[llvm] [LV] Teach LoopVectorizationLegality about struct vector calls (PR #119221)

[Florian Hahn via llvm-commits]

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@@ -943,11 +955,24 @@ bool LoopVectorizationLegality::canVectorizeInstrs() {
       if (CI && !VFDatabase::getMappings(*CI).empty())
         VecCallVariantsFound = true;
 
+      auto canWidenInstruction = [this](Instruction const &Inst) {
+        Type *InstTy = Inst.getType();
+        if (isa<CallInst>(Inst) && isa<StructType>(InstTy) &&
+            canWidenCallReturnType(InstTy)) {
+          StructVecVecCallFound = true;
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fhahn wrote:

What's the benefit of tracking this via a global variable instead of exiting early  as for the other cases of return types we cannot vectorize?

Could we just emit the message for call directly here?

https://github.com/llvm/llvm-project/pull/119221