Changes in directory llvm/lib/Transforms/Scalar:
InstructionCombining.cpp updated: 1.689 -> 1.690 --- Log message: implement Transforms/InstCombine/cast2.ll:test3 and PR1263: http://llvm.org/PR1263 --- Diffs of the changes: (+21 -1) InstructionCombining.cpp | 22 +++++++++++++++++++++- 1 files changed, 21 insertions(+), 1 deletion(-) Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.689 llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.690 --- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.689 Sun Mar 25 14:55:33 2007 +++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp Sun Mar 25 15:43:09 2007 @@ -7896,10 +7896,22 @@ if (GEP.getNumOperands() == 2 && HasZeroPointerIndex) return ReplaceInstUsesWith(GEP, PtrOp); + // Keep track of whether all indices are zero constants integers. + bool AllZeroIndices = true; + // Eliminate unneeded casts for indices. bool MadeChange = false; + gep_type_iterator GTI = gep_type_begin(GEP); - for (unsigned i = 1, e = GEP.getNumOperands(); i != e; ++i, ++GTI) + for (unsigned i = 1, e = GEP.getNumOperands(); i != e; ++i, ++GTI) { + // Track whether this GEP has all zero indices, if so, it doesn't move the + // input pointer, it just changes its type. + if (AllZeroIndices) { + if (ConstantInt *CI = dyn_cast<ConstantInt>(GEP.getOperand(i))) + AllZeroIndices = CI->isNullValue(); + else + AllZeroIndices = false; + } if (isa<SequentialType>(*GTI)) { if (CastInst *CI = dyn_cast<CastInst>(GEP.getOperand(i))) { if (CI->getOpcode() == Instruction::ZExt || @@ -7929,8 +7941,16 @@ MadeChange = true; } } + } if (MadeChange) return &GEP; + // If this GEP instruction doesn't move the pointer, and if the input operand + // is a bitcast of another pointer, just replace the GEP with a bitcast of the + // real input to the dest type. + if (AllZeroIndices && isa<BitCastInst>(GEP.getOperand(0))) + return new BitCastInst(cast<BitCastInst>(GEP.getOperand(0))->getOperand(0), + GEP.getType()); + // Combine Indices - If the source pointer to this getelementptr instruction // is a getelementptr instruction, combine the indices of the two // getelementptr instructions into a single instruction. _______________________________________________ llvm-commits mailing list llvm-commits@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
