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| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/tree-ssa-loop-prefetch.c | 8 |
2 files changed, 10 insertions, 4 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 8babd20..960d11c 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2010-06-09 Changpeng Fang <changpeng.fang@amd.com> + + * tree-ssa-loop-prefetch.c (PREFETCH_MOD_TO_UNROLL_FACTOR_RATIO) : + Change the PREFETCH_MOD_TO_UNROLL_FACTOR_RATIO threshold value from + 8 to 4. Minor change of the related comments. + 2010-06-09 Sebastian Pop <sebastian.pop@amd.com> * tree-scalar-evolution.c (instantiate_scev_name): Do not fail diff --git a/gcc/tree-ssa-loop-prefetch.c b/gcc/tree-ssa-loop-prefetch.c index 9ccf72e..705ee81 100644 --- a/gcc/tree-ssa-loop-prefetch.c +++ b/gcc/tree-ssa-loop-prefetch.c @@ -228,13 +228,13 @@ struct mem_ref_group /* Do not generate a prefetch if the unroll factor is significantly less than what is required by the prefetch. This is to avoid redundant - prefetches. For example, if prefetch_mod is 16 and unroll_factor is - 1, this means prefetching requires unrolling the loop 16 times, but - the loop is not going to be unrolled. In this case (ratio = 16), + prefetches. For example, when prefetch_mod is 16 and unroll_factor is + 2, prefetching requires unrolling the loop 16 times, but + the loop is actually unrolled twice. In this case (ratio = 8), prefetching is not likely to be beneficial. */ #ifndef PREFETCH_MOD_TO_UNROLL_FACTOR_RATIO -#define PREFETCH_MOD_TO_UNROLL_FACTOR_RATIO 8 +#define PREFETCH_MOD_TO_UNROLL_FACTOR_RATIO 4 #endif /* The memory reference. */ |