diff options
Diffstat (limited to 'gnulib-m4/signbit.m4')
| -rw-r--r-- | gnulib-m4/signbit.m4 | 274 |
1 files changed, 176 insertions, 98 deletions
diff --git a/gnulib-m4/signbit.m4 b/gnulib-m4/signbit.m4 index 56ff825..21b9bf5 100644 --- a/gnulib-m4/signbit.m4 +++ b/gnulib-m4/signbit.m4 @@ -1,5 +1,5 @@ -# signbit.m4 serial 6 -dnl Copyright (C) 2007-2010 Free Software Foundation, Inc. +# signbit.m4 serial 13 +dnl Copyright (C) 2007-2015 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. @@ -7,9 +7,11 @@ dnl with or without modifications, as long as this notice is preserved. AC_DEFUN([gl_SIGNBIT], [ AC_REQUIRE([gl_MATH_H_DEFAULTS]) + AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles AC_CACHE_CHECK([for signbit macro], [gl_cv_func_signbit], [ - AC_TRY_RUN([ + AC_RUN_IFELSE( + [AC_LANG_SOURCE([[ #include <math.h> /* If signbit is defined as a function, don't use it, since calling it for 'float' or 'long double' arguments would involve conversions. @@ -23,8 +25,16 @@ AC_DEFUN([gl_SIGNBIT], #endif #include <string.h> ]gl_SIGNBIT_TEST_PROGRAM -, [gl_cv_func_signbit=yes], [gl_cv_func_signbit=no], - [gl_cv_func_signbit="guessing no"]) +])], + [gl_cv_func_signbit=yes], + [gl_cv_func_signbit=no], + [case "$host_os" in + # Guess yes on glibc systems. + *-gnu*) gl_cv_func_signbit="guessing yes" ;; + # If we don't know, assume the worst. + *) gl_cv_func_signbit="guessing no" ;; + esac + ]) ]) dnl GCC 4.0 and newer provides three built-ins for signbit. dnl They can be used without warnings, also in C++, regardless of <math.h>. @@ -32,7 +42,8 @@ AC_DEFUN([gl_SIGNBIT], dnl libc. AC_CACHE_CHECK([for signbit compiler built-ins], [gl_cv_func_signbit_gcc], [ - AC_TRY_RUN([ + AC_RUN_IFELSE( + [AC_LANG_SOURCE([[ #if __GNUC__ >= 4 # define signbit(x) \ (sizeof (x) == sizeof (long double) ? __builtin_signbitl (x) : \ @@ -43,84 +54,102 @@ AC_DEFUN([gl_SIGNBIT], #endif #include <string.h> ]gl_SIGNBIT_TEST_PROGRAM -, [gl_cv_func_signbit_gcc=yes], [gl_cv_func_signbit_gcc=no], - [gl_cv_func_signbit_gcc="guessing no"]) +])], + [gl_cv_func_signbit_gcc=yes], + [gl_cv_func_signbit_gcc=no], + [case "$host_os" in + # Guess yes on glibc systems. + *-gnu*) gl_cv_func_signbit_gcc="guessing yes" ;; + # If we don't know, assume the worst. + *) gl_cv_func_signbit_gcc="guessing no" ;; + esac + ]) ]) dnl Use the compiler built-ins whenever possible, because they are more dnl efficient than the system library functions (if they exist). - if test "$gl_cv_func_signbit_gcc" = yes; then - REPLACE_SIGNBIT_USING_GCC=1 - else - if test "$gl_cv_func_signbit" != yes; then - REPLACE_SIGNBIT=1 - AC_LIBOBJ([signbitf]) - AC_LIBOBJ([signbitd]) - AC_LIBOBJ([signbitl]) - gl_FLOAT_SIGN_LOCATION - gl_DOUBLE_SIGN_LOCATION - gl_LONG_DOUBLE_SIGN_LOCATION - if test "$gl_cv_cc_float_signbit" = unknown; then - dnl Test whether copysignf() is declared. - AC_CHECK_DECLS([copysignf], , , [#include <math.h>]) - if test "$ac_cv_have_decl_copysignf" = yes; then - dnl Test whether copysignf() can be used without libm. - AC_CACHE_CHECK([whether copysignf can be used without linking with libm], - [gl_cv_func_copysignf_no_libm], - [ - AC_TRY_LINK([#include <math.h> - float x, y;], - [return copysignf (x, y) < 0;], - [gl_cv_func_copysignf_no_libm=yes], - [gl_cv_func_copysignf_no_libm=no]) - ]) - if test $gl_cv_func_copysignf_no_libm = yes; then - AC_DEFINE([HAVE_COPYSIGNF_IN_LIBC], [1], - [Define if the copysignf function is declared in <math.h> and available in libc.]) + case "$gl_cv_func_signbit_gcc" in + *yes) + REPLACE_SIGNBIT_USING_GCC=1 + ;; + *) + case "$gl_cv_func_signbit" in + *yes) ;; + *) + dnl REPLACE_SIGNBIT=1 makes sure the signbit[fdl] functions get built. + REPLACE_SIGNBIT=1 + gl_FLOAT_SIGN_LOCATION + gl_DOUBLE_SIGN_LOCATION + gl_LONG_DOUBLE_SIGN_LOCATION + if test "$gl_cv_cc_float_signbit" = unknown; then + dnl Test whether copysignf() is declared. + AC_CHECK_DECLS([copysignf], , , [[#include <math.h>]]) + if test "$ac_cv_have_decl_copysignf" = yes; then + dnl Test whether copysignf() can be used without libm. + AC_CACHE_CHECK([whether copysignf can be used without linking with libm], + [gl_cv_func_copysignf_no_libm], + [ + AC_LINK_IFELSE( + [AC_LANG_PROGRAM( + [[#include <math.h> + float x, y;]], + [[return copysignf (x, y) < 0;]])], + [gl_cv_func_copysignf_no_libm=yes], + [gl_cv_func_copysignf_no_libm=no]) + ]) + if test $gl_cv_func_copysignf_no_libm = yes; then + AC_DEFINE([HAVE_COPYSIGNF_IN_LIBC], [1], + [Define if the copysignf function is declared in <math.h> and available in libc.]) + fi + fi fi - fi - fi - if test "$gl_cv_cc_double_signbit" = unknown; then - dnl Test whether copysign() is declared. - AC_CHECK_DECLS([copysign], , , [#include <math.h>]) - if test "$ac_cv_have_decl_copysign" = yes; then - dnl Test whether copysign() can be used without libm. - AC_CACHE_CHECK([whether copysign can be used without linking with libm], - [gl_cv_func_copysign_no_libm], - [ - AC_TRY_LINK([#include <math.h> - double x, y;], - [return copysign (x, y) < 0;], - [gl_cv_func_copysign_no_libm=yes], - [gl_cv_func_copysign_no_libm=no]) - ]) - if test $gl_cv_func_copysign_no_libm = yes; then - AC_DEFINE([HAVE_COPYSIGN_IN_LIBC], [1], - [Define if the copysign function is declared in <math.h> and available in libc.]) + if test "$gl_cv_cc_double_signbit" = unknown; then + dnl Test whether copysign() is declared. + AC_CHECK_DECLS([copysign], , , [[#include <math.h>]]) + if test "$ac_cv_have_decl_copysign" = yes; then + dnl Test whether copysign() can be used without libm. + AC_CACHE_CHECK([whether copysign can be used without linking with libm], + [gl_cv_func_copysign_no_libm], + [ + AC_LINK_IFELSE( + [AC_LANG_PROGRAM( + [[#include <math.h> + double x, y;]], + [[return copysign (x, y) < 0;]])], + [gl_cv_func_copysign_no_libm=yes], + [gl_cv_func_copysign_no_libm=no]) + ]) + if test $gl_cv_func_copysign_no_libm = yes; then + AC_DEFINE([HAVE_COPYSIGN_IN_LIBC], [1], + [Define if the copysign function is declared in <math.h> and available in libc.]) + fi + fi fi - fi - fi - if test "$gl_cv_cc_long_double_signbit" = unknown; then - dnl Test whether copysignl() is declared. - AC_CHECK_DECLS([copysignl], , , [#include <math.h>]) - if test "$ac_cv_have_decl_copysignl" = yes; then - dnl Test whether copysignl() can be used without libm. - AC_CACHE_CHECK([whether copysignl can be used without linking with libm], - [gl_cv_func_copysignl_no_libm], - [ - AC_TRY_LINK([#include <math.h> - long double x, y;], - [return copysignl (x, y) < 0;], - [gl_cv_func_copysignl_no_libm=yes], - [gl_cv_func_copysignl_no_libm=no]) - ]) - if test $gl_cv_func_copysignl_no_libm = yes; then - AC_DEFINE([HAVE_COPYSIGNL_IN_LIBC], [1], - [Define if the copysignl function is declared in <math.h> and available in libc.]) + if test "$gl_cv_cc_long_double_signbit" = unknown; then + dnl Test whether copysignl() is declared. + AC_CHECK_DECLS([copysignl], , , [[#include <math.h>]]) + if test "$ac_cv_have_decl_copysignl" = yes; then + dnl Test whether copysignl() can be used without libm. + AC_CACHE_CHECK([whether copysignl can be used without linking with libm], + [gl_cv_func_copysignl_no_libm], + [ + AC_LINK_IFELSE( + [AC_LANG_PROGRAM( + [[#include <math.h> + long double x, y;]], + [[return copysignl (x, y) < 0;]])], + [gl_cv_func_copysignl_no_libm=yes], + [gl_cv_func_copysignl_no_libm=no]) + ]) + if test $gl_cv_func_copysignl_no_libm = yes; then + AC_DEFINE([HAVE_COPYSIGNL_IN_LIBC], [1], + [Define if the copysignl function is declared in <math.h> and available in libc.]) + fi + fi fi - fi - fi - fi - fi + ;; + esac + ;; + esac ]) AC_DEFUN([gl_SIGNBIT_TEST_PROGRAM], [[ @@ -141,14 +170,15 @@ double m0d = -p0d; /* On HP-UX 10.20, negating 0.0L does not yield -0.0L. So we use another constant expression instead. But that expression does not work on other platforms, such as when - cross-compiling to PowerPC on MacOS X 10.5. */ + cross-compiling to PowerPC on Mac OS X 10.5. */ long double p0l = 0.0L; #if defined __hpux || defined __sgi long double m0l = -LDBL_MIN * LDBL_MIN; #else long double m0l = -p0l; #endif - if (signbit (vf)) + int result = 0; + if (signbit (vf)) /* link check */ vf++; { float plus_inf = 1.0f / p0f; @@ -159,9 +189,9 @@ long double m0l = -p0l; && (memcmp (&m0f, &p0f, sizeof (float)) == 0 || signbit (m0f)) && !signbit (plus_inf) && signbit (minus_inf))) - return 1; + result |= 1; } - if (signbit (vd)) + if (signbit (vd)) /* link check */ vd++; { double plus_inf = 1.0 / p0d; @@ -172,22 +202,27 @@ long double m0l = -p0l; && (memcmp (&m0d, &p0d, sizeof (double)) == 0 || signbit (m0d)) && !signbit (plus_inf) && signbit (minus_inf))) - return 1; + result |= 2; } - if (signbit (vl)) + if (signbit (vl)) /* link check */ vl++; { long double plus_inf = 1.0L / p0l; long double minus_inf = -1.0L / p0l; - if (!(!signbit (255.0L) - && signbit (-255.0L) - && !signbit (p0l) - && (memcmp (&m0l, &p0l, sizeof (long double)) == 0 || signbit (m0l)) - && !signbit (plus_inf) - && signbit (minus_inf))) - return 1; + if (signbit (255.0L)) + result |= 4; + if (!signbit (-255.0L)) + result |= 4; + if (signbit (p0l)) + result |= 8; + if (!(memcmp (&m0l, &p0l, sizeof (long double)) == 0 || signbit (m0l))) + result |= 16; + if (signbit (plus_inf)) + result |= 32; + if (!signbit (minus_inf)) + result |= 64; } - return 0; + return result; } ]]) @@ -211,7 +246,8 @@ AC_DEFUN([gl_FLOATTYPE_SIGN_LOCATION], AC_CACHE_CHECK([where to find the sign bit in a '$1'], [$2], [ - AC_TRY_RUN([ + AC_RUN_IFELSE( + [AC_LANG_SOURCE([[ #include <stddef.h> #include <stdio.h> #define NWORDS \ @@ -236,7 +272,7 @@ int main () { /* More than one bit difference. */ fprintf (fp, "unknown"); - return 1; + return 2; } if (x) { @@ -248,7 +284,7 @@ int main () { /* No difference. */ fprintf (fp, "unknown"); - return 1; + return 3; } /* Now m = plus.word[k] ^ ~minus.word[k]. */ if (plus.word[k] & ~minus.word[k]) @@ -256,15 +292,17 @@ int main () /* Oh? The sign bit is set in the positive and cleared in the negative numbers? */ fprintf (fp, "unknown"); - return 1; + return 4; } for (i = 0; ; i++) if ((m >> i) & 1) break; fprintf (fp, "word %d bit %d", (int) k, (int) i); - return (fclose (fp) != 0); + if (fclose (fp) != 0) + return 5; + return 0; } - ], + ]])], [$2=`cat conftest.out`], [$2="unknown"], [ @@ -285,3 +323,43 @@ int main () ;; esac ]) + +# Expands to code that defines a function signbitf(float). +# It extracts the sign bit of a non-NaN value. +AC_DEFUN([gl_FLOAT_SIGNBIT_CODE], +[ + gl_FLOATTYPE_SIGNBIT_CODE([float], [f], [f]) +]) + +# Expands to code that defines a function signbitd(double). +# It extracts the sign bit of a non-NaN value. +AC_DEFUN([gl_DOUBLE_SIGNBIT_CODE], +[ + gl_FLOATTYPE_SIGNBIT_CODE([double], [d], []) +]) + +# Expands to code that defines a function signbitl(long double). +# It extracts the sign bit of a non-NaN value. +AC_DEFUN([gl_LONG_DOUBLE_SIGNBIT_CODE], +[ + gl_FLOATTYPE_SIGNBIT_CODE([long double], [l], [L]) +]) + +AC_DEFUN([gl_FLOATTYPE_SIGNBIT_CODE], +[[ +static int +signbit$2 ($1 value) +{ + typedef union { $1 f; unsigned char b[sizeof ($1)]; } float_union; + static float_union plus_one = { 1.0$3 }; /* unused bits are zero here */ + static float_union minus_one = { -1.0$3 }; /* unused bits are zero here */ + /* Compute the sign bit mask as the XOR of plus_one and minus_one. */ + float_union u; + unsigned int i; + u.f = value; + for (i = 0; i < sizeof ($1); i++) + if (u.b[i] & (plus_one.b[i] ^ minus_one.b[i])) + return 1; + return 0; +} +]]) |