/* Loop manipulation code for GNU compiler.
- Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
This file is part of GCC.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA. */
+Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA. */
#include "config.h"
#include "system.h"
#include "tm.h"
#include "rtl.h"
#include "hard-reg-set.h"
+#include "obstack.h"
#include "basic-block.h"
#include "cfgloop.h"
#include "cfglayout.h"
+#include "cfghooks.h"
#include "output.h"
-static struct loop * duplicate_loop (struct loops *, struct loop *,
- struct loop *);
static void duplicate_subloops (struct loops *, struct loop *, struct loop *);
static void copy_loops_to (struct loops *, struct loop **, int,
struct loop *);
static int find_path (edge, basic_block **);
static bool alp_enum_p (basic_block, void *);
static void add_loop (struct loops *, struct loop *);
-static void fix_loop_placements (struct loops *, struct loop *);
+static void fix_loop_placements (struct loops *, struct loop *, bool *);
static bool fix_bb_placement (struct loops *, basic_block);
-static void fix_bb_placements (struct loops *, basic_block);
+static void fix_bb_placements (struct loops *, basic_block, bool *);
static void place_new_loop (struct loops *, struct loop *);
static void scale_loop_frequencies (struct loop *, int, int);
-static void scale_bbs_frequencies (basic_block *, int, int, int);
static basic_block create_preheader (struct loop *, int);
-static void fix_irreducible_loops (basic_block);
+static void unloop (struct loops *, struct loop *, bool *);
#define RDIV(X,Y) (((X) + (Y) / 2) / (Y))
-/* Splits basic block BB after INSN, returns created edge. Updates loops
- and dominators. */
-edge
-split_loop_bb (basic_block bb, rtx insn)
-{
- edge e;
-
- /* Split the block. */
- e = split_block (bb, insn);
-
- /* Add dest to loop. */
- add_bb_to_loop (e->dest, e->src->loop_father);
-
- return e;
-}
-
/* Checks whether basic block BB is dominated by DATA. */
static bool
rpe_enum_p (basic_block bb, void *data)
static int
find_path (edge e, basic_block **bbs)
{
- gcc_assert (!e->dest->pred->pred_next);
+ gcc_assert (EDGE_COUNT (e->dest->preds) <= 1);
/* Find bbs in the path. */
- *bbs = xcalloc (n_basic_blocks, sizeof (basic_block));
+ *bbs = XCNEWVEC (basic_block, n_basic_blocks);
return dfs_enumerate_from (e->dest, 0, rpe_enum_p, *bbs,
n_basic_blocks, e->dest);
}
fix_bb_placement (struct loops *loops, basic_block bb)
{
edge e;
+ edge_iterator ei;
struct loop *loop = loops->tree_root, *act;
- for (e = bb->succ; e; e = e->succ_next)
+ FOR_EACH_EDGE (e, ei, bb->succs)
{
if (e->dest == EXIT_BLOCK_PTR)
continue;
its predecessors that may change if placement of FROM changed. Also fix
placement of subloops of FROM->loop_father, that might also be altered due
to this change; the condition for them is similar, except that instead of
- successors we consider edges coming out of the loops. */
+ successors we consider edges coming out of the loops.
+
+ If the changes may invalidate the information about irreducible regions,
+ IRRED_INVALIDATED is set to true. */
+
static void
-fix_bb_placements (struct loops *loops, basic_block from)
+fix_bb_placements (struct loops *loops, basic_block from,
+ bool *irred_invalidated)
{
sbitmap in_queue;
basic_block *queue, *qtop, *qbeg, *qend;
/* Prevent us from going out of the base_loop. */
SET_BIT (in_queue, base_loop->header->index);
- queue = xmalloc ((base_loop->num_nodes + 1) * sizeof (basic_block));
+ queue = XNEWVEC (basic_block, base_loop->num_nodes + 1);
qtop = queue + base_loop->num_nodes + 1;
qbeg = queue;
qend = queue + 1;
while (qbeg != qend)
{
+ edge_iterator ei;
from = *qbeg;
qbeg++;
if (qbeg == qtop)
continue;
}
+ FOR_EACH_EDGE (e, ei, from->succs)
+ {
+ if (e->flags & EDGE_IRREDUCIBLE_LOOP)
+ *irred_invalidated = true;
+ }
+
/* Something has changed, insert predecessors into queue. */
- for (e = from->pred; e; e = e->pred_next)
+ FOR_EACH_EDGE (e, ei, from->preds)
{
basic_block pred = e->src;
struct loop *nca;
+ if (e->flags & EDGE_IRREDUCIBLE_LOOP)
+ *irred_invalidated = true;
+
if (TEST_BIT (in_queue, pred->index))
continue;
free (queue);
}
-/* Basic block from has lost one or more of its predecessors, so it might
- mo longer be part irreducible loop. Fix it and proceed recursively
- for its successors if needed. */
-static void
-fix_irreducible_loops (basic_block from)
-{
- basic_block bb;
- basic_block *stack;
- int stack_top;
- sbitmap on_stack;
- edge *edges, e;
- unsigned n_edges, i;
-
- if (!(from->flags & BB_IRREDUCIBLE_LOOP))
- return;
-
- on_stack = sbitmap_alloc (last_basic_block);
- sbitmap_zero (on_stack);
- SET_BIT (on_stack, from->index);
- stack = xmalloc (from->loop_father->num_nodes * sizeof (basic_block));
- stack[0] = from;
- stack_top = 1;
-
- while (stack_top)
- {
- bb = stack[--stack_top];
- RESET_BIT (on_stack, bb->index);
-
- for (e = bb->pred; e; e = e->pred_next)
- if (e->flags & EDGE_IRREDUCIBLE_LOOP)
- break;
- if (e)
- continue;
-
- bb->flags &= ~BB_IRREDUCIBLE_LOOP;
- if (bb->loop_father->header == bb)
- edges = get_loop_exit_edges (bb->loop_father, &n_edges);
- else
- {
- n_edges = 0;
