[llvm] [SROA] Prevent load atomic vector from being generated (PR #112432)

[Matt Arsenault via llvm-commits]

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@@ -2853,6 +2853,11 @@ class AllocaSliceRewriter : public InstVisitor<AllocaSliceRewriter, bool> {
 
   bool visitLoadInst(LoadInst &LI) {
     LLVM_DEBUG(dbgs() << "    original: " << LI << "\n");
+
+    // load atomic vector would be generated, which is illegal
+    if (LI.isAtomic() && NewAI.getAllocatedType()->isVectorTy())
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arsenm wrote:

The restriction is dumb and we should relax it. Instead of just hardcoding isVectorTy here, should have some kind of LoadInst::isValidAtomicType or something 

https://github.com/llvm/llvm-project/pull/112432