2 dnl Copyright (C) 2012 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
7 AC_DEFUN([gl_FUNC_LOG1PF],
9 m4_divert_text([DEFAULTS], [gl_log1pf_required=plain])
10 AC_REQUIRE([gl_MATH_H_DEFAULTS])
11 AC_REQUIRE([gl_FUNC_LOG1P])
13 dnl Persuade glibc <math.h> to declare log1pf().
14 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
16 dnl Test whether log1pf() exists. Assume that log1pf(), if it exists, is
17 dnl defined in the same library as log1p().
19 LIBS="$LIBS $LOG1P_LIBM"
20 AC_CHECK_FUNCS([log1pf])
22 if test $ac_cv_func_log1pf = yes; then
23 LOG1PF_LIBM="$LOG1P_LIBM"
26 LIBS="$LIBS $LOG1PF_LIBM"
29 case "$gl_cv_func_log1pf_works" in
31 *) REPLACE_LOG1PF=1 ;;
34 m4_ifdef([gl_FUNC_LOG1PF_IEEE], [
35 if test $gl_log1pf_required = ieee && test $REPLACE_LOG1PF = 0; then
36 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
37 AC_CACHE_CHECK([whether log1pf works according to ISO C 99 with IEC 60559],
38 [gl_cv_func_log1pf_ieee],
41 LIBS="$LIBS $LOG1PF_LIBM"
44 #ifndef __NO_MATH_INLINES
45 # define __NO_MATH_INLINES 1 /* for glibc */
48 ]gl_FLOAT_MINUS_ZERO_CODE[
49 ]gl_FLOAT_SIGNBIT_CODE[
50 static float dummy (float x) { return 0; }
51 int main (int argc, char *argv[])
53 float (*my_log1pf) (float) = argc ? log1pf : dummy;
54 /* This test fails on OpenBSD 4.9, AIX 7.1. */
55 float y = my_log1pf (minus_zerof);
56 if (!(y == 0.0f) || (signbitf (minus_zerof) && !signbitf (y)))
61 [gl_cv_func_log1pf_ieee=yes],
62 [gl_cv_func_log1pf_ieee=no],
64 # Guess yes on glibc systems.
65 *-gnu*) gl_cv_func_log1pf_ieee="guessing yes" ;;
66 # If we don't know, assume the worst.
67 *) gl_cv_func_log1pf_ieee="guessing no" ;;
72 case "$gl_cv_func_log1pf_ieee" in
74 *) REPLACE_LOG1PF=1 ;;
81 if test $HAVE_LOG1PF = 0 || test $REPLACE_LOG1PF = 1; then
82 dnl Find libraries needed to link lib/log1pf.c.
83 LOG1PF_LIBM="$LOG1P_LIBM"
85 AC_SUBST([LOG1PF_LIBM])
88 dnl Test whether log1pf() works.
89 dnl On IRIX 6.5, log1pf(-1.0f) returns +Infinity instead of -Infinity.
90 AC_DEFUN([gl_FUNC_LOG1PF_WORKS],
92 AC_REQUIRE([AC_PROG_CC])
93 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
94 AC_CACHE_CHECK([whether log1pf works], [gl_cv_func_log1pf_works],
105 if (!(y + y == y && y < 0.0f))
110 [gl_cv_func_log1pf_works=yes],
111 [gl_cv_func_log1pf_works=no],
113 irix*) gl_cv_func_log1pf_works="guessing no";;
114 *) gl_cv_func_log1pf_works="guessing yes";;