- for (e = bb->succ; e; e = e->succ_next)
- n_edges++;
- edges = xmalloc (n_edges * sizeof (edge));
- n_edges = 0;
- for (e = bb->succ; e; e = e->succ_next)
- edges[n_edges++] = e;
- }
-
- for (i = 0; i < n_edges; i++)
- {
- e = edges[i];
-
- if (e->flags & EDGE_IRREDUCIBLE_LOOP)
- {
- if (!flow_bb_inside_loop_p (from->loop_father, e->dest))
- continue;
-
- e->flags &= ~EDGE_IRREDUCIBLE_LOOP;
- if (TEST_BIT (on_stack, e->dest->index))
- continue;
-
- SET_BIT (on_stack, e->dest->index);
- stack[stack_top++] = e->dest;
- }
- }
- free (edges);
- }
-
- free (on_stack);
- free (stack);
-}
-
/* Removes path beginning at edge E, i.e. remove basic blocks dominated by E
and update loop structure stored in LOOPS and dominators. Return true if
we were able to remove the path, false otherwise (and nothing is affected
basic_block *rem_bbs, *bord_bbs, *dom_bbs, from, bb;
int i, nrem, n_bord_bbs, n_dom_bbs;
sbitmap seen;
- bool deleted;
+ bool deleted, irred_invalidated = false;
if (!loop_delete_branch_edge (e, 0))
return false;
+ /* Keep track of whether we need to update information about irreducible
+ regions. This is the case if the removed area is a part of the
+ irreducible region, or if the set of basic blocks that belong to a loop
+ that is inside an irreducible region is changed, or if such a loop is
+ removed. */
+ if (e->flags & EDGE_IRREDUCIBLE_LOOP)
+ irred_invalidated = true;
+
/* We need to check whether basic blocks are dominated by the edge
e, but we only have basic block dominators. This is easy to
fix -- when e->dest has exactly one predecessor, this corresponds
to blocks dominated by e->dest, if not, split the edge. */
- if (e->dest->pred->pred_next)
- e = loop_split_edge_with (e, NULL_RTX)->pred;
+ if (!single_pred_p (e->dest))
+ e = single_pred_edge (loop_split_edge_with (e, NULL_RTX));
/* It may happen that by removing path we remove one or more loops
we belong to. In this case first unloop the loops, then proceed
while (e->src->loop_father->outer
&& dominated_by_p (CDI_DOMINATORS,
e->src->loop_father->latch, e->dest))
- unloop (loops, e->src->loop_father);
+ unloop (loops, e->src->loop_father, &irred_invalidated);
/* Identify the path. */
nrem = find_path (e, &rem_bbs);
n_bord_bbs = 0;
- bord_bbs = xcalloc (n_basic_blocks, sizeof (basic_block));
+ bord_bbs = XCNEWVEC (basic_block, n_basic_blocks);
seen = sbitmap_alloc (last_basic_block);
sbitmap_zero (seen);
SET_BIT (seen, rem_bbs[i]->index);
for (i = 0; i < nrem; i++)
{
+ edge_iterator ei;
bb = rem_bbs[i];
- for (ae = rem_bbs[i]->succ; ae; ae = ae->succ_next)
+ FOR_EACH_EDGE (ae, ei, rem_bbs[i]->succs)
if (ae->dest != EXIT_BLOCK_PTR && !TEST_BIT (seen, ae->dest->index))
{
SET_BIT (seen, ae->dest->index);
bord_bbs[n_bord_bbs++] = ae->dest;
+
+ if (ae->flags & EDGE_IRREDUCIBLE_LOOP)
+ irred_invalidated = true;
}
}
from = e->src;
deleted = loop_delete_branch_edge (e, 1);
gcc_assert (deleted);
- dom_bbs = xcalloc (n_basic_blocks, sizeof (basic_block));
+ dom_bbs = XCNEWVEC (basic_block, n_basic_blocks);
/* Cancel loops contained in the path. */
for (i = 0; i < nrem; i++)
/* Recount dominators. */
iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, n_dom_bbs);
free (dom_bbs);
-
- /* These blocks have lost some predecessor(s), thus their irreducible
- status could be changed. */
- for (i = 0; i < n_bord_bbs; i++)
- fix_irreducible_loops (bord_bbs[i]);
free (bord_bbs);
/* Fix placements of basic blocks inside loops and the placement of
loops in the loop tree. */
- fix_bb_placements (loops, from);
- fix_loop_placements (loops, from->loop_father);
+ fix_bb_placements (loops, from, &irred_invalidated);
+ fix_loop_placements (loops, from->loop_father, &irred_invalidated);
+
+ if (irred_invalidated
+ && (loops->state & LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS) != 0)
+ mark_irreducible_loops (loops);
return true;
}
loop->level = 1;
/* Find its nodes. */
- bbs = xcalloc (n_basic_blocks, sizeof (basic_block));
+ bbs = XCNEWVEC (basic_block, n_basic_blocks);
n = dfs_enumerate_from (loop->latch, 1, alp_enum_p,
bbs, n_basic_blocks, loop->header);
free (bbs);
}
-/* Multiply all frequencies of basic blocks in array BBS of length NBBS
- by NUM/DEN. */
-static void
-scale_bbs_frequencies (basic_block *bbs, int nbbs, int num, int den)
-{
- int i;
- edge e;
-
- for (i = 0; i < nbbs; i++)
- {
- bbs[i]->frequency = (bbs[i]->frequency * num) / den;
- bbs[i]->count = RDIV (bbs[i]->count * num, den);
- for (e = bbs[i]->succ; e; e = e->succ_next)
- e->count = (e->count * num) /den;
- }
-}
-
/* Multiply all frequencies in LOOP by NUM/DEN. */
static void
scale_loop_frequencies (struct loop *loop, int num, int den)
basic_block *bbs;
bbs = get_loop_body (loop);
- scale_bbs_frequencies (bbs, loop->num_nodes, num, den);
+ scale_bbs_frequencies_int (bbs, loop->num_nodes, num, den);
free (bbs);
}
accordingly. Everything between them plus LATCH_EDGE destination must
be dominated by HEADER_EDGE destination, and back-reachable from
LATCH_EDGE source. HEADER_EDGE is redirected to basic block SWITCH_BB,
- FALLTHRU_EDGE (SWITCH_BB) to original destination of HEADER_EDGE and
- BRANCH_EDGE (SWITCH_BB) to original destination of LATCH_EDGE.
