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77 lines
1.2 KiB
C
77 lines
1.2 KiB
C
/*
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!!DESCRIPTION!! Implementation of Duff's device (loop unrolling).
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!!ORIGIN!!
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!!LICENCE!! GPL, read COPYING.GPL
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*/
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#include <stdio.h>
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#include <limits.h>
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#define ASIZE (100)
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unsigned char success=0;
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unsigned char failures=0;
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unsigned char dummy=0;
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#ifdef SUPPORT_BIT_TYPES
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bit bit0 = 0;
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#endif
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void done()
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{
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dummy++;
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}
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int acmp(char* a, char* b, int count)
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{
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int i;
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for(i = 0; i < count; i++) {
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if(a[i] != b[i]) {
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return 1;
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}
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}
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return 0;
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}
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void duffit (char* to, char* from, int count)
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{
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int n = (count + 7) / 8;
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switch(count % 8) {
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case 0: do { *to++ = *from++;
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case 7: *to++ = *from++;
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case 6: *to++ = *from++;
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case 5: *to++ = *from++;
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case 4: *to++ = *from++;
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case 3: *to++ = *from++;
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case 2: *to++ = *from++;
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case 1: *to++ = *from++;
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} while(--n > 0);
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}
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}
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int main(void)
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{
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char a[ASIZE] = {1};
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char b[ASIZE] = {2};
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/* a and b should be different */
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if(!acmp(a, b, ASIZE)) {
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failures++;
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}
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duffit(a, b, ASIZE);
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/* a and b should be the same */
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if(acmp(a, b, ASIZE)) {
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failures++;
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}
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success=failures;
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done();
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printf("failures: %d\n",failures);
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return failures;
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}
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