Use __HAVE_DISTINCT_FLOAT128 in tgmath.h [committed]

Use __HAVE_DISTINCT_FLOAT128 in tgmath.h [committed]

[Joseph Myers]

When _Float128 is ABI-equivalent to long double, there is no need for
tgmath.h to have any special _Float128 handling: it's always OK to
call the long double versions of functions for _Float128 arguments in
that case, and the logic to determine return types is generic.  Thus,
this patch changes the use of __HAVE_FLOAT128 to
__HAVE_DISTINCT_FLOAT128, as a minor optimization to reduce the size
of the macro expansions in the ABI-equivalent case.

Tested for x86_64.  Committed.

2017-08-25  Joseph Myers  <joseph@codesourcery.com>

	* math/tgmath.h [__HAVE_FLOAT128]: Change conditional to
	[__HAVE_DISTINCT_FLOAT128].

diff --git a/math/tgmath.h b/math/tgmath.h
index 68cee64..243813c 100644
--- a/math/tgmath.h
+++ b/math/tgmath.h
@@ -118,7 +118,7 @@
 /* Expand to text that checks if ARG_COMB has type _Float128, and if
    so calls the appropriately suffixed FCT (which may include a cast),
    or FCT and CFCT for complex functions, with arguments ARG_CALL.  */
-# if __HAVE_FLOAT128 && __GLIBC_USE (IEC_60559_TYPES_EXT)
+# if __HAVE_DISTINCT_FLOAT128 && __GLIBC_USE (IEC_60559_TYPES_EXT)
 #  define __TGMATH_F128(arg_comb, fct, arg_call) \
   __builtin_types_compatible_p (__typeof (+(arg_comb)), _Float128)	\
   ? fct ## f128 arg_call :

-- 
Joseph S. Myers
joseph@codesourcery.com