Changes in directory llvm/lib/Transforms/Scalar:
InstructionCombining.cpp updated: 1.678 -> 1.679
---
Log message:
switch AddReachableCodeToWorklist from being recursive to being iterative.
---
Diffs of the changes: (+54 -46)
InstructionCombining.cpp | 100 +++++++++++++++++++++++++----------------------
1 files changed, 54 insertions(+), 46 deletions(-)
Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp
diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.678
llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.679
--- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.678 Fri Mar 23
13:46:34 2007
+++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp Fri Mar 23 14:17:18 2007
@@ -9989,58 +9989,66 @@
SmallPtrSet<BasicBlock*, 64> &Visited,
InstCombiner &IC,
const TargetData *TD) {
- // We have now visited this block! If we've already been here, bail out.
- if (!Visited.insert(BB)) return;
-
- for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ) {
- Instruction *Inst = BBI++;
+ std::vector<BasicBlock*> Worklist;
+ Worklist.push_back(BB);
+
+ while (!Worklist.empty()) {
+ BB = Worklist.back();
+ Worklist.pop_back();
- // DCE instruction if trivially dead.
- if (isInstructionTriviallyDead(Inst)) {
- ++NumDeadInst;
- DOUT << "IC: DCE: " << *Inst;
- Inst->eraseFromParent();
- continue;
- }
+ // We have now visited this block! If we've already been here, ignore it.
+ if (!Visited.insert(BB)) continue;
- // ConstantProp instruction if trivially constant.
- if (Constant *C = ConstantFoldInstruction(Inst, TD)) {
- DOUT << "IC: ConstFold to: " << *C << " from: " << *Inst;
- Inst->replaceAllUsesWith(C);
- ++NumConstProp;
- Inst->eraseFromParent();
- continue;
+ for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E; ) {
+ Instruction *Inst = BBI++;
+
+ // DCE instruction if trivially dead.
+ if (isInstructionTriviallyDead(Inst)) {
+ ++NumDeadInst;
+ DOUT << "IC: DCE: " << *Inst;
+ Inst->eraseFromParent();
+ continue;
+ }
+
+ // ConstantProp instruction if trivially constant.
+ if (Constant *C = ConstantFoldInstruction(Inst, TD)) {
+ DOUT << "IC: ConstFold to: " << *C << " from: " << *Inst;
+ Inst->replaceAllUsesWith(C);
+ ++NumConstProp;
+ Inst->eraseFromParent();
+ continue;
+ }
+
+ IC.AddToWorkList(Inst);
}
-
- IC.AddToWorkList(Inst);
- }
- // Recursively visit successors. If this is a branch or switch on a
constant,
- // only visit the reachable successor.
- TerminatorInst *TI = BB->getTerminator();
- if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
- if (BI->isConditional() && isa<ConstantInt>(BI->getCondition())) {
- bool CondVal = cast<ConstantInt>(BI->getCondition())->getZExtValue();
- AddReachableCodeToWorklist(BI->getSuccessor(!CondVal), Visited, IC, TD);
- return;
- }
- } else if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) {
- if (ConstantInt *Cond = dyn_cast<ConstantInt>(SI->getCondition())) {
- // See if this is an explicit destination.
- for (unsigned i = 1, e = SI->getNumSuccessors(); i != e; ++i)
- if (SI->getCaseValue(i) == Cond) {
- AddReachableCodeToWorklist(SI->getSuccessor(i), Visited, IC, TD);
- return;
- }
-
- // Otherwise it is the default destination.
- AddReachableCodeToWorklist(SI->getSuccessor(0), Visited, IC, TD);
- return;
+ // Recursively visit successors. If this is a branch or switch on a
+ // constant, only visit the reachable successor.
+ TerminatorInst *TI = BB->getTerminator();
+ if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
+ if (BI->isConditional() && isa<ConstantInt>(BI->getCondition())) {
+ bool CondVal = cast<ConstantInt>(BI->getCondition())->getZExtValue();
+ Worklist.push_back(BI->getSuccessor(!CondVal));
+ continue;
+ }
+ } else if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) {
+ if (ConstantInt *Cond = dyn_cast<ConstantInt>(SI->getCondition())) {
+ // See if this is an explicit destination.
+ for (unsigned i = 1, e = SI->getNumSuccessors(); i != e; ++i)
+ if (SI->getCaseValue(i) == Cond) {
+ Worklist.push_back(SI->getSuccessor(i));
+ continue;
+ }
+
+ // Otherwise it is the default destination.
+ Worklist.push_back(SI->getSuccessor(0));
+ continue;
+ }
}
+
+ for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
+ Worklist.push_back(TI->getSuccessor(i));
}
-
- for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
- AddReachableCodeToWorklist(TI->getSuccessor(i), Visited, IC, TD);
}
bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) {
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