[clang] [CLANG] Full support of complex multiplication and division. (PR #81514)

[Andy Kaylor via cfe-commits]

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@@ -283,9 +283,48 @@ class ComplexExprEmitter
   ComplexPairTy EmitComplexBinOpLibCall(StringRef LibCallName,
                                         const BinOpInfo &Op);
 
-  QualType getPromotionType(QualType Ty) {
+  QualType HigherPrecisionTypeForComplexArithmetic(QualType ElementType,
+                                                   bool IsDivOpCode) {
+    const TargetInfo &TI = CGF.getContext().getTargetInfo();
+    if (const auto *BT = dyn_cast<BuiltinType>(ElementType)) {
+      switch (BT->getKind()) {
+      case BuiltinType::Kind::Float16:
+      case BuiltinType::Kind::BFloat16: {
+        return CGF.getContext().getComplexType(CGF.getContext().FloatTy);
+      }
+      case BuiltinType::Kind::Float:
+        return CGF.getContext().getComplexType(CGF.getContext().DoubleTy);
+      case BuiltinType::Kind::Double:
+        if (TI.hasLongDoubleType()) {
+          return CGF.getContext().getComplexType(CGF.getContext().LongDoubleTy);
+        } else {
+          return QualType();
+        }
+      case BuiltinType::Kind::LongDouble:
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andykaylor wrote:

This is more complicated than what you have here. The C "long double" type may be 64-bit, 80-bit, or 128-bit, depending on the target. You can get the size from LangOpts::LongDoubleSize if that's accessible here.

https://github.com/llvm/llvm-project/pull/81514