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e74c2e86cb
Fixes PR15570: SEGV: SCEV back-edge info invalid after dead code removal. Indvars creates a SCEV expression for the loop's back edge taken count, then determines that the comparison is always true and removes it. When loop-unroll asks for the expression, it contains a NULL SCEVUnknkown (as a CallbackVH). forgetMemoizedResults should invalidate the loop back edges expression. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177986 91177308-0d34-0410-b5e6-96231b3b80d8
35 lines
814 B
LLVM
35 lines
814 B
LLVM
; RUN: opt < %s -S -indvars -loop-unroll | FileCheck %s
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;
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; PR15570: SEGV: SCEV back-edge info invalid after dead code removal.
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;
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; Indvars creates a SCEV expression for the loop's back edge taken
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; count, then determines that the comparison is always true and
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; removes it.
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;
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; When loop-unroll asks for the expression, it contains a NULL
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; SCEVUnknkown (as a CallbackVH).
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;
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; forgetMemoizedResults should invalidate the backedge taken count expression.
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; CHECK: @test
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; CHECK-NOT: phi
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; CHECK-NOT: icmp
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; CHECK: ret void
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define void @test() {
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entry:
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%xor1 = xor i32 0, 1
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br label %b17
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b17:
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br i1 undef, label %b22, label %b18
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b18:
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%phi1 = phi i32 [ %add1, %b18 ], [ %xor1, %b17 ]
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%add1 = add nsw i32 %phi1, -1
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%cmp1 = icmp sgt i32 %add1, 0
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br i1 %cmp1, label %b18, label %b22
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b22:
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ret void
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}
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