1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-23 19:23:23 +01:00
llvm-mirror/test/Analysis/ScalarEvolution/scev-invalid.ll
Andrew Trick 57ddfcf201 Fix SCEV forgetMemoizedResults should search and destroy backedge exprs.
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.

llvm-svn: 177986
2013-03-26 03:14:53 +00:00

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
}