[NFC] [Clang] Use global enum for explicit float mode

[qiucf]

Summary

Currently, there're multiple float types that can be represented by __attribute__((mode(xx))). It's parsed, and then a corresponding type is created if available.

This refactor moves the enum for mode into a global enum class visible to ASTContext, as discussed in D109950.

[aaron.ballman]

LGTM, thanks for the cleanup!

clang/lib/Sema/SemaDeclAttr.cpp

4209

This bit looks like it's not an NFC change -- we never used to set this value before. However, it is an NFC change because the caller always sets ExplicitType to NoFloat, so this is more for safety when adding new callers, which is fine by me.

clang/include/clang/AST/ASTContext.h

 class CXXConstructorDecl;
 class CXXMethodDecl;
 class CXXRecordDecl;
 class DiagnosticsEngine;
 class ParentMapContext;
 class DynTypedNode;
 class DynTypedNodeList;
 class Expr;
+enum class FloatModeKind;
 class GlobalDecl;
 class ItaniumMangleContext;
 class MangleContext;
 class MangleNumberingContext;
 class MaterializeTemporaryExpr;
 class MemberSpecializationInfo;
 class Module;
 struct MSGuidDeclParts;

   /// bitwidth, signed/unsigned.
   /// Returns empty type if there is no appropriate target types.
   QualType getIntTypeForBitwidth(unsigned DestWidth,
                                  unsigned Signed) const;
 
   /// getRealTypeForBitwidth -
   /// sets floating point QualTy according to specified bitwidth.
   /// Returns empty type if there is no appropriate target types.
-  QualType getRealTypeForBitwidth(unsigned DestWidth, bool ExplicitIEEE) const;
+  QualType getRealTypeForBitwidth(unsigned DestWidth,
+                                  FloatModeKind ExplicitType) const;
 
   bool AtomicUsesUnsupportedLibcall(const AtomicExpr *E) const;
 
   const LangOptions& getLangOpts() const { return LangOpts; }
 
   // If this condition is false, typo correction must be performed eagerly
   // rather than delayed in many places, as it makes use of dependent types.
   // the condition is false for clang's C-only codepath, as it doesn't support

clang/include/clang/Basic/TargetInfo.h

 class CodeGenOptions;
 class MacroBuilder;
 class QualType;
 class SourceLocation;
 class SourceManager;
 
 namespace Builtin { struct Info; }
 
+enum class FloatModeKind {
+  NoFloat = 255,
+  Float = 0,
+  Double,
+  LongDouble,
+  Float128,
+  Ibm128
+};
+
 /// Fields controlling how types are laid out in memory; these may need to
 /// be copied for targets like AMDGPU that base their ABIs on an auxiliary
 /// CPU target.
 struct TransferrableTargetInfo {
   unsigned char PointerWidth, PointerAlign;
   unsigned char BoolWidth, BoolAlign;
   unsigned char IntWidth, IntAlign;
   unsigned char HalfWidth, HalfAlign;

     SignedInt,
     UnsignedInt,
     SignedLong,
     UnsignedLong,
     SignedLongLong,
     UnsignedLongLong
   };
 
-  enum RealType {
-    NoFloat = 255,
-    Float = 0,
-    Double,
-    LongDouble,
-    Float128,
-    Ibm128
-  };
-
 protected:
   IntType SizeType, IntMaxType, PtrDiffType, IntPtrType, WCharType, WIntType,
       Char16Type, Char32Type, Int64Type, Int16Type, SigAtomicType,
       ProcessIDType;
 
   /// Whether Objective-C's built-in boolean type should be signed char.
   ///
   /// Otherwise, when this flag is not set, the normal built-in boolean type is

                                          bool IsSigned) const;
 
   /// Return floating point type with specified width. On PPC, there are
   /// three possible types for 128-bit floating point: "PPC double-double",
   /// IEEE 754R quad precision, and "long double" (which under the covers
   /// is represented as one of those two). At this time, there is no support
   /// for an explicit "PPC double-double" type (i.e. __ibm128) so we only
   /// need to differentiate between "long double" and IEEE quad precision.
-  RealType getRealTypeByWidth(unsigned BitWidth, bool ExplicitIEEE) const;
+  FloatModeKind getRealTypeByWidth(unsigned BitWidth,
+                                   FloatModeKind ExplicitType) const;
 
