#include "llvm/Analysis/MustExecute.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/Passes.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/AssemblyAnnotationWriter.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Support/raw_ostream.h"

Include dependency graph for MustExecute.cpp:

Functions
static bool	CanProveNotTakenFirstIteration (const BasicBlock ExitBlock, const DominatorTree DT, const Loop *CurLoop)
	Return true if we can prove that the given ExitBlock is not reached on the first iteration of the given loop. More...

static void	collectTransitivePredecessors (const Loop CurLoop, const BasicBlock BB, SmallPtrSetImpl< const BasicBlock *> &Predecessors)
	Collect all blocks from `CurLoop` which lie on all possible paths from the header of `CurLoop` (inclusive) to BB (exclusive) into the set `Predecessors`. More...

	INITIALIZE_PASS_BEGIN (MustExecutePrinter, "print-mustexecute", "Instructions which execute on loop entry", false, true) INITIALIZE_PASS_END(MustExecutePrinter

static bool	isMustExecuteIn (const Instruction &I, Loop L, DominatorTree DT)

Variables
print	mustexecute

print Instructions which execute on loop	entry

print Instructions which execute on loop	false

Function Documentation

◆ CanProveNotTakenFirstIteration()

static bool CanProveNotTakenFirstIteration	(	const BasicBlock *	ExitBlock,
		const DominatorTree *	DT,
		const Loop *	CurLoop
	)

static

Return true if we can prove that the given ExitBlock is not reached on the first iteration of the given loop.

That is, the backedge of the loop must be executed before the ExitBlock is executed in any dynamic execution trace.

Definition at line 110 of file MustExecute.cpp.

References assert(), llvm::LoopBase< BlockT, LoopT >::contains(), llvm::dyn_cast(), llvm::Module::getDataLayout(), llvm::LoopBase< BlockT, LoopT >::getHeader(), llvm::LoopBase< BlockT, LoopT >::getLoopPreheader(), llvm::BasicBlock::getModule(), llvm::User::getOperand(), llvm::BasicBlock::getSinglePredecessor(), llvm::BranchInst::getSuccessor(), and llvm::SimplifyCmpInst().

Referenced by llvm::LoopSafetyInfo::allLoopPathsLeadToBlock().

◆ collectTransitivePredecessors()

static void collectTransitivePredecessors	(	const Loop *	CurLoop,
		const BasicBlock *	BB,
		SmallPtrSetImpl< const BasicBlock *> &	Predecessors
	)

static

Collect all blocks from CurLoop which lie on all possible paths from the header of CurLoop (inclusive) to BB (exclusive) into the set Predecessors.

If BB is the header, Predecessors will be empty.

Definition at line 153 of file MustExecute.cpp.

References assert(), llvm::LoopBase< BlockT, LoopT >::contains(), llvm::SmallVectorBase::empty(), llvm::SmallPtrSetImplBase::empty(), llvm::LoopBase< BlockT, LoopT >::getHeader(), llvm::SmallPtrSetImpl< PtrType >::insert(), llvm::SmallVectorImpl< T >::pop_back_val(), llvm::predecessors(), and llvm::SmallVectorTemplateBase< T >::push_back().

Referenced by llvm::LoopSafetyInfo::allLoopPathsLeadToBlock(), and llvm::ICFLoopSafetyInfo::doesNotWriteMemoryBefore().