jump_dest_block);
cbranch_jump_edge->flags |= EDGE_FALLTHRU;
cbranch_fallthru_edge->flags &= ~EDGE_FALLTHRU;
+ update_br_prob_note (cbranch_block);
/* Delete the block with the unconditional jump, and clean up the mess. */
flow_delete_block (jump_block);
set1 = pc_set (e->src->end);
set2 = pc_set (b->end);
if (((e->flags & EDGE_FALLTHRU) != 0)
- != (XEXP (SET_SRC (set1), 0) == pc_rtx))
+ != (XEXP (SET_SRC (set1), 1) == pc_rtx))
reverse1 = true;
cond1 = XEXP (SET_SRC (set1), 0);
cond2 = XEXP (SET_SRC (set2), 0);
if (reverse1)
- code1 = reversed_comparison_code (cond1, b->end);
+ code1 = reversed_comparison_code (cond1, e->src->end);
else
code1 = GET_CODE (cond1);
BITMAP_XFREE (nonequal);
cselib_finish ();
if ((comparison_dominates_p (code1, code2) != 0)
- != (XEXP (SET_SRC (set2), 0) == pc_rtx))
+ != (XEXP (SET_SRC (set2), 1) == pc_rtx))
return BRANCH_EDGE (b);
else
return FALLTHRU_EDGE (b);
int mode;
{
bool changed = false;
- edge e, next, threaded_edge;
+ edge e, next, *threaded_edges = NULL;
for (e = b->succ; e; e = next)
{
basic_block target, first;
int counter;
bool threaded = false;
+ int nthreaded_edges = 0;
next = e->succ_next;
/* Allow to thread only over one edge at time to simplify updating
of probabilities. */
- else if ((mode & CLEANUP_THREADING) && !threaded)
+ else if (mode & CLEANUP_THREADING)
{
- threaded_edge = thread_jump (mode, e, target);
- if (threaded_edge)
+ edge t = thread_jump (mode, e, target);
+ if (t)
{
- new_target = threaded_edge->dest;
+ if (!threaded_edges)
+ threaded_edges = xmalloc (sizeof (*threaded_edges)
+ * n_basic_blocks);
+ else
+ {
+ int i;
+
+ /* Detect an infinite loop across blocks not
+ including the start block. */
+ for (i = 0; i < nthreaded_edges; ++i)
+ if (threaded_edges[i] == t)
+ break;
+ if (i < nthreaded_edges)
+ {
+ counter = n_basic_blocks;
+ break;
+ }
+ }
+
+ /* Detect an infinite loop across the start block. */
+ if (t->dest == b)
+ break;
+
+ if (nthreaded_edges >= n_basic_blocks)
+ abort ();
+ threaded_edges[nthreaded_edges++] = t;
+
+ new_target = t->dest;
new_target_threaded = true;
}
}
gcov_type edge_count = e->count;
int edge_probability = e->probability;
int edge_frequency;
+ int n = 0;
/* Don't force if target is exit block. */
if (threaded && target != EXIT_BLOCK_PTR)
edge t;
first->count -= edge_count;
- first->succ->count -= edge_count;
+ if (first->count < 0)
+ first->count = 0;
first->frequency -= edge_frequency;
+ if (first->frequency < 0)
+ first->frequency = 0;
if (first->succ->succ_next)
- t = threaded_edge;
+ {
+ edge e;
+ int prob;
+ if (n >= nthreaded_edges)
+ abort ();
+ t = threaded_edges [n++];
+ if (t->src != first)
+ abort ();
+ if (first->frequency)
+ prob = edge_frequency * REG_BR_PROB_BASE / first->frequency;
+ else
+ prob = 0;
+ if (prob > t->probability)
+ prob = t->probability;
+ t->probability -= prob;
+ prob = REG_BR_PROB_BASE - prob;
+ if (prob <= 0)
+ {
+ first->succ->probability = REG_BR_PROB_BASE;
+ first->succ->succ_next->probability = 0;
+ }
+ else
+ for (e = first->succ; e; e = e->succ_next)
+ e->probability = ((e->probability * REG_BR_PROB_BASE)
+ / (double) prob);
+ update_br_prob_note (first);
+ }
else
- t = first->succ;
