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

[Zahira Ammarguellat via cfe-commits]

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@@ -287,9 +288,47 @@ class ComplexExprEmitter
   ComplexPairTy EmitComplexBinOpLibCall(StringRef LibCallName,
                                         const BinOpInfo &Op);
 
-  QualType getPromotionType(QualType Ty) {
+  QualType GetHigherPrecisionFPType(QualType ElementType) {
+    const auto *CurrentBT = dyn_cast<BuiltinType>(ElementType);
+    switch (CurrentBT->getKind()) {
+    case BuiltinType::Kind::Float16:
+      return CGF.getContext().FloatTy;
+    case BuiltinType::Kind::Float:
+    case BuiltinType::Kind::BFloat16:
+      return CGF.getContext().DoubleTy;
+    case BuiltinType::Kind::Double:
+      return CGF.getContext().LongDoubleTy;
+    default:
+      return ElementType;
+    }
+  }
+
+  QualType HigherPrecisionTypeForComplexArithmetic(QualType ElementType,
+                                                   bool IsDivOpCode) {
+    QualType HigherElementType = GetHigherPrecisionFPType(ElementType);
+    const llvm::fltSemantics &ElementTypeSemantics =
+        CGF.getContext().getFloatTypeSemantics(ElementType);
+    const llvm::fltSemantics &HigherElementTypeSemantics =
+        CGF.getContext().getFloatTypeSemantics(HigherElementType);
+    if (llvm::APFloat::semanticsMaxExponent(ElementTypeSemantics) * 2 + 1 <=
+        llvm::APFloat::semanticsMaxExponent(HigherElementTypeSemantics)) {
+      return CGF.getContext().getComplexType(HigherElementType);
+    } else {
+      FPHasBeenPromoted = LangOptions::ComplexRangeKind::CX_Improved;
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zahiraam wrote:

The test is at line #2319 of CodeGen/cx-complex-range.c. 


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