+ FALSE_EDGE of SWITCH_BB to original destination of HEADER_EDGE and
+ TRUE_EDGE of SWITCH_BB to original destination of LATCH_EDGE.
Returns newly created loop. */
struct loop *
-loopify (struct loops *loops, edge latch_edge, edge header_edge,
- basic_block switch_bb)
+loopify (struct loops *loops, edge latch_edge, edge header_edge,
+ basic_block switch_bb, edge true_edge, edge false_edge,
+ bool redirect_all_edges)
{
basic_block succ_bb = latch_edge->dest;
basic_block pred_bb = header_edge->src;
basic_block *dom_bbs, *body;
unsigned n_dom_bbs, i;
sbitmap seen;
- struct loop *loop = xcalloc (1, sizeof (struct loop));
+ struct loop *loop = XCNEW (struct loop);
struct loop *outer = succ_bb->loop_father->outer;
int freq, prob, tot_prob;
gcov_type cnt;
edge e;
+ edge_iterator ei;
loop->header = header_edge->dest;
loop->latch = latch_edge->src;
freq = EDGE_FREQUENCY (header_edge);
cnt = header_edge->count;
- prob = switch_bb->succ->probability;
- tot_prob = prob + switch_bb->succ->succ_next->probability;
+ prob = EDGE_SUCC (switch_bb, 0)->probability;
+ tot_prob = prob + EDGE_SUCC (switch_bb, 1)->probability;
if (tot_prob == 0)
tot_prob = 1;
/* Redirect edges. */
loop_redirect_edge (latch_edge, loop->header);
- loop_redirect_edge (BRANCH_EDGE (switch_bb), succ_bb);
+ loop_redirect_edge (true_edge, succ_bb);
- loop_redirect_edge (header_edge, switch_bb);
- loop_redirect_edge (FALLTHRU_EDGE (switch_bb), loop->header);
+ /* During loop versioning, one of the switch_bb edge is already properly
+ set. Do not redirect it again unless redirect_all_edges is true. */
+ if (redirect_all_edges)
+ {
+ loop_redirect_edge (header_edge, switch_bb);
+ loop_redirect_edge (false_edge, loop->header);
- /* Update dominators. */
- set_immediate_dominator (CDI_DOMINATORS, switch_bb, pred_bb);
- set_immediate_dominator (CDI_DOMINATORS, loop->header, switch_bb);
+ /* Update dominators. */
+ set_immediate_dominator (CDI_DOMINATORS, switch_bb, pred_bb);
+ set_immediate_dominator (CDI_DOMINATORS, loop->header, switch_bb);
+ }
set_immediate_dominator (CDI_DOMINATORS, succ_bb, switch_bb);
/* Fix frequencies. */
switch_bb->frequency = freq;
switch_bb->count = cnt;
- for (e = switch_bb->succ; e; e = e->succ_next)
+ FOR_EACH_EDGE (e, ei, switch_bb->succs)
e->count = (switch_bb->count * e->probability) / REG_BR_PROB_BASE;
scale_loop_frequencies (loop, prob, tot_prob);
scale_loop_frequencies (succ_bb->loop_father, tot_prob - prob, tot_prob);
/* Update dominators of blocks outside of LOOP. */
- dom_bbs = xcalloc (n_basic_blocks, sizeof (basic_block));
+ dom_bbs = XCNEWVEC (basic_block, n_basic_blocks);
n_dom_bbs = 0;
seen = sbitmap_alloc (last_basic_block);
sbitmap_zero (seen);
/* Remove the latch edge of a LOOP and update LOOPS tree to indicate that
the LOOP was removed. After this function, original loop latch will
- have no successor, which caller is expected to fix somehow. */
-void
-unloop (struct loops *loops, struct loop *loop)
+ have no successor, which caller is expected to fix somehow.