   /// Return the alignment (in bits) of the specified integer type enum.
   ///
   /// For example, SignedInt -> getIntAlign().
   unsigned getTypeAlign(IntType T) const;
 
   /// Returns true if the type is signed; false otherwise.
   static bool isTypeSigned(IntType T);

   /// Return the printf format modifier for the specified
   /// integer type enum.
   ///
   /// For example, SignedLong -> "l".
   static const char *getTypeFormatModifier(IntType T);
 
   /// Check whether the given real type should use the "fpret" flavor of
   /// Objective-C message passing on this target.
-  bool useObjCFPRetForRealType(RealType T) const {
-    return RealTypeUsesObjCFPRet & (1 << T);
+  bool useObjCFPRetForRealType(FloatModeKind T) const {
+    return RealTypeUsesObjCFPRet & (1 << (int)T);
   }
 
   /// Check whether _Complex long double should use the "fp2ret" flavor
   /// of Objective-C message passing on this target.
   bool useObjCFP2RetForComplexLongDouble() const {
     return ComplexLongDoubleUsesFP2Ret;
   }
 

clang/lib/AST/ASTContext.cpp

     return Signed ? Int128Ty : UnsignedInt128Ty;
   return QualTy;
 }
 
 /// getRealTypeForBitwidth -
 /// sets floating point QualTy according to specified bitwidth.
 /// Returns empty type if there is no appropriate target types.
 QualType ASTContext::getRealTypeForBitwidth(unsigned DestWidth,
-                                            bool ExplicitIEEE) const {
-  TargetInfo::RealType Ty =
-      getTargetInfo().getRealTypeByWidth(DestWidth, ExplicitIEEE);
+                                            FloatModeKind ExplicitType) const {
+  FloatModeKind Ty =
+      getTargetInfo().getRealTypeByWidth(DestWidth, ExplicitType);
   switch (Ty) {
-  case TargetInfo::Float:
+  case FloatModeKind::Float:
     return FloatTy;
-  case TargetInfo::Double:
+  case FloatModeKind::Double:
     return DoubleTy;
-  case TargetInfo::LongDouble:
+  case FloatModeKind::LongDouble:
     return LongDoubleTy;
-  case TargetInfo::Float128:
+  case FloatModeKind::Float128:
     return Float128Ty;
-  case TargetInfo::Ibm128:
+  case FloatModeKind::Ibm128:
     return Ibm128Ty;
-  case TargetInfo::NoFloat:
+  case FloatModeKind::NoFloat:
     return {};
   }
 
   llvm_unreachable("Unhandled TargetInfo::RealType value");
 }
 
 void ASTContext::setManglingNumber(const NamedDecl *ND, unsigned Number) {
   if (Number > 1)

clang/lib/Basic/TargetInfo.cpp

     return IsSigned ? SignedInt : UnsignedInt;
   if (getLongWidth() >= BitWidth)
     return IsSigned ? SignedLong : UnsignedLong;
   if (getLongLongWidth() >= BitWidth)
     return IsSigned ? SignedLongLong : UnsignedLongLong;
   return NoInt;
 }
 
-TargetInfo::RealType TargetInfo::getRealTypeByWidth(unsigned BitWidth,
-                                                    bool ExplicitIEEE) const {
+FloatModeKind TargetInfo::getRealTypeByWidth(unsigned BitWidth,
+                                             FloatModeKind ExplicitType) const {
   if (getFloatWidth() == BitWidth)
-    return Float;
+    return FloatModeKind::Float;
   if (getDoubleWidth() == BitWidth)
-    return Double;
+    return FloatModeKind::Double;
 
