ref: c6ae1e72c02c0a2998684f7eb903a96aee1f5fc3
parent: 10c879266abb00bd9378f37ac8f674411b5083eb
author: Erik de Castro Lopo <erikd@mega-nerd.com>
date: Sat Feb 28 05:28:49 EST 2004
Update AC_C_CLIP_MODE.
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -265,6 +265,9 @@
[Define if you have C99's llrint function.])
fi
])# AC_C99_FUNC_LLRINT
+
+
+
dnl @synopsis AC_C_CLIP_MODE
dnl
dnl Determine the clipping mode when converting float to int.
@@ -279,10 +282,6 @@
-
-
-
-
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.
@@ -295,7 +294,6 @@
ac_cv_c_clip_positive=unknown
ac_cv_c_clip_negative=unknown
-
if test $ac_cv_c_clip_positive = unknown ; then
AC_TRY_RUN(
[[
@@ -305,24 +303,26 @@
#define __USE_ISOC9X 1
#include <math.h>
int main (void)
- { double fval [] = { 1.0 * 0x7FFFFFFF, 1.1 * 0x7FFFFFFF, 1.2 * 0x7FFFFFFF } ;+ { double fval ;+ int k, ival ;
- if (lrint (fval [0]) < 0)
- return 0 ;
+ fval = 1.0 * 0x7FFFFFFF ;
+ for (k = 0 ; k < 100 ; k++)
+ { ival = (lrint (fval)) >> 24 ;+ if (ival != 127)
+ return 1 ;
- if (lrint (fval [1]) < 0)
- return 0 ;
+ fval *= 1.2499999 ;
+ } ;
- if (lrint (fval [2]) < 0)
return 0 ;
-
- return 1 ;
}
- ]], , ac_cv_c_clip_positive=yes,
+ ]],
+ 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
@@ -331,20 +331,23 @@
#define __USE_ISOC9X 1
#include <math.h>
int main (void)
- { double fval [] = { -8.0 * 0x10000000, -8.8 * 0x10000000, -9.6 * 0x10000000 } ;+ { double fval ;+ int k, ival ;
- if (lrint (fval [0]) > 0)
- return 0 ;
+ fval = -8.0 * 0x10000000 ;
+ for (k = 0 ; k < 100 ; k++)
+ { ival = (lrint (fval)) >> 24 ;+ if (ival != -128)
+ return 1 ;
- if (lrint (fval [1]) > 0)
- return 0 ;
+ fval *= 1.2499999 ;
+ } ;
- if (lrint (fval [2]) > 0)
return 0 ;
-
- return 1 ;
}
- ]], , ac_cv_c_clip_negative=yes,
+ ]],
+ ac_cv_c_clip_negative=yes,
+ ac_cv_c_clip_negative=no,
ac_cv_c_clip_negative=unknown
)