[clang] [CIR] Upstream ThreeWayCmpOp (PR #169963)

[Hendrik Hübner via cfe-commits]

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@@ -298,8 +299,63 @@ class AggExprEmitter : public StmtVisitor<AggExprEmitter> {
     Visit(e->getRHS());
   }
   void VisitBinCmp(const BinaryOperator *e) {
-    cgf.cgm.errorNYI(e->getSourceRange(), "AggExprEmitter: VisitBinCmp");
+    assert(cgf.getContext().hasSameType(e->getLHS()->getType(),
+                                        e->getRHS()->getType()));
+    const ComparisonCategoryInfo &cmpInfo =
+        cgf.getContext().CompCategories.getInfoForType(e->getType());
+    assert(cmpInfo.Record->isTriviallyCopyable() &&
+           "cannot copy non-trivially copyable aggregate");
+
+    QualType argTy = e->getLHS()->getType();
+
+    if (!argTy->isIntegralOrEnumerationType() && !argTy->isRealFloatingType() &&
+        !argTy->isNullPtrType() && !argTy->isPointerType() &&
+        !argTy->isMemberPointerType() && !argTy->isAnyComplexType())
+      llvm_unreachable("aggregate three-way comparison");
+
+    mlir::Location loc = cgf.getLoc(e->getSourceRange());
+    CIRGenBuilderTy builder = cgf.getBuilder();
+
+    if (e->getType()->isAnyComplexType())
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HendrikHuebner wrote:

Yes, good catch.

https://github.com/llvm/llvm-project/pull/169963