   switch (BitWidth) {
   case 96:
     if (&getLongDoubleFormat() == &llvm::APFloat::x87DoubleExtended())
-      return LongDouble;
+      return FloatModeKind::LongDouble;
     break;
   case 128:
     // The caller explicitly asked for an IEEE compliant type but we still
     // have to check if the target supports it.
-    if (ExplicitIEEE)
-      return hasFloat128Type() ? Float128 : NoFloat;
+    if (ExplicitType == FloatModeKind::Float128)
+      return hasFloat128Type() ? FloatModeKind::Float128
+                               : FloatModeKind::NoFloat;
     if (&getLongDoubleFormat() == &llvm::APFloat::PPCDoubleDouble() ||
         &getLongDoubleFormat() == &llvm::APFloat::IEEEquad())
-      return LongDouble;
+      return FloatModeKind::LongDouble;
     if (hasFloat128Type())
-      return Float128;
+      return FloatModeKind::Float128;
     break;
   }
 
-  return NoFloat;
+  return FloatModeKind::NoFloat;
 }
 
 /// getTypeAlign - Return the alignment (in bits) of the specified integer type
 /// enum. For example, SignedInt -> getIntAlign().
 unsigned TargetInfo::getTypeAlign(IntType T) const {
   switch (T) {
   default: llvm_unreachable("not an integer!");
   case SignedChar:

clang/lib/Basic/Targets/X86.h

         Triple.isOSBinFormatMachO() ? "_" : "");
     SizeType = UnsignedInt;
     PtrDiffType = SignedInt;
     IntPtrType = SignedInt;
     RegParmMax = 3;
 
     // Use fpret for all types.
     RealTypeUsesObjCFPRet =
-        ((1 << TargetInfo::Float) | (1 << TargetInfo::Double) |
-         (1 << TargetInfo::LongDouble));
+        ((1 << (int)FloatModeKind::Float) | (1 << (int)FloatModeKind::Double) |
+         (1 << (int)FloatModeKind::LongDouble));
 
     // x86-32 has atomics up to 8 bytes
     MaxAtomicPromoteWidth = 64;
     MaxAtomicInlineWidth = 32;
   }
 
   BuiltinVaListKind getBuiltinVaListKind() const override {
     return TargetInfo::CharPtrBuiltinVaList;

     resetDataLayout(IsX32 ? "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-"
                             "i64:64-f80:128-n8:16:32:64-S128"
                           : IsWinCOFF ? "e-m:w-p270:32:32-p271:32:32-p272:64:"
                                         "64-i64:64-f80:128-n8:16:32:64-S128"
                                       : "e-m:e-p270:32:32-p271:32:32-p272:64:"
                                         "64-i64:64-f80:128-n8:16:32:64-S128");
 
     // Use fpret only for long double.
-    RealTypeUsesObjCFPRet = (1 << TargetInfo::LongDouble);
+    RealTypeUsesObjCFPRet = (1 << (int)FloatModeKind::LongDouble);
 
     // Use fp2ret for _Complex long double.
     ComplexLongDoubleUsesFP2Ret = true;
 
     // Make __builtin_ms_va_list available.
     HasBuiltinMSVaList = true;
 
     // x86-64 has atomics up to 16 bytes.

clang/lib/CodeGen/CGCall.cpp

 }
 
 bool CodeGenModule::ReturnTypeUsesFPRet(QualType ResultType) {
   if (const BuiltinType *BT = ResultType->getAs<BuiltinType>()) {
     switch (BT->getKind()) {
     default:
       return false;
     case BuiltinType::Float:
-      return getTarget().useObjCFPRetForRealType(TargetInfo::Float);
+      return getTarget().useObjCFPRetForRealType(FloatModeKind::Float);
     case BuiltinType::Double:
-      return getTarget().useObjCFPRetForRealType(TargetInfo::Double);
+      return getTarget().useObjCFPRetForRealType(FloatModeKind::Double);
     case BuiltinType::LongDouble:
-      return getTarget().useObjCFPRetForRealType(TargetInfo::LongDouble);
+      return getTarget().useObjCFPRetForRealType(FloatModeKind::LongDouble);
     }
   }
 
   return false;
 }
 
 bool CodeGenModule::ReturnTypeUsesFP2Ret(QualType ResultType) {
   if (const ComplexType *CT = ResultType->getAs<ComplexType>()) {

clang/lib/Sema/SemaDeclAttr.cpp

   Diag(RD->getDefinition()->getLocation(), diag::note_defined_here) << RD;
   return true;
 }
 
