//===- subzero/src/IceIntrinsics.cpp - Functions related to intrinsics ----===//
//
//                        The Subzero Code Generator
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief Implements the Intrinsics utilities for matching and then dispatching
/// by name.
///
//===----------------------------------------------------------------------===//

#include "IceIntrinsics.h"

#include "IceCfg.h"
#include "IceCfgNode.h"
#include "IceInst.h"
#include "IceLiveness.h"
#include "IceOperand.h"
#include "IceStringPool.h"

#include <utility>

namespace Ice {

static_assert(sizeof(Intrinsics::IntrinsicInfo) == 4,
              "Unexpected sizeof(IntrinsicInfo)");

namespace {

#define INTRIN(ID, SE, RT)                                                     \
  { Intrinsics::ID, Intrinsics::SE, Intrinsics::RT }

// Build list of intrinsics with their attributes and expected prototypes. List
// is sorted alphabetically.
const struct IceIntrinsicsEntry_ {
  Intrinsics::FullIntrinsicInfo Info;
  const char *IntrinsicName;
} IceIntrinsicsTable[] = {

#define AtomicCmpxchgInit(Overload, NameSuffix)                                \
  {                                                                            \
    {                                                                          \
      INTRIN(AtomicCmpxchg, SideEffects_T, ReturnsTwice_F), {Overload,         \
                                                             IceType_i32,      \
                                                             Overload,         \
                                                             Overload,         \
                                                             IceType_i32,      \
                                                             IceType_i32},     \
          6                                                                    \
    }                                                                          \
    , "llvm.nacl.atomic.cmpxchg." NameSuffix                                   \
  }
    AtomicCmpxchgInit(IceType_i8, "i8"),
    AtomicCmpxchgInit(IceType_i16, "i16"),
    AtomicCmpxchgInit(IceType_i32, "i32"),
    AtomicCmpxchgInit(IceType_i64, "i64"),
#undef AtomicCmpxchgInit

    {{INTRIN(AtomicFence, SideEffects_T, ReturnsTwice_F),
      {IceType_void, IceType_i32},
      2},
     "llvm.nacl.atomic.fence"},
    {{INTRIN(AtomicFenceAll, SideEffects_T, ReturnsTwice_F), {IceType_void}, 1},
     "llvm.nacl.atomic.fence.all"},
    {{INTRIN(AtomicIsLockFree, SideEffects_F, ReturnsTwice_F),
      {IceType_i1, IceType_i32, IceType_i32},
      3},
     "llvm.nacl.atomic.is.lock.free"},

#define AtomicLoadInit(Overload, NameSuffix)                                   \
  {                                                                            \
    {                                                                          \
      INTRIN(AtomicLoad, SideEffects_T, ReturnsTwice_F),                       \
          {Overload, IceType_i32, IceType_i32}, 3                              \
    }                                                                          \
    , "llvm.nacl.atomic.load." NameSuffix                                      \
  }
    AtomicLoadInit(IceType_i8, "i8"),
    AtomicLoadInit(IceType_i16, "i16"),
    AtomicLoadInit(IceType_i32, "i32"),
    AtomicLoadInit(IceType_i64, "i64"),
#undef AtomicLoadInit

#define AtomicRMWInit(Overload, NameSuffix)                                    \
  {                                                                            \
    {                                                                          \
      INTRIN(AtomicRMW, SideEffects_T, ReturnsTwice_F)                         \
      , {Overload, IceType_i32, IceType_i32, Overload, IceType_i32}, 5         \
    }                                                                          \
    , "llvm.nacl.atomic.rmw." NameSuffix                                       \
  }
    AtomicRMWInit(IceType_i8, "i8"),
    AtomicRMWInit(IceType_i16, "i16"),
    AtomicRMWInit(IceType_i32, "i32"),
    AtomicRMWInit(IceType_i64, "i64"),
#undef AtomicRMWInit

#define AtomicStoreInit(Overload, NameSuffix)                                  \
  {                                                                            \
    {                                                                          \
      INTRIN(AtomicStore, SideEffects_T, ReturnsTwice_F)                       \
      , {IceType_void, Overload, IceType_i32, IceType_i32}, 4                  \
    }                                                                          \
    , "llvm.nacl.atomic.store." NameSuffix                                     \
  }
    AtomicStoreInit(IceType_i8, "i8"),
    AtomicStoreInit(IceType_i16, "i16"),
    AtomicStoreInit(IceType_i32, "i32"),
    AtomicStoreInit(IceType_i64, "i64"),
#undef AtomicStoreInit

