[llvm] [LoopVectorize] Don't replicate blocks with optsize (PR #129265)

[Florian Hahn via llvm-commits]

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@@ -1074,33 +1074,52 @@ define void @merge_with_dead_gep_between_regions(i32 %n, ptr noalias %src, ptr n
 ; CHECK-NEXT:     pred.store.continue:
 ; CHECK-NEXT:     No successors
 ; CHECK-NEXT:   }
-; CHECK-NEXT:   Successor(s): loop.1
+; CHECK-NEXT:   Successor(s): loop.then.1
 ; CHECK-EMPTY:
-; CHECK-NEXT:   loop.1:
-; CHECK-NEXT:     EMIT vp<[[CAN_IV_NEXT:%.+]]> = add vp<[[CAN_IV]]>, vp<[[VFxUF]]>
+; CHECK-NEXT:   loop.then.1:
+; CHECK-NEXT:     EMIT vp<[[CAN_IV_NEXT:%.+]]> = add nuw vp<[[CAN_IV]]>, vp<[[VFxUF]]>
 ; CHECK-NEXT:     EMIT branch-on-count  vp<[[CAN_IV_NEXT]]>, vp<[[VEC_TC]]>
 ; CHECK-NEXT:   No successors
 ; CHECK-NEXT: }
 ; CHECK-NEXT: Successor(s): middle.block
 ; CHECK-EMPTY:
 ; CHECK-NEXT: middle.block:
-; CHECK-NEXT: Successor(s): ir-bb<exit>
+; CHECK-NEXT:   EMIT vp<[[CMP:%.+]]> = icmp eq ir<%n>, vp<[[VEC_TC]]>
+; CHECK-NEXT:   EMIT branch-on-cond vp<[[CMP]]>
+; CHECK-NEXT: Successor(s): ir-bb<exit>, scalar.ph
+; CHECK-EMPTY:
+; CHECK-NEXT: scalar.ph:
+; CHECK-NEXT:   EMIT vp<[[RESUME:%.+]]> = resume-phi vp<[[END]]>, ir<%n>
+; CHECK-NEXT: Successor(s): ir-bb<loop>
+; CHECK-EMPTY:
+; CHECK-NEXT: ir-bb<loop>:
+; CHECK-NEXT:   IR   %iv = phi i32 [ %n, %entry ], [ %iv.next, %loop.latch ] (extra operand: vp<[[RESUME]]> from scalar.ph)
+; CHECK-NEXT:   IR   %iv.next = add nsw i32 %iv, -1
+; CHECK-NEXT:   IR   %cond = icmp ult i32 %iv, %k
+; CHECK-NEXT: No successors
 ; CHECK-EMPTY:
-; CHECK-NEXT: ir-bb<exit>
+; CHECK-NEXT: ir-bb<exit>:
 ; CHECK-NEXT: No successors
 ; CHECK-NEXT: }
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fhahn wrote:

Could drop those lines, as they aren't super interesting for the test

https://github.com/llvm/llvm-project/pull/129265