+
+ If this may cause the information about irreducible regions to become
+ invalid, IRRED_INVALIDATED is set to true. */
+
+static void
+unloop (struct loops *loops, struct loop *loop, bool *irred_invalidated)
{
basic_block *body;
struct loop *ploop;
unsigned i, n;
basic_block latch = loop->latch;
- edge *edges;
- unsigned n_edges;
+ bool dummy = false;
+
+ if (loop_preheader_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP)
+ *irred_invalidated = true;
/* This is relatively straightforward. The dominators are unchanged, as
loop header dominates loop latch, so the only thing we have to care of
its work. */
body = get_loop_body (loop);
- edges = get_loop_exit_edges (loop, &n_edges);
n = loop->num_nodes;
for (i = 0; i < n; i++)
if (body[i]->loop_father == loop)
loops->parray[loop->num] = NULL;
flow_loop_free (loop);
- remove_edge (latch->succ);
- fix_bb_placements (loops, latch);
-
- /* If the loop was inside an irreducible region, we would have to somehow
- update the irreducible marks inside its body. While it is certainly
- possible to do, it is a bit complicated and this situation should be
- very rare, so we just remark all loops in this case. */
- for (i = 0; i < n_edges; i++)
- if (edges[i]->flags & EDGE_IRREDUCIBLE_LOOP)
- break;
- if (i != n_edges)
- mark_irreducible_loops (loops);
- free (edges);
+ remove_edge (single_succ_edge (latch));
+
+ /* We do not pass IRRED_INVALIDATED to fix_bb_placements here, as even if
+ there is an irreducible region inside the cancelled loop, the flags will
+ be still correct. */
+ fix_bb_placements (loops, latch, &dummy);
}
/* Fix placement of LOOP inside loop tree, i.e. find the innermost superloop
FATHER of LOOP such that all of the edges coming out of LOOP belong to
- FATHER, and set it as outer loop of LOOP. Return 1 if placement of
+ FATHER, and set it as outer loop of LOOP. Return true if placement of
LOOP changed. */
+
int
fix_loop_placement (struct loop *loop)
{
basic_block *body;
unsigned i;
edge e;
+ edge_iterator ei;
struct loop *father = loop->pred[0], *act;
body = get_loop_body (loop);
for (i = 0; i < loop->num_nodes; i++)
- for (e = body[i]->succ; e; e = e->succ_next)
+ FOR_EACH_EDGE (e, ei, body[i]->succs)
if (!flow_bb_inside_loop_p (loop, e->dest))
{
act = find_common_loop (loop, e->dest->loop_father);
/* Fix placement of superloops of LOOP inside loop tree, i.e. ensure that
condition stated in description of fix_loop_placement holds for them.
It is used in case when we removed some edges coming out of LOOP, which
- may cause the right placement of LOOP inside loop tree to change. */
+ may cause the right placement of LOOP inside loop tree to change.
+
+ IRRED_INVALIDATED is set to true if a change in the loop structures might
+ invalidate the information about irreducible regions. */
+
static void
-fix_loop_placements (struct loops *loops, struct loop *loop)
+fix_loop_placements (struct loops *loops, struct loop *loop,
+ bool *irred_invalidated)
{
struct loop *outer;
{
outer = loop->outer;
if (!fix_loop_placement (loop))
- break;
+ break;
/* Changing the placement of a loop in the loop tree may alter the
validity of condition 2) of the description of fix_bb_placement
for its preheader, because the successor is the header and belongs
to the loop. So call fix_bb_placements to fix up the placement
of the preheader and (possibly) of its predecessors. */
- fix_bb_placements (loops, loop_preheader_edge (loop)->src);
+ fix_bb_placements (loops, loop_preheader_edge (loop)->src,
+ irred_invalidated);
loop = outer;
}
}
/* Copies copy of LOOP as subloop of TARGET loop, placing newly
created loop into LOOPS structure. */
-static struct loop *
+struct loop *
duplicate_loop (struct loops *loops, struct loop *loop, struct loop *target)
{
struct loop *cloop;
- cloop = xcalloc (1, sizeof (struct loop));
+ cloop = XCNEW (struct loop);
place_new_loop (loops, cloop);
/* Initialize copied loop. */
int irr;
edge snd;
- gcc_assert (src->succ->succ_next);
-
+ gcc_assert (EDGE_COUNT (src->succs) > 1);
+
/* Cannot handle more than two exit edges. */
- if (src->succ->succ_next->succ_next)
+ if (EDGE_COUNT (src->succs) > 2)
return false;
/* And it must be just a simple branch. */
if (!any_condjump_p (BB_END (src)))
return false;
- snd = e == src->succ ? src->succ->succ_next : src->succ;
+ snd = e == EDGE_SUCC (src, 0) ? EDGE_SUCC (src, 1) : EDGE_SUCC (src, 0);
newdest = snd->dest;
if (newdest == EXIT_BLOCK_PTR)
return false;
if (!redirect_edge_and_branch (e, newdest))
return false;
- src->succ->flags &= ~EDGE_IRREDUCIBLE_LOOP;
- src->succ->flags |= irr;
-
+ single_succ_edge (src)->flags &= ~EDGE_IRREDUCIBLE_LOOP;
+ single_succ_edge (src)->flags |= irr;
+
return true;
}
ret = can_copy_bbs_p (bbs, loop->num_nodes);
free (bbs);
-
+
return ret;
}
unsigned i;
for (i = 0; i < nbbs; i++)
- bbs[i]->rbi->duplicated = 1;
+ bbs[i]->flags |= BB_DUPLICATED;
