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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 | d3449df32687ee9a2ae11cd6cae044b63de9555a (patch) | |
| tree | 86e6bdc63d09c961450e11c9169d787c8422bd91 | |
| parent | 7fa2758b45834158b0fc7cadb5252242c99bbc89 (diff) | |
| download | bcm5719-llvm-d3449df32687ee9a2ae11cd6cae044b63de9555a.tar.gz bcm5719-llvm-d3449df32687ee9a2ae11cd6cae044b63de9555a.zip | |
Fix for PR2479: correctly optimize expressions like (a > 13) & (a ==
15).
See also PR1800, which is about the signed case.
llvm-svn: 52608
| -rw-r--r-- | llvm/lib/Transforms/Scalar/InstructionCombining.cpp | 3 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/2008-06-21-CompareMiscomp.ll | 11 |
2 files changed, 12 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp index 54e611d2a1e..37637bbe63b 100644 --- a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/llvm/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/llvm/test/Transforms/InstCombine/2008-06-21-CompareMiscomp.ll b/llvm/test/Transforms/InstCombine/2008-06-21-CompareMiscomp.ll new file mode 100644 index 00000000000..e2d71007848 --- /dev/null +++ b/llvm/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 +} + |