 /// parseModeAttrArg - Parses attribute mode string and returns parsed type
 /// attribute.
 static void parseModeAttrArg(Sema &S, StringRef Str, unsigned &DestWidth,
                              bool &IntegerMode, bool &ComplexMode,
-                             bool &ExplicitIEEE) {
+                             FloatModeKind &ExplicitType) {
   IntegerMode = true;
   ComplexMode = false;
+  ExplicitType = FloatModeKind::NoFloat;
   switch (Str.size()) {
   case 2:
     switch (Str[0]) {
     case 'Q':
       DestWidth = 8;
       break;
     case 'H':
       DestWidth = 16;
       break;
     case 'S':
       DestWidth = 32;
       break;
     case 'D':
       DestWidth = 64;
       break;
     case 'X':
       DestWidth = 96;
       break;
     case 'K': // KFmode - IEEE quad precision (__float128)
-      ExplicitIEEE = true;
+      ExplicitType = FloatModeKind::Float128;
       DestWidth = Str[1] == 'I' ? 0 : 128;
       break;
     case 'T':
-      ExplicitIEEE = false;
+      ExplicitType = FloatModeKind::LongDouble;
       DestWidth = 128;
       break;
     }
     if (Str[1] == 'F') {
       IntegerMode = false;
     } else if (Str[1] == 'C') {
       IntegerMode = false;
       ComplexMode = true;

                        IdentifierInfo *Name, bool InInstantiation) {
   StringRef Str = Name->getName();
   normalizeName(Str);
   SourceLocation AttrLoc = CI.getLoc();
 
   unsigned DestWidth = 0;
   bool IntegerMode = true;
   bool ComplexMode = false;
-  bool ExplicitIEEE = false;
+  FloatModeKind ExplicitType = FloatModeKind::NoFloat;
   llvm::APInt VectorSize(64, 0);
   if (Str.size() >= 4 && Str[0] == 'V') {
     // Minimal length of vector mode is 4: 'V' + NUMBER(>=1) + TYPE(>=2).
     size_t StrSize = Str.size();
     size_t VectorStringLength = 0;
     while ((VectorStringLength + 1) < StrSize &&
            isdigit(Str[VectorStringLength + 1]))
       ++VectorStringLength;
     if (VectorStringLength &&
         !Str.substr(1, VectorStringLength).getAsInteger(10, VectorSize) &&
         VectorSize.isPowerOf2()) {
       parseModeAttrArg(*this, Str.substr(VectorStringLength + 1), DestWidth,
-                       IntegerMode, ComplexMode, ExplicitIEEE);
+                       IntegerMode, ComplexMode, ExplicitType);
       // Avoid duplicate warning from template instantiation.
       if (!InInstantiation)
         Diag(AttrLoc, diag::warn_vector_mode_deprecated);
     } else {
       VectorSize = 0;
     }
   }
 
   if (!VectorSize)
     parseModeAttrArg(*this, Str, DestWidth, IntegerMode, ComplexMode,
-                     ExplicitIEEE);
+                     ExplicitType);
 
   // FIXME: Sync this with InitializePredefinedMacros; we need to match int8_t
   // and friends, at least with glibc.
   // FIXME: Make sure floating-point mappings are accurate
   // FIXME: Support XF and TF types
   if (!DestWidth) {
     Diag(AttrLoc, diag::err_machine_mode) << 0 /*Unknown*/ << Name;
     return;

   }
 
   QualType NewElemTy;
 
   if (IntegerMode)
     NewElemTy = Context.getIntTypeForBitwidth(DestWidth,
                                               OldElemTy->isSignedIntegerType());
   else
-    NewElemTy = Context.getRealTypeForBitwidth(DestWidth, ExplicitIEEE);
+    NewElemTy = Context.getRealTypeForBitwidth(DestWidth, ExplicitType);
 
   if (NewElemTy.isNull()) {
     Diag(AttrLoc, diag::err_machine_mode) << 1 /*Unsupported*/ << Name;
     return;
   }
 
   if (ComplexMode) {
     NewElemTy = Context.getComplexType(NewElemTy);