third_party/llvm-16.0/llvm/lib/CodeGen/MachineBlockFrequencyInfo.cpp - SwiftShader - Git at Google

 //===- MachineBlockFrequencyInfo.cpp - MBB Frequency Analysis -------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 //
 // Loops should be simplified before this analysis.
 //
 //===----------------------------------------------------------------------===//

 #include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/iterator.h"
 #include "llvm/Analysis/BlockFrequencyInfoImpl.h"
 #include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineLoopInfo.h"
 #include "llvm/InitializePasses.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/GraphWriter.h"
 #include <optional>
 #include <string>

 using namespace llvm;

 #define DEBUG_TYPE "machine-block-freq"

 namespace llvm {
 static cl::opt<GVDAGType> ViewMachineBlockFreqPropagationDAG(
     "view-machine-block-freq-propagation-dags", cl::Hidden,
     cl::desc("Pop up a window to show a dag displaying how machine block "
              "frequencies propagate through the CFG."),
     cl::values(clEnumValN(GVDT_None, "none", "do not display graphs."),
                clEnumValN(GVDT_Fraction, "fraction",
                           "display a graph using the "
                           "fractional block frequency representation."),
                clEnumValN(GVDT_Integer, "integer",
                           "display a graph using the raw "
                           "integer fractional block frequency representation."),
                clEnumValN(GVDT_Count, "count", "display a graph using the real "
                                                "profile count if available.")));

 // Similar option above, but used to control BFI display only after MBP pass
 cl::opt<GVDAGType> ViewBlockLayoutWithBFI(
     "view-block-layout-with-bfi", cl::Hidden,
     cl::desc(
         "Pop up a window to show a dag displaying MBP layout and associated "
         "block frequencies of the CFG."),
     cl::values(clEnumValN(GVDT_None, "none", "do not display graphs."),
                clEnumValN(GVDT_Fraction, "fraction",
                           "display a graph using the "
                           "fractional block frequency representation."),
                clEnumValN(GVDT_Integer, "integer",
                           "display a graph using the raw "
                           "integer fractional block frequency representation."),
                clEnumValN(GVDT_Count, "count",
                           "display a graph using the real "
                           "profile count if available.")));

 // Command line option to specify the name of the function for CFG dump
 // Defined in Analysis/BlockFrequencyInfo.cpp:  -view-bfi-func-name=
 extern cl::opt<std::string> ViewBlockFreqFuncName;

 // Command line option to specify hot frequency threshold.
 // Defined in Analysis/BlockFrequencyInfo.cpp:  -view-hot-freq-perc=
 extern cl::opt<unsigned> ViewHotFreqPercent;

 static cl::opt<bool> PrintMachineBlockFreq(
     "print-machine-bfi", cl::init(false), cl::Hidden,
     cl::desc("Print the machine block frequency info."));

 // Command line option to specify the name of the function for block frequency
 // dump. Defined in Analysis/BlockFrequencyInfo.cpp.
 extern cl::opt<std::string> PrintBlockFreqFuncName;
 } // namespace llvm

 static GVDAGType getGVDT() {
   if (ViewBlockLayoutWithBFI != GVDT_None)
     return ViewBlockLayoutWithBFI;

   return ViewMachineBlockFreqPropagationDAG;
 }

 namespace llvm {

 template <> struct GraphTraits<MachineBlockFrequencyInfo *> {
   using NodeRef = const MachineBasicBlock *;
   using ChildIteratorType = MachineBasicBlock::const_succ_iterator;
   using nodes_iterator = pointer_iterator<MachineFunction::const_iterator>;

   static NodeRef getEntryNode(const MachineBlockFrequencyInfo *G) {
     return &G->getFunction()->front();
   }

   static ChildIteratorType child_begin(const NodeRef N) {
     return N->succ_begin();
   }

   static ChildIteratorType child_end(const NodeRef N) { return N->succ_end(); }

   static nodes_iterator nodes_begin(const MachineBlockFrequencyInfo *G) {
     return nodes_iterator(G->getFunction()->begin());
   }

