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| author | Eli Friedman <eli.friedman@gmail.com> | 2010-07-30 06:44:31 +0000 |
|---|---|---|
| committer | Eli Friedman <eli.friedman@gmail.com> | 2010-07-30 06:44:31 +0000 |
| commit | ad78a88711979aa84a89a32576b615ff13b3de15 (patch) | |
| tree | b866b05db2593ef00bbfbcbea9a2bafdee9979ce /lib/CodeGen/SelectionDAG/TargetLowering.cpp | |
| parent | 80a098583b3a9754fd83bf93322a8be679ce0036 (diff) | |
| download | external_llvm-ad78a88711979aa84a89a32576b615ff13b3de15.zip external_llvm-ad78a88711979aa84a89a32576b615ff13b3de15.tar.gz external_llvm-ad78a88711979aa84a89a32576b615ff13b3de15.tar.bz2 | |
Fix for bug reported by Evzen Muller on llvm-commits: make sure to correctly
check the range of the constant when optimizing a comparison between a
constant and a sign_extend_inreg node.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109854 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/SelectionDAG/TargetLowering.cpp')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/TargetLowering.cpp | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp index 12185a3..908a9d8 100644 --- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp +++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp @@ -1968,12 +1968,9 @@ TargetLowering::SimplifySetCC(EVT VT, SDValue N0, SDValue N1, EVT ExtDstTy = N0.getValueType(); unsigned ExtDstTyBits = ExtDstTy.getSizeInBits(); - // If the extended part has any inconsistent bits, it cannot ever - // compare equal. In other words, they have to be all ones or all - // zeros. - APInt ExtBits = - APInt::getHighBitsSet(ExtDstTyBits, ExtDstTyBits - ExtSrcTyBits); - if ((C1 & ExtBits) != 0 && (C1 & ExtBits) != ExtBits) + // If the constant doesn't fit into the number of bits for the source of + // the sign extension, it is impossible for both sides to be equal. + if (C1.getMinSignedBits() > ExtSrcTyBits) return DAG.getConstant(Cond == ISD::SETNE, VT); SDValue ZextOp; |