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

[via llvm-commits]

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@@ -2392,7 +2391,51 @@ 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 memory operations only demand the first lane of
+    // their address, unless the same operand is also stored. That latter can
+    // happen with opaque pointers.
+    return Op == getAddr() && isConsecutive();
+  }
+};
 
+/// A recipe for widening load operations with vector-predication intrinsics,
+/// using the address to load from, the explicit vector length and an optional
+/// mask.
+struct VPWidenVPLoadRecipe final : public VPWidenMemoryRecipe, public VPValue {
+  VPWidenVPLoadRecipe(LoadInst &Load, VPValue *Addr, VPValue *EVL,
+                      VPValue *Mask, bool IsConsecutive, DebugLoc DL)
+      : VPWidenMemoryRecipe(VPDef::VPWidenVPLoadSC, Load, {Addr, EVL},
+                            IsConsecutive, false, DL),
+        VPValue(this, &Load) {
+    setMask(Mask);
+  }
+
+  VPRecipeBase *clone() override {
+    return new VPWidenVPLoadRecipe(cast<LoadInst>(Ingredient), getAddr(),
+                                   getEVL(), getMask(), isConsecutive(),
+                                   getDebugLoc());
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ayalz wrote:

+1
Currently clone() is called only for epilog vectorization, so this is unreachable.
Can define it unreachable at the VPWidenMemoryRecipe parent, instead of pure virtual.

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