From e2bc4ec8d5c6cfcf1caacbfab229a22728a11d75 Mon Sep 17 00:00:00 2001 From: tejohnson Date: Mon, 29 Apr 2013 13:22:46 +0000 Subject: [PATCH] This patch fixes PR bootstrap/57077. Certain new uses of apply_probability are actually scaling the counts up, and the scale factor should not be treated as a probability as the value may exceed REG_BR_PROB_BASE. One example (from the PR) is when scaling counts up in LTO when merging profiles. Another example I found when preparing the patch to use the rounding divide in more places is when inlining COMDAT functions. Add new helper function apply_scale that does the scaling without the probability range check. I audited the new uses of apply_probability and changed the calls as appropriate. 2013-04-29 Teresa Johnson PR bootstrap/57077 * basic-block.h (apply_scale): New function. (apply_probability): Use apply_scale. * gimple-streamer-in.c (input_bb): Ditto. * lto-streamer-in.c (input_cfg): Ditto. * lto-cgraph.c (merge_profile_summaries): Ditto. * tree-optimize.c (execute_fixup_cfg): Ditto. * tree-inline.c (copy_bb): Update comment to use apply_scale. (copy_edges_for_bb): Ditto. (copy_cfg_body): Ditto. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@198416 138bc75d-0d04-0410-961f-82ee72b054a4 --- gcc/ChangeLog | 14 ++++++++++++++ gcc/basic-block.h | 14 ++++++++++++-- gcc/gimple-streamer-in.c | 4 ++-- gcc/lto-cgraph.c | 16 ++++++++-------- gcc/lto-streamer-in.c | 4 ++-- gcc/tree-inline.c | 6 +++--- gcc/tree-optimize.c | 10 +++++----- 7 files changed, 46 insertions(+), 22 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 34dcd58..1529dd3 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,17 @@ +2013-04-29 Teresa Johnson + + PR bootstrap/57077 + * basic-block.h (apply_scale): New function. + (apply_probability): Use apply_scale. + * gimple-streamer-in.c (input_bb): Ditto. + * lto-streamer-in.c (input_cfg): Ditto. + * lto-cgraph.c (merge_profile_summaries): Ditto. + * tree-optimize.c (execute_fixup_cfg): Ditto. + * tree-inline.c (copy_bb): Update comment to use + apply_scale. + (copy_edges_for_bb): Ditto. + (copy_cfg_body): Ditto. + 2013-04-29 Tom de Vries * tree-ssa-tail-merge.c (find_same_succ_bb): Skip loop latch bbs. diff --git a/gcc/basic-block.h b/gcc/basic-block.h index 9b5192e..eed320c 100644 --- a/gcc/basic-block.h +++ b/gcc/basic-block.h @@ -500,7 +500,7 @@ struct edge_list REG_BR_PROB_BASE) /* Compute a scale factor (or probability) suitable for scaling of - gcov_type values via apply_probability(). */ + gcov_type values via apply_probability() and apply_scale(). */ #define GCOV_COMPUTE_SCALE(num,den) \ ((den) ? RDIV ((num) * REG_BR_PROB_BASE, (den)) : REG_BR_PROB_BASE) @@ -952,13 +952,23 @@ combine_probabilities (int prob1, int prob2) return RDIV (prob1 * prob2, REG_BR_PROB_BASE); } +/* Apply scale factor SCALE on frequency or count FREQ. Use this + interface when potentially scaling up, so that SCALE is not + constrained to be < REG_BR_PROB_BASE. */ + +static inline gcov_type +apply_scale (gcov_type freq, int scale) +{ + return RDIV (freq * scale, REG_BR_PROB_BASE); +} + /* Apply probability PROB on frequency or count FREQ. */ static inline gcov_type apply_probability (gcov_type freq, int prob) { check_probability (prob); - return RDIV (freq * prob, REG_BR_PROB_BASE); + return apply_scale (freq, prob); } /* Return inverse probability for PROB. */ diff --git a/gcc/gimple-streamer-in.c b/gcc/gimple-streamer-in.c index a27f0d6..03fbe91 100644 --- a/gcc/gimple-streamer-in.c +++ b/gcc/gimple-streamer-in.c @@ -329,8 +329,8 @@ input_bb (struct lto_input_block *ib, enum LTO_tags tag, index = streamer_read_uhwi (ib); bb = BASIC_BLOCK_FOR_FUNCTION (fn, index); - bb->count = apply_probability (streamer_read_gcov_count (ib), - count_materialization_scale); + bb->count = apply_scale (streamer_read_gcov_count (ib), + count_materialization_scale); bb->frequency = streamer_read_hwi (ib); bb->flags = streamer_read_hwi (ib); diff --git a/gcc/lto-cgraph.c b/gcc/lto-cgraph.c index 69f5e3a..cead76b 100644 --- a/gcc/lto-cgraph.c +++ b/gcc/lto-cgraph.c @@ -1347,10 +1347,10 @@ merge_profile_summaries (struct lto_file_decl_data **file_data_vec) file_data->profile_info.runs); lto_gcov_summary.sum_max = MAX (lto_gcov_summary.sum_max, - apply_probability (file_data->profile_info.sum_max, scale)); + apply_scale (file_data->profile_info.sum_max, scale)); lto_gcov_summary.sum_all = MAX (lto_gcov_summary.sum_all, - apply_probability (file_data->profile_info.sum_all, scale)); + apply_scale (file_data->profile_info.sum_all, scale)); /* Save a pointer to the profile_info with the largest scaled sum_all and the scale for use