d82f0b74de
In degenerate cases, the backedge value can be folded to poison. Fixes https://github.com/llvm/llvm-project/issues/64891.
28 lines
796 B
LLVM
28 lines
796 B
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2
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; RUN: opt -S -passes=indvars < %s | FileCheck %s
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target datalayout = "n8:16:32:64"
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; Just make sure this doesn't crash.
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; SCEVExpander produces a degenerate phi node for the widened IV here,
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; where the "increment" instruction folds to a poison value.
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define i32 @main() {
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; CHECK-LABEL: define i32 @main() {
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; CHECK-NEXT: entry:
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; CHECK-NEXT: br label [[LOOP:%.*]]
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; CHECK: loop:
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; CHECK-NEXT: br label [[LOOP]]
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;
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entry:
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%div = sdiv i32 1, 0
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%trunc = trunc i32 %div to i16
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br label %loop
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loop:
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%phi = phi i16 [ 0, %entry ], [ %or, %loop ]
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%or = or i16 %phi, %trunc
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%phi.ext = sext i16 %phi to i64
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%add.ptr = getelementptr i8, ptr null, i64 %phi.ext
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br label %loop
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}
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