[llvm] [LV][EVL]Support reversed loads/stores. (PR #88025)

[Florian Hahn via llvm-commits]

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@@ -9459,7 +9464,14 @@ void VPWidenStoreEVLRecipe::execute(VPTransformState &State) {
   CallInst *NewSI = nullptr;
   Value *StoredVal = State.get(StoredValue, 0);
   Value *EVL = State.get(getEVL(), VPIteration(0, 0));
-  // FIXME: Support reverse store after vp_reverse is added.
+  if (isReverse()) {
+    auto *StoredValTy = cast<VectorType>(StoredVal->getType());
+    Value *MaskVal = Builder.CreateVectorSplat(StoredValTy->getElementCount(),
+                                               Builder.getTrue());
+    StoredVal = Builder.CreateIntrinsic(
+        StoredValTy, Intrinsic::experimental_vp_reverse,
+        {StoredVal, MaskVal, EVL}, nullptr, "vp.reverse");
+  }
   Value *Mask = getMask()
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fhahn wrote:

I think the mask also needs reversing here, same as for loads?

https://github.com/llvm/llvm-project/pull/88025