#include "llvm/Transforms/Scalar/LowerExpectIntrinsic.h"
#include "ScalarOptions.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/MDBuilder.h"
#include "llvm/IR/ProfDataUtils.h"
#include "llvm/Transforms/Utils/MisExpect.h"
#include <cmath>

Macros
#define	DEBUG_TYPE "lower-expect-intrinsic"

Functions
	STATISTIC (ExpectIntrinsicsHandled, "Number of 'expect' intrinsic instructions handled")
static std::tuple< uint32_t, uint32_t >	getBranchWeight (const ScalarOptions &Opts, Intrinsic::ID IntrinsicID, CallInst *CI, int BranchCount)
static bool	handleSwitchExpect (const ScalarOptions &Opts, SwitchInst &SI)
static void	handlePhiDef (const ScalarOptions &Opts, CallInst *Expect)
	Handler for PHINodes that define the value argument to an @llvm.expect call.
template<class BrSelInst>
static bool	handleBrSelExpect (const ScalarOptions &Opts, BrSelInst &BSI)
static bool	lowerExpectIntrinsic (Function &F)

Macro Definition Documentation

◆ DEBUG_TYPE

#define DEBUG_TYPE "lower-expect-intrinsic"

Definition at line 31 of file LowerExpectIntrinsic.cpp.

Function Documentation

◆ getBranchWeight()

std::tuple< uint32_t, uint32_t > getBranchWeight	(	const ScalarOptions &	Opts,
		Intrinsic::ID	IntrinsicID,
		CallInst *	CI,
		int	BranchCount )

static

Definition at line 44 of file LowerExpectIntrinsic.cpp.

References assert(), llvm::cast(), llvm::CallBase::getArgOperand(), and llvm::User::getNumOperands().

Referenced by handleBrSelExpect(), handlePhiDef(), and handleSwitchExpect().

◆ handleBrSelExpect()

template<class BrSelInst>

bool handleBrSelExpect	(	const ScalarOptions &	Opts,
		BrSelInst &	BSI )

static

Definition at line 264 of file LowerExpectIntrinsic.cpp.

References llvm::misexpect::checkFrontendInstrumentation(), llvm::MDBuilder::createBranchWeights(), llvm::dyn_cast(), llvm::CallBase::getArgOperand(), llvm::ConstantInt::getBitWidth(), getBranchWeight(), llvm::CallBase::getCalledFunction(), llvm::Value::getContext(), llvm::Function::getIntrinsicID(), llvm::User::getOperand(), llvm::CmpInst::getPredicate(), llvm::ConstantInt::getZExtValue(), llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::User::setOperand(), and uint64_t.

Referenced by lowerExpectIntrinsic().

◆ handlePhiDef()

void handlePhiDef	(	const ScalarOptions &	Opts,
		CallInst *	Expect )

static

Handler for PHINodes that define the value argument to an @llvm.expect call.

If the operand of the phi has a constant value and it 'contradicts' with the expected value of phi def, then the corresponding incoming edge of the phi is unlikely to be taken. Using that information, the branch probability info for the originating branch can be inferred.

Definition at line 107 of file LowerExpectIntrinsic.cpp.

References llvm::cast(), llvm::MDBuilder::createBranchWeights(), llvm::dyn_cast(), llvm::CallBase::getArgOperand(), getBranchWeight(), llvm::CallBase::getCalledFunction(), llvm::Function::getIntrinsicID(), llvm::BinaryOperator::getOpcode(), llvm::User::getOperand(), llvm::ilist_detail::node_parent_access< NodeTy, ParentTy >::getParent(), llvm::BasicBlock::getSinglePredecessor(), llvm::CondBrInst::getSuccessor(), llvm::BasicBlock::getTerminator(), llvm::ConstantInt::getValue(), llvm::isa(), llvm_unreachable, llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::reverse(), llvm::Instruction::setMetadata(), and std::swap().