for (; loop->outer; loop = loop->outer)
{
if (!loop->single_exit)
continue;
- if (loop->single_exit->src->rbi->duplicated)
+ if (loop->single_exit->src->flags & BB_DUPLICATED)
loop->single_exit = NULL;
}
for (i = 0; i < nbbs; i++)
- bbs[i]->rbi->duplicated = 0;
+ bbs[i]->flags &= ~BB_DUPLICATED;
}
-
/* Duplicates body of LOOP to given edge E NDUPL times. Takes care of updating
LOOPS structure and dominators. E's destination must be LOOP header for
this to work, i.e. it must be entry or latch edge of this loop; these are
original LOOP body, the other copies are numbered in order given by control
flow through them) into TO_REMOVE array. Returns false if duplication is
impossible. */
-int
+bool
duplicate_loop_to_header_edge (struct loop *loop, edge e, struct loops *loops,
unsigned int ndupl, sbitmap wont_exit,
edge orig, edge *to_remove,
int p, freq_in, freq_le, freq_out_orig;
int prob_pass_thru, prob_pass_wont_exit, prob_pass_main;
int add_irreducible_flag;
+ basic_block place_after;
gcc_assert (e->dest == loop->header);
gcc_assert (ndupl > 0);
gcc_assert (!flow_bb_inside_loop_p (loop, orig->dest));
}
- bbs = get_loop_body (loop);
+ n = loop->num_nodes;
+ bbs = get_loop_body_in_dom_order (loop);
+ gcc_assert (bbs[0] == loop->header);
+ gcc_assert (bbs[n - 1] == loop->latch);
/* Check whether duplication is possible. */
if (!can_copy_bbs_p (bbs, loop->num_nodes))
free (bbs);
return false;
}
- new_bbs = xmalloc (sizeof (basic_block) * loop->num_nodes);
+ new_bbs = XNEWVEC (basic_block, loop->num_nodes);
/* In case we are doing loop peeling and the loop is in the middle of
irreducible region, the peeled copies will be inside it too. */
prob_pass_wont_exit =
RDIV (REG_BR_PROB_BASE * (freq_le + freq_out_orig), freq_in);
- scale_step = xmalloc (ndupl * sizeof (int));
+ scale_step = XNEWVEC (int, ndupl);
for (i = 1; i <= ndupl; i++)
scale_step[i - 1] = TEST_BIT (wont_exit, i)
? prob_pass_wont_exit
: prob_pass_thru;
- if (is_latch)
+ /* Complete peeling is special as the probability of exit in last
+ copy becomes 1. */
+ if (flags & DLTHE_FLAG_COMPLETTE_PEEL)
+ {
+ int wanted_freq = EDGE_FREQUENCY (e);
+
+ if (wanted_freq > freq_in)
+ wanted_freq = freq_in;
+
+ gcc_assert (!is_latch);
+ /* First copy has frequency of incoming edge. Each subsequent
+ frequency should be reduced by prob_pass_wont_exit. Caller
+ should've managed the flags so all except for original loop
+ has won't exist set. */
+ scale_act = RDIV (wanted_freq * REG_BR_PROB_BASE, freq_in);
+ /* Now simulate the duplication adjustments and compute header
+ frequency of the last copy. */
+ for (i = 0; i < ndupl; i++)
+ wanted_freq = RDIV (wanted_freq * scale_step[i], REG_BR_PROB_BASE);
+ scale_main = RDIV (wanted_freq * REG_BR_PROB_BASE, freq_in);
+ }
+ else if (is_latch)
{
prob_pass_main = TEST_BIT (wont_exit, 0)
? prob_pass_wont_exit
n_orig_loops = 0;
for (aloop = loop->inner; aloop; aloop = aloop->next)
n_orig_loops++;
- orig_loops = xcalloc (n_orig_loops, sizeof (struct loop *));
+ orig_loops = XCNEWVEC (struct loop *, n_orig_loops);
for (aloop = loop->inner, i = 0; aloop; aloop = aloop->next, i++)
orig_loops[i] = aloop;
loop->copy = target;
- n = loop->num_nodes;
-
- first_active = xmalloc (n * sizeof (basic_block));
+ first_active = XNEWVEC (basic_block, n);
if (is_latch)
{
memcpy (first_active, bbs, n * sizeof (basic_block));
spec_edges[SE_ORIG] = orig;
spec_edges[SE_LATCH] = latch_edge;
+ place_after = e->src;
for (j = 0; j < ndupl; j++)
{
/* Copy loops. */
copy_loops_to (loops, orig_loops, n_orig_loops, target);
/* Copy bbs. */
- copy_bbs (bbs, n, new_bbs, spec_edges, 2, new_spec_edges, loop);
+ copy_bbs (bbs, n, new_bbs, spec_edges, 2, new_spec_edges, loop,
+ place_after);
+ place_after = new_spec_edges[SE_LATCH]->src;
+
+ if (flags & DLTHE_RECORD_COPY_NUMBER)
+ for (i = 0; i < n; i++)
+ {
+ gcc_assert (!new_bbs[i]->aux);
+ new_bbs[i]->aux = (void *)(size_t)(j + 1);
+ }
/* Note whether the blocks and edges belong to an irreducible loop. */
if (add_irreducible_flag)
{
for (i = 0; i < n; i++)
- new_bbs[i]->rbi->duplicated = 1;
+ new_bbs[i]->flags |= BB_DUPLICATED;
for (i = 0; i < n; i++)
{
+ edge_iterator ei;
new_bb = new_bbs[i];
if (new_bb->loop_father == target)
new_bb->flags |= BB_IRREDUCIBLE_LOOP;
- for (ae = new_bb->succ; ae; ae = ae->succ_next)
- if (ae->dest->rbi->duplicated
+ FOR_EACH_EDGE (ae, ei, new_bb->succs)
+ if ((ae->dest->flags & BB_DUPLICATED)
&& (ae->src->loop_father == target
|| ae->dest->loop_father == target))
ae->flags |= EDGE_IRREDUCIBLE_LOOP;
}
for (i = 0; i < n; i++)
- new_bbs[i]->rbi->duplicated = 0;
+ new_bbs[i]->flags &= ~BB_DUPLICATED;
}
/* Redirect the special edges. */
redirect_edge_and_branch_force (new_spec_edges[SE_LATCH],
loop->header);
set_immediate_dominator (CDI_DOMINATORS, new_bbs[0], latch);
- latch = loop->latch = new_bbs[1];
+ latch = loop->latch = new_bbs[n - 1];
e = latch_edge = new_spec_edges[SE_LATCH];
}
else
