value *Upd = UpdateOp(OldExprVal, Builder);
Builder.CreateStore(Upd, NewAtomicAddr);
LoadInst *DesiredVal = Builder.CreateLoad(IntCastTy, NewAtomicIntAddr);
Value *XAddr =
(IsIntTy)
? X
: Builder.CreateBitCast(X, IntCastTy->getPointerTo(Addrspace));
AtomicOrdering Failure =
llvm::AtomicCmpXchgInst::getStrongestFailureOrdering(AO);
AtomicCmpXchgInst *Result = Builder.CreateAtomicCmpXchg(
XAddr, PHI, DesiredVal, llvm::MaybeAlign(), AO, Failure);
Result->setVolatile(VolatileX);
Value *PreviousVal = Builder.CreateExtractValue(Result, /*Idxs=*/0);
Value *SuccessFailureVal = Builder.CreateExtractValue(Result, /*Idxs=*/1);
PHI->addIncoming(PreviousVal, Builder.GetInsertBlock());
Builder.CreateCondBr(SuccessFailureVal, ExitBB, ContBB);
Res.first = OldExprVal;
Res.second = Upd;
// set Insertion point in exit block
if (UnreachableInst *ExitTI =
dyn_cast<UnreachableInst>(ExitBB->getTerminator())) {
CurBBTI->eraseFromParent();
Builder.SetInsertPoint(ExitBB);
} else {
Builder.SetInsertPoint(ExitTI);
}
}
return Res;
}
OpenMPIRBuilder::InsertPointTy OpenMPIRBuilder::createAtomicCapture(
const LocationDescription &Loc, InsertPointTy AllocaIP, AtomicOpValue &X,
AtomicOpValue &V, Value *Expr, AtomicOrdering AO,
AtomicRMWInst::BinOp RMWOp, AtomicUpdateCallbackTy &UpdateOp,
bool UpdateExpr, bool IsPostfixUpdate, bool IsXBinopExpr) {
if (!updateToLocation(Loc))
return Loc.IP;
LLVM_DEBUG({
Type *XTy = X.Var->getType();
assert(XTy->isPointerTy() &&
"OMP Atomic expects a pointer to target memory");
Type *XElemTy = X.ElemTy;
assert((XElemTy->isFloatingPointTy() || XElemTy->isIntegerTy() ||
XElemTy->isPointerTy()) &&
"OMP atomic capture expected a scalar type");
assert((RMWOp != AtomicRMWInst::Max) && (RMWOp != AtomicRMWInst::Min) &&
"OpenMP atomic does not support LT or GT operations");
});
// If UpdateExpr is 'x' updated with some `expr` not based on 'x',
// 'x' is simply atomically rewritten with 'expr'.
AtomicRMWInst::BinOp AtomicOp = (UpdateExpr ? RMWOp : AtomicRMWInst::Xchg);
std::pair<Value *, Value *> Result =
emitAtomicUpdate(AllocaIP, X.Var, X.ElemTy, Expr, AO, AtomicOp, UpdateOp,
X.IsVolatile, IsXBinopExpr);
Value *CapturedVal = (IsPostfixUpdate ? Result.first : Result.second);
Builder.CreateStore(CapturedVal, V.Var, V.IsVolatile);
checkAndEmitFlushAfterAtomic(Loc, AO, AtomicKind::Capture);
return Builder.saveIP();
}
OpenMPIRBuilder::InsertPointTy OpenMPIRBuilder::createAtomicCompare(
const LocationDescription &Loc, AtomicOpValue &X, AtomicOpValue &V,
AtomicOpValue &R, Value *E, Value *D, AtomicOrdering AO,
omp::OMPAtomicCompareOp Op, bool IsXBinopExpr, bool IsPostfixUpdate,
bool IsFailOnly) {
if (!updateToLocation(Loc))
return Loc.IP;
assert(X.Var->getType()->isPointerTy() &&
"OMP atomic expects a pointer to target memory");
// compare capture
if (V.Var) {
assert(V.Var->getType()->isPointerTy() && "v.var must be of pointer type");
assert(V.ElemTy == X.ElemTy && "x and v must be of same type");
}
bool IsInteger = E->getType()->isIntegerTy();
if (Op == OMPAtomicCompareOp::EQ) {
