diff options
Diffstat (limited to 'gcc/final.c')
| -rw-r--r-- | gcc/final.c | 168 |
1 files changed, 52 insertions, 116 deletions
diff --git a/gcc/final.c b/gcc/final.c index 821a814..d3224819 100644 --- a/gcc/final.c +++ b/gcc/final.c @@ -632,6 +632,11 @@ static struct label_alignment *label_align; void init_insn_lengths () { + if (label_align) + { + free (label_align); + label_align = 0; + } if (uid_shuid) { free (uid_shuid); @@ -775,19 +780,11 @@ get_attr_length (insn) #endif #ifndef LABEL_ALIGN_AFTER_BARRIER -#define LABEL_ALIGN_AFTER_BARRIER(LABEL) 1 +#define LABEL_ALIGN_AFTER_BARRIER(LABEL) align_jumps_log #endif #ifndef LABEL_ALIGN_AFTER_BARRIER_MAX_SKIP -#define LABEL_ALIGN_AFTER_BARRIER_MAX_SKIP 0 -#endif - -#ifndef JUMP_ALIGN -#define JUMP_ALIGN(LABEL) align_jumps_log -#endif - -#ifndef JUMP_ALIGN_MAX_SKIP -#define JUMP_ALIGN_MAX_SKIP (align_jumps-1) +#define LABEL_ALIGN_AFTER_BARRIER_MAX_SKIP (align_jumps-1) #endif #ifndef ADDR_VEC_ALIGN @@ -938,85 +935,6 @@ insn_current_reference_address (branch) } #endif /* HAVE_ATTR_length */ -void -compute_alignments () -{ - int i; - int log, max_skip, max_log; - - if (label_align) - { - free (label_align); - label_align = 0; - } - - max_labelno = max_label_num (); - min_labelno = get_first_label_num (); - label_align = (struct label_alignment *) xcalloc ((max_labelno - min_labelno + 1), - sizeof (struct label_alignment)); - - /* If not optimizing or optimizing for size, don't assign any alignments. */ - for (i = 0; i < n_basic_blocks; i++) - { - basic_block bb = BASIC_BLOCK (i); - rtx label = bb->head; - int fallthru_frequency = 0, branch_frequency = 0, has_fallthru = 0; - edge e; - - if (GET_CODE (label) != CODE_LABEL) - continue; - max_log = LABEL_ALIGN (label); - max_skip = LABEL_ALIGN_MAX_SKIP; - - for (e = bb->pred; e; e = e->pred_next) - { - if (e->flags & EDGE_FALLTHRU) - has_fallthru = 1, fallthru_frequency += EDGE_FREQUENCY (e); - else - branch_frequency += EDGE_FREQUENCY (e); - } - - /* There are two purposes to align block with no fallthru incomming edge: - 1) to avoid fetch stalls when branch destination is near cache boundary - 2) to improve cache effciency in case the previous block is not executed - (so it does not need to be in the cache). - - We to catch first case, we align frequently executed blocks. - To catch the second, we align blocks that are executed more frequently - than the predecesor and the predecesor is likely to not be executed - when function is called. */ - - if (!has_fallthru - && (branch_frequency > BB_FREQ_MAX / 10 - || (bb->frequency > BASIC_BLOCK (i - 1)->frequency * 10 - && (BASIC_BLOCK (i - 1)->frequency - <= ENTRY_BLOCK_PTR->frequency / 2)))) - { - log = JUMP_ALIGN (label); - if (max_log < log) - { - max_log = log; - max_skip = JUMP_ALIGN_MAX_SKIP; - } - } - /* In case block is frequent and reached mostly by non-fallthru edge, - align it. It is most likely an first block of loop. */ - if (has_fallthru - && branch_frequency + fallthru_frequency > BB_FREQ_MAX / 10 - && branch_frequency > fallthru_frequency * 5) - { - log = LOOP_ALIGN (label); - if (max_log < log) - { - max_log = log; - max_skip = LOOP_ALIGN_MAX_SKIP; - } - } - LABEL_TO_ALIGNMENT (label) = max_log; - LABEL_TO_MAX_SKIP (label) = max_skip; - } -} - /* Make a pass over all insns and compute their actual lengths by shortening any branches of variable length if possible. */ @@ -1054,29 +972,20 @@ shorten_branches (first) #endif - /* Compute maximum UID and allocate label_align / uid_shuid. */ - max_uid = get_max_uid (); + /* We must do some computations even when not actually shortening, in + order to get the alignment information for the labels. */ - uid_shuid = (int *) xmalloc (max_uid * sizeof *uid_shuid); + init_insn_lengths (); - if (max_labelno != max_label_num ()) - { - int old = max_labelno; - int n_labels; - int n_old_labels; - - max_labelno = max_label_num (); - - n_labels = max_labelno - min_labelno + 1; - n_old_labels = old - min_labelno + 1; + /* Compute maximum UID and allocate label_align / uid_shuid. */ + max_uid = get_max_uid (); - label_align = (struct label_alignment *) xrealloc - (label_align, n_labels * sizeof (struct label_alignment)); + max_labelno = max_label_num (); + min_labelno = get_first_label_num (); + label_align = (struct label_alignment *) + xcalloc ((max_labelno - min_labelno + 1), sizeof (struct label_alignment)); - if (n_old_labels < n_labels) - memset (label_align + n_old_labels, 0, - (n_labels - n_old_labels) * sizeof (struct label_alignment)); - } + uid_shuid = (int *) xmalloc (max_uid * sizeof *uid_shuid); /* Initialize label_align and set up uid_shuid to be strictly monotonically rising with insn order. */ @@ -1103,14 +1012,6 @@ shorten_branches (first) else if (GET_CODE (insn) == CODE_LABEL) { rtx next; - - /* Merge in alignments computed by compute_alignments. */ - log = LABEL_TO_ALIGNMENT (insn); - if (max_log < log) - { - max_log = log; - max_skip = LABEL_TO_MAX_SKIP (insn); - } log = LABEL_ALIGN (insn); if (max_log < log) @@ -1162,6 +1063,41 @@ shorten_branches (first) break; } } + /* Again, we allow NOTE_INSN_LOOP_BEG - INSN - CODE_LABEL + sequences in order to handle reorg output efficiently. */ + else if (GET_CODE (insn) == NOTE + && NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG) + { + rtx label; + int nest = 0; + + /* Search for the label that starts the loop. + Don't skip past the end of the loop, since that could + lead to putting an alignment where it does not belong. + However, a label after a nested (non-)loop would be OK. */ + for (label = insn; label; label = NEXT_INSN (label)) + { + if (GET_CODE (label) == NOTE + && NOTE_LINE_NUMBER (label) == NOTE_INSN_LOOP_BEG) + nest++; + else if (GET_CODE (label) == NOTE + && NOTE_LINE_NUMBER (label) == NOTE_INSN_LOOP_END + && --nest == 0) + break; + else if (GET_CODE (label) == CODE_LABEL) + { + log = LOOP_ALIGN (label); + if (max_log < log) + { + max_log = log; + max_skip = LOOP_ALIGN_MAX_SKIP; + } + break; + } + } + } + else + continue; } #ifdef HAVE_ATTR_length |