if (!first_active_latch)
{
memcpy (first_active, new_bbs, n * sizeof (basic_block));
- first_active_latch = new_bbs[1];
+ first_active_latch = new_bbs[n - 1];
}
/* Set counts and frequencies. */
if (flags & DLTHE_FLAG_UPDATE_FREQ)
{
- scale_bbs_frequencies (new_bbs, n, scale_act, REG_BR_PROB_BASE);
+ scale_bbs_frequencies_int (new_bbs, n, scale_act, REG_BR_PROB_BASE);
scale_act = RDIV (scale_act * scale_step[j], REG_BR_PROB_BASE);
}
}
free (new_bbs);
free (orig_loops);
-
+
/* Update the original loop. */
if (!is_latch)
set_immediate_dominator (CDI_DOMINATORS, e->dest, e->src);
if (flags & DLTHE_FLAG_UPDATE_FREQ)
{
- scale_bbs_frequencies (bbs, n, scale_main, REG_BR_PROB_BASE);
+ scale_bbs_frequencies_int (bbs, n, scale_main, REG_BR_PROB_BASE);
free (scale_step);
}
int n_dom_bbs,j;
bb = bbs[i];
+ bb->aux = 0;
+
n_dom_bbs = get_dominated_by (CDI_DOMINATORS, bb, &dom_bbs);
for (j = 0; j < n_dom_bbs; j++)
{
continue;
dom_bb = nearest_common_dominator (
CDI_DOMINATORS, first_active[i], first_active_latch);
- set_immediate_dominator (CDI_DOMINATORS, dominated, dom_bb);
+ set_immediate_dominator (CDI_DOMINATORS, dominated, dom_bb);
}
free (dom_bbs);
}
static void
mfb_update_loops (basic_block jump)
{
- struct loop *loop = jump->succ->dest->loop_father;
+ struct loop *loop = single_succ (jump)->loop_father;
if (dom_computed[CDI_DOMINATORS])
- set_immediate_dominator (CDI_DOMINATORS, jump, jump->pred->src);
+ set_immediate_dominator (CDI_DOMINATORS, jump, single_pred (jump));
add_bb_to_loop (jump, loop);
loop->latch = jump;
}
struct loop *cloop, *ploop;
int nentry = 0;
bool irred = false;
+ bool latch_edge_was_fallthru;
+ edge one_succ_pred = 0;
+ edge_iterator ei;
cloop = loop->outer;
- for (e = loop->header->pred; e; e = e->pred_next)
+ FOR_EACH_EDGE (e, ei, loop->header->preds)
{
if (e->src == loop->latch)
continue;
irred |= (e->flags & EDGE_IRREDUCIBLE_LOOP) != 0;
nentry++;
+ if (single_succ_p (e->src))
+ one_succ_pred = e;
}
gcc_assert (nentry);
if (nentry == 1)
{
- for (e = loop->header->pred; e->src == loop->latch; e = e->pred_next);
- if (!(flags & CP_SIMPLE_PREHEADERS)
- || !e->src->succ->succ_next)
+ /* Get an edge that is different from the one from loop->latch
+ to loop->header. */
+ e = EDGE_PRED (loop->header,
+ EDGE_PRED (loop->header, 0)->src == loop->latch);
+
+ if (!(flags & CP_SIMPLE_PREHEADERS) || single_succ_p (e->src))
return NULL;
}
mfb_kj_edge = loop_latch_edge (loop);
+ latch_edge_was_fallthru = (mfb_kj_edge->flags & EDGE_FALLTHRU) != 0;
fallthru = make_forwarder_block (loop->header, mfb_keep_just,
mfb_update_loops);
dummy = fallthru->src;
if (ploop->latch == dummy)
ploop->latch = fallthru->dest;
- /* Reorganize blocks so that the preheader is not stuck in the middle of the
- loop. */
- for (e = dummy->pred; e; e = e->pred_next)
- if (e->src != loop->latch)
- break;
- move_block_after (dummy, e->src);
+ /* Try to be clever in placing the newly created preheader. The idea is to
+ avoid breaking any "fallthruness" relationship between blocks.
+
+ The preheader was created just before the header and all incoming edges
+ to the header were redirected to the preheader, except the latch edge.
+ So the only problematic case is when this latch edge was a fallthru
+ edge: it is not anymore after the preheader creation so we have broken
+ the fallthruness. We're therefore going to look for a better place. */
+ if (latch_edge_was_fallthru)
+ {
+ if (one_succ_pred)
+ e = one_succ_pred;
+ else
+ e = EDGE_PRED (dummy, 0);
+
+ move_block_after (dummy, e->src);
+ }
loop->header->loop_father = loop;
add_bb_to_loop (dummy, cloop);
if (irred)
{
dummy->flags |= BB_IRREDUCIBLE_LOOP;
- dummy->succ->flags |= EDGE_IRREDUCIBLE_LOOP;
+ single_succ_edge (dummy)->flags |= EDGE_IRREDUCIBLE_LOOP;
}
if (dump_file)
for (i = 1; i < loops->num; i++)
{
loop = loops->parray[i];
- if (loop->latch != loop->header
- && !loop->latch->succ->succ_next)
+ if (loop->latch != loop->header && single_succ_p (loop->latch))
continue;
- for (e = loop->header->pred; e->src != loop->latch; e = e->pred_next)
- continue;
+ e = find_edge (loop->latch, loop->header);
loop_split_edge_with (e, NULL_RTX);
}
{
basic_block src, dest, new_bb;
struct loop *loop_c;
- edge new_e;
src = e->src;
dest = e->dest;
new_bb = split_edge (e);
add_bb_to_loop (new_bb, loop_c);
- new_bb->flags = insns ? BB_SUPERBLOCK : 0;
-
- new_e = new_bb->succ;
- if (e->flags & EDGE_IRREDUCIBLE_LOOP)
- {
- new_bb->flags |= BB_IRREDUCIBLE_LOOP;
- new_e->flags |= EDGE_IRREDUCIBLE_LOOP;
- }
+ new_bb->flags |= (insns ? BB_SUPERBLOCK : 0);
if (insns)
emit_insn_after (insns, BB_END (new_bb));
return new_bb;
}
-/* Uses the natural loop discovery to recreate loop notes. */
+/* This function is called from loop_version. It splits the entry edge
+ of the loop we want to version, adds the versioning condition, and
+ adjust the edges to the two versions of the loop appropriately.