   static nodes_iterator nodes_end(const MachineBlockFrequencyInfo *G) {
     return nodes_iterator(G->getFunction()->end());
   }
 };

 using MBFIDOTGraphTraitsBase =
     BFIDOTGraphTraitsBase<MachineBlockFrequencyInfo,
                           MachineBranchProbabilityInfo>;

 template <>
 struct DOTGraphTraits<MachineBlockFrequencyInfo *>
     : public MBFIDOTGraphTraitsBase {
   const MachineFunction *CurFunc = nullptr;
   DenseMap<const MachineBasicBlock *, int> LayoutOrderMap;

   explicit DOTGraphTraits(bool isSimple = false)
       : MBFIDOTGraphTraitsBase(isSimple) {}

   std::string getNodeLabel(const MachineBasicBlock *Node,
                            const MachineBlockFrequencyInfo *Graph) {
     int layout_order = -1;
     // Attach additional ordering information if 'isSimple' is false.
     if (!isSimple()) {
       const MachineFunction *F = Node->getParent();
       if (!CurFunc || F != CurFunc) {
         if (CurFunc)
           LayoutOrderMap.clear();

         CurFunc = F;
         int O = 0;
         for (auto MBI = F->begin(); MBI != F->end(); ++MBI, ++O) {
           LayoutOrderMap[&*MBI] = O;
         }
       }
       layout_order = LayoutOrderMap[Node];
     }
     return MBFIDOTGraphTraitsBase::getNodeLabel(Node, Graph, getGVDT(),
                                                 layout_order);
   }

   std::string getNodeAttributes(const MachineBasicBlock *Node,
                                 const MachineBlockFrequencyInfo *Graph) {
     return MBFIDOTGraphTraitsBase::getNodeAttributes(Node, Graph,
                                                      ViewHotFreqPercent);
   }

   std::string getEdgeAttributes(const MachineBasicBlock *Node, EdgeIter EI,
                                 const MachineBlockFrequencyInfo *MBFI) {
     return MBFIDOTGraphTraitsBase::getEdgeAttributes(
         Node, EI, MBFI, MBFI->getMBPI(), ViewHotFreqPercent);
   }
 };

 } // end namespace llvm

 INITIALIZE_PASS_BEGIN(MachineBlockFrequencyInfo, DEBUG_TYPE,
                       "Machine Block Frequency Analysis", true, true)
 INITIALIZE_PASS_DEPENDENCY(MachineBranchProbabilityInfo)
 INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
 INITIALIZE_PASS_END(MachineBlockFrequencyInfo, DEBUG_TYPE,
                     "Machine Block Frequency Analysis", true, true)

 char MachineBlockFrequencyInfo::ID = 0;

 MachineBlockFrequencyInfo::MachineBlockFrequencyInfo()
     : MachineFunctionPass(ID) {
   initializeMachineBlockFrequencyInfoPass(*PassRegistry::getPassRegistry());
 }

 MachineBlockFrequencyInfo::MachineBlockFrequencyInfo(
       MachineFunction &F,
       MachineBranchProbabilityInfo &MBPI,
       MachineLoopInfo &MLI) : MachineFunctionPass(ID) {
   calculate(F, MBPI, MLI);
 }

 MachineBlockFrequencyInfo::~MachineBlockFrequencyInfo() = default;

 void MachineBlockFrequencyInfo::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addRequired<MachineBranchProbabilityInfo>();
   AU.addRequired<MachineLoopInfo>();
   AU.setPreservesAll();
   MachineFunctionPass::getAnalysisUsage(AU);
 }

