diff options
Diffstat (limited to 'lib/Transforms/InstCombine/InstCombineCasts.cpp')
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineCasts.cpp | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp index 32ab123f10..6f70de8657 100644 --- a/lib/Transforms/InstCombine/InstCombineCasts.cpp +++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp @@ -913,8 +913,13 @@ Instruction *InstCombiner::transformSExtICmp(ICmpInst *ICI, Instruction &CI) { if (KnownZeroMask.isPowerOf2()) { Value *In = ICI->getOperand(0); - assert((Op1C->isZero() || Op1C->getValue() == KnownZeroMask) && - "Constant icmp not folded?"); + // If the icmp tests for a known zero bit we can constant fold it. + if (!Op1C->isZero() && Op1C->getValue() != KnownZeroMask) { + Value *V = Pred == ICmpInst::ICMP_NE ? + ConstantInt::getAllOnesValue(CI.getType()) : + ConstantInt::getNullValue(CI.getType()); + return ReplaceInstUsesWith(CI, V); + } if (!Op1C->isZero() == (Pred == ICmpInst::ICMP_NE)) { // sext ((x & 2^n) == 0) -> (x >> n) - 1 |