729466dc68
Recently normalization (av_normalize_sf) of output was added to av_add_sf. This normalization is used for better precision for small values and the purpose of this (quite simple) test case is to test difference between double and softfloat. The values used are tailored to maximally highlighte problem with precison when normalization is not used. Signed-off-by: Nedeljko Babic <nedeljko.babic@imgtec.com> Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
99 lines
2.7 KiB
C
99 lines
2.7 KiB
C
/*
|
|
* copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#include <inttypes.h>
|
|
#include <stdio.h>
|
|
#include "softfloat.h"
|
|
#include "common.h"
|
|
#include "log.h"
|
|
|
|
#undef printf
|
|
|
|
static const SoftFloat FLOAT_0_017776489257 = {0x1234, 12};
|
|
static const SoftFloat FLOAT_1374_40625 = {0xabcd, 25};
|
|
static const SoftFloat FLOAT_0_1249694824218 = {0xFFF, 15};
|
|
|
|
|
|
static av_const double av_sf2double(SoftFloat v) {
|
|
v.exp -= ONE_BITS +1;
|
|
if(v.exp > 0) return (double)v.mant * (double)(1 << v.exp);
|
|
else return (double)v.mant / (double)(1 << (-v.exp));
|
|
}
|
|
|
|
int main(void){
|
|
SoftFloat one= av_int2sf(1, 0);
|
|
SoftFloat sf1, sf2, sf3;
|
|
double d1, d2, d3;
|
|
int i, j;
|
|
av_log_set_level(AV_LOG_DEBUG);
|
|
|
|
d1= 1;
|
|
for(i= 0; i<10; i++){
|
|
d1= 1/(d1+1);
|
|
}
|
|
printf("test1 double=%d\n", (int)(d1 * (1<<24)));
|
|
|
|
sf1= one;
|
|
for(i= 0; i<10; i++){
|
|
sf1= av_div_sf(one, av_normalize_sf(av_add_sf(one, sf1)));
|
|
}
|
|
printf("test1 sf =%d\n", av_sf2int(sf1, 24));
|
|
|
|
|
|
for(i= 0; i<100; i++){
|
|
START_TIMER
|
|
d1= i;
|
|
d2= i/100.0;
|
|
for(j= 0; j<1000; j++){
|
|
d1= (d1+1)*d2;
|
|
}
|
|
STOP_TIMER("float add mul")
|
|
}
|
|
printf("test2 double=%d\n", (int)(d1 * (1<<24)));
|
|
|
|
for(i= 0; i<100; i++){
|
|
START_TIMER
|
|
sf1= av_int2sf(i, 0);
|
|
sf2= av_div_sf(av_int2sf(i, 2), av_int2sf(200, 3));
|
|
for(j= 0; j<1000; j++){
|
|
sf1= av_mul_sf(av_add_sf(sf1, one),sf2);
|
|
}
|
|
STOP_TIMER("softfloat add mul")
|
|
}
|
|
printf("test2 sf =%d (%d %d)\n", av_sf2int(sf1, 24), sf1.exp, sf1.mant);
|
|
|
|
d1 = 0.0177764893;
|
|
d2 = 1374.40625;
|
|
d3 = 0.1249694824;
|
|
d2 += d1;
|
|
d3 += d2;
|
|
printf("test3 double: %.10lf\n", d3);
|
|
|
|
sf1 = FLOAT_0_017776489257;
|
|
sf2 = FLOAT_1374_40625;
|
|
sf3 = FLOAT_0_1249694824218;
|
|
sf2 = av_add_sf(sf1, sf2);
|
|
sf3 = av_add_sf(sf3, sf2);
|
|
printf("test3 softfloat: %.10lf (0x%08x %d)\n", (double)av_sf2double(sf3), sf3.mant, sf3.exp);
|
|
|
|
return 0;
|
|
|
|
}
|