Enable support for __float128 in Clang

This patch corresponds to review:
http://reviews.llvm.org/D15120

It adds support for the __float128 keyword, literals and a target feature to
enable it. This support is disabled by default on all targets and any target
that has support for this type is free to add it.

Based on feedback that I've received from target maintainers, this appears to
be the right thing for most targets. I have not heard from the maintainers of
X86 which I believe supports this type. I will subsequently investigate the
impact of enabling this on X86.

llvm-svn: 266186

1 files changed, 16 insertions, 9 deletions

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index fb4c80bd7fd..2b103308bb2 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -58,7 +58,7 @@ unsigned ASTContext::NumImplicitDestructors;
 unsigned ASTContext::NumImplicitDestructorsDeclared;
 
 enum FloatingRank {
-  HalfRank, FloatRank, DoubleRank, LongDoubleRank
+  HalfRank, FloatRank, DoubleRank, LongDoubleRank, Float128Rank
 };
 
 RawComment *ASTContext::getRawCommentForDeclNoCache(const Decl *D) const {
@@ -967,14 +967,6 @@ TypedefDecl *ASTContext::getUInt128Decl() const {
   return UInt128Decl;
 }
 
-TypeDecl *ASTContext::getFloat128StubType() const {
-  assert(LangOpts.CPlusPlus && "should only be called for c++");
-  if (!Float128StubDecl)
-    Float128StubDecl = buildImplicitRecord("__float128");
-
-  return Float128StubDecl;
-}
-
 void ASTContext::InitBuiltinType(CanQualType &R, BuiltinType::Kind K) {
   BuiltinType *Ty = new (*this, TypeAlignment) BuiltinType(K);
   R = CanQualType::CreateUnsafe(QualType(Ty, 0));
@@ -1023,6 +1015,9 @@ void ASTContext::InitBuiltinTypes(const TargetInfo &Target,
   InitBuiltinType(DoubleTy,            BuiltinType::Double);
   InitBuiltinType(LongDoubleTy,        BuiltinType::LongDouble);
 
+  // GNU extension, __float128 for IEEE quadruple precision
+  InitBuiltinType(Float128Ty,          BuiltinType::Float128);
+
   // GNU extension, 128-bit integers.
   InitBuiltinType(Int128Ty,            BuiltinType::Int128);
   InitBuiltinType(UnsignedInt128Ty,    BuiltinType::UInt128);
@@ -1084,6 +1079,7 @@ void ASTContext::InitBuiltinTypes(const TargetInfo &Target,
   FloatComplexTy      = getComplexType(FloatTy);
   DoubleComplexTy     = getComplexType(DoubleTy);
   LongDoubleComplexTy = getComplexType(LongDoubleTy);
+  Float128ComplexTy   = getComplexType(Float128Ty);
 
   // Builtin types for 'id', 'Class', and 'SEL'.
   InitBuiltinType(ObjCBuiltinIdTy, BuiltinType::ObjCId);
@@ -1341,6 +1337,7 @@ const llvm::fltSemantics &ASTContext::getFloatTypeSemantics(QualType T) const {
   case BuiltinType::Float:      return Target->getFloatFormat();
   case BuiltinType::Double:     return Target->getDoubleFormat();
   case BuiltinType::LongDouble: return Target->getLongDoubleFormat();
+  case BuiltinType::Float128:   return Target->getFloat128Format();
   }
 }
 
@@ -1651,6 +1648,10 @@ TypeInfo ASTContext::getTypeInfoImpl(const Type *T) const {
       Width = Target->getLongDoubleWidth();
       Align = Target->getLongDoubleAlign();
       break;
+    case BuiltinType::Float128:
+      Width = Target->getFloat128Width();
+      Align = Target->getFloat128Align();
+      break;
     case BuiltinType::NullPtr:
       Width = Target->getPointerWidth(0); // C++ 3.9.1p11: sizeof(nullptr_t)
       Align = Target->getPointerAlign(0); //   == sizeof(void*)
@@ -4635,6 +4636,7 @@ static FloatingRank getFloatingRank(QualType T) {
   case BuiltinType::Float:      return FloatRank;
   case BuiltinType::Double:     return DoubleRank;
   case BuiltinType::LongDouble: return LongDoubleRank;
+  case BuiltinType::Float128:   return Float128Rank;
   }
 }
 
@@ -4651,6 +4653,7 @@ QualType ASTContext::getFloatingTypeOfSizeWithinDomain(QualType Size,
     case FloatRank:      return FloatComplexTy;
     case DoubleRank:     return DoubleComplexTy;
     case LongDoubleRank: return LongDoubleComplexTy;
+    case Float128Rank:   return Float128ComplexTy;
     }
   }
 
@@ -4660,6 +4663,7 @@ QualType ASTContext::getFloatingTypeOfSizeWithinDomain(QualType Size,
   case FloatRank:      return FloatTy;
   case DoubleRank:     return DoubleTy;
   case LongDoubleRank: return LongDoubleTy;
+  case Float128Rank:   return Float128Ty;
   }
   llvm_unreachable("getFloatingRank(): illegal value for rank");
 }
@@ -5489,6 +5493,7 @@ static char getObjCEncodingForPrimitiveKind(const ASTContext *C,
     case BuiltinType::LongDouble: return 'D';
     case BuiltinType::NullPtr:    return '*'; // like char*
 
+    case BuiltinType::Float128:
     case BuiltinType::Half:
       // FIXME: potentially need @encodes for these!
       return ' ';
@@ -8679,6 +8684,8 @@ QualType ASTContext::getRealTypeForBitwidth(unsigned DestWidth) const {
     return DoubleTy;
   case TargetInfo::LongDouble:
     return LongDoubleTy;
+  case TargetInfo::Float128:
+    return Float128Ty;
   case TargetInfo::NoFloat:
     return QualType();
   }