X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=gcc%2Floop-unroll.c;h=de319c4f1d73cf29296f5284d5703ab423d777a9;hb=2cd45f0e6826ddcc92216a508104b2802eddece3;hp=776b2e1f6b15f854d14cfb6364372129a9d2fcfc;hpb=d73be2683d8be63e92ade52ba9613e3c7382c809;p=gcc.git
diff --git a/gcc/loop-unroll.c b/gcc/loop-unroll.c
index 776b2e1f6b1..de319c4f1d7 100644
--- a/gcc/loop-unroll.c
+++ b/gcc/loop-unroll.c
@@ -1,11 +1,12 @@
/* Loop unrolling and peeling.
- Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008, 2010, 2011
+ 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
@@ -14,9 +15,8 @@ FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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
+. */
#include "config.h"
#include "system.h"
@@ -27,12 +27,12 @@ Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
#include "obstack.h"
#include "basic-block.h"
#include "cfgloop.h"
-#include "cfglayout.h"
#include "params.h"
-#include "output.h"
#include "expr.h"
#include "hashtab.h"
-#include "recog.h"
+#include "recog.h"
+#include "target.h"
+#include "dumpfile.h"
/* This pass performs loop unrolling and peeling. We only perform these
optimizations on innermost loops (with single exception) because
@@ -74,14 +74,16 @@ Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
struct iv_to_split
{
rtx insn; /* The insn in that the induction variable occurs. */
+ rtx orig_var; /* The variable (register) for the IV before split. */
rtx base_var; /* The variable on that the values in the further
iterations are based. */
rtx step; /* Step of the induction variable. */
+ struct iv_to_split *next; /* Next entry in walking order. */
unsigned n_loc;
unsigned loc[3]; /* Location where the definition of the induction
variable occurs in the insn. For example if
N_LOC is 2, the expression is located at
- XEXP (XEXP (single_set, loc[0]), loc[1]). */
+ XEXP (XEXP (single_set, loc[0]), loc[1]). */
};
/* Information about accumulators to expand. */
@@ -90,13 +92,14 @@ struct var_to_expand
{
rtx insn; /* The insn in that the variable expansion occurs. */
rtx reg; /* The accumulator which is expanded. */
- VEC(rtx,heap) *var_expansions; /* The copies of the accumulator which is expanded. */
- enum rtx_code op; /* The type of the accumulation - addition, subtraction
+ vec var_expansions; /* The copies of the accumulator which is expanded. */
+ struct var_to_expand *next; /* Next entry in walking order. */
+ enum rtx_code op; /* The type of the accumulation - addition, subtraction
or multiplication. */
int expansion_count; /* Count the number of expansions generated so far. */
int reuse_expansion; /* The expansion we intend to reuse to expand
- the accumulator. If REUSE_EXPANSION is 0 reuse
- the original accumulator. Else use
+ the accumulator. If REUSE_EXPANSION is 0 reuse
+ the original accumulator. Else use
var_expansions[REUSE_EXPANSION - 1]. */
};
@@ -106,8 +109,12 @@ struct var_to_expand
struct opt_info
{
htab_t insns_to_split; /* A hashtable of insns to split. */
+ struct iv_to_split *iv_to_split_head; /* The first iv to split. */
+ struct iv_to_split **iv_to_split_tail; /* Pointer to the tail of the list. */
htab_t insns_with_var_to_expand; /* A hashtable of insns with accumulators
to expand. */
+ struct var_to_expand *var_to_expand_head; /* The first var to expand. */
+ struct var_to_expand **var_to_expand_tail; /* Pointer to the tail of the list. */
unsigned first_new_block; /* The first basic block that was
duplicated. */
basic_block loop_exit; /* The loop exit basic block. */
@@ -132,20 +139,22 @@ static void opt_info_start_duplication (struct opt_info *);
static void apply_opt_in_copies (struct opt_info *, unsigned, bool, bool);
static void free_opt_info (struct opt_info *);
static struct var_to_expand *analyze_insn_to_expand_var (struct loop*, rtx);
-static bool referenced_in_one_insn_in_loop_p (struct loop *, rtx);
+static bool referenced_in_one_insn_in_loop_p (struct loop *, rtx, int *);
static struct iv_to_split *analyze_iv_to_split_insn (rtx);
static void expand_var_during_unrolling (struct var_to_expand *, rtx);
-static int insert_var_expansion_initialization (void **, void *);
-static int combine_var_copies_in_loop_exit (void **, void *);
-static int release_var_copies (void **, void *);
+static void insert_var_expansion_initialization (struct var_to_expand *,
+ basic_block);
+static void combine_var_copies_in_loop_exit (struct var_to_expand *,
+ basic_block);
static rtx get_expansion (struct var_to_expand *);
/* Unroll and/or peel (depending on FLAGS) LOOPS. */
void
unroll_and_peel_loops (int flags)
{
- struct loop *loop, *next;
+ struct loop *loop;
bool check;
+ loop_iterator li;
/* First perform complete loop peeling (it is almost surely a win,
and affects parameters for further decision a lot). */
@@ -154,22 +163,9 @@ unroll_and_peel_loops (int flags)
/* Now decide rest of unrolling and peeling. */
decide_unrolling_and_peeling (flags);
- loop = current_loops->tree_root;
- while (loop->inner)
- loop = loop->inner;
-
/* Scan the loops, inner ones first. */
- while (loop != current_loops->tree_root)
+ FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST)
{
- if (loop->next)
- {
- next = loop->next;
- while (next->inner)
- next = next->inner;
- }
- else
- next = loop->outer;
-
check = true;
/* And perform the appropriate transformations. */
switch (loop->lpt_decision.decision)
@@ -198,11 +194,9 @@ unroll_and_peel_loops (int flags)
if (check)
{
#ifdef ENABLE_CHECKING
- verify_dominators (CDI_DOMINATORS);
verify_loop_structure ();
#endif
}
- loop = next;
}
iv_analysis_done ();
@@ -222,7 +216,7 @@ loop_exit_at_end_p (struct loop *loop)
/* Check that the latch is empty. */
FOR_BB_INSNS (loop->latch, insn)
{
- if (INSN_P (insn))
