125 lines
2.3 KiB
Plaintext
125 lines
2.3 KiB
Plaintext
|
dnl @synopsis MN_C_CLIP_MODE
|
||
|
|
dnl
|
||
|
|
dnl Determine the clipping mode when converting float to int.
|
||
|
|
dnl @version 1.0 May 17 2003
|
||
|
|
dnl @author Erik de Castro Lopo <erikd AT mega-nerd DOT com>
|
||
|
|
dnl
|
||
|
|
dnl Permission to use, copy, modify, distribute, and sell this file for any
|
||
|
|
dnl purpose is hereby granted without fee, provided that the above copyright
|
||
|
|
dnl and this permission notice appear in all copies. No representations are
|
||
|
|
dnl made about the suitability of this software for any purpose. It is
|
||
|
|
dnl provided "as is" without express or implied warranty.
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
dnl Find the clipping mode in the following way:
|
||
|
|
dnl 1) If we are not cross compiling test it.
|
||
|
|
dnl 2) IF we are cross compiling, assume that clipping isn't done correctly.
|
||
|
|
|
||
|
|
AC_DEFUN([MN_C_CLIP_MODE],
|
||
|
|
[AC_CACHE_CHECK(processor clipping capabilities,
|
||
|
|
ac_cv_c_clip_type,
|
||
|
|
|
||
|
|
# Initialize to unknown
|
||
|
|
ac_cv_c_clip_positive=unknown
|
||
|
|
ac_cv_c_clip_negative=unknown
|
||
|
|
|
||
|
|
|
||
|
|
if test $ac_cv_c_clip_positive = unknown ; then
|
||
|
|
AC_TRY_RUN(
|
||
|
|
[[
|
||
|
|
#define _ISOC9X_SOURCE 1
|
||
|
|
#define _ISOC99_SOURCE 1
|
||
|
|
#define __USE_ISOC99 1
|
||
|
|
#define __USE_ISOC9X 1
|
||
|
|
#include <math.h>
|
||
|
|
int main (void)
|
||
|
|
{ double fval ;
|
||
|
|
int k, ival ;
|
||
|
|
|
||
|
|
fval = 1.0 * 0x7FFFFFFF ;
|
||
|
|
for (k = 0 ; k < 100 ; k++)
|
||
|
|
{ ival = (lrint (fval)) >> 24 ;
|
||
|
|
if (ival != 127)
|
||
|
|
return 1 ;
|
||
|
|
|
||
|
|
fval *= 1.2499999 ;
|
||
|
|
} ;
|
||
|
|
|
||
|
|
return 0 ;
|
||
|
|
}
|
||
|
|
]],
|
||
|
|
ac_cv_c_clip_positive=yes,
|
||
|
|
ac_cv_c_clip_positive=no,
|
||
|
|
ac_cv_c_clip_positive=unknown
|
||
|
|
)
|
||
|
|
|
||
|
|
AC_TRY_RUN(
|
||
|
|
[[
|
||
|
|
#define _ISOC9X_SOURCE 1
|
||
|
|
#define _ISOC99_SOURCE 1
|
||
|
|
#define __USE_ISOC99 1
|
||
|
|
#define __USE_ISOC9X 1
|
||
|
|
#include <math.h>
|
||
|
|
int main (void)
|
||
|
|
{ double fval ;
|
||
|
|
int k, ival ;
|
||
|
|
|
||
|
|
fval = -8.0 * 0x10000000 ;
|
||
|
|
for (k = 0 ; k < 100 ; k++)
|
||
|
|
{ ival = (lrint (fval)) >> 24 ;
|
||
|
|
if (ival != -128)
|
||
|
|
return 1 ;
|
||
|
|
|
||
|
|
fval *= 1.2499999 ;
|
||
|
|
} ;
|
||
|
|
|
||
|
|
return 0 ;
|
||
|
|
}
|
||
|
|
]],
|
||
|
|
ac_cv_c_clip_negative=yes,
|
||
|
|
ac_cv_c_clip_negative=no,
|
||
|
|
ac_cv_c_clip_negative=unknown
|
||
|
|
)
|
||
|
|
fi
|
||
|
|
|
||
|
|
if test $ac_cv_c_clip_positive = yes ; then
|
||
|
|
ac_cv_c_clip_positive=1
|
||
|
|
else
|
||
|
|
ac_cv_c_clip_positive=0
|
||
|
|
fi
|
||
|
|
|
||
|
|
if test $ac_cv_c_clip_negative = yes ; then
|
||
|
|
ac_cv_c_clip_negative=1
|
||
|
|
else
|
||
|
|
ac_cv_c_clip_negative=0
|
||
|
|
fi
|
||
|
|
|
||
|
|
[[
|
||
|
|
case "$ac_cv_c_clip_positive$ac_cv_c_clip_negative" in
|
||
|
|
"00")
|
||
|
|
ac_cv_c_clip_type="none"
|
||
|
|
;;
|
||
|
|
"10")
|
||
|
|
ac_cv_c_clip_type="positive"
|
||
|
|
;;
|
||
|
|
"01")
|
||
|
|
ac_cv_c_clip_type="negative"
|
||
|
|
;;
|
||
|
|
"11")
|
||
|
|
ac_cv_c_clip_type="both"
|
||
|
|
;;
|
||
|
|
esac
|
||
|
|
]]
|
||
|
|
|
||
|
|
)
|
||
|
|
]
|
||
|
|
|
||
|
|
)# MN_C_CLIP_MODE
|
||
|
|
|
||
|
|
|