diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp index a934e0aa68e..582f69fb2d2 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp @@ -498,6 +498,13 @@ Instruction *InstCombiner::narrowRotate(TruncInst &Trunc) { shouldChangeType(Trunc.getSrcTy(), Trunc.getType())) && "Don't narrow to an illegal scalar type"); + // Bail out on strange types. It is possible to handle some of these patterns + // even with non-power-of-2 sizes, but it is not a likely scenario. + Type *DestTy = Trunc.getType(); + unsigned NarrowWidth = DestTy->getScalarSizeInBits(); + if (!isPowerOf2_32(NarrowWidth)) + return nullptr; + // First, find an or'd pair of opposite shifts with the same shifted operand: // trunc (or (lshr ShVal, ShAmt0), (shl ShVal, ShAmt1)) Value *Or0, *Or1; @@ -538,8 +545,6 @@ Instruction *InstCombiner::narrowRotate(TruncInst &Trunc) { return nullptr; }; - Type *DestTy = Trunc.getType(); - unsigned NarrowWidth = DestTy->getScalarSizeInBits(); Value *ShAmt = matchShiftAmount(ShAmt0, ShAmt1, NarrowWidth); bool SubIsOnLHS = false; if (!ShAmt) { |