-
+ {
+ /* It is possible that as the result of
+ threading we've removed edge as it is
+ threaded to the fallthru edge. Avoid
+ getting out of sync. */
+ if (n < nthreaded_edges
+ && first == threaded_edges [n]->src)
+ n++;
+ t = first->succ;
+ }
+
+ t->count -= edge_count;
+ if (t->count < 0)
+ t->count = 0;
first = t->dest;
}
while (first != target);
}
}
+ if (threaded_edges)
+ free (threaded_edges);
return changed;
}
\f
/* If B has a fallthru edge to C, no need to move anything. */
if (e->flags & EDGE_FALLTHRU)
{
+ int b_index = b->index, c_index = c->index;
/* We need to update liveness in case C already has broken liveness
or B ends by conditional jump to next instructions that will be
removed. */
if (rtl_dump_file)
fprintf (rtl_dump_file, "Merged %d and %d without moving.\n",
- b->index, c->index);
+ b_index, c_index);
return true;
}
we will only have one branch prediction bit to work with. Thus
we require the existing branches to have probabilities that are
roughly similar. */
- /* ??? We should use bb->frequency to allow merging in infrequently
- executed blocks, but at the moment it is not available when
- cleanup_cfg is run. */
- if (match && !optimize_size)
+ if (match
+ && !optimize_size
+ && bb1->frequency > BB_FREQ_MAX / 1000
+ && bb2->frequency > BB_FREQ_MAX / 1000)
{
- rtx note1, note2;
- int prob1, prob2;
+ int prob2;
- note1 = find_reg_note (bb1->end, REG_BR_PROB, 0);
- note2 = find_reg_note (bb2->end, REG_BR_PROB, 0);
+ if (b1->dest == b2->dest)
+ prob2 = b2->probability;
+ else
+ /* Do not use f2 probability as f2 may be forwarded. */
+ prob2 = REG_BR_PROB_BASE - b2->probability;
- if (note1 && note2)
+ /* Fail if the difference in probabilities is
+ greater than 5%. */
+ if (abs (b1->probability - prob2) > REG_BR_PROB_BASE / 20)
{
- prob1 = INTVAL (XEXP (note1, 0));
- prob2 = INTVAL (XEXP (note2, 0));
- if (reverse)
- prob2 = REG_BR_PROB_BASE - prob2;
-
- /* Fail if the difference in probabilities is
- greater than 5%. */
- if (abs (prob1 - prob2) > REG_BR_PROB_BASE / 20)
- return false;
- }
+ if (rtl_dump_file)
+ fprintf (rtl_dump_file,
+ "Outcomes of branch in bb %i and %i differs to much (%i %i)\n",
+ bb1->index, bb2->index, b1->probability, prob2);
- else if (note1 || note2)
- return false;
+ return false;
+ }
}
if (rtl_dump_file && match)
edge s;
rtx last;
rtx label;
- rtx note;
/* Search backward through forwarder blocks. We don't need to worry
about multiple entry or chained forwarders, as they will be optimized
if (FORWARDER_BLOCK_P (s2->dest))
{
s2->dest->succ->count -= s2->count;
+ if (s2->dest->succ->count < 0)
+ s2->dest->succ->count = 0;
s2->dest->count -= s2->count;
s2->dest->frequency -= EDGE_FREQUENCY (s);
+ if (s2->dest->frequency < 0)
+ s2->dest->frequency = 0;
+ if (s2->dest->count < 0)
+ s2->dest->count = 0;
}
if (!redirect_to->frequency && !src1->frequency)
/ (redirect_to->frequency + src1->frequency));
}
- note = find_reg_note (redirect_to->end, REG_BR_PROB, 0);
- if (note)
- XEXP (note, 0) = GEN_INT (BRANCH_EDGE (redirect_to)->probability);
+ update_br_prob_note (redirect_to);
/* Edit SRC1 to go to REDIRECT_TO at NEWPOS1. */
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