[llvm] [LV] Convert scatter w/uniform addr and mask being header mask to scalar store. (PR #172799)

[Elvis Wang via llvm-commits]

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@@ -58,7 +58,7 @@ target triple = "aarch64-unknown-linux-gnu"
 ; CHECK-NEXT: }
 
 ;; Check that the vectorized plan contains a histogram recipe instead.
-; CHECK: VPlan 'Initial VPlan for VF={vscale x 2,vscale x 4},UF>=1' {
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ElvisWang123 wrote:

After this patch, vplan printing only shows the first VF because the range is clamped/added after VPlanTransforms::optimize().

To fix this, we could either set the VF range before optimization (and handle the subsequent VF removal) or keep the range symbolic during the optimization stage such as `VF >= vscale x 2`

Do you have a preference between these two, or other better solution?

https://github.com/llvm/llvm-project/pull/172799