diff options
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/profile.c | 72 |
2 files changed, 52 insertions, 25 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 2ecc65c..41a53e2 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +Wed Nov 21 12:38:37 CET 2001 Jan Hubicka + + * profile.c (compute_branch_probabilites): Compute probabilities + for entry/exit edges; estimate probabilities for zero counts. + 2001-11-21 Jakub Jelinek <jakub@redhat.com> * explow.c (probe_stack_range): Use LCT_NORMAL as second argument diff --git a/gcc/profile.c b/gcc/profile.c index 57a1c72..1aea559 100644 --- a/gcc/profile.c +++ b/gcc/profile.c @@ -411,38 +411,32 @@ compute_branch_probabilities () num_never_executed = 0; num_branches = 0; - for (i = 0; i < n_basic_blocks; i++) + for (i = 0; i <= n_basic_blocks + 1; i++) { - basic_block bb = BASIC_BLOCK (i); + basic_block bb = GCOV_INDEX_TO_BB (i); edge e; gcov_type total; rtx note; total = bb->count; if (total) - for (e = bb->succ; e; e = e->succ_next) - { - e->probability = (e->count * REG_BR_PROB_BASE + total / 2) / total; - if (e->probability < 0 || e->probability > REG_BR_PROB_BASE) - { - error ("Corrupted profile info: prob for %d-%d thought to be %d", - e->src->index, e->dest->index, e->probability); - e->probability = REG_BR_PROB_BASE / 2; - } - } - if (any_condjump_p (bb->end) - && bb->succ->succ_next) { - int prob; - edge e; - - if (total == 0) - prob = -1; - else - if (total == -1) - num_never_executed++; - else + for (e = bb->succ; e; e = e->succ_next) { + e->probability = (e->count * REG_BR_PROB_BASE + total / 2) / total; + if (e->probability < 0 || e->probability > REG_BR_PROB_BASE) + { + error ("Corrupted profile info: prob for %d-%d thought to be %d", + e->src->index, e->dest->index, e->probability); + e->probability = REG_BR_PROB_BASE / 2; + } + } + if (bb->index >= 0 + && any_condjump_p (bb->end) + && bb->succ->succ_next) + { + int prob; + edge e; int index; /* Find the branch edge. It is possible that we do have fake @@ -467,9 +461,37 @@ compute_branch_probabilities () REG_NOTES (bb->end) = gen_rtx_EXPR_LIST (REG_BR_PROB, GEN_INT (prob), REG_NOTES (bb->end)); + num_branches++; } - num_branches++; - + } + /* Otherwise distribute the probabilities evenly so we get sane sum. + Use simple heuristics that if there are normal edges, give all abnormals + frequency of 0, otherwise distribute the frequency over abnormals + (this is the case of noreturn calls). */ + else + { + for (e = bb->succ; e; e = e->succ_next) + if (!(e->flags & (EDGE_COMPLEX | EDGE_FAKE))) + total ++; + if (total) + { + for (e = bb->succ; e; e = e->succ_next) + if (!(e->flags & (EDGE_COMPLEX | EDGE_FAKE))) + e->probability = REG_BR_PROB_BASE / total; + else + e->probability = 0; + } + else + { + for (e = bb->succ; e; e = e->succ_next) + total ++; + for (e = bb->succ; e; e = e->succ_next) + e->probability = REG_BR_PROB_BASE / total; + } + if (bb->index >= 0 + && any_condjump_p (bb->end) + && bb->succ->succ_next) + num_branches++, num_never_executed; } } |