diff options
| author | Dan Gohman <gohman@apple.com> | 2008-05-07 00:35:55 +0000 |
|---|---|---|
| committer | Dan Gohman <gohman@apple.com> | 2008-05-07 00:35:55 +0000 |
| commit | 42ac929ed968939d22a715769e583aeed8f6c823 (patch) | |
| tree | ba6422054e5b84ba6016f0a5a3e90f70fb94c42d | |
| parent | 69cedcbcece7e1138c77aac5b34a1377006254c1 (diff) | |
Fix a bug in the ComputeMaskedBits logic for multiply.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50793 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 4 | ||||
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 4 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/mul-masked-bits.ll | 10 |
3 files changed, 14 insertions, 4 deletions
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index 3e75f7b305..3d5a126df1 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -1244,8 +1244,8 @@ void SelectionDAG::ComputeMaskedBits(SDOperand Op, const APInt &Mask, unsigned TrailZ = KnownZero.countTrailingOnes() + KnownZero2.countTrailingOnes(); unsigned LeadZ = std::max(KnownZero.countLeadingOnes() + - KnownZero2.countLeadingOnes() + - 1, BitWidth) - BitWidth; + KnownZero2.countLeadingOnes(), + BitWidth) - BitWidth; TrailZ = std::min(TrailZ, BitWidth); LeadZ = std::min(LeadZ, BitWidth); diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 2afa6c5162..66d5326b9f 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -767,8 +767,8 @@ void InstCombiner::ComputeMaskedBits(Value *V, const APInt &Mask, unsigned TrailZ = KnownZero.countTrailingOnes() + KnownZero2.countTrailingOnes(); unsigned LeadZ = std::max(KnownZero.countLeadingOnes() + - KnownZero2.countLeadingOnes() + - 1, BitWidth) - BitWidth; + KnownZero2.countLeadingOnes(), + BitWidth) - BitWidth; TrailZ = std::min(TrailZ, BitWidth); LeadZ = std::min(LeadZ, BitWidth); diff --git a/test/Transforms/InstCombine/mul-masked-bits.ll b/test/Transforms/InstCombine/mul-masked-bits.ll new file mode 100644 index 0000000000..9b0a5bfe20 --- /dev/null +++ b/test/Transforms/InstCombine/mul-masked-bits.ll @@ -0,0 +1,10 @@ +; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep ashr + +define i32 @foo(i32 %x, i32 %y) { + %a = and i32 %x, 7 + %b = and i32 %y, 7 + %c = mul i32 %a, %b + %d = shl i32 %c, 26 + %e = ashr i32 %d, 26 + ret i32 %e +} |