+ if (NONDEBUG_INSN_P (insn))
return false;
}
@@ -234,15 +228,11 @@ static void
peel_loops_completely (int flags)
{
struct loop *loop;
- unsigned i;
+ loop_iterator li;
/* Scan the loops, the inner ones first. */
- for (i = current_loops->num - 1; i > 0; i--)
+ FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST)
{
- loop = current_loops->parray[i];
- if (!loop)
- continue;
-
loop->lpt_decision.decision = LPT_NONE;
if (dump_file)
@@ -260,7 +250,6 @@ peel_loops_completely (int flags)
{
peel_loop_completely (loop);
#ifdef ENABLE_CHECKING
- verify_dominators (CDI_DOMINATORS);
verify_loop_structure ();
#endif
}
@@ -271,34 +260,22 @@ peel_loops_completely (int flags)
static void
decide_unrolling_and_peeling (int flags)
{
- struct loop *loop = current_loops->tree_root, *next;
-
- while (loop->inner)
- loop = loop->inner;
+ struct loop *loop;
+ loop_iterator li;
/* Scan the loops, inner ones first. */
- while (loop != current_loops->tree_root)
+ FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST)
{
- if (loop->next)
- {
- next = loop->next;
- while (next->inner)
- next = next->inner;
- }
- else
- next = loop->outer;
-
loop->lpt_decision.decision = LPT_NONE;
if (dump_file)
fprintf (dump_file, "\n;; *** Considering loop %d ***\n", loop->num);
/* Do not peel cold areas. */
- if (!maybe_hot_bb_p (loop->header))
+ if (optimize_loop_for_size_p (loop))
{
if (dump_file)
fprintf (dump_file, ";; Not considering loop, cold area\n");
- loop = next;
continue;
}
@@ -308,7 +285,6 @@ decide_unrolling_and_peeling (int flags)
if (dump_file)
fprintf (dump_file,
";; Not considering loop, cannot duplicate\n");
- loop = next;
continue;
}
@@ -317,7 +293,6 @@ decide_unrolling_and_peeling (int flags)
{
if (dump_file)
fprintf (dump_file, ";; Not considering loop, is not innermost\n");
- loop = next;
continue;
}
@@ -334,8 +309,6 @@ decide_unrolling_and_peeling (int flags)
decide_unroll_stupid (loop, flags);
if (loop->lpt_decision.decision == LPT_NONE)
decide_peel_simple (loop, flags);
-
- loop = next;
}
}
@@ -365,7 +338,8 @@ decide_peel_once_rolling (struct loop *loop, int flags ATTRIBUTE_UNUSED)
|| desc->assumptions
|| desc->infinite
|| !desc->const_iter
- || desc->niter != 0)
+ || (desc->niter != 0
+ && max_loop_iterations_int (loop) != 0))
{
if (dump_file)
fprintf (dump_file,
@@ -398,7 +372,7 @@ decide_peel_completely (struct loop *loop, int flags ATTRIBUTE_UNUSED)
}
/* Do not peel cold areas. */
- if (!maybe_hot_bb_p (loop->header))
+ if (optimize_loop_for_size_p (loop))
{
if (dump_file)
fprintf (dump_file, ";; Not considering loop, cold area\n");
@@ -479,34 +453,34 @@ peel_loop_completely (struct loop *loop)
{
sbitmap wont_exit;
unsigned HOST_WIDE_INT npeel;
- unsigned n_remove_edges, i;
- edge *remove_edges, ein;
+ unsigned i;
+ vec remove_edges;
+ edge ein;
struct niter_desc *desc = get_simple_loop_desc (loop);
struct opt_info *opt_info = NULL;
-
+
npeel = desc->niter;
if (npeel)
{
bool ok;
-
+
wont_exit = sbitmap_alloc (npeel + 1);
- sbitmap_ones (wont_exit);
- RESET_BIT (wont_exit, 0);
+ bitmap_ones (wont_exit);
+ bitmap_clear_bit (wont_exit, 0);
if (desc->noloop_assumptions)
- RESET_BIT (wont_exit, 1);
+ bitmap_clear_bit (wont_exit, 1);
- remove_edges = XCNEWVEC (edge, npeel);
- n_remove_edges = 0;
+ remove_edges.create (0);
if (flag_split_ivs_in_unroller)
opt_info = analyze_insns_in_loop (loop);
-
+
opt_info_start_duplication (opt_info);
ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
npeel,
wont_exit, desc->out_edge,
- remove_edges, &n_remove_edges,
+ &remove_edges,
DLTHE_FLAG_UPDATE_FREQ
| DLTHE_FLAG_COMPLETTE_PEEL
| (opt_info
@@ -514,7 +488,7 @@ peel_loop_completely (struct loop *loop)
gcc_assert (ok);
free (wont_exit);
-
+
if (opt_info)
{
apply_opt_in_copies (opt_info, npeel, false, true);
@@ -522,9 +496,9 @@ peel_loop_completely (struct loop *loop)
}
/* Remove the exit edges. */
- for (i = 0; i < n_remove_edges; i++)
- remove_path (remove_edges[i]);
- free (remove_edges);
+ FOR_EACH_VEC_ELT (remove_edges, i, ein)
+ remove_path (ein);
+ remove_edges.release ();
}
ein = desc->in_edge;
@@ -546,6 +520,7 @@ decide_unroll_constant_iterations (struct loop *loop, int flags)
{
unsigned nunroll, nunroll_by_av, best_copies, best_unroll = 0, n_copies, i;
struct niter_desc *desc;
+ double_int iterations;
if (!(flags & UAP_UNROLL))
{
@@ -588,8 +563,14 @@ decide_unroll_constant_iterations (struct loop *loop, int flags)
return;
}
- /* Check whether the loop rolls enough to consider. */
- if (desc->niter < 2 * nunroll)
+ /* Check whether the loop rolls enough to consider.
+ Consult also loop bounds and profile; in the case the loop has more
+ than one exit it may well loop less than determined maximal number
+ of iterations. */
+ if (desc->niter < 2 * nunroll
+ || ((estimated_loop_iterations (loop, &iterations)
+ || max_loop_iterations (loop, &iterations))
+ && iterations.ult (double_int::from_shwi (2 * nunroll))))
{
if (dump_file)
fprintf (dump_file, ";; Not unrolling loop, doesn't roll\n");
@@ -625,26 +606,21 @@ decide_unroll_constant_iterations (struct loop *loop, int flags)
}
}
- if (dump_file)
- fprintf (dump_file, ";; max_unroll %d (%d copies, initial %d).\n",
- best_unroll + 1, best_copies, nunroll);
-
loop->lpt_decision.decision = LPT_UNROLL_CONSTANT;
loop->lpt_decision.times = best_unroll;
-
+
if (dump_file)
- fprintf (dump_file,
- ";; Decided to unroll the constant times rolling loop, %d times.\n",
- loop->lpt_decision.times);
+ fprintf (dump_file, ";; Decided to unroll the loop %d times (%d copies).\n",
+ loop->lpt_decision.times, best_copies);
}
-/* Unroll LOOP with constant number of iterations LOOP->LPT_DECISION.TIMES + 1
- times. The transformation does this:
+/* Unroll LOOP with constant number of iterations LOOP->LPT_DECISION.TIMES times.