#define BswapInit(Overload, NameSuffix)                                        \
  {                                                                            \
    {                                                                          \
      INTRIN(Bswap, SideEffects_F, ReturnsTwice_F)                             \
      , {Overload, Overload}, 2                                                \
    }                                                                          \
    , "llvm.bswap." NameSuffix                                                 \
  }
    BswapInit(IceType_i16, "i16"),
    BswapInit(IceType_i32, "i32"),
    BswapInit(IceType_i64, "i64"),
#undef BswapInit

#define CtlzInit(Overload, NameSuffix)                                         \
  {                                                                            \
    {                                                                          \
      INTRIN(Ctlz, SideEffects_F, ReturnsTwice_F)                              \
      , {Overload, Overload, IceType_i1}, 3                                    \
    }                                                                          \
    , "llvm.ctlz." NameSuffix                                                  \
  }
    CtlzInit(IceType_i32, "i32"),
    CtlzInit(IceType_i64, "i64"),
#undef CtlzInit

#define CtpopInit(Overload, NameSuffix)                                        \
  {                                                                            \
    {                                                                          \
      INTRIN(Ctpop, SideEffects_F, ReturnsTwice_F)                             \
      , {Overload, Overload}, 2                                                \
    }                                                                          \
    , "llvm.ctpop." NameSuffix                                                 \
  }
    CtpopInit(IceType_i32, "i32"),
    CtpopInit(IceType_i64, "i64"),
#undef CtpopInit

#define CttzInit(Overload, NameSuffix)                                         \
  {                                                                            \
    {                                                                          \
      INTRIN(Cttz, SideEffects_F, ReturnsTwice_F)                              \
      , {Overload, Overload, IceType_i1}, 3                                    \
    }                                                                          \
    , "llvm.cttz." NameSuffix                                                  \
  }
    CttzInit(IceType_i32, "i32"),
    CttzInit(IceType_i64, "i64"),
#undef CttzInit

#define FabsInit(Overload, NameSuffix)                                         \
  {                                                                            \
    { INTRIN(Fabs, SideEffects_F, ReturnsTwice_F), {Overload, Overload}, 2 }   \
    , "llvm.fabs." NameSuffix                                                  \
  }
    FabsInit(IceType_f32, "f32"),
    FabsInit(IceType_f64, "f64"),
    FabsInit(IceType_v4f32, "v4f32"),
#undef FabsInit

    {{INTRIN(Longjmp, SideEffects_T, ReturnsTwice_F),
      {IceType_void, IceType_i32, IceType_i32},
      3},
     "llvm.nacl.longjmp"},
    {{INTRIN(Memcpy, SideEffects_T, ReturnsTwice_F),
      {IceType_void, IceType_i32, IceType_i32, IceType_i32, IceType_i32,
       IceType_i1},
      6},
     "llvm.memcpy.p0i8.p0i8.i32"},
    {{INTRIN(Memmove, SideEffects_T, ReturnsTwice_F),
      {IceType_void, IceType_i32, IceType_i32, IceType_i32, IceType_i32,
       IceType_i1},
      6},
     "llvm.memmove.p0i8.p0i8.i32"},
    {{INTRIN(Memset, SideEffects_T, ReturnsTwice_F),
      {IceType_void, IceType_i32, IceType_i8, IceType_i32, IceType_i32,
       IceType_i1},
      6},
     "llvm.memset.p0i8.i32"},
    {{INTRIN(NaClReadTP, SideEffects_F, ReturnsTwice_F), {IceType_i32}, 1},
     "llvm.nacl.read.tp"},
    {{INTRIN(Setjmp, SideEffects_T, ReturnsTwice_T),
      {IceType_i32, IceType_i32},
      2},
     "llvm.nacl.setjmp"},

#define SqrtInit(Overload, NameSuffix)                                         \
  {                                                                            \
    { INTRIN(Sqrt, SideEffects_F, ReturnsTwice_F), {Overload, Overload}, 2 }   \
    , "llvm.sqrt." NameSuffix                                                  \
  }
    SqrtInit(IceType_f32, "f32"),
    SqrtInit(IceType_f64, "f64"),
#undef SqrtInit

    {{INTRIN(Stacksave, SideEffects_T, ReturnsTwice_F), {IceType_i32}, 1},
     "llvm.stacksave"},
    {{INTRIN(Stackrestore, SideEffects_T, ReturnsTwice_F),
      {IceType_void, IceType_i32},
      2},
     "llvm.stackrestore"},
    {{INTRIN(Trap, SideEffects_T, ReturnsTwice_F), {IceType_void}, 1},
     "llvm.trap"}};
const size_t IceIntrinsicsTableSize = llvm::array_lengthof(IceIntrinsicsTable);

