Adjust __MATH_EVAL_FMT2 definition to handle _Float16 better.

Continuing the preparation for additional _FloatN / _FloatNx type
support, this patch adds an additional case in the definition of
__MATH_EVAL_FMT2, as used in defining iseqsig: when
__FLT_EVAL_METHOD__ is 0 or 32, it adds 0.0f to the arguments, so that
the correct function would be selected in the case of _Float16
arguments with excess precision (were glibc to support _Float16, which
of course __MATH_TG and other facilities do not at present - and
_Float16 support is not part of what this patch series is aiming for,
but this particular fix is simple so is included anyway).

Tested for x86_64.

	* math/math.h
	[__FLT_EVAL_METHOD__ == 0 || __FLT_EVAL_METHOD__ == 32]
	(__MATH_EVAL_FMT2): Define to add 0.0f.

1 files changed, 6 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 2bf841cfd1..52ee8ee2f1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2017-10-31  Joseph Myers  <joseph@codesourcery.com>
+
+	* math/math.h
+	[__FLT_EVAL_METHOD__ == 0 || __FLT_EVAL_METHOD__ == 32]
+	(__MATH_EVAL_FMT2): Define to add 0.0f.
+
 2017-10-31  Alan Modra  <amodra@gmail.com>
 
 	* sysdeps/powerpc/powerpc64/fpu/multiarch/e_expf-power8.S: Don't