mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-24 22:32:47 +00:00
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
|
|
;
|
|
; 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 backedge taken count expression.
|
|
|
|
; CHECK: @test
|
|
; CHECK-NOT: phi
|
|
; CHECK-NOT: icmp
|
|
; CHECK: ret void
|
|
define void @test() {
|
|
entry:
|
|
%xor1 = xor i32 0, 1
|
|
br label %b17
|
|
|
|
b17:
|
|
br i1 undef, label %b22, label %b18
|
|
|
|
b18:
|
|
%phi1 = phi i32 [ %add1, %b18 ], [ %xor1, %b17 ]
|
|
%add1 = add nsw i32 %phi1, -1
|
|
%cmp1 = icmp sgt i32 %add1, 0
|
|
br i1 %cmp1, label %b18, label %b22
|
|
|
|
b22:
|
|
ret void
|
|
}
|