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Diffstat (limited to 'gcc-4.4.3/gcc/profile.h')
| -rw-r--r-- | gcc-4.4.3/gcc/profile.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/gcc-4.4.3/gcc/profile.h b/gcc-4.4.3/gcc/profile.h index a12d9af12..ec6570992 100644 --- a/gcc-4.4.3/gcc/profile.h +++ b/gcc-4.4.3/gcc/profile.h @@ -45,4 +45,10 @@ extern void mcf_smooth_cfg (void); /* Return sum of edge counts in input edges */ extern gcov_type sum_edge_counts (VEC (edge, gc) *edges); +/* Implement sampling to avoid writing to edge counters very often. + Many concurrent writes to the same counters, or to counters that share + the same cache line leads to up to 30x slowdown on an application running + on 8 CPUs. With sampling, the slowdown reduced to 2x. */ +extern void add_sampling_to_edge_counters (void); + #endif /* PROFILE_H */ |