 void MachineBlockFrequencyInfo::calculate(
     const MachineFunction &F, const MachineBranchProbabilityInfo &MBPI,
     const MachineLoopInfo &MLI) {
   if (!MBFI)
     MBFI.reset(new ImplType);
   MBFI->calculate(F, MBPI, MLI);
   if (ViewMachineBlockFreqPropagationDAG != GVDT_None &&
       (ViewBlockFreqFuncName.empty() ||
        F.getName().equals(ViewBlockFreqFuncName))) {
     view("MachineBlockFrequencyDAGS." + F.getName());
   }
   if (PrintMachineBlockFreq &&
       (PrintBlockFreqFuncName.empty() ||
        F.getName().equals(PrintBlockFreqFuncName))) {
     MBFI->print(dbgs());
   }
 }

 bool MachineBlockFrequencyInfo::runOnMachineFunction(MachineFunction &F) {
   MachineBranchProbabilityInfo &MBPI =
       getAnalysis<MachineBranchProbabilityInfo>();
   MachineLoopInfo &MLI = getAnalysis<MachineLoopInfo>();
   calculate(F, MBPI, MLI);
   return false;
 }

 void MachineBlockFrequencyInfo::releaseMemory() { MBFI.reset(); }

 /// Pop up a ghostview window with the current block frequency propagation
 /// rendered using dot.
 void MachineBlockFrequencyInfo::view(const Twine &Name, bool isSimple) const {
   // This code is only for debugging.
   ViewGraph(const_cast<MachineBlockFrequencyInfo *>(this), Name, isSimple);
 }

 BlockFrequency
 MachineBlockFrequencyInfo::getBlockFreq(const MachineBasicBlock *MBB) const {
   return MBFI ? MBFI->getBlockFreq(MBB) : 0;
 }

 std::optional<uint64_t> MachineBlockFrequencyInfo::getBlockProfileCount(
     const MachineBasicBlock *MBB) const {
   if (!MBFI)
     return std::nullopt;

   const Function &F = MBFI->getFunction()->getFunction();
   return MBFI->getBlockProfileCount(F, MBB);
 }

 std::optional<uint64_t>
 MachineBlockFrequencyInfo::getProfileCountFromFreq(uint64_t Freq) const {
   if (!MBFI)
     return std::nullopt;

   const Function &F = MBFI->getFunction()->getFunction();
   return MBFI->getProfileCountFromFreq(F, Freq);
 }

 bool MachineBlockFrequencyInfo::isIrrLoopHeader(
     const MachineBasicBlock *MBB) const {
   assert(MBFI && "Expected analysis to be available");
   return MBFI->isIrrLoopHeader(MBB);
 }

 void MachineBlockFrequencyInfo::onEdgeSplit(
     const MachineBasicBlock &NewPredecessor,
     const MachineBasicBlock &NewSuccessor,
     const MachineBranchProbabilityInfo &MBPI) {
   assert(MBFI && "Expected analysis to be available");
   auto NewSuccFreq = MBFI->getBlockFreq(&NewPredecessor) *
                      MBPI.getEdgeProbability(&NewPredecessor, &NewSuccessor);

   MBFI->setBlockFreq(&NewSuccessor, NewSuccFreq.getFrequency());
 }

 const MachineFunction *MachineBlockFrequencyInfo::getFunction() const {
   return MBFI ? MBFI->getFunction() : nullptr;
 }

 const MachineBranchProbabilityInfo *MachineBlockFrequencyInfo::getMBPI() const {
   return MBFI ? &MBFI->getBPI() : nullptr;
 }

 raw_ostream &
 MachineBlockFrequencyInfo::printBlockFreq(raw_ostream &OS,
                                           const BlockFrequency Freq) const {
   return MBFI ? MBFI->printBlockFreq(OS, Freq) : OS;
 }

 raw_ostream &
 MachineBlockFrequencyInfo::printBlockFreq(raw_ostream &OS,
                                           const MachineBasicBlock *MBB) const {
   return MBFI ? MBFI->printBlockFreq(OS, MBB) : OS;
 }

 uint64_t MachineBlockFrequencyInfo::getEntryFreq() const {
   return MBFI ? MBFI->getEntryFreq() : 0;
 }
	//===- MachineBlockFrequencyInfo.cpp - MBB Frequency Analysis -------------===//
	//
	// 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
	//
	//===----------------------------------------------------------------------===//
	//
	// Loops should be simplified before this analysis.
	//
	//===----------------------------------------------------------------------===//

