LoopUnrollRuntime.cpp File Reference

#include "llvm/Transforms/Utils/UnrollLoop.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/LoopIterator.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/ScalarEvolutionExpander.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include <algorithm>

Include dependency graph for LoopUnrollRuntime.cpp:

Go to the source code of this file.

Defines
#define	DEBUG_TYPE   "loop-unroll"
Functions
	STATISTIC (NumRuntimeUnrolled,"Number of loops unrolled with run-time trip counts")
static void	ConnectProlog (Loop *L, Value *TripCount, unsigned Count, BasicBlock *LastPrologBB, BasicBlock *PrologEnd, BasicBlock *OrigPH, BasicBlock *NewPH, ValueToValueMapTy &LVMap, Pass *P)
static void	CloneLoopBlocks (Loop *L, bool FirstCopy, BasicBlock *InsertTop, BasicBlock *InsertBot, std::vector< BasicBlock * > &NewBlocks, LoopBlocksDFS &LoopBlocks, ValueToValueMapTy &VMap, ValueToValueMapTy &LVMap, LoopInfo *LI)

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Define Documentation

#define DEBUG_TYPE   "loop-unroll"

Definition at line 39 of file LoopUnrollRuntime.cpp.

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Function Documentation

static void CloneLoopBlocks	(	Loop *	L,
		bool	FirstCopy,
		BasicBlock *	InsertTop,
		BasicBlock *	InsertBot,
		std::vector< BasicBlock * > &	NewBlocks,
		LoopBlocksDFS &	LoopBlocks,
		ValueToValueMapTy &	VMap,
		ValueToValueMapTy &	LVMap,
		LoopInfo *	LI
	)		[static]

Create a clone of the blocks in a loop and connect them together. This function doesn't create a clone of the loop structure.

There are two value maps that are defined and used. VMap is for the values in the current loop instance. LVMap contains the values from the last loop instance. We need the LVMap values to update the initial values for the current loop instance.

Definition at line 137 of file LoopUnrollRuntime.cpp.

References llvm::ValueMap< KeyT, ValueT, Config >::begin(), llvm::BasicBlock::begin(), llvm::LoopBlocksDFS::beginRPO(), llvm::CloneBasicBlock(), llvm::LoopBase< BlockT, LoopT >::contains(), llvm::BranchInst::Create(), llvm::ValueMap< KeyT, ValueT, Config >::end(), llvm::LoopBlocksDFS::endRPO(), llvm::ValueMap< KeyT, ValueT, Config >::erase(), llvm::iplist< NodeTy, Traits >::erase(), llvm::Instruction::eraseFromParent(), F(), llvm::LoopInfo::getBase(), llvm::PHINode::getBasicBlockIndex(), llvm::LoopBase< BlockT, LoopT >::getHeader(), llvm::PHINode::getIncomingValue(), llvm::PHINode::getIncomingValueForBlock(), llvm::BasicBlock::getInstList(), llvm::LoopBase< BlockT, LoopT >::getLoopLatch(), llvm::LoopBase< BlockT, LoopT >::getLoopPreheader(), llvm::BasicBlock::getParent(), llvm::LoopBase< BlockT, LoopT >::getParentLoop(), llvm::BasicBlock::getTerminator(), I, llvm::PHINode::setIncomingBlock(), llvm::PHINode::setIncomingValue(), and llvm::TerminatorInst::setSuccessor().

Referenced by llvm::UnrollRuntimeLoopProlog().

static void ConnectProlog	(	Loop *	L,
		Value *	TripCount,
		unsigned	Count,
		BasicBlock *	LastPrologBB,
		BasicBlock *	PrologEnd,
		BasicBlock *	OrigPH,
		BasicBlock *	NewPH,
		ValueToValueMapTy &	LVMap,
		Pass *	P
	)		[static]

Connect the unrolling prolog code to the original loop. The unrolling prolog code contains code to execute the 'extra' iterations if the run-time trip count modulo the unroll count is non-zero.

This function performs the following:

• Create PHI nodes at prolog end block to combine values that exit the prolog code and jump around the prolog.
• Add a PHI operand to a PHI node at the loop exit block for values that exit the prolog and go around the loop.
• Branch around the original loop if the trip count is less than the unroll factor.

Definition at line 57 of file LoopUnrollRuntime.cpp.

References llvm::PHINode::addIncoming(), llvm::LoopBase< BlockT, LoopT >::contains(), llvm::PHINode::Create(), llvm::BranchInst::Create(), llvm::dyn_cast(), llvm::Instruction::eraseFromParent(), llvm::ConstantInt::get(), llvm::PHINode::getBasicBlockIndex(), llvm::PHINode::getIncomingValueForBlock(), llvm::LoopBase< BlockT, LoopT >::getLoopLatch(), llvm::Value::getName(), llvm::Constant::getNullValue(), llvm::BasicBlock::getTerminator(), llvm::Value::getType(), llvm::Loop::getUniqueExitBlock(), I, llvm::CmpInst::ICMP_ULT, llvm::BasicBlock::isLandingPad(), llvm::pred_begin(), llvm::pred_end(), llvm::PHINode::setIncomingValue(), llvm::SplitBlockPredecessors(), llvm::SplitLandingPadPredecessors(), llvm::succ_begin(), and llvm::succ_end().

Referenced by llvm::UnrollRuntimeLoopProlog().

STATISTIC	(	NumRuntimeUnrolled	,
		"Number of loops unrolled with run-time trip counts"
	)