1# hypotl.m4 serial 5 2dnl Copyright (C) 2012-2014 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_HYPOTL], 8[ 9 m4_divert_text([DEFAULTS], [gl_hypotl_required=plain]) 10 AC_REQUIRE([gl_MATH_H_DEFAULTS]) 11 AC_REQUIRE([gl_FUNC_HYPOT]) 12 13 dnl Persuade glibc <math.h> to declare hypotl(). 14 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) 15 16 dnl Test whether hypotl() exists. Assume that hypotl(), if it exists, is 17 dnl defined in the same library as hypot(). 18 save_LIBS="$LIBS" 19 LIBS="$LIBS $HYPOT_LIBM" 20 AC_CHECK_FUNCS([hypotl]) 21 LIBS="$save_LIBS" 22 if test $ac_cv_func_hypotl = yes; then 23 HYPOTL_LIBM="$HYPOT_LIBM" 24 25 save_LIBS="$LIBS" 26 LIBS="$LIBS $HYPOTL_LIBM" 27 gl_FUNC_HYPOTL_WORKS 28 LIBS="$save_LIBS" 29 case "$gl_cv_func_hypotl_works" in 30 *yes) ;; 31 *) REPLACE_HYPOTL=1 ;; 32 esac 33 34 m4_ifdef([gl_FUNC_HYPOTL_IEEE], [ 35 if test $gl_hypotl_required = ieee && test $REPLACE_HYPOTL = 0; then 36 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles 37 AC_CACHE_CHECK([whether hypotl works according to ISO C 99 with IEC 60559], 38 [gl_cv_func_hypotl_ieee], 39 [ 40 save_LIBS="$LIBS" 41 LIBS="$LIBS $HYPOTL_LIBM" 42 AC_RUN_IFELSE( 43 [AC_LANG_SOURCE([[ 44#ifndef __NO_MATH_INLINES 45# define __NO_MATH_INLINES 1 /* for glibc */ 46#endif 47#include <math.h> 48/* Compare two numbers with ==. 49 This is a separate function because IRIX 6.5 "cc -O" miscompiles an 50 'x == x' test. */ 51static int 52numeric_equal (long double x, long double y) 53{ 54 return x == y; 55} 56static long double dummy (long double x, long double y) { return 0; } 57long double zero; 58long double one = 1.0L; 59int main (int argc, char *argv[]) 60{ 61 long double (*my_hypotl) (long double, long double) = argc ? hypotl : dummy; 62 long double f; 63 /* Test hypotl(NaN,Infinity). 64 This test fails on OSF/1 5.1 and native Windows. */ 65 f = my_hypotl (zero / zero, one / zero); 66 if (!numeric_equal (f, f)) 67 return 1; 68 return 0; 69} 70 ]])], 71 [gl_cv_func_hypotl_ieee=yes], 72 [gl_cv_func_hypotl_ieee=no], 73 [case "$host_os" in 74 # Guess yes on glibc systems. 75 *-gnu*) gl_cv_func_hypotl_ieee="guessing yes" ;; 76 # If we don't know, assume the worst. 77 *) gl_cv_func_hypotl_ieee="guessing no" ;; 78 esac 79 ]) 80 LIBS="$save_LIBS" 81 ]) 82 case "$gl_cv_func_hypotl_ieee" in 83 *yes) ;; 84 *) REPLACE_HYPOTL=1 ;; 85 esac 86 fi 87 ]) 88 else 89 HAVE_HYPOTL=0 90 fi 91 if test $HAVE_HYPOTL = 0 || test $REPLACE_HYPOTL = 1; then 92 dnl Find libraries needed to link lib/hypotl.c. 93 if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then 94 HYPOTL_LIBM="$HYPOT_LIBM" 95 else 96 AC_REQUIRE([gl_FUNC_FABSL]) 97 AC_REQUIRE([gl_FUNC_FREXPL]) 98 AC_REQUIRE([gl_FUNC_LDEXPL]) 99 AC_REQUIRE([gl_FUNC_SQRTL]) 100 HYPOTL_LIBM= 101 dnl Append $FABSL_LIBM to HYPOTL_LIBM, avoiding gratuitous duplicates. 102 case " $HYPOTL_LIBM " in 103 *" $FABSL_LIBM "*) ;; 104 *) HYPOTL_LIBM="$HYPOTL_LIBM $FABSL_LIBM" ;; 105 esac 106 dnl Append $FREXPL_LIBM to HYPOTL_LIBM, avoiding gratuitous duplicates. 107 case " $HYPOTL_LIBM " in 108 *" $FREXPL_LIBM "*) ;; 109 *) HYPOTL_LIBM="$HYPOTL_LIBM $FREXPL_LIBM" ;; 110 esac 111 dnl Append $LDEXPL_LIBM to HYPOTL_LIBM, avoiding gratuitous duplicates. 112 case " $HYPOTL_LIBM " in 113 *" $LDEXPL_LIBM "*) ;; 114 *) HYPOTL_LIBM="$HYPOTL_LIBM $LDEXPL_LIBM" ;; 115 esac 116 dnl Append $SQRTL_LIBM to HYPOTL_LIBM, avoiding gratuitous duplicates. 117 case " $HYPOTL_LIBM " in 118 *" $SQRTL_LIBM "*) ;; 119 *) HYPOTL_LIBM="$HYPOTL_LIBM $SQRTL_LIBM" ;; 120 esac 121 fi 122 fi 123 AC_SUBST([HYPOTL_LIBM]) 124]) 125 126dnl Test whether hypotl() works. 127dnl On OpenBSD 5.1/SPARC, 128dnl hypotl (2.5541394760659556563446062497337725156L, 7.7893454113437840832487794525518765265L) 129dnl has rounding errors that eat up the last 8 to 9 decimal digits. 130AC_DEFUN([gl_FUNC_HYPOTL_WORKS], 131[ 132 AC_REQUIRE([AC_PROG_CC]) 133 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles 134 AC_CACHE_CHECK([whether hypotl works], [gl_cv_func_hypotl_works], 135 [ 136 AC_RUN_IFELSE( 137 [AC_LANG_SOURCE([[ 138#include <float.h> 139#include <math.h> 140static long double 141my_ldexpl (long double x, int d) 142{ 143 for (; d > 0; d--) 144 x *= 2.0L; 145 for (; d < 0; d++) 146 x *= 0.5L; 147 return x; 148} 149volatile long double x; 150volatile long double y; 151volatile long double z; 152int main () 153{ 154 long double err; 155 156 x = 2.5541394760659556563446062497337725156L; 157 y = 7.7893454113437840832487794525518765265L; 158 z = hypotl (x, y); 159 err = z * z - (x * x + y * y); 160 err = my_ldexpl (err, LDBL_MANT_DIG); 161 if (err < 0) 162 err = - err; 163 if (err > 1000.0L) 164 return 1; 165 return 0; 166} 167]])], 168 [gl_cv_func_hypotl_works=yes], 169 [gl_cv_func_hypotl_works=no], 170 [case "$host_os" in 171 openbsd*) gl_cv_func_hypotl_works="guessing no";; 172 *) gl_cv_func_hypotl_works="guessing yes";; 173 esac 174 ]) 175 ]) 176]) 177