+ The transformation does this:
for (i = 0; i < 102; i++)
body;
- ==>
+ ==> (LOOP->LPT_DECISION.TIMES == 3)
i = 0;
body; i++;
@@ -663,14 +639,15 @@ unroll_loop_constant_iterations (struct loop *loop)
unsigned HOST_WIDE_INT niter;
unsigned exit_mod;
sbitmap wont_exit;
- unsigned n_remove_edges, i;
- edge *remove_edges;
+ unsigned i;
+ vec remove_edges;
+ edge e;
unsigned max_unroll = loop->lpt_decision.times;
struct niter_desc *desc = get_simple_loop_desc (loop);
bool exit_at_end = loop_exit_at_end_p (loop);
struct opt_info *opt_info = NULL;
bool ok;
-
+
niter = desc->niter;
/* Should not get here (such loop should be peeled instead). */
@@ -679,14 +656,13 @@ unroll_loop_constant_iterations (struct loop *loop)
exit_mod = niter % (max_unroll + 1);
wont_exit = sbitmap_alloc (max_unroll + 1);
- sbitmap_ones (wont_exit);
+ bitmap_ones (wont_exit);
- remove_edges = XCNEWVEC (edge, max_unroll + exit_mod + 1);
- n_remove_edges = 0;
- if (flag_split_ivs_in_unroller
+ remove_edges.create (0);
+ if (flag_split_ivs_in_unroller
|| flag_variable_expansion_in_unroller)
opt_info = analyze_insns_in_loop (loop);
-
+
if (!exit_at_end)
{
/* The exit is not at the end of the loop; leave exit test
@@ -694,12 +670,12 @@ unroll_loop_constant_iterations (struct loop *loop)
of exit condition have continuous body after unrolling. */
if (dump_file)
- fprintf (dump_file, ";; Condition on beginning of loop.\n");
+ fprintf (dump_file, ";; Condition at beginning of loop.\n");
/* Peel exit_mod iterations. */
- RESET_BIT (wont_exit, 0);
+ bitmap_clear_bit (wont_exit, 0);
if (desc->noloop_assumptions)
- RESET_BIT (wont_exit, 1);
+ bitmap_clear_bit (wont_exit, 1);
if (exit_mod)
{
@@ -707,7 +683,7 @@ unroll_loop_constant_iterations (struct loop *loop)
ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
exit_mod,
wont_exit, desc->out_edge,
- remove_edges, &n_remove_edges,
+ &remove_edges,
DLTHE_FLAG_UPDATE_FREQ
| (opt_info && exit_mod > 1
? DLTHE_RECORD_COPY_NUMBER
@@ -715,14 +691,20 @@ unroll_loop_constant_iterations (struct loop *loop)
gcc_assert (ok);
if (opt_info && exit_mod > 1)
- apply_opt_in_copies (opt_info, exit_mod, false, false);
-
+ apply_opt_in_copies (opt_info, exit_mod, false, false);
+
desc->noloop_assumptions = NULL_RTX;
desc->niter -= exit_mod;
- desc->niter_max -= exit_mod;
+ loop->nb_iterations_upper_bound -= double_int::from_uhwi (exit_mod);
+ if (loop->any_estimate
+ && double_int::from_uhwi (exit_mod).ule
+ (loop->nb_iterations_estimate))
+ loop->nb_iterations_estimate -= double_int::from_uhwi (exit_mod);
+ else
+ loop->any_estimate = false;
}
- SET_BIT (wont_exit, 1);
+ bitmap_set_bit (wont_exit, 1);
}
else
{
@@ -730,7 +712,7 @@ unroll_loop_constant_iterations (struct loop *loop)
the loop tests the condition at the end of loop body. */
if (dump_file)
- fprintf (dump_file, ";; Condition on end of loop.\n");
+ fprintf (dump_file, ";; Condition at end of loop.\n");
/* We know that niter >= max_unroll + 2; so we do not need to care of
case when we would exit before reaching the loop. So just peel
@@ -738,42 +720,48 @@ unroll_loop_constant_iterations (struct loop *loop)
if (exit_mod != max_unroll
|| desc->noloop_assumptions)
{
- RESET_BIT (wont_exit, 0);
+ bitmap_clear_bit (wont_exit, 0);
if (desc->noloop_assumptions)
- RESET_BIT (wont_exit, 1);
-
+ bitmap_clear_bit (wont_exit, 1);
+
opt_info_start_duplication (opt_info);
ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
exit_mod + 1,
wont_exit, desc->out_edge,
- remove_edges, &n_remove_edges,
+ &remove_edges,
DLTHE_FLAG_UPDATE_FREQ
| (opt_info && exit_mod > 0
? DLTHE_RECORD_COPY_NUMBER
: 0));
gcc_assert (ok);
-
+
if (opt_info && exit_mod > 0)
apply_opt_in_copies (opt_info, exit_mod + 1, false, false);
desc->niter -= exit_mod + 1;
- desc->niter_max -= exit_mod + 1;
+ loop->nb_iterations_upper_bound -= double_int::from_uhwi (exit_mod + 1);
+ if (loop->any_estimate
+ && double_int::from_uhwi (exit_mod + 1).ule
+ (loop->nb_iterations_estimate))
+ loop->nb_iterations_estimate -= double_int::from_uhwi (exit_mod + 1);
+ else
+ loop->any_estimate = false;
desc->noloop_assumptions = NULL_RTX;
- SET_BIT (wont_exit, 0);
- SET_BIT (wont_exit, 1);
+ bitmap_set_bit (wont_exit, 0);
+ bitmap_set_bit (wont_exit, 1);
}
- RESET_BIT (wont_exit, max_unroll);
+ bitmap_clear_bit (wont_exit, max_unroll);
}
/* Now unroll the loop. */
-
+
opt_info_start_duplication (opt_info);
ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop),
max_unroll,
wont_exit, desc->out_edge,
- remove_edges, &n_remove_edges,
+ &remove_edges,
DLTHE_FLAG_UPDATE_FREQ
| (opt_info
? DLTHE_RECORD_COPY_NUMBER
@@ -792,7 +780,7 @@ unroll_loop_constant_iterations (struct loop *loop)
{
basic_block exit_block = get_bb_copy (desc->in_edge->src);
/* Find a new in and out edge; they are in the last copy we have made. */
-
+
if (EDGE_SUCC (exit_block, 0)->dest == desc->out_edge->dest)
{
desc->out_edge = EDGE_SUCC (exit_block, 0);
@@ -806,13 +794,21 @@ unroll_loop_constant_iterations (struct loop *loop)
}
desc->niter /= max_unroll + 1;
- desc->niter_max /= max_unroll + 1;
+ loop->nb_iterations_upper_bound
+ = loop->nb_iterations_upper_bound.udiv (double_int::from_uhwi (max_unroll
+ + 1),
+ TRUNC_DIV_EXPR);
+ if (loop->any_estimate)
+ loop->nb_iterations_estimate
+ = loop->nb_iterations_estimate.udiv (double_int::from_uhwi (max_unroll
+ + 1),
+ TRUNC_DIV_EXPR);
desc->niter_expr = GEN_INT (desc->niter);
