Add support for a limited subset of TS 18661-3 math builtins.

These just overloads for _Float128. They're supported by GCC 7 and used
by glibc. APFloat support is already there so just add the overloads.

__builtin_copysignf128
__builtin_fabsf128
__builtin_huge_valf128
__builtin_inff128
__builtin_nanf128
__builtin_nansf128

This is the same support that GCC has, according to the documentation,
but limited to _Float128.

llvm-svn: 321948

1 files changed, 4 insertions, 2 deletions

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index b9a23ed9642..2e906247cc1 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -8929,10 +8929,12 @@ static QualType DecodeTypeFromStr(const char *&Str, const ASTContext &Context,
     Type = Context.FloatTy;
     break;
   case 'd':
-    assert(HowLong < 2 && !Signed && !Unsigned &&
+    assert(HowLong < 3 && !Signed && !Unsigned &&
            "Bad modifiers used with 'd'!");
-    if (HowLong)
+    if (HowLong == 1)
       Type = Context.LongDoubleTy;
+    else if (HowLong == 2)
+      Type = Context.Float128Ty;
     else
       Type = Context.DoubleTy;
     break;