| Andrew Trick | 9093e15 | 2013-03-26 03:14:53 +0000 | [diff] [blame] | 1 | ; RUN: opt < %s -S -indvars -loop-unroll | FileCheck %s |
| 2 | ; |
| 3 | ; PR15570: SEGV: SCEV back-edge info invalid after dead code removal. |
| 4 | ; |
| 5 | ; Indvars creates a SCEV expression for the loop's back edge taken |
| 6 | ; count, then determines that the comparison is always true and |
| 7 | ; removes it. |
| 8 | ; |
| 9 | ; When loop-unroll asks for the expression, it contains a NULL |
| 10 | ; SCEVUnknkown (as a CallbackVH). |
| 11 | ; |
| 12 | ; forgetMemoizedResults should invalidate the backedge taken count expression. |
| 13 | |
| 14 | ; CHECK: @test |
| 15 | ; CHECK-NOT: phi |
| 16 | ; CHECK-NOT: icmp |
| 17 | ; CHECK: ret void |
| 18 | define void @test() { |
| 19 | entry: |
| 20 | %xor1 = xor i32 0, 1 |
| 21 | br label %b17 |
| 22 | |
| 23 | b17: |
| 24 | br i1 undef, label %b22, label %b18 |
| 25 | |
| 26 | b18: |
| 27 | %phi1 = phi i32 [ %add1, %b18 ], [ %xor1, %b17 ] |
| 28 | %add1 = add nsw i32 %phi1, -1 |
| 29 | %cmp1 = icmp sgt i32 %add1, 0 |
| 30 | br i1 %cmp1, label %b18, label %b22 |
| 31 | |
| 32 | b22: |
| 33 | ret void |
| 34 | } |