/* Remove the edges. */
- for (i = 0; i < n_remove_edges; i++)
- remove_path (remove_edges[i]);
- free (remove_edges);
+ FOR_EACH_VEC_ELT (remove_edges, i, e)
+ remove_path (e);
+ remove_edges.release ();
if (dump_file)
fprintf (dump_file,
@@ -827,6 +823,7 @@ decide_unroll_runtime_iterations (struct loop *loop, int flags)
{
unsigned nunroll, nunroll_by_av, i;
struct niter_desc *desc;
+ double_int iterations;
if (!(flags & UAP_UNROLL))
{
@@ -848,6 +845,9 @@ decide_unroll_runtime_iterations (struct loop *loop, int flags)
if (nunroll > (unsigned) PARAM_VALUE (PARAM_MAX_UNROLL_TIMES))
nunroll = PARAM_VALUE (PARAM_MAX_UNROLL_TIMES);
+ if (targetm.loop_unroll_adjust)
+ nunroll = targetm.loop_unroll_adjust (nunroll, loop);
+
/* Skip big loops. */
if (nunroll <= 1)
{
@@ -876,8 +876,10 @@ decide_unroll_runtime_iterations (struct loop *loop, int flags)
return;
}
- /* If we have profile feedback, check whether the loop rolls. */
- if (loop->header->count && expected_loop_iterations (loop) < 2 * nunroll)
+ /* Check whether the loop rolls. */
+ if ((estimated_loop_iterations (loop, &iterations)
+ || max_loop_iterations (loop, &iterations))
+ && iterations.ult (double_int::from_shwi (2 * nunroll)))
{
if (dump_file)
fprintf (dump_file, ";; Not unrolling loop, doesn't roll\n");
@@ -891,11 +893,9 @@ decide_unroll_runtime_iterations (struct loop *loop, int flags)
loop->lpt_decision.decision = LPT_UNROLL_RUNTIME;
loop->lpt_decision.times = i - 1;
-
+
if (dump_file)
- fprintf (dump_file,
- ";; Decided to unroll the runtime computable "
- "times rolling loop, %d times.\n",
+ fprintf (dump_file, ";; Decided to unroll the loop %d times.\n",
loop->lpt_decision.times);
}
@@ -910,20 +910,50 @@ split_edge_and_insert (edge e, rtx insns)
if (!insns)
return NULL;
- bb = split_edge (e);
+ bb = split_edge (e);
emit_insn_after (insns, BB_END (bb));
- bb->flags |= BB_SUPERBLOCK;
+
+ /* ??? We used to assume that INSNS can contain control flow insns, and
+ that we had to try to find sub basic blocks in BB to maintain a valid
+ CFG. For this purpose we used to set the BB_SUPERBLOCK flag on BB
+ and call break_superblocks when going out of cfglayout mode. But it
+ turns out that this never happens; and that if it does ever happen,
+ the TODO_verify_flow at the end of the RTL loop passes would fail.
+
+ There are two reasons why we expected we could have control flow insns
+ in INSNS. The first is when a comparison has to be done in parts, and
+ the second is when the number of iterations is computed for loops with
+ the number of iterations known at runtime. In both cases, test cases
+ to get control flow in INSNS appear to be impossible to construct:
+
+ * If do_compare_rtx_and_jump needs several branches to do comparison
+ in a mode that needs comparison by parts, we cannot analyze the
+ number of iterations of the loop, and we never get to unrolling it.
+
+ * The code in expand_divmod that was suspected to cause creation of
+ branching code seems to be only accessed for signed division. The
+ divisions used by # of iterations analysis are always unsigned.
+ Problems might arise on architectures that emits branching code
+ for some operations that may appear in the unroller (especially
+ for division), but we have no such architectures.
+
+ Considering all this, it was decided that we should for now assume
+ that INSNS can in theory contain control flow insns, but in practice
+ it never does. So we don't handle the theoretical case, and should
+ a real failure ever show up, we have a pretty good clue for how to
+ fix it. */
+
return bb;
}
-/* Unroll LOOP for that we are able to count number of iterations in runtime
- LOOP->LPT_DECISION.TIMES + 1 times. The transformation does this (with some
+/* Unroll LOOP for which we are able to count number of iterations in runtime
+ LOOP->LPT_DECISION.TIMES times. The transformation does this (with some
extra care for case n < 0):
for (i = 0; i < n; i++)
body;
- ==>
+ ==> (LOOP->LPT_DECISION.TIMES == 3)
i = 0;
mod = n % 4;
@@ -952,39 +982,39 @@ unroll_loop_runtime_iterations (struct loop *loop)
{
rtx old_niter, niter, init_code, branch_code, tmp;
unsigned i, j, p;
- basic_block preheader, *body, *dom_bbs, swtch, ezc_swtch;
- unsigned n_dom_bbs;
+ basic_block preheader, *body, swtch, ezc_swtch;
+ vec dom_bbs;
sbitmap wont_exit;
int may_exit_copy;
- unsigned n_peel, n_remove_edges;
- edge *remove_edges, e;
+ unsigned n_peel;
+ vec remove_edges;
+ edge e;
bool extra_zero_check, last_may_exit;
unsigned max_unroll = loop->lpt_decision.times;
struct niter_desc *desc = get_simple_loop_desc (loop);
bool exit_at_end = loop_exit_at_end_p (loop);
struct opt_info *opt_info = NULL;
bool ok;
-
+
if (flag_split_ivs_in_unroller
|| flag_variable_expansion_in_unroller)
opt_info = analyze_insns_in_loop (loop);
-
+
/* Remember blocks whose dominators will have to be updated. */
- dom_bbs = XCNEWVEC (basic_block, n_basic_blocks);
- n_dom_bbs = 0;
+ dom_bbs.create (0);
body = get_loop_body (loop);
for (i = 0; i < loop->num_nodes; i++)
{
- unsigned nldom;
- basic_block *ldom;
+ vec ldom;
+ basic_block bb;
- nldom = get_dominated_by (CDI_DOMINATORS, body[i], &ldom);
- for (j = 0; j < nldom; j++)
- if (!flow_bb_inside_loop_p (loop, ldom[j]))
- dom_bbs[n_dom_bbs++] = ldom[j];
+ ldom = get_dominated_by (CDI_DOMINATORS, body[i]);
+ FOR_EACH_VEC_ELT (ldom, j, bb)
+ if (!flow_bb_inside_loop_p (loop, bb))
+ dom_bbs.safe_push (bb);
