[llvm] [VPlan] Get Addr computation cost with scalar type if it is uniform for gather/scatter. (PR #150371)

[Luke Lau via llvm-commits]

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@@ -6932,6 +6932,12 @@ static bool planContainsAdditionalSimplifications(VPlan &Plan,
   auto Iter = vp_depth_first_deep(Plan.getVectorLoopRegion()->getEntry());
   for (VPBasicBlock *VPBB : VPBlockUtils::blocksOnly<VPBasicBlock>(Iter)) {
     for (VPRecipeBase &R : *VPBB) {
+      if (auto *MR = dyn_cast<VPWidenMemoryRecipe>(&R)) {
+        // The address computation cost can be query as scalar type if the
+        // address is uniform.
+        if (!MR->isConsecutive() && vputils::isSingleScalar(MR->getAddr()))
+          return true;
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lukel97 wrote:

Were you seeing any cost model assertions with this PR? I guess the VPlan cost model never passed in the pointer SCEV to begin with so is it already out of sync on other targets?

https://github.com/llvm/llvm-project/pull/150371