On glibc systems, use of copysign() does not require linking with libm.
This patch ensures that COPYSIGN_LIBM gets set to empty rather than to -lm.
2010-07-31 Bruno Haible <br...@clisp.org>
copysign: Does not require -lm on glibc systems.
* modules/copysign (configure.ac): Use gl_MATHFUNC, not
gl_COMMON_DOUBLE_MATHFUNC.
* m4/mathfunc.m4 (gl_COMMON_DOUBLE_MATHFUNC): Update comments.
--- modules/copysign.orig Sat Jul 31 12:08:11 2010
+++ modules/copysign Sat Jul 31 12:06:01 2010
@@ -7,7 +7,7 @@
Depends-on:
configure.ac:
-gl_COMMON_DOUBLE_MATHFUNC([copysign])
+gl_MATHFUNC([copysign], [double], [(double, double)])
Makefile.am:
--- m4/mathfunc.m4.orig Sat Jul 31 12:08:11 2010
+++ m4/mathfunc.m4 Sat Jul 31 12:07:53 2010
@@ -1,4 +1,4 @@
-# mathfunc.m4 serial 4
+# mathfunc.m4 serial 5
dnl Copyright (C) 2010 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -65,8 +65,8 @@
# It sets FUNC_LIBM to empty or "-lm" accordingly.
# FUNC must be one of the following functions, that are present on all systems
# and provided by libm on all systems except MacOS X, BeOS, Haiku:
-# acos asin atan atan2 cbrt copysign cos cosh erf erfc exp fmod hypot j0 j1
-# jn lgamma log log10 log1p pow remainder sin sinh sqrt tan tanh y0 y1 yn
+# acos asin atan atan2 cbrt cos cosh erf erfc exp fmod hypot j0 j1 jn lgamma
+# log log10 log1p pow remainder sin sinh sqrt tan tanh y0 y1 yn
AC_DEFUN([gl_COMMON_DOUBLE_MATHFUNC],
[
@@ -86,7 +86,6 @@
dnl gl_MATHFUNC([atan], [double], [(double)])
dnl gl_MATHFUNC([atan2], [double], [(double, double)])
dnl gl_MATHFUNC([cbrt], [double], [(double)])
- dnl gl_MATHFUNC([copysign], [double], [(double, double)])
dnl gl_MATHFUNC([cos], [double], [(double)])
dnl gl_MATHFUNC([cosh], [double], [(double)])
dnl gl_MATHFUNC([erf], [double], [(double)])
