[問題] Matrix Multiplication 的陣列問題
下列是一段Matrix Multiplication程式中宣告三個陣列A,B,C的一段程式,
請問各位知道星號內那段code的意思是什麼嗎?
感謝
#define N 2048
float *A, *B,*C;
float *AUnaligned, *BUnaligned,*CUnaligned;
void allocandpopulate() {
AUnaligned=A=new float[N*N+16];
BUnaligned=B=new float[N*N+16];
CUnaligned=C=new float[N*N+16];
***********
int alignA=(((unsigned long long) A) & 31)/4;
int alignB=(((unsigned long long) A) & 31)/4;
int alignC=(((unsigned long long) A) & 31)/4;
A+=8-alignA
B+=8-alignB
C+=8-alignC
************
for (int i=0;i<N*N;i++)
{
A[i]=(rand()+0.5f)/(RAND_MAX+1.f);
B[i]=(rand()+0.5f)/(RAND_MAX+1.f);
}
}
--
Sent from my Windows
--
※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 137.44.91.1
※ 文章網址: https://www.ptt.cc/bbs/C_and_CPP/M.1446121382.A.F8C.html
推
10/29 20:37, , 1F
10/29 20:37, 1F
→
10/29 20:37, , 2F
10/29 20:37, 2F
→
10/29 20:52, , 3F
10/29 20:52, 3F
→
10/29 20:55, , 4F
10/29 20:55, 4F
推
10/29 21:54, , 5F
10/29 21:54, 5F
推
10/30 01:08, , 6F
10/30 01:08, 6F
→
10/30 01:08, , 7F
10/30 01:08, 7F
→
10/30 01:10, , 8F
10/30 01:10, 8F
討論串 (同標題文章)
以下文章回應了本文:
完整討論串 (本文為第 1 之 2 篇):