| /* { dg-do compile { target { i?86-*-* x86_64-*-* } } } */ |
| /* { dg-options "-O2 -fno-tree-vectorize -fprefetch-loop-arrays -march=amdfam10 --param simultaneous-prefetches=100 --param min-insn-to-prefetch-ratio=6 -fdump-tree-aprefetch-details" } */ |
| |
| #define N 1000 |
| #define K 900 |
| |
| double a[N][N]; |
| |
| double test(void) |
| { |
| unsigned i, j; |
| double sum = 0; |
| |
| /* Here, we should use non-temporal prefetch instruction. */ |
| for (i = 0; i < K; i++) |
| for (j = 0; j < K; j++) |
| sum += a[i][j]; |
| |
| /* Here, we should not use non-temporal prefetch instruction, since the |
| value of a[i+10][j] is reused in L2 cache. */ |
| for (i = 0; i < K; i++) |
| for (j = 0; j < K; j++) |
| sum += a[i][j] * a[i + 10][j]; |
| |
| /* Here, we should use non-temporal prefetch instruction, since the |
| value of a[i+100][j] is too far to be reused in L2 cache. */ |
| for (i = 0; i < K; i++) |
| for (j = 0; j < K; j++) |
| sum += a[i][j] * a[i + 100][j]; |
| |
| /* Here, temporal prefetches should be used, since the volume of the |
| memory accesses is smaller than L2 cache. */ |
| for (i = 0; i < 100; i++) |
| for (j = 0; j < 100; j++) |
| sum += a[i][j] * a[i + 100][j]; |
| |
| /* Temporal prefetches should be used here (even though the accesses to |
| a[j][i] are independent, the same cache line is almost always hit |
| every N iterations). */ |
| for (i = 0; i < N; i++) |
| for (j = 0; j < N; j++) |
| sum += a[j][i]; |
| |
| return sum; |
| } |
| |
| /* { dg-final { scan-tree-dump-times "Issued prefetch" 5 "aprefetch" } } */ |
| /* { dg-final { scan-tree-dump-times "Issued nontemporal prefetch" 3 "aprefetch" } } */ |