diff options
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index c0d0591c9b..fad2730d84 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -844,11 +844,18 @@ Instruction *InstCombiner::visitDiv(BinaryOperator &I) { Instruction *InstCombiner::visitRem(BinaryOperator &I) { + if (I.getType()->isSigned()) + if (Value *RHSNeg = dyn_castNegVal(I.getOperand(1))) + if (RHSNeg != I.getOperand(1)) { // Avoid problems with MININT + // X % -Y -> X % Y + AddUsesToWorkList(I); + I.setOperand(1, RHSNeg); + return &I; + } + if (ConstantInt *RHS = dyn_cast<ConstantInt>(I.getOperand(1))) { if (RHS->equalsInt(1)) // X % 1 == 0 return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType())); - if (RHS->isAllOnesValue()) // X % -1 == 0 - return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType())); // Check to see if this is an unsigned remainder with an exact power of 2, // if so, convert to a bitwise and. |