+ e is an incoming edge. Returns the basic block containing the
+ condition.
+
+ --- edge e ---- > [second_head]
+
+ Split it and insert new conditional expression and adjust edges.
+
+ --- edge e ---> [cond expr] ---> [first_head]
+ |
+ +---------> [second_head]
+*/
+
+static basic_block
+lv_adjust_loop_entry_edge (basic_block first_head,
+ basic_block second_head,
+ edge e,
+ void *cond_expr)
+{
+ basic_block new_head = NULL;
+ edge e1;
+
+ gcc_assert (e->dest == second_head);
+
+ /* Split edge 'e'. This will create a new basic block, where we can
+ insert conditional expr. */
+ new_head = split_edge (e);
+
+
+ lv_add_condition_to_bb (first_head, second_head, new_head,
+ cond_expr);
+
+ /* Don't set EDGE_TRUE_VALUE in RTL mode, as it's invalid there. */
+ e1 = make_edge (new_head, first_head, ir_type () ? EDGE_TRUE_VALUE : 0);
+ set_immediate_dominator (CDI_DOMINATORS, first_head, new_head);
+ set_immediate_dominator (CDI_DOMINATORS, second_head, new_head);
+
+ /* Adjust loop header phi nodes. */
+ lv_adjust_loop_header_phi (first_head, second_head, new_head, e1);
+
+ return new_head;
+}
+
+/* Main entry point for Loop Versioning transformation.
+
+ This transformation given a condition and a loop, creates
+ -if (condition) { loop_copy1 } else { loop_copy2 },
+ where loop_copy1 is the loop transformed in one way, and loop_copy2
+ is the loop transformed in another way (or unchanged). 'condition'
+ may be a run time test for things that were not resolved by static
+ analysis (overlapping ranges (anti-aliasing), alignment, etc.).
+
+ If PLACE_AFTER is true, we place the new loop after LOOP in the
+ instruction stream, otherwise it is placed before LOOP. */
+
+struct loop *
+loop_version (struct loops *loops, struct loop * loop,
+ void *cond_expr, basic_block *condition_bb,
+ bool place_after)
+{
+ basic_block first_head, second_head;
+ edge entry, latch_edge, exit, true_edge, false_edge;
+ int irred_flag;
+ struct loop *nloop;
+ basic_block cond_bb;
+
+ /* CHECKME: Loop versioning does not handle nested loop at this point. */
+ if (loop->inner)
+ return NULL;
+
+ /* Record entry and latch edges for the loop */
+ entry = loop_preheader_edge (loop);
+ irred_flag = entry->flags & EDGE_IRREDUCIBLE_LOOP;
+ entry->flags &= ~EDGE_IRREDUCIBLE_LOOP;
+
+ /* Note down head of loop as first_head. */
+ first_head = entry->dest;
+
+ /* Duplicate loop. */
+ if (!cfg_hook_duplicate_loop_to_header_edge (loop, entry, loops, 1,
+ NULL, NULL, NULL, NULL, 0))
+ return NULL;
+
+ /* After duplication entry edge now points to new loop head block.
+ Note down new head as second_head. */
+ second_head = entry->dest;
+
+ /* Split loop entry edge and insert new block with cond expr. */
+ cond_bb = lv_adjust_loop_entry_edge (first_head, second_head,
+ entry, cond_expr);
+ if (condition_bb)
+ *condition_bb = cond_bb;
+
+ if (!cond_bb)
+ {
+ entry->flags |= irred_flag;
+ return NULL;
+ }
+
+ latch_edge = single_succ_edge (get_bb_copy (loop->latch));
+
+ extract_cond_bb_edges (cond_bb, &true_edge, &false_edge);
+ nloop = loopify (loops,
+ latch_edge,
+ single_pred_edge (get_bb_copy (loop->header)),
+ cond_bb, true_edge, false_edge,
+ false /* Do not redirect all edges. */);
+
+ exit = loop->single_exit;
+ if (exit)
+ nloop->single_exit = find_edge (get_bb_copy (exit->src), exit->dest);
+
+ /* loopify redirected latch_edge. Update its PENDING_STMTS. */
+ lv_flush_pending_stmts (latch_edge);
+
+ /* loopify redirected condition_bb's succ edge. Update its PENDING_STMTS. */
+ extract_cond_bb_edges (cond_bb, &true_edge, &false_edge);
+ lv_flush_pending_stmts (false_edge);
+ /* Adjust irreducible flag. */
+ if (irred_flag)
+ {
+ cond_bb->flags |= BB_IRREDUCIBLE_LOOP;
+ loop_preheader_edge (loop)->flags |= EDGE_IRREDUCIBLE_LOOP;
+ loop_preheader_edge (nloop)->flags |= EDGE_IRREDUCIBLE_LOOP;
+ single_pred_edge (cond_bb)->flags |= EDGE_IRREDUCIBLE_LOOP;
+ }
+
+ if (place_after)
+ {
+ basic_block *bbs = get_loop_body_in_dom_order (nloop), after;
+ unsigned i;
+
+ after = loop->latch;
+
+ for (i = 0; i < nloop->num_nodes; i++)
+ {
+ move_block_after (bbs[i], after);
+ after = bbs[i];
+ }
+ free (bbs);
+ }
+
+ /* At this point condition_bb is loop predheader with two successors,
+ first_head and second_head. Make sure that loop predheader has only
+ one successor. */
+ loop_split_edge_with (loop_preheader_edge (loop), NULL);
+ loop_split_edge_with (loop_preheader_edge (nloop), NULL);
+
+ return nloop;
+}
+
+/* The structure of LOOPS might have changed. Some loops might get removed
+ (and their headers and latches were set to NULL), loop exists might get
+ removed (thus the loop nesting may be wrong), and some blocks and edges
+ were changed (so the information about bb --> loop mapping does not have
+ to be correct). But still for the remaining loops the header dominates
+ the latch, and loops did not get new subloobs (new loops might possibly
+ get created, but we are not interested in them). Fix up the mess.
