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| author | Chris Lattner <sabre@nondot.org> | 2009-03-25 00:28:58 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2009-03-25 00:28:58 +0000 |
| commit | e8e4921967994726e2e64c9906e23fec52f00cf7 (patch) | |
| tree | 55131c127aece37955a17b639adc90b94f72b6f4 | |
| parent | 86bda4174a90eff1305e51b0407a47a8dcecbe7b (diff) | |
Fix PR3874 by restoring a condition I removed, but making it more
precise than it used to be.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67662 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 3 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/2009-03-24-InfLoop.ll | 9 |
2 files changed, 11 insertions, 1 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index f631d61457..1f80444632 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -6582,7 +6582,8 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, // preferable because it allows the C<<Y expression to be hoisted out // of a loop if Y is invariant and X is not. if (Shift && Shift->hasOneUse() && RHSV == 0 && - ICI.isEquality() && !Shift->isArithmeticShift()) { + ICI.isEquality() && !Shift->isArithmeticShift() && + !isa<Constant>(Shift->getOperand(0))) { // Compute C << Y. Value *NS; if (Shift->getOpcode() == Instruction::LShr) { diff --git a/test/Transforms/InstCombine/2009-03-24-InfLoop.ll b/test/Transforms/InstCombine/2009-03-24-InfLoop.ll new file mode 100644 index 0000000000..6d5a7bf77d --- /dev/null +++ b/test/Transforms/InstCombine/2009-03-24-InfLoop.ll @@ -0,0 +1,9 @@ +; PR3874 +; RUN: llvm-as < %s | opt -instcombine | llvm-dis + define i1 @test(i32 %x) { + %A = lshr i32 3968, %x + %B = and i32 %A, 1 + %C = icmp eq i32 %B, 0 + ret i1 %C + } + |