[Clang] Enable KF and KC mode for [_Complex] __float128

The headers provided with recent GNU toolchains for PPC have code that includes
typedefs such as:

typedef _Complex float __cfloat128 __attribute__ ((__mode__ (__KC__)))

This patch allows clang to compile programs that contain
#include <math.h>

with -mfloat128 which it currently fails to compile.

Fixes: https://bugs.llvm.org/show_bug.cgi?id=46068

Differential revision: https://reviews.llvm.org/D80374

1 files changed, 6 insertions, 1 deletions

diff --git a/clang/lib/Basic/TargetInfo.cpp b/clang/lib/Basic/TargetInfo.cpp
index 2f1e044..a3c8da5 100644
--- a/clang/lib/Basic/TargetInfo.cpp
+++ b/clang/lib/Basic/TargetInfo.cpp
@@ -265,7 +265,8 @@ TargetInfo::IntType TargetInfo::getLeastIntTypeByWidth(unsigned BitWidth,
   return NoInt;
 }
 
-TargetInfo::RealType TargetInfo::getRealTypeByWidth(unsigned BitWidth) const {
+TargetInfo::RealType TargetInfo::getRealTypeByWidth(unsigned BitWidth,
+                                                    bool ExplicitIEEE) const {
   if (getFloatWidth() == BitWidth)
     return Float;
   if (getDoubleWidth() == BitWidth)
@@ -277,6 +278,10 @@ TargetInfo::RealType TargetInfo::getRealTypeByWidth(unsigned BitWidth) const {
       return 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 (&getLongDoubleFormat() == &llvm::APFloat::PPCDoubleDouble() ||
         &getLongDoubleFormat() == &llvm::APFloat::IEEEquad())
       return LongDouble;