diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp | 13 |
1 files changed, 2 insertions, 11 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp b/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp index 1eaff16c593..1f98a0d22e1 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp @@ -337,21 +337,12 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, Constant *Op1, GetShiftedValue(Op0, COp1->getZExtValue(), isLeftShift, *this)); } - // See if we can simplify any instructions used by the instruction whose sole // purpose is to compute bits we don't care about. uint32_t TypeBits = Op0->getType()->getScalarSizeInBits(); - // shl i32 X, 32 = 0 and srl i8 Y, 9 = 0, ... just don't eliminate - // a signed shift. - // - if (COp1->uge(TypeBits)) { - if (I.getOpcode() != Instruction::AShr) - return ReplaceInstUsesWith(I, Constant::getNullValue(Op0->getType())); - // ashr i32 X, 32 --> ashr i32 X, 31 - I.setOperand(1, ConstantInt::get(I.getType(), TypeBits-1)); - return &I; - } + assert(!COp1->uge(TypeBits) && + "Shift over the type width should have been removed already"); // ((X*C1) << C2) == (X * (C1 << C2)) if (BinaryOperator *BO = dyn_cast<BinaryOperator>(Op0)) |