AtomicOrdering Failure = AtomicCmpXchgInst::getStrongestFailureOrdering(AO);
AtomicCmpXchgInst *Result = nullptr;
if (!IsInteger) {
unsigned Addrspace =
cast<PointerType>(X.Var->getType())->getAddressSpace();
IntegerType *IntCastTy =
IntegerType::get(M.getContext(), X.ElemTy->getScalarSizeInBits());
Value *XBCast =
Builder.CreateBitCast(X.Var, IntCastTy->getPointerTo(Addrspace));
Value *EBCast = Builder.CreateBitCast(E, IntCastTy);
Value *DBCast = Builder.CreateBitCast(D, IntCastTy);
Result = Builder.CreateAtomicCmpXchg(XBCast, EBCast, DBCast, MaybeAlign(),
AO, Failure);
} else {
Result =
Builder.CreateAtomicCmpXchg(X.Var, E, D, MaybeAlign(), AO, Failure);
}
if (V.Var) {
Value *OldValue = Builder.CreateExtractValue(Result, /*Idxs=*/0);
if (!IsInteger)
OldValue = Builder.CreateBitCast(OldValue, X.ElemTy);
assert(OldValue->getType() == V.ElemTy &&
"OldValue and V must be of same type");
if (IsPostfixUpdate) {
Builder.CreateStore(OldValue, V.Var, V.IsVolatile);
} else {
Value *SuccessOrFail = Builder.CreateExtractValue(Result, /*Idxs=*/1);
if (IsFailOnly) {
// CurBB----
// | |
// v |
// ContBB |
// | |
// v |
// ExitBB <-
//
// where ContBB only contains the store of old value to 'v'.
BasicBlock *CurBB = Builder.GetInsertBlock();
Instruction *CurBBTI = CurBB->getTerminator();
CurBBTI = CurBBTI ? CurBBTI : Builder.CreateUnreachable();
BasicBlock *ExitBB = CurBB->splitBasicBlock(
CurBBTI, X.Var->getName() + ".atomic.exit");
BasicBlock *ContBB = CurBB->splitBasicBlock(
CurBB->getTerminator(), X.Var->getName() + ".atomic.cont");
ContBB->getTerminator()->eraseFromParent();
CurBB->getTerminator()->eraseFromParent();
Builder.CreateCondBr(SuccessOrFail, ExitBB, ContBB);
Builder.SetInsertPoint(ContBB);
Builder.CreateStore(OldValue, V.Var);
Builder.CreateBr(ExitBB);
if (UnreachableInst *ExitTI =
dyn_cast<UnreachableInst>(ExitBB->getTerminator())) {
CurBBTI->eraseFromParent();
Builder.SetInsertPoint(ExitBB);
} else {
Builder.SetInsertPoint(ExitTI);
}
} else {
Value *CapturedValue =
Builder.CreateSelect(SuccessOrFail, E, OldValue);
Builder.CreateStore(CapturedValue, V.Var, V.IsVolatile);
}
}
}
// The comparison result has to be stored.
if (R.Var) {
assert(R.Var->getType()->isPointerTy() &&
"r.var must be of pointer type");
assert(R.ElemTy->isIntegerTy() && "r must be of integral type");
Value *SuccessFailureVal = Builder.CreateExtractValue(Result, /*Idxs=*/1);
Value *ResultCast = R.IsSigned
? Builder.CreateSExt(SuccessFailureVal, R.ElemTy)
: Builder.CreateZExt(SuccessFailureVal, R.ElemTy);
Builder.CreateStore(ResultCast, R.Var, R.IsVolatile);
}
} else {
assert((Op == OMPAtomicCompareOp::MAX || Op == OMPAtomicCompareOp::MIN) &&
"Op should be either max or min at this point");
assert(!IsFailOnly && "IsFailOnly is only valid when the comparison is ==");
// Reverse the ordop as the OpenMP forms are different from LLVM forms.
// Let's take max as example.
// OpenMP form:
// x = x > expr ? expr : x;
// LLVM form:
// *ptr = *ptr > val ? *ptr : val;
// We need to transform to LLVM form.