- free (ldom);
+ ldom.release ();
}
free (body);
@@ -1024,12 +1054,12 @@ unroll_loop_runtime_iterations (struct loop *loop)
init_code = get_insns ();
end_sequence ();
+ unshare_all_rtl_in_chain (init_code);
/* Precondition the loop. */
split_edge_and_insert (loop_preheader_edge (loop), init_code);
- remove_edges = XCNEWVEC (edge, max_unroll + n_peel + 1);
- n_remove_edges = 0;
+ remove_edges.create (0);
wont_exit = sbitmap_alloc (max_unroll + 2);
@@ -1037,14 +1067,14 @@ unroll_loop_runtime_iterations (struct loop *loop)
here; the only exception is when we have extra zero check and the number
of iterations is reliable. Also record the place of (possible) extra
zero check. */
- sbitmap_zero (wont_exit);
+ bitmap_clear (wont_exit);
if (extra_zero_check
&& !desc->noloop_assumptions)
- SET_BIT (wont_exit, 1);
+ bitmap_set_bit (wont_exit, 1);
ezc_swtch = loop_preheader_edge (loop)->src;
ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
1, wont_exit, desc->out_edge,
- remove_edges, &n_remove_edges,
+ &remove_edges,
DLTHE_FLAG_UPDATE_FREQ);
gcc_assert (ok);
@@ -1054,12 +1084,12 @@ unroll_loop_runtime_iterations (struct loop *loop)
for (i = 0; i < n_peel; i++)
{
/* Peel the copy. */
- sbitmap_zero (wont_exit);
+ bitmap_clear (wont_exit);
if (i != n_peel - 1 || !last_may_exit)
- SET_BIT (wont_exit, 1);
+ bitmap_set_bit (wont_exit, 1);
ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
1, wont_exit, desc->out_edge,
- remove_edges, &n_remove_edges,
+ &remove_edges,
DLTHE_FLAG_UPDATE_FREQ);
gcc_assert (ok);
@@ -1081,6 +1111,7 @@ unroll_loop_runtime_iterations (struct loop *loop)
single_pred_edge (swtch)->probability = REG_BR_PROB_BASE - p;
e = make_edge (swtch, preheader,
single_succ_edge (swtch)->flags & EDGE_IRREDUCIBLE_LOOP);
+ e->count = RDIV (preheader->count * REG_BR_PROB_BASE, p);
e->probability = p;
}
@@ -1100,28 +1131,29 @@ unroll_loop_runtime_iterations (struct loop *loop)
single_succ_edge (swtch)->probability = REG_BR_PROB_BASE - p;
e = make_edge (swtch, preheader,
single_succ_edge (swtch)->flags & EDGE_IRREDUCIBLE_LOOP);
+ e->count = RDIV (preheader->count * REG_BR_PROB_BASE, p);
e->probability = p;
}
/* Recount dominators for outer blocks. */
- iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, n_dom_bbs);
+ iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, false);
/* And unroll loop. */
- sbitmap_ones (wont_exit);
- RESET_BIT (wont_exit, may_exit_copy);
+ bitmap_ones (wont_exit);
+ bitmap_clear_bit (wont_exit, may_exit_copy);
opt_info_start_duplication (opt_info);
-
+
ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop),
max_unroll,
wont_exit, desc->out_edge,
- remove_edges, &n_remove_edges,
+ &remove_edges,
DLTHE_FLAG_UPDATE_FREQ
| (opt_info
? DLTHE_RECORD_COPY_NUMBER
: 0));
gcc_assert (ok);
-
+
if (opt_info)
{
apply_opt_in_copies (opt_info, max_unroll, true, true);
@@ -1135,7 +1167,7 @@ unroll_loop_runtime_iterations (struct loop *loop)
basic_block exit_block = get_bb_copy (desc->in_edge->src);
/* Find a new in and out edge; they are in the last copy we have
made. */
-
+
if (EDGE_SUCC (exit_block, 0)->dest == desc->out_edge->dest)
{
desc->out_edge = EDGE_SUCC (exit_block, 0);
@@ -1149,9 +1181,9 @@ unroll_loop_runtime_iterations (struct loop *loop)
}
/* Remove the edges. */
- for (i = 0; i < n_remove_edges; i++)
- remove_path (remove_edges[i]);
- free (remove_edges);
+ FOR_EACH_VEC_ELT (remove_edges, i, e)
+ remove_path (e);
+ remove_edges.release ();
/* We must be careful when updating the number of iterations due to
preconditioning and the fact that the value must be valid at entry
@@ -1161,13 +1193,26 @@ unroll_loop_runtime_iterations (struct loop *loop)
desc->niter_expr =
simplify_gen_binary (UDIV, desc->mode, old_niter,
GEN_INT (max_unroll + 1));
- desc->niter_max /= max_unroll + 1;
+ loop->nb_iterations_upper_bound
+ = loop->nb_iterations_upper_bound.udiv (double_int::from_uhwi (max_unroll
+ + 1),
+ TRUNC_DIV_EXPR);
+ if (loop->any_estimate)
+ loop->nb_iterations_estimate
+ = loop->nb_iterations_estimate.udiv (double_int::from_uhwi (max_unroll
+ + 1),
+ TRUNC_DIV_EXPR);
if (exit_at_end)
{
desc->niter_expr =
simplify_gen_binary (MINUS, desc->mode, desc->niter_expr, const1_rtx);
desc->noloop_assumptions = NULL_RTX;
- desc->niter_max--;
+ --loop->nb_iterations_upper_bound;
+ if (loop->any_estimate
+ && loop->nb_iterations_estimate != double_int_zero)
+ --loop->nb_iterations_estimate;
+ else
+ loop->any_estimate = false;
}
if (dump_file)
@@ -1176,8 +1221,7 @@ unroll_loop_runtime_iterations (struct loop *loop)
"in runtime, %i insns\n",
max_unroll, num_loop_insns (loop));
- if (dom_bbs)
- free (dom_bbs);
+ dom_bbs.release ();
}
/* Decide whether to simply peel LOOP and how much. */
@@ -1185,7 +1229,7 @@ static void
decide_peel_simple (struct loop *loop, int flags)
{
unsigned npeel;
- struct niter_desc *desc;
+ double_int iterations;
if (!(flags & UAP_PEEL))
{
@@ -1209,43 +1253,45 @@ decide_peel_simple (struct loop *loop, int flags)
return;
}
- /* Check for simple loops. */
- desc = get_simple_loop_desc (loop);
-
- /* Check number of iterations. */
- if (desc->simple_p && !desc->assumptions && desc->const_iter)
- {
- if (dump_file)
- fprintf (dump_file, ";; Loop iterates constant times\n");
- return;
- }
-
/* Do not simply peel loops with branches inside -- it increases number
- of mispredicts. */
- if (num_loop_branches (loop) > 1)
+ of mispredicts.
