diff options
Diffstat (limited to 'libs/cairo-1.16.0/build/aclocal.float.m4')
-rw-r--r-- | libs/cairo-1.16.0/build/aclocal.float.m4 | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/libs/cairo-1.16.0/build/aclocal.float.m4 b/libs/cairo-1.16.0/build/aclocal.float.m4 new file mode 100644 index 0000000..85adf6d --- /dev/null +++ b/libs/cairo-1.16.0/build/aclocal.float.m4 @@ -0,0 +1,65 @@ +# AX_C_FLOAT_WORDS_BIGENDIAN ([ACTION-IF-TRUE], [ACTION-IF-FALSE], +# [ACTION-IF-UNKNOWN]) +# +# Checks the ordering of words within a multi-word float. This check +# is necessary because on some systems (e.g. certain ARM systems), the +# float word ordering can be different from the byte ordering. In a +# multi-word float context, "big-endian" implies that the word containing +# the sign bit is found in the memory location with the lowest address. +# This implemenation was inspired by the AC_C_BIGENDIAN macro in autoconf. +# ------------------------------------------------------------------------- +AC_DEFUN([AX_C_FLOAT_WORDS_BIGENDIAN], + [AC_CACHE_CHECK(whether float word ordering is bigendian, + ax_cv_c_float_words_bigendian, [ + +# The endianness is detected by first compiling C code that contains a special +# double float value, then grepping the resulting object file for certain +# strings of ascii values. The double is specially crafted to have a +# binary representation that corresponds with a simple string. In this +# implementation, the string "noonsees" was selected because the individual +# word values ("noon" and "sees") are palindromes, thus making this test +# byte-order agnostic. If grep finds the string "noonsees" in the object +# file, the target platform stores float words in big-endian order. If grep +# finds "seesnoon", float words are in little-endian order. If neither value +# is found, the user is instructed to specify the ordering. + +ax_cv_c_float_words_bigendian=unknown +AC_LINK_IFELSE([AC_LANG_SOURCE([[ + +double d __attribute__((used)) = 90904234967036810337470478905505011476211692735615632014797120844053488865816695273723469097858056257517020191247487429516932130503560650002327564517570778480236724525140520121371739201496540132640109977779420565776568942592.0; +int main() { return 0; } + +]])], [ + +if strings -a conftest$ac_exeext | grep noonsees >/dev/null ; then + ax_cv_c_float_words_bigendian=yes +fi +if strings -a conftest$ac_exeext | grep seesnoon >/dev/null ; then + if test "$ax_cv_c_float_words_bigendian" = unknown; then + ax_cv_c_float_words_bigendian=no + else + ax_cv_c_float_words_bigendian=unknown + fi +fi + +])]) + +case $ax_cv_c_float_words_bigendian in + yes) + m4_default([$1], + [AC_DEFINE([FLOAT_WORDS_BIGENDIAN], 1, + [Define to 1 if your system stores words within floats + with the most significant word first])]) ;; + no) + $2 ;; + *) + m4_default([$3], + [AC_MSG_ERROR([ + +Unknown float word ordering. You need to manually preset +ax_cv_c_float_words_bigendian=no (or yes) according to your system. + + ])]) ;; +esac + +])# AX_C_FLOAT_WORDS_BIGENDIAN |