	#include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
	#include "llvm/ADT/DenseMap.h"
	#include "llvm/ADT/iterator.h"
	#include "llvm/Analysis/BlockFrequencyInfoImpl.h"
	#include "llvm/CodeGen/MachineBasicBlock.h"
	#include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
	#include "llvm/CodeGen/MachineFunction.h"
	#include "llvm/CodeGen/MachineLoopInfo.h"
	#include "llvm/InitializePasses.h"
	#include "llvm/Pass.h"
	#include "llvm/Support/CommandLine.h"
	#include "llvm/Support/GraphWriter.h"
	#include <optional>
	#include <string>

	using namespace llvm;

	#define DEBUG_TYPE "machine-block-freq"

	namespace llvm {
	static cl::opt<GVDAGType> ViewMachineBlockFreqPropagationDAG(
	"view-machine-block-freq-propagation-dags", cl::Hidden,
	cl::desc("Pop up a window to show a dag displaying how machine block "
	"frequencies propagate through the CFG."),
	cl::values(clEnumValN(GVDT_None, "none", "do not display graphs."),
	clEnumValN(GVDT_Fraction, "fraction",
	"display a graph using the "
	"fractional block frequency representation."),
	clEnumValN(GVDT_Integer, "integer",
	"display a graph using the raw "
	"integer fractional block frequency representation."),
	clEnumValN(GVDT_Count, "count", "display a graph using the real "
	"profile count if available.")));

	// Similar option above, but used to control BFI display only after MBP pass
	cl::opt<GVDAGType> ViewBlockLayoutWithBFI(
	"view-block-layout-with-bfi", cl::Hidden,
	cl::desc(
	"Pop up a window to show a dag displaying MBP layout and associated "
	"block frequencies of the CFG."),
	cl::values(clEnumValN(GVDT_None, "none", "do not display graphs."),
	clEnumValN(GVDT_Fraction, "fraction",
	"display a graph using the "
	"fractional block frequency representation."),
	clEnumValN(GVDT_Integer, "integer",
	"display a graph using the raw "
	"integer fractional block frequency representation."),
	clEnumValN(GVDT_Count, "count",
	"display a graph using the real "
	"profile count if available.")));

	// Command line option to specify the name of the function for CFG dump
	// Defined in Analysis/BlockFrequencyInfo.cpp: -view-bfi-func-name=
	extern cl::opt<std::string> ViewBlockFreqFuncName;

	// Command line option to specify hot frequency threshold.
	// Defined in Analysis/BlockFrequencyInfo.cpp: -view-hot-freq-perc=
	extern cl::opt<unsigned> ViewHotFreqPercent;

	static cl::opt<bool> PrintMachineBlockFreq(
	"print-machine-bfi", cl::init(false), cl::Hidden,
	cl::desc("Print the machine block frequency info."));

	// Command line option to specify the name of the function for block frequency
	// dump. Defined in Analysis/BlockFrequencyInfo.cpp.
	extern cl::opt<std::string> PrintBlockFreqFuncName;
	} // namespace llvm

	static GVDAGType getGVDT() {
	if (ViewBlockLayoutWithBFI != GVDT_None)
	return ViewBlockLayoutWithBFI;

	return ViewMachineBlockFreqPropagationDAG;
	}

	namespace llvm {

	template <> struct GraphTraits<MachineBlockFrequencyInfo *> {
	using NodeRef = const MachineBasicBlock *;
	using ChildIteratorType = MachineBasicBlock::const_succ_iterator;
	using nodes_iterator = pointer_iterator<MachineFunction::const_iterator>;

	static NodeRef getEntryNode(const MachineBlockFrequencyInfo *G) {
	return &G->getFunction()->front();
	}

	static ChildIteratorType child_begin(const NodeRef N) {
	return N->succ_begin();
	}

