1# cbrtf.m4 serial 4
2dnl Copyright (C) 2012-2021 Free Software Foundation, Inc.
3dnl This file is free software; the Free Software Foundation
4dnl gives unlimited permission to copy and/or distribute it,
5dnl with or without modifications, as long as this notice is preserved.
6
7AC_DEFUN([gl_FUNC_CBRTF],
8[
9  AC_REQUIRE([gl_MATH_H_DEFAULTS])
10  AC_REQUIRE([gl_FUNC_CBRT])
11
12  dnl Persuade glibc <math.h> to declare cbrtf().
13  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
14
15  dnl Test whether cbrtf() exists. Assume that cbrtf(), if it exists, is
16  dnl defined in the same library as cbrt().
17  save_LIBS="$LIBS"
18  LIBS="$LIBS $CBRT_LIBM"
19  AC_CHECK_FUNCS([cbrtf])
20  LIBS="$save_LIBS"
21  if test $ac_cv_func_cbrtf = yes; then
22    CBRTF_LIBM="$CBRT_LIBM"
23    dnl Also check whether it's declared.
24    dnl IRIX 6.5 has cbrtf() in libm but doesn't declare it in <math.h>.
25    AC_CHECK_DECL([cbrtf], , [HAVE_DECL_CBRTF=0], [[#include <math.h>]])
26    save_LIBS="$LIBS"
27    LIBS="$LIBS $CBRTF_LIBM"
28    gl_FUNC_CBRTF_WORKS
29    LIBS="$save_LIBS"
30    case "$gl_cv_func_cbrtf_works" in
31      *yes) ;;
32      *) REPLACE_CBRTF=1 ;;
33    esac
34  else
35    HAVE_CBRTF=0
36    HAVE_DECL_CBRTF=0
37  fi
38  if test $HAVE_CBRTF = 0 || test $REPLACE_CBRTF = 1; then
39    dnl Find libraries needed to link lib/cbrtf.c.
40    AC_REQUIRE([gl_FUNC_FABSF])
41    AC_REQUIRE([gl_FUNC_FREXPF])
42    AC_REQUIRE([gl_FUNC_LDEXPF])
43    CBRTF_LIBM=
44    dnl Append $FABSF_LIBM to CBRTF_LIBM, avoiding gratuitous duplicates.
45    case " $CBRTF_LIBM " in
46      *" $FABSF_LIBM "*) ;;
47      *) CBRTF_LIBM="$CBRTF_LIBM $FABSF_LIBM" ;;
48    esac
49    dnl Append $FREXPF_LIBM to CBRTF_LIBM, avoiding gratuitous duplicates.
50    case " $CBRTF_LIBM " in
51      *" $FREXPF_LIBM "*) ;;
52      *) CBRTF_LIBM="$CBRTF_LIBM $FREXPF_LIBM" ;;
53    esac
54    dnl Append $LDEXPF_LIBM to CBRTF_LIBM, avoiding gratuitous duplicates.
55    case " $CBRTF_LIBM " in
56      *" $LDEXPF_LIBM "*) ;;
57      *) CBRTF_LIBM="$CBRTF_LIBM $LDEXPF_LIBM" ;;
58    esac
59  fi
60  AC_SUBST([CBRTF_LIBM])
61])
62
63dnl Test whether cbrtf() works.
64dnl It returns wrong values on IRIX 6.5.
65AC_DEFUN([gl_FUNC_CBRTF_WORKS],
66[
67  AC_REQUIRE([AC_PROG_CC])
68  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
69  AC_CACHE_CHECK([whether cbrtf works], [gl_cv_func_cbrtf_works],
70    [
71      AC_RUN_IFELSE(
72        [AC_LANG_SOURCE([[
73#include <math.h>
74volatile float x;
75volatile float y;
76int main ()
77{
78  extern
79  #ifdef __cplusplus
80  "C"
81  #endif
82  float cbrtf (float);
83  /* This test fails on IRIX 6.5.  */
84  x = - 0.0f;
85  y = cbrtf (x);
86  if (!(y == 0.0f))
87    return 1;
88  return 0;
89}
90]])],
91        [gl_cv_func_cbrtf_works=yes],
92        [gl_cv_func_cbrtf_works=no],
93        [case "$host_os" in
94           irix*)  gl_cv_func_cbrtf_works="guessing no";;
95                   # Guess yes on native Windows.
96           mingw*) gl_cv_func_cbrtf_works="guessing yes";;
97           *)      gl_cv_func_cbrtf_works="guessing yes";;
98         esac
99        ])
100    ])
101])
102