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| author | Eli Friedman <eli.friedman@gmail.com> | 2008-06-21 23:36:13 +0000 |
|---|---|---|
| committer | Eli Friedman <eli.friedman@gmail.com> | 2008-06-21 23:36:13 +0000 |
| commit | 5c1f17221344fe24f8ba78fdbac7db4f79ded257 (patch) | |
| tree | 9e5896866a1c7723953ccd6f2315979f8a459236 | |
| parent | 1adec83ae84031bfa9f0bf209c5ee6c64906a1ff (diff) | |
| download | llvm-5c1f17221344fe24f8ba78fdbac7db4f79ded257.tar.gz llvm-5c1f17221344fe24f8ba78fdbac7db4f79ded257.tar.bz2 llvm-5c1f17221344fe24f8ba78fdbac7db4f79ded257.tar.xz | |
Fix for PR2479: correctly optimize expressions like (a > 13) & (a ==
15).
See also PR1800, which is about the signed case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52608 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 3 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/2008-06-21-CompareMiscomp.ll | 11 |
2 files changed, 12 insertions, 2 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 54e611d2a1..37637bbe63 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -3691,8 +3691,7 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) { case ICmpInst::ICMP_UGT: switch (RHSCC) { default: assert(0 && "Unknown integer condition code!"); - case ICmpInst::ICMP_EQ: // (X u> 13 & X == 15) -> X > 13 - return ReplaceInstUsesWith(I, LHS); + case ICmpInst::ICMP_EQ: // (X u> 13 & X == 15) -> X == 15 case ICmpInst::ICMP_UGT: // (X u> 13 & X u> 15) -> X u> 15 return ReplaceInstUsesWith(I, RHS); case ICmpInst::ICMP_SGT: // (X u> 13 & X s> 15) -> no change diff --git a/test/Transforms/InstCombine/2008-06-21-CompareMiscomp.ll b/test/Transforms/InstCombine/2008-06-21-CompareMiscomp.ll new file mode 100644 index 0000000000..e2d7100784 --- /dev/null +++ b/test/Transforms/InstCombine/2008-06-21-CompareMiscomp.ll @@ -0,0 +1,11 @@ +; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep {icmp eq i32 %In, 15} +; PR2479 +; (See also PR1800.) + +define i1 @test(i32 %In) { + %c1 = icmp ugt i32 %In, 13 + %c2 = icmp eq i32 %In, 15 + %V = and i1 %c1, %c2 + ret i1 %V +} + |