// x = x <= expr ? x : expr;
AtomicRMWInst::BinOp NewOp;
if (IsXBinopExpr) {
if (IsInteger) {
if (X.IsSigned)
NewOp = Op == OMPAtomicCompareOp::MAX ? AtomicRMWInst::Min
: AtomicRMWInst::Max;
else
NewOp = Op == OMPAtomicCompareOp::MAX ? AtomicRMWInst::UMin
: AtomicRMWInst::UMax;
} else {
NewOp = Op == OMPAtomicCompareOp::MAX ? AtomicRMWInst::FMin
: AtomicRMWInst::FMax;
}
} else {
if (IsInteger) {
if (X.IsSigned)
NewOp = Op == OMPAtomicCompareOp::MAX ? AtomicRMWInst::Max
: AtomicRMWInst::Min;
else
NewOp = Op == OMPAtomicCompareOp::MAX ? AtomicRMWInst::UMax
: AtomicRMWInst::UMin;
} else {
NewOp = Op == OMPAtomicCompareOp::MAX ? AtomicRMWInst::FMax
: AtomicRMWInst::FMin;
}
}
AtomicRMWInst *OldValue =
Builder.CreateAtomicRMW(NewOp, X.Var, E, MaybeAlign(), AO);
if (V.Var) {
Value *CapturedValue = nullptr;
if (IsPostfixUpdate) {
CapturedValue = OldValue;
} else {
CmpInst::Predicate Pred;
switch (NewOp) {
case AtomicRMWInst::Max:
Pred = CmpInst::ICMP_SGT;
break;
case AtomicRMWInst::UMax:
Pred = CmpInst::ICMP_UGT;
break;
case AtomicRMWInst::FMax:
Pred = CmpInst::FCMP_OGT;
break;
case AtomicRMWInst::Min:
Pred = CmpInst::ICMP_SLT;
break;
case AtomicRMWInst::UMin:
Pred = CmpInst::ICMP_ULT;
break;
case AtomicRMWInst::FMin:
Pred = CmpInst::FCMP_OLT;
break;
default:
llvm_unreachable("unexpected comparison op");
}
Value *NonAtomicCmp = Builder.CreateCmp(Pred, OldValue, E);
CapturedValue = Builder.CreateSelect(NonAtomicCmp, E, OldValue);
}
Builder.CreateStore(CapturedValue, V.Var, V.IsVolatile);
}
}
checkAndEmitFlushAfterAtomic(Loc, AO, AtomicKind::Compare);
return Builder.saveIP();
}
GlobalVariable *
OpenMPIRBuilder::createOffloadMapnames(SmallVectorImpl<llvm::Constant *> &Names,
std::string VarName) {
llvm::Constant *MapNamesArrayInit = llvm::ConstantArray::get(
llvm::ArrayType::get(
llvm::Type::getInt8Ty(M.getContext())->getPointerTo(), Names.size()),
Names);
auto *MapNamesArrayGlobal = new llvm::GlobalVariable(
M, MapNamesArrayInit->getType(),
/*isConstant=*/true, llvm::GlobalValue::PrivateLinkage, MapNamesArrayInit,
VarName);
return MapNamesArrayGlobal;
}
// Create all simple and struct types exposed by the runtime and remember
// the llvm::PointerTypes of them for easy access later.
void OpenMPIRBuilder::initializeTypes(Module &M) {
LLVMContext &Ctx = M.getContext();
StructType *T;
#define OMP_TYPE(VarName, InitValue) VarName = InitValue;
#define OMP_ARRAY_TYPE(VarName, ElemTy, ArraySize) \
VarName##Ty = ArrayType::get(ElemTy, ArraySize); \
VarName##PtrTy = PointerType::getUnqual(VarName##Ty);
#define OMP_FUNCTION_TYPE(VarName, IsVarArg, ReturnType, ...) \
VarName = FunctionType::get(ReturnType, {__VA_ARGS__}, IsVarArg); \
VarName##Ptr = PointerType::getUnqual(VarName);
#define OMP_STRUCT_TYPE(VarName, StructName, Packed, ...) \
T = StructType::getTypeByName(Ctx, StructName); \
if (!T) \
T = StructType::create(Ctx, {__VA_ARGS__}, StructName, Packed); \
VarName = T; \
VarName##Ptr = PointerType::getUnqual(T);
#include "llvm/Frontend/OpenMP/OMPKinds.def"
}
void OpenMPIRBuilder::OutlineInfo::collectBlocks(
SmallPtrSetImpl<BasicBlock *> &BlockSet,
SmallVectorImpl<BasicBlock *> &BlockVector) {
SmallVector<BasicBlock *, 32> Worklist;
BlockSet.insert(EntryBB);
BlockSet.insert(ExitBB);
Worklist.push_back(EntryBB);
while (!Worklist.empty()) {
BasicBlock *BB = Worklist.pop_back_val();
BlockVector.push_back(BB);
for (BasicBlock *SuccBB : successors(BB))
if (BlockSet.insert(SuccBB).second)
Worklist.push_back(SuccBB);
}
}
void OpenMPIRBuilder::createOffloadEntry(Constant *ID, Constant *Addr,
uint64_t Size, int32_t Flags,
GlobalValue::LinkageTypes) {
if (!Config.isTargetCodegen()) {
emitOffloadingEntry(ID, Addr->getName(), Size, Flags);
return;
}
// TODO: Add support for global variables on the device after declare target
// support.