+ Exception is when we do have profile and we however have good chance
+ to peel proper number of iterations loop will iterate in practice.
+ TODO: this heuristic needs tunning; while for complette unrolling
+ the branch inside loop mostly eliminates any improvements, for
+ peeling it is not the case. Also a function call inside loop is
+ also branch from branch prediction POV (and probably better reason
+ to not unroll/peel). */
+ if (num_loop_branches (loop) > 1
+ && profile_status != PROFILE_READ)
{
if (dump_file)
fprintf (dump_file, ";; Not peeling, contains branches\n");
return;
}
- if (loop->header->count)
+ /* If we have realistic estimate on number of iterations, use it. */
+ if (estimated_loop_iterations (loop, &iterations))
{
- unsigned niter = expected_loop_iterations (loop);
- if (niter + 1 > npeel)
+ if (double_int::from_shwi (npeel).ule (iterations))
{
if (dump_file)
{
fprintf (dump_file, ";; Not peeling loop, rolls too much (");
fprintf (dump_file, HOST_WIDEST_INT_PRINT_DEC,
- (HOST_WIDEST_INT) (niter + 1));
+ (HOST_WIDEST_INT) (iterations.to_shwi () + 1));
fprintf (dump_file, " iterations > %d [maximum peelings])\n",
npeel);
}
return;
}
- npeel = niter + 1;
+ npeel = iterations.to_shwi () + 1;
}
+ /* If we have small enough bound on iterations, we can still peel (completely
+ unroll). */
+ else if (max_loop_iterations (loop, &iterations)
+ && iterations.ult (double_int::from_shwi (npeel)))
+ npeel = iterations.to_shwi () + 1;
else
{
/* For now we have no good heuristics to decide whether loop peeling
@@ -1259,22 +1305,25 @@ decide_peel_simple (struct loop *loop, int flags)
/* Success. */
loop->lpt_decision.decision = LPT_PEEL_SIMPLE;
loop->lpt_decision.times = npeel;
-
+
if (dump_file)
- fprintf (dump_file, ";; Decided to simply peel the loop, %d times.\n",
+ fprintf (dump_file, ";; Decided to simply peel the loop %d times.\n",
loop->lpt_decision.times);
}
-/* Peel a LOOP LOOP->LPT_DECISION.TIMES times. The transformation:
+/* Peel a LOOP LOOP->LPT_DECISION.TIMES times. The transformation does this:
+
while (cond)
body;
- ==>
+ ==> (LOOP->LPT_DECISION.TIMES == 3)
if (!cond) goto end;
body;
if (!cond) goto end;
body;
+ if (!cond) goto end;
+ body;
while (cond)
body;
end: ;
@@ -1287,18 +1336,17 @@ peel_loop_simple (struct loop *loop)
struct niter_desc *desc = get_simple_loop_desc (loop);
struct opt_info *opt_info = NULL;
bool ok;
-
+
if (flag_split_ivs_in_unroller && npeel > 1)
opt_info = analyze_insns_in_loop (loop);
-
+
wont_exit = sbitmap_alloc (npeel + 1);
- sbitmap_zero (wont_exit);
-
+ bitmap_clear (wont_exit);
+
opt_info_start_duplication (opt_info);
-
+
ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
- npeel, wont_exit,
- NULL, NULL,
+ npeel, wont_exit, NULL,
NULL, DLTHE_FLAG_UPDATE_FREQ
| (opt_info
? DLTHE_RECORD_COPY_NUMBER
@@ -1306,7 +1354,7 @@ peel_loop_simple (struct loop *loop)
gcc_assert (ok);
free (wont_exit);
-
+
if (opt_info)
{
apply_opt_in_copies (opt_info, npeel, false, false);
@@ -1340,6 +1388,7 @@ decide_unroll_stupid (struct loop *loop, int flags)
{
unsigned nunroll, nunroll_by_av, i;
struct niter_desc *desc;
+ double_int iterations;
if (!(flags & UAP_UNROLL_ALL))
{
@@ -1360,6 +1409,9 @@ decide_unroll_stupid (struct loop *loop, int flags)
if (nunroll > (unsigned) PARAM_VALUE (PARAM_MAX_UNROLL_TIMES))
nunroll = PARAM_VALUE (PARAM_MAX_UNROLL_TIMES);
+ if (targetm.loop_unroll_adjust)
+ nunroll = targetm.loop_unroll_adjust (nunroll, loop);
+
/* Skip big loops. */
if (nunroll <= 1)
{
@@ -1380,7 +1432,9 @@ decide_unroll_stupid (struct loop *loop, int flags)
}
/* Do not unroll loops with branches inside -- it increases number
- of mispredicts. */
+ of mispredicts.
