2 dnl Copyright (C) 2012-2020 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_LOG1PL],
9 m4_divert_text([DEFAULTS], [gl_log1pl_required=plain])
10 AC_REQUIRE([gl_MATH_H_DEFAULTS])
11 AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
12 AC_REQUIRE([gl_FUNC_LOG1P])
14 dnl Persuade glibc <math.h> to declare log1pl().
15 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
17 dnl Test whether log1pl() exists. Assume that log1pl(), if it exists, is
18 dnl defined in the same library as log1p().
20 LIBS="$LIBS $LOG1P_LIBM"
21 AC_CHECK_FUNCS([log1pl])
23 if test $ac_cv_func_log1pl = yes; then
24 LOG1PL_LIBM="$LOG1P_LIBM"
25 m4_ifdef([gl_FUNC_LOG1PL_IEEE], [
26 if test $gl_log1pl_required = ieee && test $REPLACE_LOG1PL = 0; then
27 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
28 AC_CACHE_CHECK([whether log1pl works according to ISO C 99 with IEC 60559],
29 [gl_cv_func_log1pl_ieee],
32 LIBS="$LIBS $LOG1PL_LIBM"
35 #ifndef __NO_MATH_INLINES
36 # define __NO_MATH_INLINES 1 /* for glibc */
39 ]gl_LONG_DOUBLE_MINUS_ZERO_CODE[
40 ]gl_LONG_DOUBLE_SIGNBIT_CODE[
41 static long double dummy (long double x) { return 0; }
42 int main (int argc, char *argv[])
44 long double (* volatile my_log1pl) (long double) = argc ? log1pl : dummy;
45 /* This test fails on AIX 7.1, IRIX 6.5. */
46 long double y = my_log1pl (minus_zerol);
47 if (!(y == 0.0L) || (signbitl (minus_zerol) && !signbitl (y)))
52 [gl_cv_func_log1pl_ieee=yes],
53 [gl_cv_func_log1pl_ieee=no],
55 # Guess yes on glibc systems.
56 *-gnu* | gnu*) gl_cv_func_log1pl_ieee="guessing yes" ;;
57 # Guess yes on musl systems.
58 *-musl*) gl_cv_func_log1pl_ieee="guessing yes" ;;
59 # Guess yes on native Windows.
60 mingw*) gl_cv_func_log1pl_ieee="guessing yes" ;;
61 # If we don't know, obey --enable-cross-guesses.
62 *) gl_cv_func_log1pl_ieee="$gl_cross_guess_normal" ;;
67 case "$gl_cv_func_log1pl_ieee" in
69 *) REPLACE_LOG1PL=1 ;;
75 dnl Find libraries needed to link lib/log1pl.c.
76 if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
77 LOG1PL_LIBM="$LOG1P_LIBM"
79 AC_REQUIRE([gl_FUNC_ISNANL])
80 AC_REQUIRE([gl_FUNC_LOGL])
81 AC_REQUIRE([gl_FUNC_ROUNDL])
83 dnl Append $ISNANL_LIBM to LOG1PL_LIBM, avoiding gratuitous duplicates.
84 case " $LOG1PL_LIBM " in
85 *" $ISNANL_LIBM "*) ;;
86 *) LOG1PL_LIBM="$LOG1PL_LIBM $ISNANL_LIBM" ;;
88 dnl Append $LOGL_LIBM to LOG1PL_LIBM, avoiding gratuitous duplicates.
89 case " $LOG1PL_LIBM " in
91 *) LOG1PL_LIBM="$LOG1PL_LIBM $LOGL_LIBM" ;;
93 dnl Append $ROUNDL_LIBM to LOG1PL_LIBM, avoiding gratuitous duplicates.
94 case " $LOG1PL_LIBM " in
95 *" $ROUNDL_LIBM "*) ;;
96 *) LOG1PL_LIBM="$LOG1PL_LIBM $ROUNDL_LIBM" ;;
100 AC_SUBST([LOG1PL_LIBM])