Function *Fn = dyn_cast<Function>(Addr);
if (!Fn)
return;
Module &M = *(Fn->getParent());
LLVMContext &Ctx = M.getContext();
// Get "nvvm.annotations" metadata node.
NamedMDNode *MD = M.getOrInsertNamedMetadata("nvvm.annotations");
Metadata *MDVals[] = {
ConstantAsMetadata::get(Fn), MDString::get(Ctx, "kernel"),
ConstantAsMetadata::get(ConstantInt::get(Type::getInt32Ty(Ctx), 1))};
// Append metadata to nvvm.annotations.
MD->addOperand(MDNode::get(Ctx, MDVals));
// Add a function attribute for the kernel.
Fn->addFnAttr(Attribute::get(Ctx, "kernel"));
}
// We only generate metadata for function that contain target regions.
void OpenMPIRBuilder::createOffloadEntriesAndInfoMetadata(
OffloadEntriesInfoManager &OffloadEntriesInfoManager,
EmitMetadataErrorReportFunctionTy &ErrorFn) {
// If there are no entries, we don't need to do anything.
if (OffloadEntriesInfoManager.empty())
return;
LLVMContext &C = M.getContext();
SmallVector<std::pair<const OffloadEntriesInfoManager::OffloadEntryInfo *,
TargetRegionEntryInfo>,
16>
OrderedEntries(OffloadEntriesInfoManager.size());
// Auxiliary methods to create metadata values and strings.
auto &&GetMDInt = [this](unsigned V) {
return ConstantAsMetadata::get(ConstantInt::get(Builder.getInt32Ty(), V));
};
auto &&GetMDString = [&C](StringRef V) { return MDString::get(C, V); };
// Create the offloading info metadata node.
NamedMDNode *MD = M.getOrInsertNamedMetadata("omp_offload.info");
auto &&TargetRegionMetadataEmitter =
[&C, MD, &OrderedEntries, &GetMDInt, &GetMDString](
const TargetRegionEntryInfo &EntryInfo,
const OffloadEntriesInfoManager::OffloadEntryInfoTargetRegion &E) {
// Generate metadata for target regions. Each entry of this metadata
// contains:
// - Entry 0 -> Kind of this type of metadata (0).
// - Entry 1 -> Device ID of the file where the entry was identified.
// - Entry 2 -> File ID of the file where the entry was identified.
// - Entry 3 -> Mangled name of the function where the entry was
// identified.
// - Entry 4 -> Line in the file where the entry was identified.
// - Entry 5 -> Count of regions at this DeviceID/FilesID/Line.
// - Entry 6 -> Order the entry was created.
// The first element of the metadata node is the kind.
Metadata *Ops[] = {
GetMDInt(E.getKind()), GetMDInt(EntryInfo.DeviceID),
GetMDInt(EntryInfo.FileID), GetMDString(EntryInfo.ParentName),
GetMDInt(EntryInfo.Line), GetMDInt(EntryInfo.Count),
GetMDInt(E.getOrder())};
// Save this entry in the right position of the ordered entries array.
OrderedEntries[E.getOrder()] = std::make_pair(&E, EntryInfo);
// Add metadata to the named metadata node.
MD->addOperand(MDNode::get(C, Ops));
};
OffloadEntriesInfoManager.actOnTargetRegionEntriesInfo(
TargetRegionMetadataEmitter);
// Create function that emits metadata for each device global variable entry;
auto &&DeviceGlobalVarMetadataEmitter =
[&C, &OrderedEntries, &GetMDInt, &GetMDString, MD](
StringRef MangledName,
const OffloadEntriesInfoManager::OffloadEntryInfoDeviceGlobalVar &E) {
// Generate metadata for global variables. Each entry of this metadata
// contains:
// - Entry 0 -> Kind of this type of metadata (1).
// - Entry 1 -> Mangled name of the variable.
// - Entry 2 -> Declare target kind.
// - Entry 3 -> Order the entry was created.
// The first element of the metadata node is the kind.
Metadata *Ops[] = {GetMDInt(E.getKind()), GetMDString(MangledName),
GetMDInt(E.getFlags()), GetMDInt(E.getOrder())};
// Save this entry in the right position of the ordered entries array.
