diff options
| -rw-r--r-- | gcc/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/profile.c | 41 |
2 files changed, 47 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 394634bc3dd..34e94e403fe 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2011-10-20 Dehao Chen <dehao@google.com> + + * profile.c (compute_branch_probabilities): Compute and dump the + overlap between the static estimation and the instrumentation profile. + (OVERLAP_BASE): New macro. + (compute_frequency_overlap): New function + 2011-10-19 Jakub Jelinek <jakub@redhat.com> * config/i386/i386.c (expand_vec_perm_vpshufb2_vpermq_even_odd): Use diff --git a/gcc/profile.c b/gcc/profile.c index 893e2cd17c7..41108394e98 100644 --- a/gcc/profile.c +++ b/gcc/profile.c @@ -437,6 +437,39 @@ read_profile_edge_counts (gcov_type *exec_counts) return num_edges; } +#define OVERLAP_BASE 10000 + +/* Compare the static estimated profile to the actual profile, and + return the "degree of overlap" measure between them. + + Degree of overlap is a number between 0 and OVERLAP_BASE. It is + the sum of each basic block's minimum relative weights between + two profiles. And overlap of OVERLAP_BASE means two profiles are + identical. */ + +static int +compute_frequency_overlap (void) +{ + gcov_type count_total = 0, freq_total = 0; + int overlap = 0; + basic_block bb; + + FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb) + { + count_total += bb->count; + freq_total += bb->frequency; + } + + if (count_total == 0 || freq_total == 0) + return 0; + + FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb) + overlap += MIN (bb->count * OVERLAP_BASE / count_total, + bb->frequency * OVERLAP_BASE / freq_total); + + return overlap; +} + /* Compute the branch probabilities for the various branches. Annotate them accordingly. @@ -607,7 +640,13 @@ compute_branch_probabilities (unsigned cfg_checksum, unsigned lineno_checksum) } } if (dump_file) - dump_flow_info (dump_file, dump_flags); + { + int overlap = compute_frequency_overlap (); + dump_flow_info (dump_file, dump_flags); + fprintf (dump_file, "Static profile overlap: %d.%d%%\n", + overlap / (OVERLAP_BASE / 100), + overlap % (OVERLAP_BASE / 100)); + } total_num_passes += passes; if (dump_file) |