d897a14c2e
During lowering of memcmp/bcmp, the check for a size of 0 is done in 2 different ways. In rare cases this can lead to a crash in SystemZSelectionDAGInfo::EmitTargetCodeForMemcmp(). The root cause is that SelectionDAGBuilder::visitMemCmpBCmpCall() checks for a constant int value which is not yet evaluated. When the value is turned into a SDValue, then the evaluation is done and results in a ConstantSDNode. But EmitTargetCodeForMemcmp() expects the special case of 0 length to be handled, which results in an assertion. The fix is to turn the value into a SDValue, so that both functions use the same check. Reviewed By: uweigand Differential Revision: https://reviews.llvm.org/D126900
21 lines
443 B
LLVM
21 lines
443 B
LLVM
; Test memcmp with 0 size.
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; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
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; REQUIRES: asserts
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declare i32 @memcmp(i8* nocapture, i8* nocapture, i64)
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define hidden void @fun() {
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; CHECK-LABEL: fun
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entry:
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%len = extractvalue [2 x i64] zeroinitializer, 1
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br i1 undef, label %end, label %call
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call:
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%res = tail call signext i32 @memcmp(i8* noundef undef, i8* noundef undef, i64 noundef %len)
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unreachable
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end:
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unreachable
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}
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