TargetRegionEntryInfo varInfo(MangledName, 0, 0, 0);
OrderedEntries[E.getOrder()] = std::make_pair(&E, varInfo);
// Add metadata to the named metadata node.
MD->addOperand(MDNode::get(C, Ops));
};
OffloadEntriesInfoManager.actOnDeviceGlobalVarEntriesInfo(
DeviceGlobalVarMetadataEmitter);
for (const auto &E : OrderedEntries) {
assert(E.first && "All ordered entries must exist!");
if (const auto *CE =
dyn_cast<OffloadEntriesInfoManager::OffloadEntryInfoTargetRegion>(
E.first)) {
if (!CE->getID() || !CE->getAddress()) {
// Do not blame the entry if the parent funtion is not emitted.
TargetRegionEntryInfo EntryInfo = E.second;
StringRef FnName = EntryInfo.ParentName;
if (!M.getNamedValue(FnName))
continue;
ErrorFn(EMIT_MD_TARGET_REGION_ERROR, EntryInfo);
continue;
}
createOffloadEntry(CE->getID(), CE->getAddress(),
/*Size=*/0, CE->getFlags(),
GlobalValue::WeakAnyLinkage);
} else if (const auto *CE = dyn_cast<
OffloadEntriesInfoManager::OffloadEntryInfoDeviceGlobalVar>(
E.first)) {
OffloadEntriesInfoManager::OMPTargetGlobalVarEntryKind Flags =
static_cast<OffloadEntriesInfoManager::OMPTargetGlobalVarEntryKind>(
CE->getFlags());
switch (Flags) {
case OffloadEntriesInfoManager::OMPTargetGlobalVarEntryTo: {
if (Config.isEmbedded() && Config.hasRequiresUnifiedSharedMemory())
continue;
if (!CE->getAddress()) {
ErrorFn(EMIT_MD_DECLARE_TARGET_ERROR, E.second);
continue;
}
// The vaiable has no definition - no need to add the entry.
if (CE->getVarSize() == 0)
continue;
break;
}
case OffloadEntriesInfoManager::OMPTargetGlobalVarEntryLink:
assert(((Config.isEmbedded() && !CE->getAddress()) ||
(!Config.isEmbedded() && CE->getAddress())) &&
"Declaret target link address is set.");
if (Config.isEmbedded())
continue;
if (!CE->getAddress()) {
ErrorFn(EMIT_MD_GLOBAL_VAR_LINK_ERROR, TargetRegionEntryInfo());
continue;
}
break;
}
// Hidden or internal symbols on the device are not externally visible.
// We should not attempt to register them by creating an offloading
// entry.
if (auto *GV = dyn_cast<GlobalValue>(CE->getAddress()))
if (GV->hasLocalLinkage() || GV->hasHiddenVisibility())
continue;
createOffloadEntry(CE->getAddress(), CE->getAddress(), CE->getVarSize(),
Flags, CE->getLinkage());
} else {
llvm_unreachable("Unsupported entry kind.");
}
}
}
void TargetRegionEntryInfo::getTargetRegionEntryFnName(
SmallVectorImpl<char> &Name, StringRef ParentName, unsigned DeviceID,
unsigned FileID, unsigned Line, unsigned Count) {
raw_svector_ostream OS(Name);
OS << "__omp_offloading" << llvm::format("_%x", DeviceID)
<< llvm::format("_%x_", FileID) << ParentName << "_l" << Line;
if (Count)
OS << "_" << Count;
}
void OffloadEntriesInfoManager::getTargetRegionEntryFnName(
SmallVectorImpl<char> &Name, const TargetRegionEntryInfo &EntryInfo) {
unsigned NewCount = getTargetRegionEntryInfoCount(EntryInfo);
TargetRegionEntryInfo::getTargetRegionEntryFnName(
Name, EntryInfo.ParentName, EntryInfo.DeviceID, EntryInfo.FileID,
EntryInfo.Line, NewCount);
}
/// Loads all the offload entries information from the host IR
/// metadata.
void OpenMPIRBuilder::loadOffloadInfoMetadata(
Module &M, OffloadEntriesInfoManager &OffloadEntriesInfoManager) {
// If we are in target mode, load the metadata from the host IR. This code has
// to match the metadata creation in createOffloadEntriesAndInfoMetadata().