in merging the histogram. */ @@ -1372,8 +1372,8 @@ merge_profile_summaries (struct lto_file_decl_data **file_data_vec) /* Scale up the min value as we did the corresponding sum_all above. Use that to find the new histogram index. */ gcov_type scaled_min - = apply_probability (saved_profile_info->histogram[h_ix].min_value, - saved_scale); + = apply_scale (saved_profile_info->histogram[h_ix].min_value, + saved_scale); /* The new index may be shared with another scaled histogram entry, so we need to account for a non-zero histogram entry at new_ix. */ unsigned new_ix = gcov_histo_index (scaled_min); @@ -1386,8 +1386,8 @@ merge_profile_summaries (struct lto_file_decl_data **file_data_vec) here and place the scaled cumulative counter value in the bucket corresponding to the scaled minimum counter value. */ lto_gcov_summary.histogram[new_ix].cum_value - += apply_probability (saved_profile_info->histogram[h_ix].cum_value, - saved_scale); + += apply_scale (saved_profile_info->histogram[h_ix].cum_value, + saved_scale); lto_gcov_summary.histogram[new_ix].num_counters += saved_profile_info->histogram[h_ix].num_counters; } @@ -1419,8 +1419,8 @@ merge_profile_summaries (struct lto_file_decl_data **file_data_vec) if (scale == REG_BR_PROB_BASE) continue; for (edge = node->callees; edge; edge = edge->next_callee) - edge->count = apply_probability (edge->count, scale); - node->count = apply_probability (node->count, scale); + edge->count = apply_scale (edge->count, scale); + node->count = apply_scale (node->count, scale); } } diff --git a/gcc/lto-streamer-in.c b/gcc/lto-streamer-in.c index f5789c0..87158bf 100644 --- a/gcc/lto-streamer-in.c +++ b/gcc/lto-streamer-in.c @@ -635,8 +635,8 @@ input_cfg (struct lto_input_block *ib, struct function *fn, dest_index = streamer_read_uhwi (ib); probability = (int) streamer_read_hwi (ib); - count = apply_probability ((gcov_type) streamer_read_gcov_count (ib), - count_materialization_scale); + count = apply_scale ((gcov_type) streamer_read_gcov_count (ib), + count_materialization_scale); edge_flags = streamer_read_uhwi (ib); dest = BASIC_BLOCK_FOR_FUNCTION (fn, dest_index); diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c index c358cbe..69455ce 100644 --- a/gcc/tree-inline.c +++ b/gcc/tree-inline.c @@ -1519,7 +1519,7 @@ copy_bb (copy_body_data *id, basic_block bb, int frequency_scale, basic_block_info automatically. */ copy_basic_block = create_basic_block (NULL, (void *) 0, (basic_block) prev->aux); - /* Update to use apply_probability(). */ + /* Update to use apply_scale(). */ copy_basic_block->count = bb->count * count_scale / REG_BR_PROB_BASE; /* We are going to rebuild frequencies from scratch. These values @@ -1891,7 +1891,7 @@ copy_edges_for_bb (basic_block bb, gcov_type count_scale, basic_block ret_bb, && old_edge->dest->aux != EXIT_BLOCK_PTR) flags |= EDGE_FALLTHRU; new_edge = make_edge (new_bb, (basic_block) old_edge->dest->aux, flags); - /* Update to use apply_probability(). */ + /* Update to use apply_scale(). */ new_edge->count = old_edge->count * count_scale / REG_BR_PROB_BASE; new_edge->probability = old_edge->probability; } @@ -2278,7 +2278,7 @@ copy_cfg_body (copy_body_data * id, gcov_type count, int frequency_scale, incoming_frequency += EDGE_FREQUENCY (e); incoming_count += e->count; } - /* Update to use apply_probability(). */ + /* Update to use apply_scale(). */ incoming_count = incoming_count * count_scale / REG_BR_PROB_BASE; /* Update to use EDGE_FREQUENCY. */ incoming_frequency diff --git a/gcc/tree-optimize.c b/gcc/tree-optimize.c index d399d8a..0948d2e 100644 --- a/gcc/tree-optimize.c +++ b/gcc/tree-optimize.c @@ -131,15 +131,15 @@ execute_fixup_cfg (void) ENTRY_BLOCK_PTR->count); ENTRY_BLOCK_PTR->count = cgraph_get_node (current_function_decl)->count; - EXIT_BLOCK_PTR->count = apply_probability (EXIT_BLOCK_PTR->count, - count_scale); + EXIT_BLOCK_PTR->count = apply_scale (EXIT_BLOCK_PTR->count, + count_scale); FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs) - e->count = apply_probability (e->count, count_scale); + e->count = apply_scale (e->count, count_scale); FOR_EACH_BB (bb) { - bb->count = apply_probability (bb->count, count_scale); + bb->count = apply_scale (bb->count, count_scale); for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) { gimple stmt = gsi_stmt (gsi); @@ -172,7 +172,7 @@ execute_fixup_cfg (void) } FOR_EACH_EDGE (e, ei, bb->succs) - e->count = apply_probability (e->count, count_scale); + e->count = apply_scale (e->count, count_scale); /* If we have a basic block with no successors that does not end with a control statement or a noreturn call end it with -- 2.7.4