#undef INTRIN

} // end of anonymous namespace

Intrinsics::Intrinsics(GlobalContext *Ctx) {
  for (size_t I = 0; I < IceIntrinsicsTableSize; ++I) {
    const struct IceIntrinsicsEntry_ &Entry = IceIntrinsicsTable[I];
    assert(Entry.Info.NumTypes <= kMaxIntrinsicParameters);
    Map.insert(
        std::make_pair(Ctx->getGlobalString(Entry.IntrinsicName), Entry.Info));
  }
}

const Intrinsics::FullIntrinsicInfo *Intrinsics::find(GlobalString Name,
                                                      bool &Error) const {
  static constexpr char LLVMPrefix[] = "llvm.";
  constexpr size_t LLVMPrefixLen = llvm::array_lengthof(LLVMPrefix) - 1;
  Error = false;
  if (Name.toString().substr(0, LLVMPrefixLen) != LLVMPrefix)
    return nullptr;
  auto Iter = Map.find(Name);
  if (Iter == Map.end()) {
    Error = true;
    return nullptr;
  }
  return &Iter->second;
}

namespace {

// Returns whether PNaCl allows the given memory ordering in general.
bool isMemoryOrderValidPNaCl(uint64_t Order) {
  switch (Order) {
  case Intrinsics::MemoryOrderAcquire:
  case Intrinsics::MemoryOrderRelease:
  case Intrinsics::MemoryOrderAcquireRelease:
  case Intrinsics::MemoryOrderSequentiallyConsistent:
    return true;
  default:
    return false;
  }
}

} // end of anonymous namespace

bool Intrinsics::isMemoryOrderValid(IntrinsicID ID, uint64_t Order,
                                    uint64_t OrderOther) {
  // Reject orderings not allowed in PNaCl.
  if (!isMemoryOrderValidPNaCl(Order))
    return false;
  if (ID == AtomicCmpxchg && !isMemoryOrderValidPNaCl(OrderOther))
    return false;
  // Reject orderings not allowed by C++11.
  switch (ID) {
  default:
    llvm_unreachable("isMemoryOrderValid: Unknown IntrinsicID");
    return false;
  case AtomicFence:
  case AtomicFenceAll:
  case AtomicRMW:
    return true;
  case AtomicCmpxchg:
    // Reject orderings that are disallowed by C++11 as invalid combinations
    // for cmpxchg.
    switch (OrderOther) {
    case MemoryOrderRelaxed:
    case MemoryOrderConsume:
    case MemoryOrderAcquire:
    case MemoryOrderSequentiallyConsistent:
      if (OrderOther > Order)
        return false;
      if (Order == MemoryOrderRelease && OrderOther != MemoryOrderRelaxed)
        return false;
      return true;
    default:
      return false;
    }
  case AtomicLoad:
    switch (Order) {
    case MemoryOrderRelease:
    case MemoryOrderAcquireRelease:
      return false;
    default:
      return true;
    }
  case AtomicStore:
    switch (Order) {
    case MemoryOrderConsume:
    case MemoryOrderAcquire:
    case MemoryOrderAcquireRelease:
      return false;
    default:
      return true;
    }
  }
}

Intrinsics::ValidateCallValue
Intrinsics::FullIntrinsicInfo::validateCall(const InstCall *Call,
                                            SizeT &ArgIndex) const {
  assert(NumTypes >= 1);
  Variable *Result = Call->getDest();
  if (Result == nullptr) {
    if (getReturnType() != IceType_void)
      return Intrinsics::BadReturnType;
  } else if (getReturnType() != Result->getType()) {
    return Intrinsics::BadReturnType;
  }
  if (Call->getNumArgs() != getNumArgs()) {
    return Intrinsics::WrongNumOfArgs;
  }
  for (size_t i = 1; i < NumTypes; ++i) {
    if (Call->getArg(i - 1)->getType() != Signature[i]) {
      ArgIndex = i - 1;
      return Intrinsics::WrongCallArgType;
    }
  }
  return Intrinsics::IsValidCall;
}

Type Intrinsics::FullIntrinsicInfo::getArgType(SizeT Index) const {
  assert(NumTypes > 1);
  assert(Index + 1 < NumTypes);
  return Signature[Index + 1];
}

} // end of namespace Ice