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| author | Benjamin Kramer <benny.kra@googlemail.com> | 2012-05-28 19:18:16 +0000 |
|---|---|---|
| committer | Benjamin Kramer <benny.kra@googlemail.com> | 2012-05-28 19:18:16 +0000 |
| commit | 37fa1c81ac49dc744899d05a8eb7f038cd1502cd (patch) | |
| tree | 3312f383bde92ba2e6abfc3309866d9f1fe495e9 /lib/Transforms | |
| parent | 21280e48c07422a43bf8e7d095bdfaf0c7012bd5 (diff) | |
InstCombine: Fix infinite loop when encountering switch on trivial icmp.
The test case feeds the following into InstCombine's visitSelect:
%tobool8 = icmp ne i32 0, 0
%phitmp = select i1 %tobool8, i32 3, i32 0
Then instcombine replaces the right side of the switch with 0, doesn't notice
that nothing changes and tries again indefinitely.
This fixes PR12897.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157587 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms')
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineSelect.cpp | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineSelect.cpp b/lib/Transforms/InstCombine/InstCombineSelect.cpp index e727b2c592..0ae00ea17a 100644 --- a/lib/Transforms/InstCombine/InstCombineSelect.cpp +++ b/lib/Transforms/InstCombine/InstCombineSelect.cpp @@ -498,7 +498,7 @@ Instruction *InstCombiner::visitSelectInstWithICmp(SelectInst &SI, // NOTE: if we wanted to, this is where to detect integer MIN/MAX - if (isa<Constant>(CmpRHS)) { + if (CmpRHS != CmpLHS && isa<Constant>(CmpRHS)) { if (CmpLHS == TrueVal && Pred == ICmpInst::ICMP_EQ) { // Transform (X == C) ? X : Y -> (X == C) ? C : Y SI.setOperand(1, CmpRHS); |