NamedMDNode *MD = M.getNamedMetadata(ompOffloadInfoName);
if (!MD)
return;
for (MDNode *MN : MD->operands()) {
auto &&GetMDInt = [MN](unsigned Idx) {
auto *V = cast<ConstantAsMetadata>(MN->getOperand(Idx));
return cast<ConstantInt>(V->getValue())->getZExtValue();
};
auto &&GetMDString = [MN](unsigned Idx) {
auto *V = cast<MDString>(MN->getOperand(Idx));
return V->getString();
};
switch (GetMDInt(0)) {
default:
llvm_unreachable("Unexpected metadata!");
break;
case OffloadEntriesInfoManager::OffloadEntryInfo::
OffloadingEntryInfoTargetRegion: {
TargetRegionEntryInfo EntryInfo(/*ParentName=*/GetMDString(3),
/*DeviceID=*/GetMDInt(1),
/*FileID=*/GetMDInt(2),
/*Line=*/GetMDInt(4),
/*Count=*/GetMDInt(5));
OffloadEntriesInfoManager.initializeTargetRegionEntryInfo(
EntryInfo, /*Order=*/GetMDInt(6));
break;
}
case OffloadEntriesInfoManager::OffloadEntryInfo::
OffloadingEntryInfoDeviceGlobalVar:
OffloadEntriesInfoManager.initializeDeviceGlobalVarEntryInfo(
/*MangledName=*/GetMDString(1),
static_cast<OffloadEntriesInfoManager::OMPTargetGlobalVarEntryKind>(
/*Flags=*/GetMDInt(2)),
/*Order=*/GetMDInt(3));
break;
}
}
}
bool OffloadEntriesInfoManager::empty() const {
return OffloadEntriesTargetRegion.empty() &&
OffloadEntriesDeviceGlobalVar.empty();
}
unsigned OffloadEntriesInfoManager::getTargetRegionEntryInfoCount(
const TargetRegionEntryInfo &EntryInfo) const {
auto It = OffloadEntriesTargetRegionCount.find(
getTargetRegionEntryCountKey(EntryInfo));
if (It == OffloadEntriesTargetRegionCount.end())
return 0;
return It->second;
}
void OffloadEntriesInfoManager::incrementTargetRegionEntryInfoCount(
const TargetRegionEntryInfo &EntryInfo) {
OffloadEntriesTargetRegionCount[getTargetRegionEntryCountKey(EntryInfo)] =
EntryInfo.Count + 1;
}
/// Initialize target region entry.
void OffloadEntriesInfoManager::initializeTargetRegionEntryInfo(
const TargetRegionEntryInfo &EntryInfo, unsigned Order) {
OffloadEntriesTargetRegion[EntryInfo] =
OffloadEntryInfoTargetRegion(Order, /*Addr=*/nullptr, /*ID=*/nullptr,
OMPTargetRegionEntryTargetRegion);
++OffloadingEntriesNum;
}
void OffloadEntriesInfoManager::registerTargetRegionEntryInfo(
TargetRegionEntryInfo EntryInfo, Constant *Addr, Constant *ID,
OMPTargetRegionEntryKind Flags) {
assert(EntryInfo.Count == 0 && "expected default EntryInfo");
// Update the EntryInfo with the next available count for this location.
EntryInfo.Count = getTargetRegionEntryInfoCount(EntryInfo);
// If we are emitting code for a target, the entry is already initialized,
// only has to be registered.
if (Config.isEmbedded()) {
// This could happen if the device compilation is invoked standalone.
if (!hasTargetRegionEntryInfo(EntryInfo)) {
return;
}
auto &Entry = OffloadEntriesTargetRegion[EntryInfo];
Entry.setAddress(Addr);
Entry.setID(ID);
Entry.setFlags(Flags);
} else {
if (Flags == OffloadEntriesInfoManager::OMPTargetRegionEntryTargetRegion &&
hasTargetRegionEntryInfo(EntryInfo, /*IgnoreAddressId*/ true))
return;
assert(!hasTargetRegionEntryInfo(EntryInfo) &&
"Target region entry already registered!");
OffloadEntryInfoTargetRegion Entry(OffloadingEntriesNum, Addr, ID, Flags);
OffloadEntriesTargetRegion[EntryInfo] = Entry;
++OffloadingEntriesNum;
}
incrementTargetRegionEntryInfoCount(EntryInfo);
}
bool OffloadEntriesInfoManager::hasTargetRegionEntryInfo(
TargetRegionEntryInfo EntryInfo, bool IgnoreAddressId) const {
// Update the EntryInfo with the next available count for this location.
