#include "llvm/Transforms/Scalar.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
+#include "llvm/IntrinsicInst.h"
#include "llvm/Instructions.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Transforms/Utils/PromoteMemToReg.h"
#include "llvm/Support/CFG.h"
-#include "llvm/Support/Compiler.h"
#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/Debug.h"
#include "llvm/ADT/Statistic.h"
#include <algorithm>
DisablePromotion("disable-licm-promotion", cl::Hidden,
cl::desc("Disable memory promotion in LICM pass"));
-// This feature is currently disabled by default because CodeGen is not yet capable
-// of rematerializing these constants in PIC mode, so it can lead to degraded
-// performance. Compile test/CodeGen/X86/remat-constant.ll with
+// This feature is currently disabled by default because CodeGen is not yet
+// capable of rematerializing these constants in PIC mode, so it can lead to
+// degraded performance. Compile test/CodeGen/X86/remat-constant.ll with
// -relocation-model=pic to see an example of this.
static cl::opt<bool>
EnableLICMConstantMotion("enable-licm-constant-variables", cl::Hidden,
"global variables"));
namespace {
- struct VISIBILITY_HIDDEN LICM : public LoopPass {
+ struct LICM : public LoopPass {
static char ID; // Pass identification, replacement for typeid
LICM() : LoopPass(&ID) {}
AU.addRequired<AliasAnalysis>();
AU.addPreserved<ScalarEvolution>();
AU.addPreserved<DominanceFrontier>();
+ AU.addPreservedID(LoopSimplifyID);
}
bool doFinalization() {
///
void HoistRegion(DomTreeNode *N);
+ // Cleanup debug information (remove stoppoints with no coressponding
+ // instructions).
+ void CleanupDbgInfoRegion(DomTreeNode *N);
+
/// inSubLoop - Little predicate that returns true if the specified basic
/// block is in a subloop of the current one, not the current one itself.
///
char LICM::ID = 0;
static RegisterPass<LICM> X("licm", "Loop Invariant Code Motion");
-LoopPass *llvm::createLICMPass() { return new LICM(); }
+Pass *llvm::createLICMPass() { return new LICM(); }
/// Hoist expressions out of the specified loop. Note, alias info for inner
/// loop is not preserved so it is not a good idea to run LICM multiple
//
SinkRegion(DT->getNode(L->getHeader()));
HoistRegion(DT->getNode(L->getHeader()));
+ CleanupDbgInfoRegion(DT->getNode(L->getHeader()));
// Now that all loop invariants have been removed from the loop, promote any
// memory references to scalars that we can...
}
}
+void LICM::CleanupDbgInfoRegion(DomTreeNode *N) {
+ BasicBlock *BB = N->getBlock();
+
+ // If this subregion is not in the top level loop at all, exit.
+ if (!CurLoop->contains(BB)) return;
+
+ // We are processing blocks in reverse dfo, so process children first...
+ const std::vector<DomTreeNode*> &Children = N->getChildren();
+ for (unsigned i = 0, e = Children.size(); i != e; ++i)
+ CleanupDbgInfoRegion(Children[i]);
+
+ // Only need to process the contents of this block if it is not part of a
+ // subloop (which would already have been processed).
+ if (inSubLoop(BB)) return;
+
+ // We modify the basicblock, so don't cache end()
+ for (BasicBlock::iterator I=BB->begin(); I != BB->end();) {
+ Instruction *Last = 0;
+ // Remove consecutive dbgstoppoints, leave only last
+ do {
+ if (Last) {
+ Last->eraseFromParent();
+ Changed = true;
+ }
+ Last = I;
+ ++I;
+ } while (isa<DbgStopPointInst>(Last) && isa<DbgStopPointInst>(I));
+ }
+}
/// HoistRegion - Walk the specified region of the CFG (defined by all blocks
/// dominated by the specified block, and that are in the current loop) in depth
// Don't hoist loads which have may-aliased stores in loop.
unsigned Size = 0;
if (LI->getType()->isSized())
- Size = AA->getTargetData().getTypeStoreSize(LI->getType());
+ Size = AA->getTypeStoreSize(LI->getType());
return !pointerInvalidatedByLoop(LI->getOperand(0), Size);
} else if (CallInst *CI = dyn_cast<CallInst>(&I)) {
+ if (isa<DbgStopPointInst>(CI)) {
+ // Don't hoist/sink dbgstoppoints, we handle them separately
+ return false;
+ }
// Handle obvious cases efficiently.
AliasAnalysis::ModRefBehavior Behavior = AA->getModRefBehavior(CI);
if (Behavior == AliasAnalysis::DoesNotAccessMemory)
/// position, and may either delete it or move it to outside of the loop.