	static ChildIteratorType child_end(const NodeRef N) { return N->succ_end(); }

	static nodes_iterator nodes_begin(const MachineBlockFrequencyInfo *G) {
	return nodes_iterator(G->getFunction()->begin());
	}

	static nodes_iterator nodes_end(const MachineBlockFrequencyInfo *G) {
	return nodes_iterator(G->getFunction()->end());
	}
	};

	using MBFIDOTGraphTraitsBase =
	BFIDOTGraphTraitsBase<MachineBlockFrequencyInfo,
	MachineBranchProbabilityInfo>;

	template <>
	struct DOTGraphTraits<MachineBlockFrequencyInfo *>
	: public MBFIDOTGraphTraitsBase {
	const MachineFunction *CurFunc = nullptr;
	DenseMap<const MachineBasicBlock *, int> LayoutOrderMap;

	explicit DOTGraphTraits(bool isSimple = false)
	: MBFIDOTGraphTraitsBase(isSimple) {}

	std::string getNodeLabel(const MachineBasicBlock *Node,
	const MachineBlockFrequencyInfo *Graph) {
	int layout_order = -1;
	// Attach additional ordering information if 'isSimple' is false.
	if (!isSimple()) {
	const MachineFunction *F = Node->getParent();
	if (!CurFunc \|\| F != CurFunc) {
	if (CurFunc)
	LayoutOrderMap.clear();

	CurFunc = F;
	int O = 0;
	for (auto MBI = F->begin(); MBI != F->end(); ++MBI, ++O) {
	LayoutOrderMap[&*MBI] = O;
	}
	}
	layout_order = LayoutOrderMap[Node];
	}
	return MBFIDOTGraphTraitsBase::getNodeLabel(Node, Graph, getGVDT(),
	layout_order);
	}

	std::string getNodeAttributes(const MachineBasicBlock *Node,
	const MachineBlockFrequencyInfo *Graph) {
	return MBFIDOTGraphTraitsBase::getNodeAttributes(Node, Graph,
	ViewHotFreqPercent);
	}

	std::string getEdgeAttributes(const MachineBasicBlock *Node, EdgeIter EI,
	const MachineBlockFrequencyInfo *MBFI) {
	return MBFIDOTGraphTraitsBase::getEdgeAttributes(
	Node, EI, MBFI, MBFI->getMBPI(), ViewHotFreqPercent);
	}
	};

	} // end namespace llvm

	INITIALIZE_PASS_BEGIN(MachineBlockFrequencyInfo, DEBUG_TYPE,
	"Machine Block Frequency Analysis", true, true)
	INITIALIZE_PASS_DEPENDENCY(MachineBranchProbabilityInfo)
	INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
	INITIALIZE_PASS_END(MachineBlockFrequencyInfo, DEBUG_TYPE,
	"Machine Block Frequency Analysis", true, true)

	char MachineBlockFrequencyInfo::ID = 0;

	MachineBlockFrequencyInfo::MachineBlockFrequencyInfo()
	: MachineFunctionPass(ID) {
	initializeMachineBlockFrequencyInfoPass(*PassRegistry::getPassRegistry());
	}

	MachineBlockFrequencyInfo::MachineBlockFrequencyInfo(
	MachineFunction &F,
	MachineBranchProbabilityInfo &MBPI,
	MachineLoopInfo &MLI) : MachineFunctionPass(ID) {
	calculate(F, MBPI, MLI);
	}

	MachineBlockFrequencyInfo::~MachineBlockFrequencyInfo() = default;

	void MachineBlockFrequencyInfo::getAnalysisUsage(AnalysisUsage &AU) const {
	AU.addRequired<MachineBranchProbabilityInfo>();
	AU.addRequired<MachineLoopInfo>();
	AU.setPreservesAll();
	MachineFunctionPass::getAnalysisUsage(AU);
	}

