LoopRotation.cpp File Reference

#include "llvm/Transforms/Scalar.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AssumptionTracker.h"
#include "llvm/Analysis/CodeMetrics.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/CFG.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/SSAUpdater.h"
#include "llvm/Transforms/Utils/ValueMapper.h"

Include dependency graph for LoopRotation.cpp:

Go to the source code of this file.

Defines
#define	DEBUG_TYPE   "loop-rotate"
Functions
	STATISTIC (NumRotated,"Number of loops rotated")
static void	RewriteUsesOfClonedInstructions (BasicBlock *OrigHeader, BasicBlock *OrigPreheader, ValueToValueMapTy &ValueMap)
static bool	shouldSpeculateInstrs (BasicBlock::iterator Begin, BasicBlock::iterator End)
Variables
static cl::opt< unsigned >	DefaultRotationThreshold ("rotation-max-header-size", cl::init(16), cl::Hidden, cl::desc("The default maximum header size for automatic loop rotation"))

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Define Documentation

#define DEBUG_TYPE   "loop-rotate"

Definition at line 35 of file LoopRotation.cpp.

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Function Documentation

static void RewriteUsesOfClonedInstructions	(	BasicBlock *	OrigHeader,
		BasicBlock *	OrigPreheader,
		ValueToValueMapTy &	ValueMap
	)		[static]

RewriteUsesOfClonedInstructions - We just cloned the instructions from the old header into the preheader. If there were uses of the values produced by these instruction that were outside of the loop, we have to insert PHI nodes to merge the two values. Do this now.

Definition at line 131 of file LoopRotation.cpp.

References llvm::SSAUpdater::AddAvailableValue(), llvm::BasicBlock::begin(), llvm::dyn_cast(), llvm::BasicBlock::end(), llvm::PHINode::getBasicBlockIndex(), llvm::Value::getName(), llvm::Instruction::getParent(), llvm::Value::getType(), llvm::Use::getUser(), I, llvm::SSAUpdater::Initialize(), llvm::PHINode::removeIncomingValue(), llvm::SSAUpdater::RewriteUse(), llvm::Value::use_begin(), llvm::Value::use_empty(), and llvm::Value::use_end().

static bool shouldSpeculateInstrs	(	BasicBlock::iterator	Begin,
		BasicBlock::iterator	End
	)		[static]

Determine whether the instructions in this range may be safely and cheaply speculated. This is not an important enough situation to develop complex heuristics. We handle a single arithmetic instruction along with any type conversions.

Definition at line 196 of file LoopRotation.cpp.

References llvm::APIntOps::And(), I, llvm::isSafeToSpeculativelyExecute(), llvm::LShr, llvm::APIntOps::Or(), llvm::SExt, llvm::Trunc, and llvm::APIntOps::Xor().

STATISTIC	(	NumRotated	,
		"Number of loops rotated"
	)

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Variable Documentation

cl::opt<unsigned> DefaultRotationThreshold("rotation-max-header-size", cl::init(16), cl::Hidden, cl::desc("The default maximum header size for automatic loop rotation")) [static]