///
void LICM::sink(Instruction &I) {
- DOUT << "LICM sinking instruction: " << I;
+ DEBUG(errs() << "LICM sinking instruction: " << I);
SmallVector<BasicBlock*, 8> ExitBlocks;
CurLoop->getExitBlocks(ExitBlocks);
// Move the instruction to the start of the exit block, after any PHI
// nodes in it.
I.removeFromParent();
-
BasicBlock::iterator InsertPt = ExitBlocks[0]->getFirstNonPHI();
ExitBlocks[0]->getInstList().insert(InsertPt, &I);
}
// Firstly, we create a stack object to hold the value...
AllocaInst *AI = 0;
- if (I.getType() != Type::VoidTy) {
+ if (I.getType() != Type::getVoidTy(I.getContext())) {
AI = new AllocaInst(I.getType(), 0, I.getName(),
I.getParent()->getParent()->getEntryBlock().begin());
CurAST->add(AI);
if (AI) {
std::vector<AllocaInst*> Allocas;
Allocas.push_back(AI);
- PromoteMemToReg(Allocas, *DT, *DF, CurAST);
+ PromoteMemToReg(Allocas, *DT, *DF, AI->getContext(), CurAST);
}
}
}
/// that is safe to hoist, this instruction is called to do the dirty work.
///
void LICM::hoist(Instruction &I) {
- DOUT << "LICM hoisting to " << Preheader->getName() << ": " << I;
+ DEBUG(errs() << "LICM hoisting to " << Preheader->getName() << ": " << I);
// Remove the instruction from its current basic block... but don't delete the
// instruction.
///
bool LICM::isSafeToExecuteUnconditionally(Instruction &Inst) {
// If it is not a trapping instruction, it is always safe to hoist.
- if (!Inst.isTrapping()) return true;
+ if (Inst.isSafeToSpeculativelyExecute())
+ return true;
// Otherwise we have to check to make sure that the instruction dominates all
// of the exit blocks. If it doesn't, then there is a path out of the loop
if (Inst.getParent() == CurLoop->getHeader())
return true;
- // It's always safe to load from a global or alloca.
- if (isa<LoadInst>(Inst))
- if (isa<AllocationInst>(Inst.getOperand(0)) ||
- isa<GlobalVariable>(Inst.getOperand(0)))
- return true;
-
// Get the exit blocks for the current loop.
SmallVector<BasicBlock*, 8> ExitBlocks;
CurLoop->getExitBlocks(ExitBlocks);
PromotedAllocas.reserve(PromotedValues.size());
for (unsigned i = 0, e = PromotedValues.size(); i != e; ++i)
PromotedAllocas.push_back(PromotedValues[i].first);
- PromoteMemToReg(PromotedAllocas, *DT, *DF, CurAST);
+ PromoteMemToReg(PromotedAllocas, *DT, *DF, Preheader->getContext(), CurAST);
}
/// FindPromotableValuesInLoop - Check the current loop for stores to definite
std::map<Value*, AllocaInst*> &ValueToAllocaMap) {
Instruction *FnStart = CurLoop->getHeader()->getParent()->begin()->begin();
- SmallVector<BasicBlock*, 4> ExitingBlocks;
- CurLoop->getExitingBlocks(ExitingBlocks);
-
// Loop over all of the alias sets in the tracker object.
for (AliasSetTracker::iterator I = CurAST->begin(), E = CurAST->end();
I != E; ++I) {
// set, if the pointer is loop invariant, and if we are not eliminating any
// volatile loads or stores.
if (AS.isForwardingAliasSet() || !AS.isMod() || !AS.isMustAlias() ||
- AS.isVolatile() || !CurLoop->isLoopInvariant(AS.begin()->first))
+ AS.isVolatile() || !CurLoop->isLoopInvariant(AS.begin()->getValue()))
continue;
assert(!AS.empty() &&
"Must alias set should have at least one pointer element in it!");
- Value *V = AS.begin()->first;
+ Value *V = AS.begin()->getValue();
// Check that all of the pointers in the alias set have the same type. We
// cannot (yet) promote a memory location that is loaded and stored in
{
bool PointerOk = true;
for (AliasSet::iterator I = AS.begin(), E = AS.end(); I != E; ++I)
- if (V->getType() != I->first->getType()) {
+ if (V->getType() != I->getValue()->getType()) {
PointerOk = false;
break;
}
CurAST->copyValue(V, AI);
for (AliasSet::iterator I = AS.begin(), E = AS.end(); I != E; ++I)
- ValueToAllocaMap.insert(std::make_pair(I->first, AI));
+ ValueToAllocaMap.insert(std::make_pair(I->getValue(), AI));
- DOUT << "LICM: Promoting value: " << *V << "\n";
+ DEBUG(errs() << "LICM: Promoting value: " << *V << "\n");
}
}