EntryInfo.Count = getTargetRegionEntryInfoCount(EntryInfo);
auto It = OffloadEntriesTargetRegion.find(EntryInfo);
if (It == OffloadEntriesTargetRegion.end()) {
return false;
}
// Fail if this entry is already registered.
if (!IgnoreAddressId && (It->second.getAddress() || It->second.getID()))
return false;
return true;
}
void OffloadEntriesInfoManager::actOnTargetRegionEntriesInfo(
const OffloadTargetRegionEntryInfoActTy &Action) {
// Scan all target region entries and perform the provided action.
for (const auto &It : OffloadEntriesTargetRegion) {
Action(It.first, It.second);
}
}
void OffloadEntriesInfoManager::initializeDeviceGlobalVarEntryInfo(
StringRef Name, OMPTargetGlobalVarEntryKind Flags, unsigned Order) {
OffloadEntriesDeviceGlobalVar.try_emplace(Name, Order, Flags);
++OffloadingEntriesNum;
}
void OffloadEntriesInfoManager::registerDeviceGlobalVarEntryInfo(
StringRef VarName, Constant *Addr, int64_t VarSize,
OMPTargetGlobalVarEntryKind Flags, GlobalValue::LinkageTypes Linkage) {
if (Config.isEmbedded()) {
// This could happen if the device compilation is invoked standalone.
if (!hasDeviceGlobalVarEntryInfo(VarName))
return;
auto &Entry = OffloadEntriesDeviceGlobalVar[VarName];
if (Entry.getAddress() && hasDeviceGlobalVarEntryInfo(VarName)) {
if (Entry.getVarSize() == 0) {
Entry.setVarSize(VarSize);
Entry.setLinkage(Linkage);
}
return;
}
Entry.setVarSize(VarSize);
Entry.setLinkage(Linkage);
Entry.setAddress(Addr);
} else {
if (hasDeviceGlobalVarEntryInfo(VarName)) {
auto &Entry = OffloadEntriesDeviceGlobalVar[VarName];
assert(Entry.isValid() && Entry.getFlags() == Flags &&
"Entry not initialized!");
if (Entry.getVarSize() == 0) {
Entry.setVarSize(VarSize);
Entry.setLinkage(Linkage);
}
return;
}
OffloadEntriesDeviceGlobalVar.try_emplace(VarName, OffloadingEntriesNum,
Addr, VarSize, Flags, Linkage);
++OffloadingEntriesNum;
}
}
void OffloadEntriesInfoManager::actOnDeviceGlobalVarEntriesInfo(
const OffloadDeviceGlobalVarEntryInfoActTy &Action) {
// Scan all target region entries and perform the provided action.
for (const auto &E : OffloadEntriesDeviceGlobalVar)
Action(E.getKey(), E.getValue());
}
void CanonicalLoopInfo::collectControlBlocks(
SmallVectorImpl<BasicBlock *> &BBs) {
// We only count those BBs as control block for which we do not need to
// reverse the CFG, i.e. not the loop body which can contain arbitrary control
// flow. For consistency, this also means we do not add the Body block, which
// is just the entry to the body code.
BBs.reserve(BBs.size() + 6);
BBs.append({getPreheader(), Header, Cond, Latch, Exit, getAfter()});
}
BasicBlock *CanonicalLoopInfo::getPreheader() const {
assert(isValid() && "Requires a valid canonical loop");
for (BasicBlock *Pred : predecessors(Header)) {
if (Pred != Latch)
return Pred;
}
llvm_unreachable("Missing preheader");
}
void CanonicalLoopInfo::setTripCount(Value *TripCount) {
assert(isValid() && "Requires a valid canonical loop");
Instruction *CmpI = &getCond()->front();
assert(isa<CmpInst>(CmpI) && "First inst must compare IV with TripCount");
CmpI->setOperand(1, TripCount);
#ifndef NDEBUG
assertOK();
#endif
}
void CanonicalLoopInfo::mapIndVar(
llvm::function_ref<Value *(Instruction *)> Updater) {
assert(isValid() && "Requires a valid canonical loop");
Instruction *OldIV = getIndVar();
// Record all uses excluding those introduced by the updater. Uses by the
// CanonicalLoopInfo itself to keep track of the number of iterations are
// excluded.
