[llvm] [VPlan] Introduce recipes for VP loads and stores. (PR #87816)

[via llvm-commits]

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@@ -2390,13 +2387,49 @@ struct VPWidenLoadRecipe final : public VPWidenMemoryRecipe, public VPValue {
   bool onlyFirstLaneUsed(const VPValue *Op) const override {
     assert(is_contained(operands(), Op) &&
            "Op must be an operand of the recipe");
-
-    // Widened, consecutive loads operations only demand the first lane of
-    // their address.
+    // Widened, consecutive memory operations only demand the first lane of
+    // their address, unless the same operand is also stored. That latter can
+    // happen with opaque pointers.
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ayalz wrote:

Retain original comment - this should still talk about loads?

https://github.com/llvm/llvm-project/pull/87816