[SystemZ] Fix linux s390x main can't bootstrap itself on SanitizerSpecialCaseList.cpp #168088 #168779
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…st.cpp llvm#168088 by pruning search tree early in a long call chain ... recursion in test
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@llvm/pr-subscribers-backend-systemz Author: None (anoopkg6) ChangesThis test has long call chain in recursion. Search tree can be pruned early by swapping CC test and recursive simplifyAssumingCCVal. Full diff: https://github.com/llvm/llvm-project/pull/168779.diff 1 Files Affected:
diff --git a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
index 06501b745b3f7..eb93024bed35c 100644
--- a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
@@ -8673,15 +8673,17 @@ SmallVector<SDValue, 4> static simplifyAssumingCCVal(SDValue &Val, SDValue &CC,
int CCValidVal = CCValid->getZExtValue();
int CCMaskVal = CCMask->getZExtValue();
- const auto &&TrueSDVals = simplifyAssumingCCVal(TrueVal, CC, DAG);
- const auto &&FalseSDVals = simplifyAssumingCCVal(FalseVal, CC, DAG);
- if (TrueSDVals.empty() || FalseSDVals.empty())
- return {};
+ // Pruning search tree early - Moving CC test and combineCCMask ahead of
+ // recursive call to simplifyAssumingCCVal.
SDValue Op4CCReg = Val.getOperand(4);
if (Op4CCReg != CC)
combineCCMask(Op4CCReg, CCValidVal, CCMaskVal, DAG);
if (Op4CCReg != CC)
return {};
+ const auto &&TrueSDVals = simplifyAssumingCCVal(TrueVal, CC, DAG);
+ const auto &&FalseSDVals = simplifyAssumingCCVal(FalseVal, CC, DAG);
+ if (TrueSDVals.empty() || FalseSDVals.empty())
+ return {};
SmallVector<SDValue, 4> MergedSDVals;
for (auto &CCVal : {0, 1, 2, 3})
MergedSDVals.emplace_back(((CCMaskVal & (1 << (3 - CCVal))) != 0)
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🐧 Linux x64 Test Results
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aadeshps-mcw
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Nov 26, 2025
…cialCaseList.cpp llvm#168088 (llvm#168779) This test has long call chain in recursion. Search tree can be pruned early by swapping CC test and recursive simplifyAssumingCCVal. Fixes: llvm#168088 Co-authored-by: anoopkg6 <anoopkg6@github.com>
Priyanshu3820
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to Priyanshu3820/llvm-project
that referenced
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Nov 26, 2025
…cialCaseList.cpp llvm#168088 (llvm#168779) This test has long call chain in recursion. Search tree can be pruned early by swapping CC test and recursive simplifyAssumingCCVal. Fixes: llvm#168088 Co-authored-by: anoopkg6 <anoopkg6@github.com>
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This test has long call chain in recursion. Search tree can be pruned early by swapping CC test and recursive simplifyAssumingCCVal.