X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fisnand.m4;h=fbb03f8795f02d29b0a573ae577f0da1b65f3789;hb=8eaac7a51d093dbcecc0c2b42a5762a882b4517b;hp=f21d38485e4454f1e3db71d7c8a73765760b7612;hpb=bc6416f35c9ea6cd1980d07896cda5a6f2983fd7;p=gnulib.git diff --git a/m4/isnand.m4 b/m4/isnand.m4 index f21d38485..fbb03f879 100644 --- a/m4/isnand.m4 +++ b/m4/isnand.m4 @@ -1,4 +1,4 @@ -# isnand.m4 serial 3 +# isnand.m4 serial 4 dnl Copyright (C) 2007-2008 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -92,113 +92,3 @@ AC_DEFUN([gl_HAVE_ISNAND_NO_LIBM], [gl_cv_func_isnand_no_libm=no]) ]) ]) - -AC_DEFUN([gl_DOUBLE_EXPONENT_LOCATION], -[ - AC_CACHE_CHECK([where to find the exponent in a 'double'], - [gl_cv_cc_double_expbit0], - [ - AC_TRY_RUN([ -#include -#include -#include -#include -#define NWORDS \ - ((sizeof (double) + sizeof (unsigned int) - 1) / sizeof (unsigned int)) -typedef union { double value; unsigned int word[NWORDS]; } memory_double; -static unsigned int ored_words[NWORDS]; -static unsigned int anded_words[NWORDS]; -static void add_to_ored_words (double x) -{ - memory_double m; - size_t i; - /* Clear it first, in case sizeof (double) < sizeof (memory_double). */ - memset (&m, 0, sizeof (memory_double)); - m.value = x; - for (i = 0; i < NWORDS; i++) - { - ored_words[i] |= m.word[i]; - anded_words[i] &= m.word[i]; - } -} -int main () -{ - size_t j; - FILE *fp = fopen ("conftest.out", "w"); - if (fp == NULL) - return 1; - for (j = 0; j < NWORDS; j++) - anded_words[j] = ~ (unsigned int) 0; - add_to_ored_words (0.25); - add_to_ored_words (0.5); - add_to_ored_words (1.0); - add_to_ored_words (2.0); - add_to_ored_words (4.0); - /* Remove bits that are common (e.g. if representation of the first mantissa - bit is explicit). */ - for (j = 0; j < NWORDS; j++) - ored_words[j] &= ~anded_words[j]; - /* Now find the nonzero word. */ - for (j = 0; j < NWORDS; j++) - if (ored_words[j] != 0) - break; - if (j < NWORDS) - { - size_t i; - for (i = j + 1; i < NWORDS; i++) - if (ored_words[i] != 0) - { - fprintf (fp, "unknown"); - return (fclose (fp) != 0); - } - for (i = 0; ; i++) - if ((ored_words[j] >> i) & 1) - { - fprintf (fp, "word %d bit %d", (int) j, (int) i); - return (fclose (fp) != 0); - } - } - fprintf (fp, "unknown"); - return (fclose (fp) != 0); -} - ], - [gl_cv_cc_double_expbit0=`cat conftest.out`], - [gl_cv_cc_double_expbit0="unknown"], - [ - dnl On ARM, there are two 'double' floating-point formats, used by - dnl different sets of instructions: The older FPA instructions assume - dnl that they are stored in big-endian word order, while the words - dnl (like integer types) are stored in little-endian byte order. - dnl The newer VFP instructions assume little-endian order consistenly. - AC_EGREP_CPP([mixed_endianness], [ -#if defined arm || defined __arm || defined __arm__ - mixed_endianness -#endif - ], - [gl_cv_cc_double_expbit0="unknown"], - [ - pushdef([AC_MSG_CHECKING],[:])dnl - pushdef([AC_MSG_RESULT],[:])dnl - pushdef([AC_MSG_RESULT_UNQUOTED],[:])dnl - AC_C_BIGENDIAN( - [gl_cv_cc_double_expbit0="word 0 bit 20"], - [gl_cv_cc_double_expbit0="word 1 bit 20"], - [gl_cv_cc_double_expbit0="unknown"]) - popdef([AC_MSG_RESULT_UNQUOTED])dnl - popdef([AC_MSG_RESULT])dnl - popdef([AC_MSG_CHECKING])dnl - ]) - ]) - rm -f conftest.out - ]) - case "$gl_cv_cc_double_expbit0" in - word*bit*) - word=`echo "$gl_cv_cc_double_expbit0" | sed -e 's/word //' -e 's/ bit.*//'` - bit=`echo "$gl_cv_cc_double_expbit0" | sed -e 's/word.*bit //'` - AC_DEFINE_UNQUOTED([DBL_EXPBIT0_WORD], [$word], - [Define as the word index where to find the exponent of 'double'.]) - AC_DEFINE_UNQUOTED([DBL_EXPBIT0_BIT], [$bit], - [Define as the bit index in the word where to find bit 0 of the exponent of 'double'.]) - ;; - esac -])