ScalarEvolutionNormalization.cpp File Reference

#include "llvm/IR/Dominators.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/ScalarEvolutionExpressions.h"
#include "llvm/Analysis/ScalarEvolutionNormalization.h"

Include dependency graph for ScalarEvolutionNormalization.cpp:

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Functions
static bool	IVUseShouldUsePostIncValue (Instruction *User, Value *Operand, const Loop *L, DominatorTree *DT)

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Function Documentation

static bool IVUseShouldUsePostIncValue	(	Instruction *	User,
		Value *	Operand,
		const Loop *	L,
		DominatorTree *	DT
	)		[static]

IVUseShouldUsePostIncValue - We have discovered a "User" of an IV expression and now we need to decide whether the user should use the preinc or post-inc value. If this user should use the post-inc version of the IV, return true.

Choosing wrong here can break dominance properties (if we choose to use the post-inc value when we cannot) or it can end up adding extra live-ranges to the loop, resulting in reg-reg copies (if we use the pre-inc value when we should use the post-inc value).

Definition at line 29 of file ScalarEvolutionNormalization.cpp.

References llvm::LoopBase< BlockT, LoopT >::contains(), llvm::DominatorTree::dominates(), llvm::dyn_cast(), llvm::PHINode::getIncomingBlock(), llvm::PHINode::getIncomingValue(), llvm::LoopBase< BlockT, LoopT >::getLoopLatch(), llvm::PHINode::getNumIncomingValues(), and llvm::Instruction::getParent().