Testing ORC - The Oil Runtime Compiler

README

Quick test of using ORC to calculate the absolute difference of two arrays.

http://code.entropywave.com/projects/orc/

One can efficiently do this by using subtract with unsigned saturate and then
OR'ing the result

ref:
http://software.intel.com/en-us/articles/absolute-difference-motion-estimation-for-intel-pentiumr-4-processors/
http://stackoverflow.com/questions/3380785/compute-the-absolute-difference-between-unsigned-integers-using-sse
http://www.tommesani.com/SSEPrimer.html
http://www.tommesani.com/MMXArithmetic.html

example1.orc

.function absdiff_u8
.dest 1 d1 char
.source 1 s1 char
.source 1 s2 char

.temp 1 t1
.temp 1 t2

subusb t1, s1, s2
subusb t2, s2, s1
orb d1, t1, t2

Makefile

all: testc testorc

clean:
	rm -f testc testorc out.c out.h

testc: out.c test.c
	$(CC) -DDISABLE_ORC=1 -o $@ $^

testorc: out.c test.c
	$(CC) -o $@ $^ `pkg-config --cflags --libs orc-0.4`

out.c: example1.orc
	orcc --header --target sse $<
	orcc --implementation --target sse $<

test.c

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <sys/time.h>
#include <sys/resource.h>

#include "test.h"
#include "out.h"

#define CPU_TIME (getrusage(RUSAGE_SELF,&ruse), ruse.ru_utime.tv_sec + \
  ruse.ru_stime.tv_sec + 1e-6 * \
  (ruse.ru_utime.tv_usec + ruse.ru_stime.tv_usec))


int
main (int argc, char *argv[])
{
    int i;
    time_t start, end;
    double first, second;
    struct rusage ruse;
    unsigned char *a,*b,*c;

    a = (unsigned char *)malloc(TESTSIZE * sizeof(unsigned char));
    b = (unsigned char *)malloc(TESTSIZE * sizeof(unsigned char));
    c = (unsigned char *)malloc(TESTSIZE * sizeof(unsigned char));

    /* Create some data in the source arrays */
    for(i=0;i < TESTSIZE;i++){
        a[i] = 120;
        b[i] = (i%2 ? 100 : 140);
    }

    time(&start);
    first = CPU_TIME;

    /* Call a function that uses Orc */;
    absdiff_u8 ((unsigned char *)c, a, b, TESTSIZE);

    time(&end);
    second = CPU_TIME;

    /* Print the results 
    for(i=0;i < TESTSIZE;i+=TESTSIZE/21){
      printf("%u: %u %u -> %u\n", i, a[i], b[i], c[i]);
    } */

    printf("cpu  : %f secs\n", second - first); 
    printf("user : %d secs\n", (int)(end - start));

    free(a);
    free(b);
    free(c);

    return 0;
}

test.h

#define TESTSIZE 200000000