+
+ If CHANGED_BBS is not NULL, basic blocks whose loop has changed are
+ marked in it. */
+
void
-create_loop_notes (void)
+fix_loop_structure (struct loops *loops, bitmap changed_bbs)
{
- rtx insn, head, end;
- struct loops loops;
- struct loop *loop;
- basic_block *first, *last, bb, pbb;
- struct loop **stack, **top;
-
-#ifdef ENABLE_CHECKING
- /* Verify that there really are no loop notes. */
- for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
- gcc_assert (!NOTE_P (insn) ||
- NOTE_LINE_NUMBER (insn) != NOTE_INSN_LOOP_BEG);
-#endif
-
- flow_loops_find (&loops, LOOP_TREE);
- free_dominance_info (CDI_DOMINATORS);
- if (loops.num > 1)
+ basic_block bb;
+ struct loop *loop, *ploop;
+ unsigned i;
+
+ /* Remove the old bb -> loop mapping. */
+ FOR_EACH_BB (bb)
+ {
+ bb->aux = (void *) (size_t) bb->loop_father->depth;
+ bb->loop_father = loops->tree_root;
+ }
+
+ /* Remove the dead loops from structures. */
+ loops->tree_root->num_nodes = n_basic_blocks;
+ for (i = 1; i < loops->num; i++)
{
- last = xcalloc (loops.num, sizeof (basic_block));
+ loop = loops->parray[i];
+ if (!loop)
+ continue;
+
+ loop->num_nodes = 0;
+ if (loop->header)
+ continue;
+
+ while (loop->inner)
+ {
+ ploop = loop->inner;
+ flow_loop_tree_node_remove (ploop);
+ flow_loop_tree_node_add (loop->outer, ploop);
+ }
+
+ /* Remove the loop and free its data. */
+ flow_loop_tree_node_remove (loop);
+ loops->parray[loop->num] = NULL;
+ flow_loop_free (loop);
+ }
- FOR_EACH_BB (bb)
+ /* Rescan the bodies of loops, starting from the outermost. */
+ loop = loops->tree_root;
+ while (1)
+ {
+ if (loop->inner)
+ loop = loop->inner;
+ else
{
- for (loop = bb->loop_father; loop->outer; loop = loop->outer)
- last[loop->num] = bb;
+ while (!loop->next
+ && loop != loops->tree_root)
+ loop = loop->outer;
+ if (loop == loops->tree_root)
+ break;
+
+ loop = loop->next;
}
- first = xcalloc (loops.num, sizeof (basic_block));
- stack = xcalloc (loops.num, sizeof (struct loop *));
- top = stack;
+ loop->num_nodes = flow_loop_nodes_find (loop->header, loop);
+ }
+
+ /* Now fix the loop nesting. */
+ for (i = 1; i < loops->num; i++)
+ {
+ loop = loops->parray[i];
+ if (!loop)
+ continue;
- FOR_EACH_BB (bb)
+ bb = loop_preheader_edge (loop)->src;
+ if (bb->loop_father != loop->outer)
{
- for (loop = bb->loop_father; loop->outer; loop = loop->outer)
- {
- if (!first[loop->num])
- {
- *top++ = loop;
- first[loop->num] = bb;
- }
-
- if (bb == last[loop->num])
- {
- /* Prevent loops from overlapping. */
- while (*--top != loop)
- last[(*top)->num] = EXIT_BLOCK_PTR;
-
- /* If loop starts with jump into it, place the note in
- front of the jump. */
- insn = PREV_INSN (BB_HEAD (first[loop->num]));
- if (insn
- && BARRIER_P (insn))
- insn = PREV_INSN (insn);
-
- if (insn
- && JUMP_P (insn)
- && any_uncondjump_p (insn)
- && onlyjump_p (insn))
- {
- pbb = BLOCK_FOR_INSN (insn);
- gcc_assert (pbb && pbb->succ && !pbb->succ->succ_next);
-
- if (!flow_bb_inside_loop_p (loop, pbb->succ->dest))
- insn = BB_HEAD (first[loop->num]);
- }
- else
- insn = BB_HEAD (first[loop->num]);
-
- head = BB_HEAD (first[loop->num]);
- emit_note_before (NOTE_INSN_LOOP_BEG, insn);
- BB_HEAD (first[loop->num]) = head;
-
- /* Position the note correctly wrto barrier. */
- insn = BB_END (last[loop->num]);
- if (NEXT_INSN (insn)
- && BARRIER_P (NEXT_INSN (insn)))
- insn = NEXT_INSN (insn);
-
- end = BB_END (last[loop->num]);
- emit_note_after (NOTE_INSN_LOOP_END, insn);
- BB_END (last[loop->num]) = end;
- }
- }
+ flow_loop_tree_node_remove (loop);
+ flow_loop_tree_node_add (bb->loop_father, loop);
}
+ }
- free (first);
- free (last);
- free (stack);
+ /* Mark the blocks whose loop has changed. */
+ FOR_EACH_BB (bb)
+ {
+ if (changed_bbs
+ && (void *) (size_t) bb->loop_father->depth != bb->aux)
+ bitmap_set_bit (changed_bbs, bb->index);
+
+ bb->aux = NULL;
}
- flow_loops_free (&loops);
+
+ if (loops->state & LOOPS_HAVE_MARKED_SINGLE_EXITS)
+ mark_single_exit_loops (loops);
+ if (loops->state & LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)
+ mark_irreducible_loops (loops);
}
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