Changes in directory llvm/lib/Transforms/Scalar:
LoopUnroll.cpp updated: 1.43 -> 1.44 --- Log message: Fix Transforms/LoopUnroll/2007-05-05-UnrollMiscomp.ll and PR1385: http://llvm.org/PR1385 . If we have a LCSSA, only modify the input value if the inval was defined by an instruction in the loop. If defined by something before the loop, it is still valid. --- Diffs of the changes: (+17 -18) LoopUnroll.cpp | 35 +++++++++++++++++------------------ 1 files changed, 17 insertions(+), 18 deletions(-) Index: llvm/lib/Transforms/Scalar/LoopUnroll.cpp diff -u llvm/lib/Transforms/Scalar/LoopUnroll.cpp:1.43 llvm/lib/Transforms/Scalar/LoopUnroll.cpp:1.44 --- llvm/lib/Transforms/Scalar/LoopUnroll.cpp:1.43 Sat May 5 13:36:36 2007 +++ llvm/lib/Transforms/Scalar/LoopUnroll.cpp Sat May 5 13:49:57 2007 @@ -203,7 +203,8 @@ // For the first iteration of the loop, we should use the precloned values for // PHI nodes. Insert associations now. - DenseMap<const Value*, Value*> LastValueMap; + typedef DenseMap<const Value*, Value*> ValueMapTy; + ValueMapTy LastValueMap; std::vector<PHINode*> OrigPHINode; for (BasicBlock::iterator I = Header->begin(); isa<PHINode>(I); ++I) { PHINode *PN = cast<PHINode>(I); @@ -231,7 +232,7 @@ for (std::vector<BasicBlock*>::iterator BB = LoopBlocks.begin(), E = LoopBlocks.end(); BB != E; ++BB) { - DenseMap<const Value*, Value*> ValueMap; + ValueMapTy ValueMap; BasicBlock *New = CloneBasicBlock(*BB, ValueMap, SuffixBuffer); Header->getParent()->getBasicBlockList().push_back(New); @@ -250,8 +251,8 @@ // Update our running map of newest clones LastValueMap[*BB] = New; - for (DenseMap<const Value*, Value*>::iterator VI = ValueMap.begin(), - VE = ValueMap.end(); VI != VE; ++VI) + for (ValueMapTy::iterator VI = ValueMap.begin(), VE = ValueMap.end(); + VI != VE; ++VI) LastValueMap[VI->first] = VI->second; L->addBasicBlockToLoop(New, *LI); @@ -291,30 +292,28 @@ } - - // Update PHI nodes that reference the final latch block + // The latch block exits the loop. If there are any PHI nodes in the + // successor blocks, update them to use the appropriate values computed as the + // last iteration of the loop. if (TripCount > 1) { SmallPtrSet<PHINode*, 8> Users; for (Value::use_iterator UI = LatchBlock->use_begin(), UE = LatchBlock->use_end(); UI != UE; ++UI) if (PHINode* phi = dyn_cast<PHINode>(*UI)) Users.insert(phi); - + + BasicBlock *LastIterationBB = cast<BasicBlock>(LastValueMap[LatchBlock]); for (SmallPtrSet<PHINode*,8>::iterator SI = Users.begin(), SE = Users.end(); SI != SE; ++SI) { PHINode *PN = *SI; - Value* InVal = PN->getIncomingValueForBlock(LatchBlock); - if (isa<Instruction>(InVal)) - InVal = LastValueMap[InVal]; - PN->removeIncomingValue(LatchBlock, false); - if (InVal) - PN->addIncoming(InVal, cast<BasicBlock>(LastValueMap[LatchBlock])); - if (PN->getNumIncomingValues() == 0) { - // Remove this phi node. - // If anyone is using this PHI, make them use a dummy value instead... - PN->replaceAllUsesWith(UndefValue::get(PN->getType())); - PN->eraseFromParent(); + Value *InVal = PN->removeIncomingValue(LatchBlock, false); + // If this value was defined in the loop, take the value defined by the + // last iteration of the loop. + if (Instruction *InValI = dyn_cast<Instruction>(InVal)) { + if (L->contains(InValI->getParent())) + InVal = LastValueMap[InVal]; } + PN->addIncoming(InVal, LastIterationBB); } } _______________________________________________ llvm-commits mailing list llvm-commits@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
