Add VPlan debug output test

Author: lukel97

llvm/test/Transforms/LoopVectorize/vplan-iv-transforms.ll

@@ -29,7 +29,7 @@ define void @iv_no_binary_op_in_descriptor(i1 %c, ptr %dst) {
 ; CHECK-NEXT: }
 ; CHECK-NEXT: Successor(s): middle.block
 ; CHECK-EMPTY:
-; CHECK-NEXT: middle.block:
+ ; CHECK-NEXT: middle.block:
 ; CHECK-NEXT:    EMIT vp<[[CMP:%.+]]> = icmp eq ir<1000>, vp<[[VEC_TC]]>
 ; CHECK-NEXT:    EMIT branch-on-cond vp<[[CMP]]>
 ; CHECK-NEXT:  Successor(s): ir-bb<exit>, scalar.ph
@@ -65,3 +65,57 @@ loop.latch:
 exit:
   ret void
 }
+
+; Check that VPWidenIntOrFPInductionRecipe is expanded into smaller recipes in
+; the final VPlan.
+define void @iv_expand(ptr %p, i64 %n) {
+; CHECK-LABEL: LV: Checking a loop in 'iv_expand'
+; CHECK:      VPlan 'Initial VPlan for VF={8},UF>=1' {
+; CHECK:      <x1> vector loop: {
+; CHECK-NEXT:   vector.body:
+; CHECK-NEXT:     EMIT vp<%3> = CANONICAL-INDUCTION ir<0>, vp<%index.next>
+; CHECK-NEXT:     ir<%i> = WIDEN-INDUCTION  ir<0>, ir<1>, vp<%0>
+; CHECK-NEXT:     vp<%4> = SCALAR-STEPS vp<%3>, ir<1>
+; CHECK-NEXT:     CLONE ir<%q> = getelementptr ir<%p>, vp<%4>
+; CHECK-NEXT:     vp<%5> = vector-pointer ir<%q>
+; CHECK-NEXT:     WIDEN ir<%x> = load vp<%5>
+; CHECK-NEXT:     WIDEN ir<%y> = add ir<%x>, ir<%i>
+; CHECK-NEXT:     vp<%6> = vector-pointer ir<%q>
+; CHECK-NEXT:     WIDEN store vp<%6>, ir<%y>
+; CHECK-NEXT:     EMIT vp<%index.next> = add nuw vp<%3>, vp<%1>
+; CHECK-NEXT:     EMIT branch-on-count vp<%index.next>, vp<%2>
+; CHECK-NEXT:   No successors
+; CHECK-NEXT: }
+; CHECK-NEXT: Successor(s): middle.block
+; CHECK:      VPlan 'Final VPlan for VF={8},UF={1}'
+; CHECK:      <x1> vector loop: {
+; CHECK-NEXT:   vector.body:
+; CHECK-NEXT:     SCALAR-PHI vp<%3> = phi ir<0>, vp<%index.next>
+; CHECK-NEXT:     WIDEN-PHI ir<%i> = phi vp<%induction>, vp<%vec.ind.next>
+; CHECK-NEXT:     vp<%4> = SCALAR-STEPS vp<%3>, ir<1>
+; CHECK-NEXT:     CLONE ir<%q> = getelementptr ir<%p>, vp<%4>
+; CHECK-NEXT:     vp<%5> = vector-pointer ir<%q>
+; CHECK-NEXT:     WIDEN ir<%x> = load vp<%5>
+; CHECK-NEXT:     WIDEN ir<%y> = add ir<%x>, ir<%i>
+; CHECK-NEXT:     vp<%6> = vector-pointer ir<%q>
+; CHECK-NEXT:     WIDEN store vp<%6>, ir<%y>
+; CHECK-NEXT:     EMIT vp<%index.next> = add nuw vp<%3>, ir<8>
+; CHECK-NEXT:     EMIT vp<%vec.ind.next> = add ir<%i>, vp<%2>
+; CHECK-NEXT:     EMIT branch-on-count vp<%index.next>, ir<%n.vec>
+; CHECK-NEXT:   No successors
+; CHECK-NEXT: }
+; CHECK-NEXT: Successor(s): middle.block
+entry:
+  br label %loop
+loop:
+  %i = phi i64 [0, %entry], [%i.next, %loop]
+  %q = getelementptr i64, ptr %p, i64 %i
+  %x = load i64, ptr %q
+  %y = add i64 %x, %i
+  store i64 %y, ptr %q
+  %i.next = add i64 %i, 1
+  %done = icmp eq i64 %i.next, %n
+  br i1 %done, label %exit, label %loop
+exit:
+  ret void
+}