+ TODO: this heuristic needs tunning; call inside the loop body
+ is also relatively good reason to not unroll. */
if (num_loop_branches (loop) > 1)
{
if (dump_file)
@@ -1388,9 +1442,10 @@ decide_unroll_stupid (struct loop *loop, int flags)
return;
}
- /* If we have profile feedback, check whether the loop rolls. */
- if (loop->header->count
- && expected_loop_iterations (loop) < 2 * nunroll)
+ /* Check whether the loop rolls. */
+ if ((estimated_loop_iterations (loop, &iterations)
+ || max_loop_iterations (loop, &iterations))
+ && iterations.ult (double_int::from_shwi (2 * nunroll)))
{
if (dump_file)
fprintf (dump_file, ";; Not unrolling loop, doesn't roll\n");
@@ -1405,18 +1460,18 @@ decide_unroll_stupid (struct loop *loop, int flags)
loop->lpt_decision.decision = LPT_UNROLL_STUPID;
loop->lpt_decision.times = i - 1;
-
+
if (dump_file)
- fprintf (dump_file,
- ";; Decided to unroll the loop stupidly, %d times.\n",
+ fprintf (dump_file, ";; Decided to unroll the loop stupidly %d times.\n",
loop->lpt_decision.times);
}
-/* Unroll a LOOP LOOP->LPT_DECISION.TIMES times. The transformation:
+/* Unroll a LOOP LOOP->LPT_DECISION.TIMES times. The transformation does this:
+
while (cond)
body;
- ==>
+ ==> (LOOP->LPT_DECISION.TIMES == 3)
while (cond)
{
@@ -1437,25 +1492,25 @@ unroll_loop_stupid (struct loop *loop)
struct niter_desc *desc = get_simple_loop_desc (loop);
struct opt_info *opt_info = NULL;
bool ok;
-
+
if (flag_split_ivs_in_unroller
|| flag_variable_expansion_in_unroller)
opt_info = analyze_insns_in_loop (loop);
-
-
+
+
wont_exit = sbitmap_alloc (nunroll + 1);
- sbitmap_zero (wont_exit);
+ bitmap_clear (wont_exit);
opt_info_start_duplication (opt_info);
-
+
ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop),
nunroll, wont_exit,
- NULL, NULL, NULL,
+ NULL, NULL,
DLTHE_FLAG_UPDATE_FREQ
| (opt_info
? DLTHE_RECORD_COPY_NUMBER
: 0));
gcc_assert (ok);
-
+
if (opt_info)
{
apply_opt_in_copies (opt_info, nunroll, true, true);
@@ -1485,7 +1540,7 @@ unroll_loop_stupid (struct loop *loop)
static hashval_t
si_info_hash (const void *ivts)
{
- return (hashval_t) INSN_UID (((struct iv_to_split *) ivts)->insn);
+ return (hashval_t) INSN_UID (((const struct iv_to_split *) ivts)->insn);
}
/* An equality functions for information about insns to split. */
@@ -1493,8 +1548,8 @@ si_info_hash (const void *ivts)
static int
si_info_eq (const void *ivts1, const void *ivts2)
{
- const struct iv_to_split *i1 = ivts1;
- const struct iv_to_split *i2 = ivts2;
+ const struct iv_to_split *const i1 = (const struct iv_to_split *) ivts1;
+ const struct iv_to_split *const i2 = (const struct iv_to_split *) ivts2;
return i1->insn == i2->insn;
}
@@ -1504,54 +1559,88 @@ si_info_eq (const void *ivts1, const void *ivts2)
static hashval_t
ve_info_hash (const void *ves)
{
- return (hashval_t) INSN_UID (((struct var_to_expand *) ves)->insn);
+ return (hashval_t) INSN_UID (((const struct var_to_expand *) ves)->insn);
}
-/* Return true if IVTS1 and IVTS2 (which are really both of type
+/* Return true if IVTS1 and IVTS2 (which are really both of type
"var_to_expand *") refer to the same instruction. */
static int
ve_info_eq (const void *ivts1, const void *ivts2)
{
- const struct var_to_expand *i1 = ivts1;
- const struct var_to_expand *i2 = ivts2;
-
+ const struct var_to_expand *const i1 = (const struct var_to_expand *) ivts1;
+ const struct var_to_expand *const i2 = (const struct var_to_expand *) ivts2;
+
return i1->insn == i2->insn;
}
-/* Returns true if REG is referenced in one insn in LOOP. */
+/* Returns true if REG is referenced in one nondebug insn in LOOP.
+ Set *DEBUG_USES to the number of debug insns that reference the
+ variable. */
bool
-referenced_in_one_insn_in_loop_p (struct loop *loop, rtx reg)
+referenced_in_one_insn_in_loop_p (struct loop *loop, rtx reg,
+ int *debug_uses)
{
basic_block *body, bb;
unsigned i;
int count_ref = 0;
rtx insn;
-
- body = get_loop_body (loop);
+
+ body = get_loop_body (loop);
for (i = 0; i < loop->num_nodes; i++)
{
bb = body[i];
-
+
FOR_BB_INSNS (bb, insn)
- {
- if (rtx_referenced_p (reg, insn))
- count_ref++;
- }
+ if (!rtx_referenced_p (reg, insn))
+ continue;
+ else if (DEBUG_INSN_P (insn))
+ ++*debug_uses;
+ else if (++count_ref > 1)
+ break;
}
+ free (body);
return (count_ref == 1);
}
+/* Reset the DEBUG_USES debug insns in LOOP that reference REG. */
+
+static void
+reset_debug_uses_in_loop (struct loop *loop, rtx reg, int debug_uses)
+{
+ basic_block *body, bb;
+ unsigned i;
+ rtx insn;
+
+ body = get_loop_body (loop);
+ for (i = 0; debug_uses && i < loop->num_nodes; i++)
+ {
+ bb = body[i];
+
+ FOR_BB_INSNS (bb, insn)
+ if (!DEBUG_INSN_P (insn) || !rtx_referenced_p (reg, insn))
+ continue;
+ else
+ {
+ validate_change (insn, &INSN_VAR_LOCATION_LOC (insn),
+ gen_rtx_UNKNOWN_VAR_LOC (), 0);
+ if (!--debug_uses)
+ break;
+ }
+ }
+ free (body);
+}
+
/* Determine whether INSN contains an accumulator
- which can be expanded into separate copies,
+ which can be expanded into separate copies,
one for each copy of the LOOP body.
-
+
for (i = 0 ; i < n; i++)
sum += a[i];
-
+
==>
-
+
sum += a[i]
....
i = i+1;
@@ -1561,30 +1650,40 @@ referenced_in_one_insn_in_loop_p (struct loop *loop, rtx reg)
sum2 += a[i];
....
- Return NULL if INSN contains no opportunity for expansion of accumulator.
- Otherwise, allocate a VAR_TO_EXPAND structure, fill it with the relevant
+ Return NULL if INSN contains no opportunity for expansion of accumulator.
+ Otherwise, allocate a VAR_TO_EXPAND structure, fill it with the relevant
information and return a pointer to it.
