| ; 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 | |
| } |