#include "llvm/Pass.h"
#include "llvm/Type.h"
#include "llvm/Support/CFG.h"
+#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/SmallPtrSet.h"
#include <map>
cl::init(1), cl::Hidden);
namespace {
- class VISIBILITY_HIDDEN TailDup : public FunctionPass {
+ class TailDup : public FunctionPass {
bool runOnFunction(Function &F);
public:
static char ID; // Pass identification, replacement for typeid
- TailDup() : FunctionPass((intptr_t)&ID) {}
+ TailDup() : FunctionPass(&ID) {}
private:
inline bool shouldEliminateUnconditionalBranch(TerminatorInst *, unsigned);
// other instructions.
if (isa<CallInst>(I) || isa<InvokeInst>(I)) return false;
- // Allso alloca and malloc.
- if (isa<AllocationInst>(I)) return false;
+ // Also alloca and malloc.
+ if (isa<AllocaInst>(I)) return false;
// Some vector instructions can expand into a number of instructions.
if (isa<ShuffleVectorInst>(I) || isa<ExtractElementInst>(I) ||
BasicBlock *DestBlock = Branch->getSuccessor(0);
assert(SourceBlock != DestBlock && "Our predicate is broken!");
- DOUT << "TailDuplication[" << SourceBlock->getParent()->getName()
- << "]: Eliminating branch: " << *Branch;
+ DEBUG(dbgs() << "TailDuplication[" << SourceBlock->getParent()->getName()
+ << "]: Eliminating branch: " << *Branch);
// See if we can avoid duplicating code by moving it up to a dominator of both
// blocks.
if (BasicBlock *DomBlock = FindObviousSharedDomOf(SourceBlock, DestBlock)) {
- DOUT << "Found shared dominator: " << DomBlock->getName() << "\n";
+ DEBUG(dbgs() << "Found shared dominator: " << DomBlock->getName() << "\n");
// If there are non-phi instructions in DestBlock that have no operands
// defined in DestBlock, and if the instruction has no side effects, we can
while (!isa<TerminatorInst>(BBI)) {
Instruction *I = BBI++;
- bool CanHoist = !I->isTrapping() && !I->mayWriteToMemory();
+ bool CanHoist = I->isSafeToSpeculativelyExecute() &&
+ !I->mayReadFromMemory();
if (CanHoist) {
for (unsigned op = 0, e = I->getNumOperands(); op != e; ++op)
if (Instruction *OpI = dyn_cast<Instruction>(I->getOperand(op)))
// Remove from DestBlock, move right before the term in DomBlock.
DestBlock->getInstList().remove(I);
DomBlock->getInstList().insert(DomBlock->getTerminator(), I);
- DOUT << "Hoisted: " << *I;
+ DEBUG(dbgs() << "Hoisted: " << *I);
}
}
}
//
BI = Branch; ++BI; // Get an iterator to the first new instruction
for (; BI != SourceBlock->end(); ++BI)
- for (unsigned i = 0, e = BI->getNumOperands(); i != e; ++i)
- if (Value *Remapped = ValueMapping[BI->getOperand(i)])
- BI->setOperand(i, Remapped);
+ for (unsigned i = 0, e = BI->getNumOperands(); i != e; ++i) {
+ std::map<Value*, Value*>::const_iterator I =
+ ValueMapping.find(BI->getOperand(i));
+ if (I != ValueMapping.end())
+ BI->setOperand(i, I->second);
+ }
// Next we check to see if any of the successors of DestBlock had PHI nodes.
// If so, we need to add entries to the PHI nodes for SourceBlock now.
Value *IV = PN->getIncomingValueForBlock(DestBlock);
// Remap the value if necessary...
- if (Value *MappedIV = ValueMapping[IV])
- IV = MappedIV;
+ std::map<Value*, Value*>::const_iterator I = ValueMapping.find(IV);
+ if (I != ValueMapping.end())
+ IV = I->second;
PN->addIncoming(IV, SourceBlock);
}
}
// instructions one last time, constant propagating and DCE'ing them, because
// they may not be needed anymore.
//
- if (HadPHINodes)
- while (BI != SourceBlock->end())
- if (!dceInstruction(BI) && !doConstantPropagation(BI))
- ++BI;
+ if (HadPHINodes) {
+ while (BI != SourceBlock->end()) {
+ Instruction *Inst = BI++;
+ if (isInstructionTriviallyDead(Inst))
+ Inst->eraseFromParent();
+ else if (Constant *C = ConstantFoldInstruction(Inst)) {
+ Inst->replaceAllUsesWith(C);
+ Inst->eraseFromParent();
+ }
+ }
+ }
++NumEliminated; // We just killed a branch!
}