#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/Instructions.h"
+#include "llvm/LLVMContext.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <set>
using namespace llvm;
if (isa<Constant>(Cond)) return 0;
// TODO: Handle: br (VARIANT|INVARIANT).
- // TODO: Hoist simple expressions out of loops.
- if (L->isLoopInvariant(Cond)) return Cond;
+
+ // Hoist simple values out.
+ if (L->makeLoopInvariant(Cond, Changed))
+ return Cond;
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(Cond))
if (BO->getOpcode() == Instruction::And ||
bool LoopUnswitch::runOnLoop(Loop *L, LPPassManager &LPM_Ref) {
LI = &getAnalysis<LoopInfo>();
LPM = &LPM_Ref;
- DF = getAnalysisToUpdate<DominanceFrontier>();
- DT = getAnalysisToUpdate<DominatorTree>();
+ DF = getAnalysisIfAvailable<DominanceFrontier>();
+ DT = getAnalysisIfAvailable<DominatorTree>();
currentLoop = L;
Function *F = currentLoop->getHeader()->getParent();
bool Changed = false;
/// and profitable.
bool LoopUnswitch::processCurrentLoop() {
bool Changed = false;
+ LLVMContext &Context = currentLoop->getHeader()->getContext();
// Loop over all of the basic blocks in the loop. If we find an interior
// block that is branching on a loop-invariant condition, we can unswitch this
Value *LoopCond = FindLIVLoopCondition(BI->getCondition(),
currentLoop, Changed);
if (LoopCond && UnswitchIfProfitable(LoopCond,
- ConstantInt::getTrue())) {
+ Context.getTrue())) {
++NumBranches;
return true;
}
Value *LoopCond = FindLIVLoopCondition(SI->getCondition(),
currentLoop, Changed);
if (LoopCond && UnswitchIfProfitable(LoopCond,
- ConstantInt::getTrue())) {
+ Context.getTrue())) {
++NumSelects;
return true;
}
// Okay, everything after this looks good, check to make sure that this block
// doesn't include any side effects.
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
- if (I->mayWriteToMemory())
+ if (I->mayHaveSideEffects())
return false;
return true;
BasicBlock **LoopExit) {
BasicBlock *Header = currentLoop->getHeader();
TerminatorInst *HeaderTerm = Header->getTerminator();
+ LLVMContext &Context = Header->getContext();
BasicBlock *LoopExitBB = 0;
if (BranchInst *BI = dyn_cast<BranchInst>(HeaderTerm)) {
// this.
if ((LoopExitBB = isTrivialLoopExitBlock(currentLoop,
BI->getSuccessor(0)))) {
- if (Val) *Val = ConstantInt::getTrue();
+ if (Val) *Val = Context.getTrue();
} else if ((LoopExitBB = isTrivialLoopExitBlock(currentLoop,
BI->getSuccessor(1)))) {
- if (Val) *Val = ConstantInt::getFalse();
+ if (Val) *Val = Context.getFalse();
}
} else if (SwitchInst *SI = dyn_cast<SwitchInst>(HeaderTerm)) {
// If this isn't a switch on Cond, we can't handle it.
// part of the loop that the code *would* execute. We already checked the
// tail, check the header now.
for (BasicBlock::iterator I = Header->begin(), E = Header->end(); I != E; ++I)
- if (I->mayWriteToMemory())
+ if (I->mayHaveSideEffects())
return false;
return true;
}
initLoopData();
Function *F = loopHeader->getParent();
- // Do not unswitch if the function is optimized for size.
- if (!F->isDeclaration() && F->hasFnAttr(Attribute::OptimizeForSize))
- return false;
// Check to see if it would be profitable to unswitch current loop.
unsigned Cost = getLoopUnswitchCost(LoopCond);
// Do not do non-trivial unswitch while optimizing for size.
if (Cost && OptimizeForSize)
return false;
+ if (Cost && !F->isDeclaration() && F->hasFnAttr(Attribute::OptimizeForSize))
+ return false;
if (Cost > Threshold) {
// FIXME: this should estimate growth by the amount of code shared by the
// resultant unswitched loops.
//
- DOUT << "NOT unswitching loop %"
- << currentLoop->getHeader()->getName() << ", cost too high: "
- << currentLoop->getBlocks().size() << "\n";
+ DEBUG(errs() << "NOT unswitching loop %"
+ << currentLoop->getHeader()->getName() << ", cost too high: "
+ << currentLoop->getBlocks().size() << "\n");
return false;
}
// code is the true version and the new code is the false version.
