[llvm] [LoopVectorizer] Prune VFs based on plan register pressure (PR #132190)

[David Sherwood via llvm-commits]

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@@ -10,72 +10,29 @@ define void @QLA_F3_r_veq_norm2_V(ptr noalias %r, ptr noalias %a, i32 %n) {
 ; CHECK-SAME: ptr noalias [[R:%.*]], ptr noalias [[A:%.*]], i32 [[N:%.*]]) {
 ; CHECK-NEXT:  [[ENTRY:.*]]:
 ; CHECK-NEXT:    [[CMP24:%.*]] = icmp sgt i32 [[N]], 0
-; CHECK-NEXT:    br i1 [[CMP24]], label %[[ITER_CHECK:.*]], label %[[FOR_END13:.*]]
-; CHECK:       [[ITER_CHECK]]:
+; CHECK-NEXT:    br i1 [[CMP24]], label %[[FOR_COND1_PREHEADER_PREHEADER:.*]], label %[[FOR_END13:.*]]
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david-arm wrote:

>From the comment above the function it looks like they are expecting it be interleaved 8 times, perhaps for optimal performance?

https://github.com/llvm/llvm-project/pull/132190