diff options
| -rw-r--r-- | include/llvm/Analysis/InstructionSimplify.h | 2 | ||||
| -rw-r--r-- | lib/Analysis/InstructionSimplify.cpp | 46 | ||||
| -rw-r--r-- | lib/Analysis/Lint.cpp | 3 |
3 files changed, 32 insertions, 19 deletions
diff --git a/include/llvm/Analysis/InstructionSimplify.h b/include/llvm/Analysis/InstructionSimplify.h index b59adc1..965e71b 100644 --- a/include/llvm/Analysis/InstructionSimplify.h +++ b/include/llvm/Analysis/InstructionSimplify.h @@ -75,8 +75,6 @@ namespace llvm { /// SimplifyInstruction - See if we can compute a simplified version of this /// instruction. If not, this returns null. - /// WARNING: If called on unreachable code, an instruction may be reported - /// to simplify to itself. Value *SimplifyInstruction(Instruction *I, const TargetData *TD = 0, const DominatorTree *DT = 0); diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp index c540d6f..5ad842b 100644 --- a/lib/Analysis/InstructionSimplify.cpp +++ b/lib/Analysis/InstructionSimplify.cpp @@ -756,34 +756,50 @@ Value *llvm::SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS, /// instruction. If not, this returns null. Value *llvm::SimplifyInstruction(Instruction *I, const TargetData *TD, const DominatorTree *DT) { + Value *Result; + switch (I->getOpcode()) { default: - return ConstantFoldInstruction(I, TD); + Result = ConstantFoldInstruction(I, TD); + break; case Instruction::Add: - return SimplifyAddInst(I->getOperand(0), I->getOperand(1), - cast<BinaryOperator>(I)->hasNoSignedWrap(), - cast<BinaryOperator>(I)->hasNoUnsignedWrap(), - TD, DT); + Result = SimplifyAddInst(I->getOperand(0), I->getOperand(1), + cast<BinaryOperator>(I)->hasNoSignedWrap(), + cast<BinaryOperator>(I)->hasNoUnsignedWrap(), + TD, DT); + break; case Instruction::And: - return SimplifyAndInst(I->getOperand(0), I->getOperand(1), TD, DT); + Result = SimplifyAndInst(I->getOperand(0), I->getOperand(1), TD, DT); + break; case Instruction::Or: - return SimplifyOrInst(I->getOperand(0), I->getOperand(1), TD, DT); + Result = SimplifyOrInst(I->getOperand(0), I->getOperand(1), TD, DT); + break; case Instruction::ICmp: - return SimplifyICmpInst(cast<ICmpInst>(I)->getPredicate(), - I->getOperand(0), I->getOperand(1), TD, DT); + Result = SimplifyICmpInst(cast<ICmpInst>(I)->getPredicate(), + I->getOperand(0), I->getOperand(1), TD, DT); + break; case Instruction::FCmp: - return SimplifyFCmpInst(cast<FCmpInst>(I)->getPredicate(), - I->getOperand(0), I->getOperand(1), TD, DT); + Result = SimplifyFCmpInst(cast<FCmpInst>(I)->getPredicate(), + I->getOperand(0), I->getOperand(1), TD, DT); + break; case Instruction::Select: - return SimplifySelectInst(I->getOperand(0), I->getOperand(1), - I->getOperand(2), TD, DT); + Result = SimplifySelectInst(I->getOperand(0), I->getOperand(1), + I->getOperand(2), TD, DT); + break; case Instruction::GetElementPtr: { SmallVector<Value*, 8> Ops(I->op_begin(), I->op_end()); - return SimplifyGEPInst(&Ops[0], Ops.size(), TD, DT); + Result = SimplifyGEPInst(&Ops[0], Ops.size(), TD, DT); + break; } case Instruction::PHI: - return SimplifyPHINode(cast<PHINode>(I), DT); + Result = SimplifyPHINode(cast<PHINode>(I), DT); + break; } + + /// If called on unreachable code, the above logic may report that the + /// instruction simplified to itself. Make life easier for users by + /// detecting that case here, returning null if it occurs. + return Result == I ? 0 : Result; } /// ReplaceAndSimplifyAllUses - Perform From->replaceAllUsesWith(To) and then diff --git a/lib/Analysis/Lint.cpp b/lib/Analysis/Lint.cpp index 8b76b87..e5e7cd3 100644 --- a/lib/Analysis/Lint.cpp +++ b/lib/Analysis/Lint.cpp @@ -616,8 +616,7 @@ Value *Lint::findValueImpl(Value *V, bool OffsetOk, // As a last resort, try SimplifyInstruction or constant folding. if (Instruction *Inst = dyn_cast<Instruction>(V)) { if (Value *W = SimplifyInstruction(Inst, TD, DT)) - if (W != Inst) - return findValueImpl(W, OffsetOk, Visited); + return findValueImpl(W, OffsetOk, Visited); } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) { if (Value *W = ConstantFoldConstantExpression(CE, TD)) if (W != V) |