Value *BranchVal = LIC;
if (!isa<ConstantInt>(Val) || Val->getType() != Type::Int1Ty)
- BranchVal = new ICmpInst(ICmpInst::ICMP_EQ, LIC, Val, "tmp", InsertPt);
- else if (Val != ConstantInt::getTrue())
+ BranchVal = new ICmpInst(InsertPt, ICmpInst::ICMP_EQ, LIC, Val, "tmp");
+ else if (Val != Val->getContext().getTrue())
// We want to enter the new loop when the condition is true.
std::swap(TrueDest, FalseDest);
void LoopUnswitch::UnswitchTrivialCondition(Loop *L, Value *Cond,
Constant *Val,
BasicBlock *ExitBlock) {
- DOUT << "loop-unswitch: Trivial-Unswitch loop %"
- << loopHeader->getName() << " [" << L->getBlocks().size()
- << " blocks] in Function " << L->getHeader()->getParent()->getName()
- << " on cond: " << *Val << " == " << *Cond << "\n";
+ DEBUG(errs() << "loop-unswitch: Trivial-Unswitch loop %"
+ << loopHeader->getName() << " [" << L->getBlocks().size()
+ << " blocks] in Function " << L->getHeader()->getParent()->getName()
+ << " on cond: " << *Val << " == " << *Cond << "\n");
// First step, split the preheader, so that we know that there is a safe place
// to insert the conditional branch. We will change loopPreheader to have a
BasicBlock* EndBlock;
if (NewExitBlock->getSinglePredecessor() == ExitBlock) {
EndBlock = NewExitBlock;
- NewExitBlock = EndBlock->getSinglePredecessor();;
+ NewExitBlock = EndBlock->getSinglePredecessor();
} else {
EndBlock = ExitBlock;
}
void LoopUnswitch::UnswitchNontrivialCondition(Value *LIC, Constant *Val,
Loop *L) {
Function *F = loopHeader->getParent();
- DOUT << "loop-unswitch: Unswitching loop %"
- << loopHeader->getName() << " [" << L->getBlocks().size()
- << " blocks] in Function " << F->getName()
- << " when '" << *Val << "' == " << *LIC << "\n";
+ DEBUG(errs() << "loop-unswitch: Unswitching loop %"
+ << loopHeader->getName() << " [" << L->getBlocks().size()
+ << " blocks] in Function " << F->getName()
+ << " when '" << *Val << "' == " << *LIC << "\n");
LoopBlocks.clear();
NewBlocks.clear();
// Anything that uses the instructions in this basic block should have their
// uses replaced with undefs.
if (!I->use_empty())
- I->replaceAllUsesWith(UndefValue::get(I->getType()));
+ I->replaceAllUsesWith(I->getContext().getUndef(I->getType()));
}
// If this is the edge to the header block for a loop, remove the loop and
// selects, switches.
std::vector<User*> Users(LIC->use_begin(), LIC->use_end());
std::vector<Instruction*> Worklist;
+ LLVMContext &Context = Val->getContext();
+
// If we know that LIC == Val, or that LIC == NotVal, just replace uses of LIC
// in the loop with the appropriate one directly.
Instruction* OldTerm = Old->getTerminator();
BranchInst::Create(Split, SISucc,
- ConstantInt::getTrue(), OldTerm);
+ Context.getTrue(), OldTerm);
LPM->deleteSimpleAnalysisValue(Old->getTerminator(), L);
Old->getTerminator()->eraseFromParent();
Worklist.pop_back();
// Simple constant folding.
- if (Constant *C = ConstantFoldInstruction(I)) {
+ if (Constant *C = ConstantFoldInstruction(I, I->getContext())) {
ReplaceUsesOfWith(I, C, Worklist, L, LPM);
continue;
}
if (!SinglePred) continue; // Nothing to do.
assert(SinglePred == Pred && "CFG broken");
- DOUT << "Merging blocks: " << Pred->getName() << " <- "
- << Succ->getName() << "\n";
+ DEBUG(errs() << "Merging blocks: " << Pred->getName() << " <- "
+ << Succ->getName() << "\n");
// Resolve any single entry PHI nodes in Succ.
while (PHINode *PN = dyn_cast<PHINode>(Succ->begin()))
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