SmallVector<Use *> ReplacableUses;
for (Use &U : OldIV->uses()) {
auto *User = dyn_cast<Instruction>(U.getUser());
if (!User)
continue;
if (User->getParent() == getCond())
continue;
if (User->getParent() == getLatch())
continue;
ReplacableUses.push_back(&U);
}
// Run the updater that may introduce new uses
Value *NewIV = Updater(OldIV);
// Replace the old uses with the value returned by the updater.
for (Use *U : ReplacableUses)
U->set(NewIV);
#ifndef NDEBUG
assertOK();
#endif
}
void CanonicalLoopInfo::assertOK() const {
#ifndef NDEBUG
// No constraints if this object currently does not describe a loop.
if (!isValid())
return;
BasicBlock *Preheader = getPreheader();
BasicBlock *Body = getBody();
BasicBlock *After = getAfter();
// Verify standard control-flow we use for OpenMP loops.
assert(Preheader);
assert(isa<BranchInst>(Preheader->getTerminator()) &&
"Preheader must terminate with unconditional branch");
assert(Preheader->getSingleSuccessor() == Header &&
"Preheader must jump to header");
assert(Header);
assert(isa<BranchInst>(Header->getTerminator()) &&
"Header must terminate with unconditional branch");
assert(Header->getSingleSuccessor() == Cond &&
"Header must jump to exiting block");
assert(Cond);
assert(Cond->getSinglePredecessor() == Header &&
"Exiting block only reachable from header");
assert(isa<BranchInst>(Cond->getTerminator()) &&
"Exiting block must terminate with conditional branch");
assert(size(successors(Cond)) == 2 &&
"Exiting block must have two successors");
assert(cast<BranchInst>(Cond->getTerminator())->getSuccessor(0) == Body &&
"Exiting block's first successor jump to the body");
assert(cast<BranchInst>(Cond->getTerminator())->getSuccessor(1) == Exit &&
"Exiting block's second successor must exit the loop");
assert(Body);
assert(Body->getSinglePredecessor() == Cond &&
"Body only reachable from exiting block");
assert(!isa<PHINode>(Body->front()));
assert(Latch);
assert(isa<BranchInst>(Latch->getTerminator()) &&
"Latch must terminate with unconditional branch");
assert(Latch->getSingleSuccessor() == Header && "Latch must jump to header");
// TODO: To support simple redirecting of the end of the body code that has
// multiple; introduce another auxiliary basic block like preheader and after.
assert(Latch->getSinglePredecessor() != nullptr);
assert(!isa<PHINode>(Latch->front()));
assert(Exit);
assert(isa<BranchInst>(Exit->getTerminator()) &&
"Exit block must terminate with unconditional branch");
assert(Exit->getSingleSuccessor() == After &&
"Exit block must jump to after block");
assert(After);
assert(After->getSinglePredecessor() == Exit &&
"After block only reachable from exit block");
assert(After->empty() || !isa<PHINode>(After->front()));
Instruction *IndVar = getIndVar();
assert(IndVar && "Canonical induction variable not found?");
assert(isa<IntegerType>(IndVar->getType()) &&
"Induction variable must be an integer");
assert(cast<PHINode>(IndVar)->getParent() == Header &&
"Induction variable must be a PHI in the loop header");
assert(cast<PHINode>(IndVar)->getIncomingBlock(0) == Preheader);
assert(
cast<ConstantInt>(cast<PHINode>(IndVar)->getIncomingValue(0))->isZero());
assert(cast<PHINode>(IndVar)->getIncomingBlock(1) == Latch);
auto *NextIndVar = cast<PHINode>(IndVar)->getIncomingValue(1);
assert(cast<Instruction>(NextIndVar)->getParent() == Latch);
assert(cast<BinaryOperator>(NextIndVar)->getOpcode() == BinaryOperator::Add);
assert(cast<BinaryOperator>(NextIndVar)->getOperand(0) == IndVar);
assert(cast<ConstantInt>(cast<BinaryOperator>(NextIndVar)->getOperand(1))
->isOne());
Value *TripCount = getTripCount();
assert(TripCount && "Loop trip count not found?");
assert(IndVar->getType() == TripCount->getType() &&
"Trip count and induction variable must have the same type");
auto *CmpI = cast<CmpInst>(&Cond->front());
assert(CmpI->getPredicate() == CmpInst::ICMP_ULT &&
"Exit condition must be a signed less-than comparison");
assert(CmpI->getOperand(0) == IndVar &&
"Exit condition must compare the induction variable");
assert(CmpI->getOperand(1) == TripCount &&
"Exit condition must compare with the trip count");
#endif
}
void CanonicalLoopInfo::invalidate() {
Header = nullptr;
Cond = nullptr;
Latch = nullptr;
Exit = nullptr;
}