	void MachineBlockFrequencyInfo::calculate(
	const MachineFunction &F, const MachineBranchProbabilityInfo &MBPI,
	const MachineLoopInfo &MLI) {
	if (!MBFI)
	MBFI.reset(new ImplType);
	MBFI->calculate(F, MBPI, MLI);
	if (ViewMachineBlockFreqPropagationDAG != GVDT_None &&
	(ViewBlockFreqFuncName.empty() \|\|
	F.getName().equals(ViewBlockFreqFuncName))) {
	view("MachineBlockFrequencyDAGS." + F.getName());
	}
	if (PrintMachineBlockFreq &&
	(PrintBlockFreqFuncName.empty() \|\|
	F.getName().equals(PrintBlockFreqFuncName))) {
	MBFI->print(dbgs());
	}
	}

	bool MachineBlockFrequencyInfo::runOnMachineFunction(MachineFunction &F) {
	MachineBranchProbabilityInfo &MBPI =
	getAnalysis<MachineBranchProbabilityInfo>();
	MachineLoopInfo &MLI = getAnalysis<MachineLoopInfo>();
	calculate(F, MBPI, MLI);
	return false;
	}

	void MachineBlockFrequencyInfo::releaseMemory() { MBFI.reset(); }

	/// Pop up a ghostview window with the current block frequency propagation
	/// rendered using dot.
	void MachineBlockFrequencyInfo::view(const Twine &Name, bool isSimple) const {
	// This code is only for debugging.
	ViewGraph(const_cast<MachineBlockFrequencyInfo *>(this), Name, isSimple);
	}

	BlockFrequency
	MachineBlockFrequencyInfo::getBlockFreq(const MachineBasicBlock *MBB) const {
	return MBFI ? MBFI->getBlockFreq(MBB) : 0;
	}

	std::optional<uint64_t> MachineBlockFrequencyInfo::getBlockProfileCount(
	const MachineBasicBlock *MBB) const {
	if (!MBFI)
	return std::nullopt;

	const Function &F = MBFI->getFunction()->getFunction();
	return MBFI->getBlockProfileCount(F, MBB);
	}

	std::optional<uint64_t>
	MachineBlockFrequencyInfo::getProfileCountFromFreq(uint64_t Freq) const {
	if (!MBFI)
	return std::nullopt;

	const Function &F = MBFI->getFunction()->getFunction();
	return MBFI->getProfileCountFromFreq(F, Freq);
	}

	bool MachineBlockFrequencyInfo::isIrrLoopHeader(
	const MachineBasicBlock *MBB) const {
	assert(MBFI && "Expected analysis to be available");
	return MBFI->isIrrLoopHeader(MBB);
	}

	void MachineBlockFrequencyInfo::onEdgeSplit(
	const MachineBasicBlock &NewPredecessor,
	const MachineBasicBlock &NewSuccessor,
	const MachineBranchProbabilityInfo &MBPI) {
	assert(MBFI && "Expected analysis to be available");
	auto NewSuccFreq = MBFI->getBlockFreq(&NewPredecessor) *
	MBPI.getEdgeProbability(&NewPredecessor, &NewSuccessor);

	MBFI->setBlockFreq(&NewSuccessor, NewSuccFreq.getFrequency());
	}

	const MachineFunction *MachineBlockFrequencyInfo::getFunction() const {
	return MBFI ? MBFI->getFunction() : nullptr;
	}

	const MachineBranchProbabilityInfo *MachineBlockFrequencyInfo::getMBPI() const {
	return MBFI ? &MBFI->getBPI() : nullptr;
	}

	raw_ostream &
	MachineBlockFrequencyInfo::printBlockFreq(raw_ostream &OS,
	const BlockFrequency Freq) const {
	return MBFI ? MBFI->printBlockFreq(OS, Freq) : OS;
	}

	raw_ostream &
	MachineBlockFrequencyInfo::printBlockFreq(raw_ostream &OS,
	const MachineBasicBlock *MBB) const {
	return MBFI ? MBFI->printBlockFreq(OS, MBB) : OS;
	}

	uint64_t MachineBlockFrequencyInfo::getEntryFreq() const {
	return MBFI ? MBFI->getEntryFreq() : 0;
	}