diff options
Diffstat (limited to 'llvm/lib/Transforms')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp index fae47ec93b9..a99eaf013e6 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp @@ -1990,6 +1990,20 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) { return I; break; + case Intrinsic::fshl: + case Intrinsic::fshr: { + // The shift amount (operand 2) of a funnel shift is modulo the bitwidth, + // so only the low bits of the shift amount are demanded if the bitwidth is + // a power-of-2. + unsigned BitWidth = II->getType()->getScalarSizeInBits(); + if (!isPowerOf2_32(BitWidth)) + break; + APInt Op2Demanded = APInt::getLowBitsSet(BitWidth, Log2_32_Ceil(BitWidth)); + KnownBits Op2Known(BitWidth); + if (SimplifyDemandedBits(II, 2, Op2Demanded, Op2Known)) + return &CI; + break; + } case Intrinsic::uadd_with_overflow: case Intrinsic::sadd_with_overflow: case Intrinsic::umul_with_overflow: |
