/* Perform doloop optimizations
- Copyright (C) 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2004-2020 Free Software Foundation, Inc.
Based on code by Michael P. Hayes (m.hayes@elec.canterbury.ac.nz)
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, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
-#include "tm.h"
+#include "backend.h"
+#include "target.h"
#include "rtl.h"
-#include "flags.h"
+#include "tree.h"
+#include "cfghooks.h"
+#include "memmodel.h"
+#include "emit-rtl.h"
+#include "dojump.h"
#include "expr.h"
-#include "hard-reg-set.h"
-#include "basic-block.h"
-#include "toplev.h"
-#include "tm_p.h"
#include "cfgloop.h"
-#include "output.h"
-#include "params.h"
-#include "target.h"
+#include "cfgrtl.h"
+#include "dumpfile.h"
+#include "loop-unroll.h"
+#include "regs.h"
+#include "df.h"
/* This module is used to modify loops with a determinable number of
iterations to use special low-overhead looping instructions.
register cannot be used for anything else but doloop -- ??? detect these
cases). */
-#ifdef HAVE_doloop_end
-
/* Return the loop termination condition for PATTERN or zero
if it is not a decrement and branch jump insn. */
rtx
-doloop_condition_get (rtx pattern)
+doloop_condition_get (rtx_insn *doloop_pat)
{
rtx cmp;
rtx inc;
rtx reg;
rtx inc_src;
rtx condition;
+ rtx pattern;
+ rtx cc_reg = NULL_RTX;
+ rtx reg_orig = NULL_RTX;
- /* The canonical doloop pattern we expect is:
+ /* The canonical doloop pattern we expect has one of the following
+ forms:
- (parallel [(set (pc) (if_then_else (condition)
- (label_ref (label))
- (pc)))
- (set (reg) (plus (reg) (const_int -1)))
- (additional clobbers and uses)])
+ 1) (parallel [(set (pc) (if_then_else (condition)
+ (label_ref (label))
+ (pc)))
+ (set (reg) (plus (reg) (const_int -1)))
+ (additional clobbers and uses)])
- Some targets (IA-64) wrap the set of the loop counter in
- an if_then_else too.
+ The branch must be the first entry of the parallel (also required
+ by jump.c), and the second entry of the parallel must be a set of
+ the loop counter register. Some targets (IA-64) wrap the set of
+ the loop counter in an if_then_else too.
- In summary, the branch must be the first entry of the
- parallel (also required by jump.c), and the second
- entry of the parallel must be a set of the loop counter
- register. */
+ 2) (set (reg) (plus (reg) (const_int -1))
+ (set (pc) (if_then_else (reg != 0)
+ (label_ref (label))
+ (pc))).
- if (GET_CODE (pattern) != PARALLEL)
- return 0;
+ Some targets (ARM) do the comparison before the branch, as in the
+ following form:
+
+ 3) (parallel [(set (cc) (compare ((plus (reg) (const_int -1), 0)))
+ (set (reg) (plus (reg) (const_int -1)))])
+ (set (pc) (if_then_else (cc == NE)
+ (label_ref (label))
+ (pc))) */
- cmp = XVECEXP (pattern, 0, 0);
- inc = XVECEXP (pattern, 0, 1);
+ pattern = PATTERN (doloop_pat);
+
+ if (GET_CODE (pattern) != PARALLEL)
+ {
+ rtx cond;
+ rtx_insn *prev_insn = prev_nondebug_insn (doloop_pat);
+ rtx cmp_arg1, cmp_arg2;
+ rtx cmp_orig;
+
+ /* In case the pattern is not PARALLEL we expect two forms
+ of doloop which are cases 2) and 3) above: in case 2) the
+ decrement immediately precedes the branch, while in case 3)
+ the compare and decrement instructions immediately precede
+ the branch. */
+
+ if (prev_insn == NULL_RTX || !INSN_P (prev_insn))
+ return 0;
+
+ cmp = pattern;
+ if (GET_CODE (PATTERN (prev_insn)) == PARALLEL)
+ {
+ /* The third case: the compare and decrement instructions
+ immediately precede the branch. */
+ cmp_orig = XVECEXP (PATTERN (prev_insn), 0, 0);
+ if (GET_CODE (cmp_orig) != SET)
+ return 0;
+ if (GET_CODE (SET_SRC (cmp_orig)) != COMPARE)
+ return 0;
+ cmp_arg1 = XEXP (SET_SRC (cmp_orig), 0);
+ cmp_arg2 = XEXP (SET_SRC (cmp_orig), 1);
+ if (cmp_arg2 != const0_rtx
+ || GET_CODE (cmp_arg1) != PLUS)
+ return 0;
+ reg_orig = XEXP (cmp_arg1, 0);
+ if (XEXP (cmp_arg1, 1) != GEN_INT (-1)
+ || !REG_P (reg_orig))
+ return 0;
+ cc_reg = SET_DEST (cmp_orig);
+
+ inc = XVECEXP (PATTERN (prev_insn), 0, 1);
+ }
+ else
+ inc = PATTERN (prev_insn);
+ if (GET_CODE (cmp) == SET && GET_CODE (SET_SRC (cmp)) == IF_THEN_ELSE)
+ {
+ /* We expect the condition to be of the form (reg != 0) */
+ cond = XEXP (SET_SRC (cmp), 0);
+ if (GET_CODE (cond) != NE || XEXP (cond, 1) != const0_rtx)
+ return 0;
+ }
+ }
+ else
+ {
+ cmp = XVECEXP (pattern, 0, 0);
+ inc = XVECEXP (pattern, 0, 1);
+ }
/* Check for (set (reg) (something)). */
if (GET_CODE (inc) != SET)
return 0;
if ((XEXP (condition, 0) == reg)
+ /* For the third case: */
+ || ((cc_reg != NULL_RTX)
+ && (XEXP (condition, 0) == cc_reg)
+ && (reg_orig == reg))
|| (GET_CODE (XEXP (condition, 0)) == PLUS
- && XEXP (XEXP (condition, 0), 0) == reg))
+ && XEXP (XEXP (condition, 0), 0) == reg))
+ {
+ if (GET_CODE (pattern) != PARALLEL)
+ /* For the second form we expect:
+
+ (set (reg) (plus (reg) (const_int -1))
+ (set (pc) (if_then_else (reg != 0)
+ (label_ref (label))
+ (pc))).
+
+ is equivalent to the following:
+
+ (parallel [(set (pc) (if_then_else (reg != 1)
+ (label_ref (label))
+ (pc)))
+ (set (reg) (plus (reg) (const_int -1)))
+ (additional clobbers and uses)])
+
+ For the third form we expect:
+
+ (parallel [(set (cc) (compare ((plus (reg) (const_int -1)), 0))
+ (set (reg) (plus (reg) (const_int -1)))])
+ (set (pc) (if_then_else (cc == NE)
+ (label_ref (label))
+ (pc)))
+
+ which is equivalent to the following:
+
+ (parallel [(set (cc) (compare (reg, 1))
+ (set (reg) (plus (reg) (const_int -1)))
+ (set (pc) (if_then_else (NE == cc)
+ (label_ref (label))
+ (pc))))])
+
+ So we return the second form instead for the two cases.
+
+ */
+ condition = gen_rtx_fmt_ee (NE, VOIDmode, inc_src, const1_rtx);
+
return condition;
+ }
/* ??? If a machine uses a funny comparison, we could return a
canonicalized form here. */
describes the number of iterations of the loop. */
static bool
-doloop_valid_p (struct loop *loop, struct niter_desc *desc)
+doloop_valid_p (class loop *loop, class niter_desc *desc)
{
basic_block *body = get_loop_body (loop), bb;
- rtx insn;
+ rtx_insn *insn;
unsigned i;
bool result = true;
return result;
}
-/* Adds test of COND jumping to DEST to the end of BB. */
+/* Adds test of COND jumping to DEST on edge *E and set *E to the new fallthru
+ edge. If the condition is always false, do not do anything. If it is always
+ true, redirect E to DEST and return false. In all other cases, true is
+ returned. */
-static void
-add_test (rtx cond, basic_block bb, basic_block dest)
+static bool
+add_test (rtx cond, edge *e, basic_block dest)
{
- rtx seq, jump, label;
- enum machine_mode mode;
+ rtx_insn *seq, *jump;
+ rtx_code_label *label;
+ machine_mode mode;
rtx op0 = XEXP (cond, 0), op1 = XEXP (cond, 1);
enum rtx_code code = GET_CODE (cond);
+ basic_block bb;
+ /* The jump is supposed to handle an unlikely special case. */
+ profile_probability prob = profile_probability::guessed_never ();
mode = GET_MODE (XEXP (cond, 0));
if (mode == VOIDmode)
op0 = force_operand (op0, NULL_RTX);
op1 = force_operand (op1, NULL_RTX);
label = block_label (dest);
- do_compare_rtx_and_jump (op0, op1, code, 0, mode, NULL_RTX, NULL_RTX, label);
+ do_compare_rtx_and_jump (op0, op1, code, 0, mode, NULL_RTX, NULL, label,
+ prob);
jump = get_last_insn ();
- JUMP_LABEL (jump) = label;
+ if (!jump || !JUMP_P (jump))
+ {
+ /* The condition is always false and the jump was optimized out. */
+ end_sequence ();
+ return true;
+ }
- /* The jump is supposed to handle an unlikely special case. */
- REG_NOTES (jump)
- = gen_rtx_EXPR_LIST (REG_BR_PROB,
- const0_rtx, REG_NOTES (jump));
+ seq = get_insns ();
+ unshare_all_rtl_in_chain (seq);
+ end_sequence ();
+
+ /* There always is at least the jump insn in the sequence. */
+ gcc_assert (seq != NULL_RTX);
+
+ bb = split_edge_and_insert (*e, seq);
+ *e = single_succ_edge (bb);
+
+ if (any_uncondjump_p (jump))
+ {
+ /* The condition is always true. */
+ delete_insn (jump);
+ redirect_edge_and_branch_force (*e, dest);
+ return false;
+ }
+
+ JUMP_LABEL (jump) = label;
LABEL_NUSES (label)++;
- seq = get_insns ();
- end_sequence ();
- emit_insn_after (seq, BB_END (bb));
+ edge e2 = make_edge (bb, dest, (*e)->flags & ~EDGE_FALLTHRU);
+ e2->probability = prob;
+ (*e)->probability = prob.invert ();
+ update_br_prob_note (e2->src);
+ return true;
}
/* Modify the loop to use the low-overhead looping insn where LOOP
DOLOOP_SEQ. COUNT is the number of iterations of the LOOP. */
static void
-doloop_modify (struct loop *loop, struct niter_desc *desc,
- rtx doloop_seq, rtx condition, rtx count)
+doloop_modify (class loop *loop, class niter_desc *desc,
+ rtx_insn *doloop_seq, rtx condition, rtx count)
{
rtx counter_reg;
rtx tmp, noloop = NULL_RTX;
- rtx sequence;
- rtx jump_insn;
- rtx jump_label;
- int nonneg = 0, irr;
+ rtx_insn *sequence;
+ rtx_insn *jump_insn;
+ rtx_code_label *jump_label;
+ int nonneg = 0;
bool increment_count;
basic_block loop_end = desc->out_edge->src;
- enum machine_mode mode;
+ scalar_int_mode mode;
+ widest_int iterations;
jump_insn = BB_END (loop_end);
{
fprintf (dump_file, "Doloop: Inserting doloop pattern (");
if (desc->const_iter)
- fprintf (dump_file, HOST_WIDEST_INT_PRINT_DEC, desc->niter);
+ fprintf (dump_file, "%" PRId64, desc->niter);
else
fputs ("runtime", dump_file);
fputs (" iterations).\n", dump_file);
counter_reg = XEXP (condition, 0);
if (GET_CODE (counter_reg) == PLUS)
counter_reg = XEXP (counter_reg, 0);
- mode = GET_MODE (counter_reg);
+ /* These patterns must operate on integer counters. */
+ mode = as_a <scalar_int_mode> (GET_MODE (counter_reg));
increment_count = false;
switch (GET_CODE (condition))
/* Determine if the iteration counter will be non-negative.
Note that the maximum value loaded is iterations_max - 1. */
- if (desc->niter_max
- <= ((unsigned HOST_WIDEST_INT) 1
- << (GET_MODE_BITSIZE (mode) - 1)))
+ if (get_max_loop_iterations (loop, &iterations)
+ && wi::leu_p (iterations,
+ wi::set_bit_in_zero <widest_int>
+ (GET_MODE_PRECISION (mode) - 1)))
nonneg = 1;
break;
/* Insert initialization of the count register into the loop header. */
start_sequence ();
+ /* count has been already copied through copy_rtx. */
+ reset_used_flags (count);
+ set_used_flags (condition);
tmp = force_operand (count, counter_reg);
convert_move (counter_reg, tmp, 1);
sequence = get_insns ();
+ unshare_all_rtl_in_chain (sequence);
end_sequence ();
emit_insn_after (sequence, BB_END (loop_preheader_edge (loop)->src));
{
rtx ass = copy_rtx (desc->noloop_assumptions);
basic_block preheader = loop_preheader_edge (loop)->src;
- basic_block set_zero
- = loop_split_edge_with (loop_preheader_edge (loop), NULL_RTX);
- basic_block new_preheader
- = loop_split_edge_with (loop_preheader_edge (loop), NULL_RTX);
- basic_block bb;
+ basic_block set_zero = split_edge (loop_preheader_edge (loop));
+ basic_block new_preheader = split_edge (loop_preheader_edge (loop));
edge te;
- gcov_type cnt;
/* Expand the condition testing the assumptions and if it does not pass,
reset the count register to 0. */
- add_test (XEXP (ass, 0), preheader, set_zero);
- single_succ_edge (preheader)->flags &= ~EDGE_FALLTHRU;
- cnt = single_succ_edge (preheader)->count;
- single_succ_edge (preheader)->probability = 0;
- single_succ_edge (preheader)->count = 0;
- irr = single_succ_edge (preheader)->flags & EDGE_IRREDUCIBLE_LOOP;
- te = make_edge (preheader, new_preheader, EDGE_FALLTHRU | irr);
- te->probability = REG_BR_PROB_BASE;
- te->count = cnt;
+ redirect_edge_and_branch_force (single_succ_edge (preheader), new_preheader);
set_immediate_dominator (CDI_DOMINATORS, new_preheader, preheader);
- set_zero->count = 0;
- set_zero->frequency = 0;
+ set_zero->count = profile_count::uninitialized ();
- for (ass = XEXP (ass, 1); ass; ass = XEXP (ass, 1))
+ te = single_succ_edge (preheader);
+ for (; ass; ass = XEXP (ass, 1))
+ if (!add_test (XEXP (ass, 0), &te, set_zero))
+ break;
+
+ if (ass)
{
- bb = loop_split_edge_with (te, NULL_RTX);
- te = single_succ_edge (bb);
- add_test (XEXP (ass, 0), bb, set_zero);
- make_edge (bb, set_zero, irr);
+ /* We reached a condition that is always true. This is very hard to
+ reproduce (such a loop does not roll, and thus it would most
+ likely get optimized out by some of the preceding optimizations).
+ In fact, I do not have any testcase for it. However, it would
+ also be very hard to show that it is impossible, so we must
+ handle this case. */
+ set_zero->count = preheader->count;
}
-
- start_sequence ();
- convert_move (counter_reg, noloop, 0);
- sequence = get_insns ();
- end_sequence ();
- emit_insn_after (sequence, BB_END (set_zero));
+
+ if (EDGE_COUNT (set_zero->preds) == 0)
+ {
+ /* All the conditions were simplified to false, remove the
+ unreachable set_zero block. */
+ delete_basic_block (set_zero);
+ }
+ else
+ {
+ /* Reset the counter to zero in the set_zero block. */
+ start_sequence ();
+ convert_move (counter_reg, noloop, 0);
+ sequence = get_insns ();
+ end_sequence ();
+ emit_insn_after (sequence, BB_END (set_zero));
+
+ set_immediate_dominator (CDI_DOMINATORS, set_zero,
+ recompute_dominator (CDI_DOMINATORS,
+ set_zero));
+ }
+
+ set_immediate_dominator (CDI_DOMINATORS, new_preheader,
+ recompute_dominator (CDI_DOMINATORS,
+ new_preheader));
}
/* Some targets (eg, C4x) need to initialize special looping
registers. */
-#ifdef HAVE_doloop_begin
- {
- rtx init;
- unsigned level = get_loop_level (loop) + 1;
- init = gen_doloop_begin (counter_reg,
- desc->const_iter ? desc->niter_expr : const0_rtx,
- desc->niter_max,
- GEN_INT (level));
- if (init)
- {
- start_sequence ();
- emit_insn (init);
- sequence = get_insns ();
- end_sequence ();
- emit_insn_after (sequence, BB_END (loop_preheader_edge (loop)->src));
- }
- }
-#endif
+ if (targetm.have_doloop_begin ())
+ if (rtx_insn *seq = targetm.gen_doloop_begin (counter_reg, doloop_seq))
+ emit_insn_after (seq, BB_END (loop_preheader_edge (loop)->src));
/* Insert the new low-overhead looping insn. */
emit_jump_insn_after (doloop_seq, BB_END (loop_end));
/* Add a REG_NONNEG note if the actual or estimated maximum number
of iterations is non-negative. */
if (nonneg)
+ add_reg_note (jump_insn, REG_NONNEG, NULL_RTX);
+
+ /* Update the REG_BR_PROB note. */
+ if (desc->in_edge->probability.initialized_p ())
+ add_reg_br_prob_note (jump_insn, desc->in_edge->probability);
+}
+
+/* Called through note_stores. */
+
+static void
+record_reg_sets (rtx x, const_rtx pat ATTRIBUTE_UNUSED, void *data)
+{
+ bitmap mod = (bitmap)data;
+ if (REG_P (x))
{
- REG_NOTES (jump_insn)
- = gen_rtx_EXPR_LIST (REG_NONNEG, NULL_RTX, REG_NOTES (jump_insn));
+ unsigned int regno = REGNO (x);
+ if (HARD_REGISTER_P (x))
+ {
+ unsigned int end_regno = end_hard_regno (GET_MODE (x), regno);
+ do
+ bitmap_set_bit (mod, regno);
+ while (++regno < end_regno);
+ }
+ else
+ bitmap_set_bit (mod, regno);
}
}
modified. */
static bool
-doloop_optimize (struct loop *loop)
+doloop_optimize (class loop *loop)
{
- enum machine_mode mode;
- rtx doloop_seq, doloop_pat, doloop_reg;
- rtx iterations, count;
- rtx iterations_max;
- rtx start_label;
+ scalar_int_mode mode;
+ rtx doloop_reg;
+ rtx count;
+ widest_int iterations, iterations_max;
+ rtx_code_label *start_label;
rtx condition;
- unsigned level, est_niter;
- struct niter_desc *desc;
+ unsigned level;
+ HOST_WIDE_INT est_niter;
+ int max_cost;
+ class niter_desc *desc;
unsigned word_mode_size;
unsigned HOST_WIDE_INT word_mode_max;
+ int entered_at_top;
if (dump_file)
fprintf (dump_file, "Doloop: Processing loop %d.\n", loop->num);
}
mode = desc->mode;
- est_niter = 3;
- if (desc->const_iter)
- est_niter = desc->niter;
- /* If the estimate on number of iterations is reliable (comes from profile
- feedback), use it. Do not use it normally, since the expected number
- of iterations of an unrolled loop is 2. */
- if (loop->header->count)
- est_niter = expected_loop_iterations (loop);
-
- if (est_niter < 3)
+ est_niter = get_estimated_loop_iterations_int (loop);
+ if (est_niter == -1)
+ est_niter = get_likely_max_loop_iterations_int (loop);
+
+ if (est_niter >= 0 && est_niter < 3)
{
if (dump_file)
fprintf (dump_file,
"Doloop: Too few iterations (%u) to be profitable.\n",
- est_niter);
+ (unsigned int)est_niter);
return false;
}
- count = copy_rtx (desc->niter_expr);
- iterations = desc->const_iter ? desc->niter_expr : const0_rtx;
- iterations_max = GEN_INT (desc->niter_max);
+ max_cost
+ = COSTS_N_INSNS (param_max_iterations_computation_cost);
+ if (set_src_cost (desc->niter_expr, mode, optimize_loop_for_speed_p (loop))
+ > max_cost)
+ {
+ if (dump_file)
+ fprintf (dump_file,
+ "Doloop: number of iterations too costly to compute.\n");
+ return false;
+ }
+
+ if (desc->const_iter)
+ iterations = widest_int::from (rtx_mode_t (desc->niter_expr, mode),
+ UNSIGNED);
+ else
+ iterations = 0;
+ if (!get_max_loop_iterations (loop, &iterations_max))
+ iterations_max = 0;
level = get_loop_level (loop) + 1;
+ entered_at_top = (loop->latch == desc->in_edge->dest
+ && contains_no_active_insn_p (loop->latch));
+ if (!targetm.can_use_doloop_p (iterations, iterations_max, level,
+ entered_at_top))
+ {
+ if (dump_file)
+ fprintf (dump_file, "Loop rejected by can_use_doloop_p.\n");
+ return false;
+ }
/* Generate looping insn. If the pattern FAILs then give up trying
to modify the loop since there is some aspect the back-end does
not like. */
+ count = copy_rtx (desc->niter_expr);
start_label = block_label (desc->in_edge->dest);
doloop_reg = gen_reg_rtx (mode);
- doloop_seq = gen_doloop_end (doloop_reg, iterations, iterations_max,
- GEN_INT (level), start_label);
+ rtx_insn *doloop_seq = targetm.gen_doloop_end (doloop_reg, start_label);
- word_mode_size = GET_MODE_BITSIZE (word_mode);
- word_mode_max
- = ((unsigned HOST_WIDE_INT) 1 << (word_mode_size - 1) << 1) - 1;
+ word_mode_size = GET_MODE_PRECISION (word_mode);
+ word_mode_max = (HOST_WIDE_INT_1U << (word_mode_size - 1) << 1) - 1;
if (! doloop_seq
&& mode != word_mode
/* Before trying mode different from the one in that # of iterations is
computed, we must be sure that the number of iterations fits into
the new mode. */
- && (word_mode_size >= GET_MODE_BITSIZE (mode)
- || desc->niter_max <= word_mode_max))
+ && (word_mode_size >= GET_MODE_PRECISION (mode)
+ || wi::leu_p (iterations_max, word_mode_max)))
{
- if (word_mode_size > GET_MODE_BITSIZE (mode))
- {
- count = simplify_gen_unary (ZERO_EXTEND, word_mode,
- count, mode);
- iterations = simplify_gen_unary (ZERO_EXTEND, word_mode,
- iterations, mode);
- iterations_max = simplify_gen_unary (ZERO_EXTEND, word_mode,
- iterations_max, mode);
- }
+ if (word_mode_size > GET_MODE_PRECISION (mode))
+ count = simplify_gen_unary (ZERO_EXTEND, word_mode, count, mode);
else
- {
- count = lowpart_subreg (word_mode, count, mode);
- iterations = lowpart_subreg (word_mode, iterations, mode);
- iterations_max = lowpart_subreg (word_mode, iterations_max, mode);
- }
+ count = lowpart_subreg (word_mode, count, mode);
PUT_MODE (doloop_reg, word_mode);
- doloop_seq = gen_doloop_end (doloop_reg, iterations, iterations_max,
- GEN_INT (level), start_label);
+ doloop_seq = targetm.gen_doloop_end (doloop_reg, start_label);
}
if (! doloop_seq)
{
}
/* If multiple instructions were created, the last must be the
- jump instruction. Also, a raw define_insn may yield a plain
- pattern. */
- doloop_pat = doloop_seq;
- if (INSN_P (doloop_pat))
- {
- while (NEXT_INSN (doloop_pat) != NULL_RTX)
- doloop_pat = NEXT_INSN (doloop_pat);
- if (JUMP_P (doloop_pat))
- doloop_pat = PATTERN (doloop_pat);
- else
- doloop_pat = NULL_RTX;
- }
-
- if (! doloop_pat
- || ! (condition = doloop_condition_get (doloop_pat)))
+ jump instruction. */
+ rtx_insn *doloop_insn = doloop_seq;
+ while (NEXT_INSN (doloop_insn) != NULL_RTX)
+ doloop_insn = NEXT_INSN (doloop_insn);
+ if (!JUMP_P (doloop_insn)
+ || !(condition = doloop_condition_get (doloop_insn)))
{
if (dump_file)
fprintf (dump_file, "Doloop: Unrecognizable doloop pattern!\n");
return false;
}
+ /* Ensure that the new sequence doesn't clobber a register that
+ is live at the end of the block. */
+ {
+ bitmap modified = BITMAP_ALLOC (NULL);
+
+ for (rtx_insn *i = doloop_seq; i != NULL; i = NEXT_INSN (i))
+ note_stores (i, record_reg_sets, modified);
+
+ basic_block loop_end = desc->out_edge->src;
+ bool fail = bitmap_intersect_p (df_get_live_out (loop_end), modified);
+ BITMAP_FREE (modified);
+
+ if (fail)
+ {
+ if (dump_file)
+ fprintf (dump_file, "Doloop: doloop pattern clobbers live out\n");
+ return false;
+ }
+ }
+
doloop_modify (loop, desc, doloop_seq, condition, count);
return true;
}
-/* This is the main entry point. Process all LOOPS using doloop_optimize. */
+/* This is the main entry point. Process all loops using doloop_optimize. */
void
-doloop_optimize_loops (struct loops *loops)
+doloop_optimize_loops (void)
{
- unsigned i;
- struct loop *loop;
+ class loop *loop;
- for (i = 1; i < loops->num; i++)
+ if (optimize == 1)
{
- loop = loops->parray[i];
- if (!loop)
- continue;
+ df_live_add_problem ();
+ df_live_set_all_dirty ();
+ }
+ FOR_EACH_LOOP (loop, 0)
+ {
doloop_optimize (loop);
}
+ if (optimize == 1)
+ df_remove_problem (df_live);
+
iv_analysis_done ();
-#ifdef ENABLE_CHECKING
- verify_dominators (CDI_DOMINATORS);
- verify_loop_structure (loops);
-#endif
+ checking_verify_loop_structure ();
}
-#endif /* HAVE_doloop_end */
-