Changes in directory llvm/lib/Transforms/Scalar:
InstructionCombining.cpp updated: 1.742 -> 1.743 --- Log message: Implement PR1201: http://llvm.org/PR1201 and test/Transforms/InstCombine/malloc-free-delete.ll --- Diffs of the changes: (+23 -8) InstructionCombining.cpp | 31 +++++++++++++++++++++++-------- 1 files changed, 23 insertions(+), 8 deletions(-) Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.742 llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.743 --- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.742 Wed Apr 11 01:57:46 2007 +++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp Fri Apr 13 19:20:02 2007 @@ -8367,13 +8367,6 @@ Instruction *InstCombiner::visitFreeInst(FreeInst &FI) { Value *Op = FI.getOperand(0); - // Change free <ty>* (cast <ty2>* X to <ty>*) into free <ty2>* X - if (CastInst *CI = dyn_cast<CastInst>(Op)) - if (isa<PointerType>(CI->getOperand(0)->getType())) { - FI.setOperand(0, CI->getOperand(0)); - return &FI; - } - // free undef -> unreachable. if (isa<UndefValue>(Op)) { // Insert a new store to null because we cannot modify the CFG here. @@ -8381,11 +8374,33 @@ UndefValue::get(PointerType::get(Type::Int1Ty)), &FI); return EraseInstFromFunction(FI); } - + // If we have 'free null' delete the instruction. This can happen in stl code // when lots of inlining happens. if (isa<ConstantPointerNull>(Op)) return EraseInstFromFunction(FI); + + // Change free <ty>* (cast <ty2>* X to <ty>*) into free <ty2>* X + if (BitCastInst *CI = dyn_cast<BitCastInst>(Op)) { + FI.setOperand(0, CI->getOperand(0)); + return &FI; + } + + // Change free (gep X, 0,0,0,0) into free(X) + if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(Op)) { + if (GEPI->hasAllZeroIndices()) { + AddToWorkList(GEPI); + FI.setOperand(0, GEPI->getOperand(0)); + return &FI; + } + } + + // Change free(malloc) into nothing, if the malloc has a single use. + if (MallocInst *MI = dyn_cast<MallocInst>(Op)) + if (MI->hasOneUse()) { + EraseInstFromFunction(FI); + return EraseInstFromFunction(*MI); + } return 0; } _______________________________________________ llvm-commits mailing list [EMAIL PROTECTED] http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
