[Clang] Add __ibm128 type to represent ppc_fp128

Currently, we have no front-end type for ppc_fp128 type in IR. PowerPC
target generates ppc_fp128 type from long double now, but there's option
(-mabi=(ieee|ibm)longdouble) to control it and we're going to do
transition from IBM extended double-double ppc_fp128 to IEEE fp128 in
the future.

This patch adds type __ibm128 which always represents ppc_fp128 in IR,
as what GCC did for that type. Without this type in Clang, compilation
will fail if compiling against future version of libstdcxx (which uses
__ibm128 in headers).

Although all operations in backend for __ibm128 is done by software,
only PowerPC enables support for it.

There's something not implemented in this commit, which can be done in
future ones:

- Literal suffix for __ibm128 type. w/W is suitable as GCC documented.
- __attribute__((mode(IF))) should be for __ibm128.
- Complex __ibm128 type.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D93377

1 files changed, 7 insertions, 0 deletions

diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index 7cec896..9f660e4 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -3929,6 +3929,10 @@ void Parser::ParseDeclarationSpecifiers(DeclSpec &DS,
       isInvalid = DS.SetTypeSpecType(DeclSpec::TST_float128, Loc, PrevSpec,
                                      DiagID, Policy);
       break;
+    case tok::kw___ibm128:
+      isInvalid = DS.SetTypeSpecType(DeclSpec::TST_ibm128, Loc, PrevSpec,
+                                     DiagID, Policy);
+      break;
     case tok::kw_wchar_t:
       isInvalid = DS.SetTypeSpecType(DeclSpec::TST_wchar, Loc, PrevSpec,
                                      DiagID, Policy);
@@ -5007,6 +5011,7 @@ bool Parser::isKnownToBeTypeSpecifier(const Token &Tok) const {
   case tok::kw__Fract:
   case tok::kw__Float16:
   case tok::kw___float128:
+  case tok::kw___ibm128:
   case tok::kw_bool:
   case tok::kw__Bool:
   case tok::kw__Decimal32:
@@ -5088,6 +5093,7 @@ bool Parser::isTypeSpecifierQualifier() {
   case tok::kw__Fract:
   case tok::kw__Float16:
   case tok::kw___float128:
+  case tok::kw___ibm128:
   case tok::kw_bool:
   case tok::kw__Bool:
   case tok::kw__Decimal32:
@@ -5258,6 +5264,7 @@ bool Parser::isDeclarationSpecifier(bool DisambiguatingWithExpression) {
   case tok::kw__Fract:
   case tok::kw__Float16:
   case tok::kw___float128:
+  case tok::kw___ibm128:
   case tok::kw_bool:
   case tok::kw__Bool:
   case tok::kw__Decimal32: