1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
|
# roundf.m4 serial 25
dnl Copyright (C) 2007-2023 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
AC_DEFUN([gl_FUNC_ROUNDF],
[
m4_divert_text([DEFAULTS], [gl_roundf_required=plain])
AC_REQUIRE([gl_MATH_H_DEFAULTS])
dnl Persuade glibc <math.h> to declare roundf().
AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
gl_CHECK_MATH_LIB([ROUNDF_LIBM], [x = roundf (x);],
[extern
#ifdef __cplusplus
"C"
#endif
float roundf (float);
])
if test "$ROUNDF_LIBM" != missing; then
HAVE_ROUNDF=1
dnl Also check whether it's declared.
dnl IRIX 6.5 has roundf() in libm but doesn't declare it in <math.h>.
AC_CHECK_DECLS([roundf], , [HAVE_DECL_ROUNDF=0], [[#include <math.h>]])
dnl Test whether roundf() produces correct results. On mingw, for
dnl x = 1/2 - 2^-25, the system's roundf() returns a wrong result.
AC_REQUIRE([AC_PROG_CC])
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
AC_CACHE_CHECK([whether roundf works], [gl_cv_func_roundf_works],
[
save_LIBS="$LIBS"
LIBS="$LIBS $ROUNDF_LIBM"
AC_RUN_IFELSE([AC_LANG_SOURCE([[
#include <float.h>
#include <math.h>
extern
#ifdef __cplusplus
"C"
#endif
float roundf (float);
#if defined _MSC_VER && !defined __clang__
# pragma fenv_access (off)
#endif
int main()
{
/* 2^FLT_MANT_DIG. */
static const float TWO_MANT_DIG =
/* Assume FLT_MANT_DIG <= 3 * 31.
Use the identity n = floor(n/3) + floor((n+1)/3) + floor((n+2)/3). */
(float) (1U << (FLT_MANT_DIG / 3))
* (float) (1U << ((FLT_MANT_DIG + 1) / 3))
* (float) (1U << ((FLT_MANT_DIG + 2) / 3));
volatile float x = 0.5f - 0.5f / TWO_MANT_DIG;
return (x < 0.5f && roundf (x) != 0.0f);
}]])], [gl_cv_func_roundf_works=yes], [gl_cv_func_roundf_works=no],
[case "$host_os" in
# Guess yes on MSVC, no on mingw.
mingw*) AC_EGREP_CPP([Known], [
#ifdef _MSC_VER
Known
#endif
],
[gl_cv_func_roundf_works="guessing yes"],
[gl_cv_func_roundf_works="guessing no"])
;;
*) gl_cv_func_roundf_works="guessing yes" ;;
esac
])
LIBS="$save_LIBS"
])
case "$gl_cv_func_roundf_works" in
*no) REPLACE_ROUNDF=1 ;;
esac
m4_ifdef([gl_FUNC_ROUNDF_IEEE], [
if test $gl_roundf_required = ieee && test $REPLACE_ROUNDF = 0; then
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
AC_CACHE_CHECK([whether roundf works according to ISO C 99 with IEC 60559],
[gl_cv_func_roundf_ieee],
[
save_LIBS="$LIBS"
LIBS="$LIBS $ROUNDF_LIBM"
AC_RUN_IFELSE(
[AC_LANG_SOURCE([[
#ifndef __NO_MATH_INLINES
# define __NO_MATH_INLINES 1 /* for glibc */
#endif
#include <math.h>
extern
#ifdef __cplusplus
"C"
#endif
float roundf (float);
]gl_FLOAT_MINUS_ZERO_CODE[
]gl_FLOAT_SIGNBIT_CODE[
static float dummy (float f) { return 0; }
int main (int argc, char *argv[])
{
float (* volatile my_roundf) (float) = argc ? roundf : dummy;
int result = 0;
/* Test whether roundf (-0.0f) is -0.0f. */
if (signbitf (minus_zerof) && !signbitf (my_roundf (minus_zerof)))
result |= 1;
/* Test whether roundf (-0.3f) is -0.0f. */
if (signbitf (-0.3f) && !signbitf (my_roundf (-0.3f)))
result |= 2;
return result;
}
]])],
[gl_cv_func_roundf_ieee=yes],
[gl_cv_func_roundf_ieee=no],
[case "$host_os" in
# Guess yes on glibc systems.
*-gnu* | gnu*) gl_cv_func_roundf_ieee="guessing yes" ;;
# Guess yes on musl systems.
*-musl* | midipix*) gl_cv_func_roundf_ieee="guessing yes" ;;
# Guess yes on MSVC, no on mingw.
mingw*) AC_EGREP_CPP([Known], [
#ifdef _MSC_VER
Known
#endif
],
[gl_cv_func_roundf_ieee="guessing yes"],
[gl_cv_func_roundf_ieee="guessing no"])
;;
# If we don't know, obey --enable-cross-guesses.
*) gl_cv_func_roundf_ieee="$gl_cross_guess_normal" ;;
esac
])
LIBS="$save_LIBS"
])
case "$gl_cv_func_roundf_ieee" in
*yes) ;;
*) REPLACE_ROUNDF=1 ;;
esac
fi
])
else
HAVE_ROUNDF=0
HAVE_DECL_ROUNDF=0
fi
if test $HAVE_ROUNDF = 0 || test $REPLACE_ROUNDF = 1; then
dnl Find libraries needed to link lib/roundf.c.
AC_CHECK_DECLS([ceilf, floorf], , , [[#include <math.h>]])
if test "$ac_cv_have_decl_floorf" = yes \
&& test "$ac_cv_have_decl_ceilf" = yes; then
gl_FUNC_FLOORF_LIBS
gl_FUNC_CEILF_LIBS
if test "$FLOORF_LIBM" != '?' && test "$CEILF_LIBM" != '?'; then
AC_DEFINE([HAVE_FLOORF_AND_CEILF], [1],
[Define if the both the floorf() and ceilf() functions exist.])
ROUNDF_LIBM=
dnl Append $FLOORF_LIBM to ROUNDF_LIBM, avoiding gratuitous duplicates.
case " $ROUNDF_LIBM " in
*" $FLOORF_LIBM "*) ;;
*) ROUNDF_LIBM="$ROUNDF_LIBM $FLOORF_LIBM" ;;
esac
dnl Append $CEILF_LIBM to ROUNDF_LIBM, avoiding gratuitous duplicates.
case " $ROUNDF_LIBM " in
*" $CEILF_LIBM "*) ;;
*) ROUNDF_LIBM="$ROUNDF_LIBM $CEILF_LIBM" ;;
esac
else
ROUNDF_LIBM=
fi
else
ROUNDF_LIBM=
fi
fi
AC_SUBST([ROUNDF_LIBM])
])
|
