2 files changed, 13 insertions, 2 deletions
diff --git a/manual/arith.texi b/manual/arith.texi
index 6ecde21b7c..5fb18f3561 100644
--- a/manual/arith.texi
+++ b/manual/arith.texi
@@ -1873,7 +1873,8 @@ undesirable.  @w{ISO C99} therefore defines comparison functions that
 do not raise exceptions when NaN is examined.  All of the functions are
 implemented as macros which allow their arguments to be of any
 floating-point type.  The macros are guaranteed to evaluate their
-arguments only once.
+arguments only once.  TS 18661-1:2014 adds such a macro for an
+equality comparison that @emph{does} raise an exception for a NaN argument.
 
 @comment math.h
 @comment ISO
@@ -1932,6 +1933,16 @@ This macro determines whether its arguments are unordered.  In other
 words, it is true if @var{x} or @var{y} are NaN, and false otherwise.
 @end deftypefn
 
+@comment math.h
+@comment ISO
+@deftypefn Macro int iseqsig (@emph{real-floating} @var{x}, @emph{real-floating} @var{y})
+@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
+This macro determines whether its arguments are equal.  It is
+equivalent to @code{(@var{x}) == (@var{y})}, but it raises the invalid
+exception and sets @code{errno} to @code{EDOM} is either argument is a
+NaN.
+@end deftypefn
+
 Not all machines provide hardware support for these operations.  On
 machines that don't, the macros can be very slow.  Therefore, you should
 not use these functions when NaN is not a concern.
diff --git a/manual/libm-err-tab.pl b/manual/libm-err-tab.pl
index b36ef94325..451547871b 100755
--- a/manual/libm-err-tab.pl
+++ b/manual/libm-err-tab.pl
@@ -78,7 +78,7 @@ use vars qw (%results @all_floats %suffices @all_functions);
     "scalbn", "sin", "sincos", "sinh", "sqrt", "tan", "tanh", "tgamma",
     "trunc", "y0", "y1", "yn" );
 # fpclassify, iscanonical, isnormal, isfinite, isinf, isnan, issignaling,
-# issubnormal, iszero, signbit, isgreater, isgreaterequal, isless,
+# issubnormal, iszero, signbit, iseqsig, isgreater, isgreaterequal, isless,
 # islessequal, islessgreater, isunordered are not tabulated.
 
 if ($#ARGV == 0) {