[clang] [CIR] Upstream CmpOp (PR #133159)

[Andy Kaylor via cfe-commits]

================
@@ -710,6 +710,89 @@ class ScalarExprEmitter : public StmtVisitor<ScalarExprEmitter, mlir::Value> {
   HANDLEBINOP(Xor)
   HANDLEBINOP(Or)
 #undef HANDLEBINOP
+
+  mlir::Value emitCmp(const BinaryOperator *e) {
+    mlir::Value result;
+    QualType lhsTy = e->getLHS()->getType();
+    QualType rhsTy = e->getRHS()->getType();
+
+    auto clangCmpToCIRCmp =
+        [](clang::BinaryOperatorKind clangCmp) -> cir::CmpOpKind {
+      switch (clangCmp) {
+      case BO_LT:
+        return cir::CmpOpKind::lt;
+      case BO_GT:
+        return cir::CmpOpKind::gt;
+      case BO_LE:
+        return cir::CmpOpKind::le;
+      case BO_GE:
+        return cir::CmpOpKind::ge;
+      case BO_EQ:
+        return cir::CmpOpKind::eq;
+      case BO_NE:
+        return cir::CmpOpKind::ne;
+      default:
+        llvm_unreachable("unsupported comparison kind");
+      }
+    };
+
+    if (lhsTy->getAs<MemberPointerType>()) {
+      assert(e->getOpcode() == BO_EQ || e->getOpcode() == BO_NE);
+      mlir::Value lhs = cgf.emitScalarExpr(e->getLHS());
+      mlir::Value rhs = cgf.emitScalarExpr(e->getRHS());
+      cir::CmpOpKind kind = clangCmpToCIRCmp(e->getOpcode());
+      result =
+          builder.createCompare(cgf.getLoc(e->getExprLoc()), kind, lhs, rhs);
+    } else if (!lhsTy->isAnyComplexType() && !rhsTy->isAnyComplexType()) {
+      BinOpInfo boInfo = emitBinOps(e);
+      mlir::Value lhs = boInfo.lhs;
+      mlir::Value rhs = boInfo.rhs;
+
+      if (lhsTy->isVectorType()) {
+        assert(!cir::MissingFeatures::vectorType());
+        cgf.cgm.errorNYI(boInfo.loc, "vector comparisons");
+        result = builder.getBool(false, cgf.getLoc(boInfo.loc));
+      } else if (boInfo.isFixedPointOp()) {
+        assert(!cir::MissingFeatures::fixedPointType());
+        cgf.cgm.errorNYI(boInfo.loc, "fixed point comparisons");
+        result = builder.getBool(false, cgf.getLoc(boInfo.loc));
+      } else if (lhsTy->hasSignedIntegerRepresentation()) {
----------------
andykaylor wrote:

```suggestion
      } else if (lhsTy->hasIntegerRepresentation()) {
```
We don't handle signed and unsigned compare differently, unlike classic codegen.

https://github.com/llvm/llvm-project/pull/133159