ÊáëçìÝñá óáò. Óôï ðáñÜñôçìá Á ôùí åêöùíÞóåùí ôçò 4çò óåéñÜò áñ÷éêïðïéåßôå ôïõò ðßíáêåò ùò åîÞò:
init_matrix(A, N); init_matrix(B, N); init_matrix(C, N);
Ôá óôïé÷åßá ôïõ ðßíáêá C üìùò äåí èá ðñÝðåé íá áñ÷éêïðïéçèïýí óôï 0; Ãéáôß Ýôóé üëá ôá óôïé÷åßá ðëçí ôïõ C[0][0] åßíáé ìç ìçäåíéêÜ êáé ëüãù ôïõ "C[i][j] +=" ðïõ Ýðåôáé, ôï áðïôÝëåóìá ðïõ ðñïêýðôåé åßíáé ïõóéáóôéêÜ C=A*A+A áíôß ãéá C=A*A. Áí êáé áõôü êáíïíéêÜ äåí áíáìÝíåôáé íá åðçñåÜóåé ôá áðïôåëÝóìáôÜ ìáò, óùóôÜ;
Åðß ôç åõêáéñßá óôéò äéáöÜíåéåò ôçò "Lec6-caches-10.pdf", óåë. 33, õðÜñ÷åé ôï åîÞò: for (j = jj; j < min(jj+B-1,N); j = j+1) Ôï óùóôü äåí èá Ýðñåðå íá åßíáé: for (j = jj; j < min(jj+B,N); j = j+1) ??
×áñáêôçñéóôéêü ðáñÜäåéãìá üôáí B=1, jj<N ôüôå äåí ðñïêýðôåé êáíÝíá iteration ãéáôß ãßíåôáé: for (j = jj; j < jj; j = j+1)
Åõ÷áñéóôþ
---------------------------------------- e-mail se latinikous xarakthres ----------------------------------------
Kalhmera sas. Sto pararthma A twn ekfwnhsewn ths 4hs seiras arxikopoieite tous pinakes ws ekshs:
init_matrix(A, N); init_matrix(B, N); init_matrix(C, N);
Ta stoixeia tou pinaka C omws den 8a prepei na arxikopoih8oun sto 0? Giati etsi ola ta stoixeia plhn tou C[0][0] einai mh mhdenika kai logw tou "C[i][j] +=" pou epetai, to apotelesma pou prokuptei einai ousiastika C=A*A+A anti gia C=A*A. An kai auto kanonika den anamenetai na ephreasei ta apotelesmata mas, swsta?
Epi th eukairia stis diafaneies ths "Lec6-caches-10.pdf", sel. 33, uparxei to ekshs: for (j = jj? j < min(jj+B-1,N)? j = j+1) To swsto den 8a eprepe na einai: for (j = jj? j < min(jj+B,N)? j = j+1) ?
Xarakthristiko paradeigma otan B=1, jj<N tote den prokuptei kanena iteration giati ginetai: for (j = jj; j < jj; j = j+1)
Euxaristw