/* Loop unswitching for GNU compiler.
- Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008
+ Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
-Software Foundation; either version 2, or (at your option) any later
+Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
for more details.
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, 51 Franklin Street, Fifth Floor, Boston, MA
-02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
containing subloops would not be very large compared to complications
with handling this case. */
-static struct loop *unswitch_loop (struct loops *, struct loop *,
- basic_block, rtx, rtx);
-static void unswitch_single_loop (struct loops *, struct loop *, rtx, int);
+static struct loop *unswitch_loop (struct loop *, basic_block, rtx, rtx);
+static void unswitch_single_loop (struct loop *, rtx, int);
static rtx may_unswitch_on (basic_block, struct loop *, rtx *);
/* Prepare a sequence comparing OP0 with OP1 using COMP and jumping to LABEL if
JUMP_LABEL (jump) = label;
LABEL_NUSES (label)++;
}
- REG_NOTES (jump) = gen_rtx_EXPR_LIST (REG_BR_PROB, GEN_INT (prob),
- REG_NOTES (jump));
+ add_reg_note (jump, REG_BR_PROB, GEN_INT (prob));
+
seq = get_insns ();
end_sequence ();
return seq;
}
-/* Main entry point. Perform loop unswitching on all suitable LOOPS. */
+/* Main entry point. Perform loop unswitching on all suitable loops. */
void
-unswitch_loops (struct loops *loops)
+unswitch_loops (void)
{
- int i, num;
+ loop_iterator li;
struct loop *loop;
/* Go through inner loops (only original ones). */
- num = loops->num;
- for (i = 1; i < num; i++)
+ FOR_EACH_LOOP (li, loop, LI_ONLY_INNERMOST)
{
- /* Removed loop? */
- loop = loops->parray[i];
- if (!loop)
- continue;
-
- if (loop->inner)
- continue;
-
- unswitch_single_loop (loops, loop, NULL_RTX, 0);
+ unswitch_single_loop (loop, NULL_RTX, 0);
#ifdef ENABLE_CHECKING
verify_dominators (CDI_DOMINATORS);
- verify_loop_structure (loops);
+ verify_loop_structure ();
#endif
}
static rtx
may_unswitch_on (basic_block bb, struct loop *loop, rtx *cinsn)
{
- rtx test, at, insn, op[2], stest;
+ rtx test, at, op[2], stest;
struct rtx_iv iv;
unsigned i;
enum machine_mode mode;
if (CONSTANT_P (op[i]))
continue;
- insn = iv_get_reaching_def (at, op[i]);
- if (!iv_analyze (insn, op[i], &iv))
+ if (!iv_analyze (at, op[i], &iv))
return NULL_RTX;
if (iv.step != const0_rtx
|| iv.first_special)
number of unswitchings done; do not allow it to grow too much, it is too
easy to create example on that the code would grow exponentially. */
static void
-unswitch_single_loop (struct loops *loops, struct loop *loop,
- rtx cond_checked, int num)
+unswitch_single_loop (struct loop *loop, rtx cond_checked, int num)
{
basic_block *bbs;
struct loop *nloop;
}
/* Do not unswitch in cold areas. */
- if (!maybe_hot_bb_p (loop->header))
+ if (optimize_loop_for_size_p (loop))
{
if (dump_file)
fprintf (dump_file, ";; Not unswitching, not hot area\n");
{
/* Remove false path. */
e = FALLTHRU_EDGE (bbs[i]);
- remove_path (loops, e);
+ remove_path (e);
free (bbs);
repeat = 1;
}
{
/* Remove true path. */
e = BRANCH_EDGE (bbs[i]);
- remove_path (loops, e);
+ remove_path (e);
free (bbs);
repeat = 1;
}
fprintf (dump_file, ";; Unswitching loop\n");
/* Unswitch the loop on this condition. */
- nloop = unswitch_loop (loops, loop, bbs[i], cond, cinsn);
+ nloop = unswitch_loop (loop, bbs[i], cond, cinsn);
gcc_assert (nloop);
/* Invoke itself on modified loops. */
- unswitch_single_loop (loops, nloop, rconds, num + 1);
- unswitch_single_loop (loops, loop, conds, num + 1);
+ unswitch_single_loop (nloop, rconds, num + 1);
+ unswitch_single_loop (loop, conds, num + 1);
free_EXPR_LIST_node (conds);
if (rcond)
NULL, it is the insn in that COND is compared. */
static struct loop *
-unswitch_loop (struct loops *loops, struct loop *loop, basic_block unswitch_on,
- rtx cond, rtx cinsn)
+unswitch_loop (struct loop *loop, basic_block unswitch_on, rtx cond, rtx cinsn)
{
edge entry, latch_edge, true_edge, false_edge, e;
basic_block switch_bb, unswitch_on_alt;
struct loop *nloop;
- sbitmap zero_bitmap;
int irred_flag, prob;
rtx seq;
/* Make a copy. */
irred_flag = entry->flags & EDGE_IRREDUCIBLE_LOOP;
entry->flags &= ~EDGE_IRREDUCIBLE_LOOP;
- zero_bitmap = sbitmap_alloc (2);
- sbitmap_zero (zero_bitmap);
- if (!duplicate_loop_to_header_edge (loop, entry, loops, 1,
- zero_bitmap, NULL, NULL, NULL, 0))
+ if (!duplicate_loop_to_header_edge (loop, entry, 1,
+ NULL, NULL, NULL, 0))
return NULL;
- free (zero_bitmap);
entry->flags |= irred_flag;
/* Record the block with condition we unswitch on. */
}
/* Loopify from the copy of LOOP body, constructing the new loop. */
- nloop = loopify (loops, latch_edge,
+ nloop = loopify (latch_edge,
single_pred_edge (get_bb_copy (loop->header)), switch_bb,
- BRANCH_EDGE (switch_bb), FALLTHRU_EDGE (switch_bb), true);
+ BRANCH_EDGE (switch_bb), FALLTHRU_EDGE (switch_bb), true,
+ prob, REG_BR_PROB_BASE - prob);
/* Remove branches that are now unreachable in new loops. */
- remove_path (loops, true_edge);
- remove_path (loops, false_edge);
-
- /* One of created loops do not have to be subloop of the outer loop now,
- so fix its placement in loop data structure. */
- fix_loop_placement (loop);
- fix_loop_placement (nloop);
+ remove_path (true_edge);
+ remove_path (false_edge);
/* Preserve the simple loop preheaders. */
- loop_split_edge_with (loop_preheader_edge (loop), NULL_RTX);
- loop_split_edge_with (loop_preheader_edge (nloop), NULL_RTX);
+ split_edge (loop_preheader_edge (loop));
+ split_edge (loop_preheader_edge (nloop));
return nloop;
}
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