diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp index e366c379e9b..4bd1246cbf7 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp @@ -1194,6 +1194,12 @@ static Instruction *foldCttzCtlz(IntrinsicInst &II, InstCombiner &IC) { return CallInst::Create(F, {X, II.getArgOperand(1)}); } + // cttz(-x) -> cttz(x) + if (IsTZ && match(Op0, m_Neg(m_Value(X)))) { + II.setOperand(0, X); + return ⅈ + } + KnownBits Known = IC.computeKnownBits(Op0, 0, &II); // Create a mask for bits above (ctlz) or below (cttz) the first known one. |
