e6b85c3027
Followup to D59363 which failed to handle the icmp(X,undef) -> isTrueWhenEqual case - similar to llvm::ConstantFoldCompareInstruction
As discussed on the review, this is affecting some previously reduced test cases, but will also prevent reductions from relying on this inconsistent behaviour in the future.
Reapplied after reversion at e1e3c75c7d with a tweak to the pseudo-probe-peep.ll test
Differential Revision: https://reviews.llvm.org/D158068
16 lines
443 B
LLVM
16 lines
443 B
LLVM
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
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; RUN: llc < %s -mtriple=aarch64-unknown-linux-gnu | FileCheck %s
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; This used to generate incorrect code because we sign extended
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; the undef to undef instead of to 0.
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define i1 @test14(i8 %X) {
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; CHECK-LABEL: test14:
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; CHECK: // %bb.0:
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; CHECK-NEXT: mov w0, wzr
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; CHECK-NEXT: ret
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%1 = shl i8 -113, %X
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%cmp = icmp slt i8 undef, %1
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ret i1 %cmp
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}
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