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authorJoseph Myers <joseph@codesourcery.com>2016-10-07 23:28:33 +0000
committerJoseph Myers <joseph@codesourcery.com>2016-10-07 23:28:33 +0000
commitd0800ae0e7162631136a0042e87eb42c641455d9 (patch)
tree2bd2e6a01da8827ad5e2536b8c3aa4ae258a481b /math/math.h
parent12e5d361a4dcfe3579f1dd263f911ac193b0fa29 (diff)
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Make iseqsig handle excess precision.
iseqsig, like other type-generic comparison macros, should behave like
a comparison operator in not removing excess range and precision from
its arguments (see C11 F.10.11).  This patch implements this by making
definitions of iseqsig appropriately conditional on
__FLT_EVAL_METHOD__ (including support for TS 18661-3 values of that
macro), with a corresponding testcase (that failed for 32-bit x86 in
the absence of the math.h changes) being added.  (Of course the
definitions may need reworking when float128 support is added, just as
with other type-generic macros.)

Tested for x86_64 and x86.

	* math/math.h [__GLIBC_USE (IEC_60559_BFP_EXT)] (iseqsig): Define
	conditional on value of [__FLT_EVAL_METHOD__].
	* math/test-iseqsig-excess-precision.c: New file.
	* math/Makefile (tests): Add test-iseqsig-excess-precision.
Diffstat (limited to 'math/math.h')
-rw-r--r--math/math.h19
1 files changed, 17 insertions, 2 deletions
diff --git a/math/math.h b/math/math.h
index 394cefae02..880b4a018c 100644
--- a/math/math.h
+++ b/math/math.h
@@ -535,17 +535,32 @@ extern int matherr (struct exception *__exc);
 /* Return X == Y but raising "invalid" and setting errno if X or Y is
    a NaN.  */
 # ifdef __NO_LONG_DOUBLE_MATH
-#  define iseqsig(x, y)				\
+#  if (__FLT_EVAL_METHOD__ == 1			\
+       || __FLT_EVAL_METHOD__ == 2		\
+       || __FLT_EVAL_METHOD__ > 32)
+#   define iseqsig(x, y) __iseqsig ((x), (y))
+#  else
+#   define iseqsig(x, y)			\
   (sizeof ((x) + (y)) == sizeof (float)		\
    ? __iseqsigf ((x), (y))			\
    : __iseqsig ((x), (y)))
+#  endif
 # else
-#  define iseqsig(x, y)				\
+#  if __FLT_EVAL_METHOD__ == 2 || __FLT_EVAL_METHOD__ > 64
+#   define iseqsig(x, y) __iseqsigl ((x), (y))
+#  elif __FLT_EVAL_METHOD__ == 1 || __FLT_EVAL_METHOD__ > 32
+#   define iseqsig(x, y)			\
+  (sizeof ((x) + (y)) <= sizeof (double)	\
+   ? __iseqsig ((x), (y))			\
+   : __iseqsigl ((x), (y)))
+#  else
+#   define iseqsig(x, y)			\
   (sizeof ((x) + (y)) == sizeof (float)		\
    ? __iseqsigf ((x), (y))			\
    : sizeof ((x) + (y)) == sizeof (double)	\
    ? __iseqsig ((x), (y))			\
    : __iseqsigl ((x), (y)))
+#  endif
 # endif
 #endif