*/
static struct var_to_expand *
analyze_insn_to_expand_var (struct loop *loop, rtx insn)
{
- rtx set, dest, src, op1;
+ rtx set, dest, src;
struct var_to_expand *ves;
- enum machine_mode mode1, mode2;
-
+ unsigned accum_pos;
+ enum rtx_code code;
+ int debug_uses = 0;
+
set = single_set (insn);
if (!set)
return NULL;
-
+
dest = SET_DEST (set);
src = SET_SRC (set);
-
- if (GET_CODE (src) != PLUS
- && GET_CODE (src) != MINUS
- && GET_CODE (src) != MULT)
+ code = GET_CODE (src);
+
+ if (code != PLUS && code != MINUS && code != MULT && code != FMA)
return NULL;
+ if (FLOAT_MODE_P (GET_MODE (dest)))
+ {
+ if (!flag_associative_math)
+ return NULL;
+ /* In the case of FMA, we're also changing the rounding. */
+ if (code == FMA && !flag_unsafe_math_optimizations)
+ return NULL;
+ }
+
/* Hmm, this is a bit paradoxical. We know that INSN is a valid insn
in MD. But if there is no optab to generate the insn, we can not
perform the variable expansion. This can happen if an MD provides
@@ -1594,48 +1693,83 @@ analyze_insn_to_expand_var (struct loop *loop, rtx insn)
So we check have_insn_for which looks for an optab for the operation
in SRC. If it doesn't exist, we can't perform the expansion even
though INSN is valid. */
- if (!have_insn_for (GET_CODE (src), GET_MODE (src)))
+ if (!have_insn_for (code, GET_MODE (src)))
return NULL;
- if (!XEXP (src, 0))
- return NULL;
-
- op1 = XEXP (src, 0);
-
if (!REG_P (dest)
&& !(GET_CODE (dest) == SUBREG
&& REG_P (SUBREG_REG (dest))))
return NULL;
-
- if (!rtx_equal_p (dest, op1))
- return NULL;
-
- if (!referenced_in_one_insn_in_loop_p (loop, dest))
+
+ /* Find the accumulator use within the operation. */
+ if (code == FMA)
+ {
+ /* We only support accumulation via FMA in the ADD position. */
+ if (!rtx_equal_p (dest, XEXP (src, 2)))
+ return NULL;
+ accum_pos = 2;
+ }
+ else if (rtx_equal_p (dest, XEXP (src, 0)))
+ accum_pos = 0;
+ else if (rtx_equal_p (dest, XEXP (src, 1)))
+ {
+ /* The method of expansion that we are using; which includes the
+ initialization of the expansions with zero and the summation of
+ the expansions at the end of the computation will yield wrong
+ results for (x = something - x) thus avoid using it in that case. */
+ if (code == MINUS)
+ return NULL;
+ accum_pos = 1;
+ }
+ else
return NULL;
-
- if (rtx_referenced_p (dest, XEXP (src, 1)))
+
+ /* It must not otherwise be used. */
+ if (code == FMA)
+ {
+ if (rtx_referenced_p (dest, XEXP (src, 0))
+ || rtx_referenced_p (dest, XEXP (src, 1)))
+ return NULL;
+ }
+ else if (rtx_referenced_p (dest, XEXP (src, 1 - accum_pos)))
return NULL;
-
- mode1 = GET_MODE (dest);
- mode2 = GET_MODE (XEXP (src, 1));
- if ((FLOAT_MODE_P (mode1)
- || FLOAT_MODE_P (mode2))
- && !flag_unsafe_math_optimizations)
+
+ /* It must be used in exactly one insn. */
+ if (!referenced_in_one_insn_in_loop_p (loop, dest, &debug_uses))
return NULL;
-
+
+ if (dump_file)
+ {
+ fprintf (dump_file, "\n;; Expanding Accumulator ");
+ print_rtl (dump_file, dest);
+ fprintf (dump_file, "\n");
+ }
+
+ if (debug_uses)
+ /* Instead of resetting the debug insns, we could replace each
+ debug use in the loop with the sum or product of all expanded
+ accummulators. Since we'll only know of all expansions at the
+ end, we'd have to keep track of which vars_to_expand a debug
+ insn in the loop references, take note of each copy of the
+ debug insn during unrolling, and when it's all done, compute
+ the sum or product of each variable and adjust the original
+ debug insn and each copy thereof. What a pain! */
+ reset_debug_uses_in_loop (loop, dest, debug_uses);
+
/* Record the accumulator to expand. */
ves = XNEW (struct var_to_expand);
ves->insn = insn;
- ves->var_expansions = VEC_alloc (rtx, heap, 1);
ves->reg = copy_rtx (dest);
+ ves->var_expansions.create (1);
+ ves->next = NULL;
ves->op = GET_CODE (src);
ves->expansion_count = 0;
ves->reuse_expansion = 0;
- return ves;
+ return ves;
}
/* Determine whether there is an induction variable in INSN that
- we would like to split during unrolling.
+ we would like to split during unrolling.
I.e. replace
@@ -1655,7 +1789,7 @@ analyze_insn_to_expand_var (struct loop *loop, rtx insn)
i = i0 + 2
...
- Return NULL if INSN contains no interesting IVs. Otherwise, allocate
+ Return NULL if INSN contains no interesting IVs. Otherwise, allocate
an IV_TO_SPLIT structure, fill it with the relevant information and return a
pointer to it. */
@@ -1700,11 +1834,13 @@ analyze_iv_to_split_insn (rtx insn)
/* Record the insn to split. */
ivts = XNEW (struct iv_to_split);
ivts->insn = insn;
+ ivts->orig_var = dest;
ivts->base_var = NULL_RTX;
ivts->step = iv.step;
+ ivts->next = NULL;
ivts->n_loc = 1;
ivts->loc[0] = 1;
-
+
return ivts;
}
@@ -1724,36 +1860,45 @@ analyze_insns_in_loop (struct loop *loop)
struct var_to_expand *ves = NULL;
PTR *slot1;
PTR *slot2;
- VEC (edge, heap) *edges = get_loop_exit_edges (loop);
+ vec edges = get_loop_exit_edges (loop);
edge exit;
bool can_apply = false;
-
+
iv_analysis_loop_init (loop);
body = get_loop_body (loop);
if (flag_split_ivs_in_unroller)
- opt_info->insns_to_split = htab_create (5 * loop->num_nodes,
- si_info_hash, si_info_eq, free);
-
+ {
+ opt_info->insns_to_split = htab_create (5 * loop->num_nodes,
+ si_info_hash, si_info_eq, free);
+ opt_info->iv_to_split_head = NULL;
+ opt_info->iv_to_split_tail = &opt_info->iv_to_split_head;
+ }
+
/* Record the loop exit bb and loop preheader before the unrolling. */
opt_info->loop_preheader = loop_preheader_edge (loop)->src;
-
- if (VEC_length (edge, edges) == 1)
+
+ if (edges.length () == 1)
{
- exit = VEC_index (edge, edges, 0);
+ exit = edges[0];
if (!(exit->flags & EDGE_COMPLEX))
{
opt_info->loop_exit = split_edge (exit);
can_apply = true;
}
}
-
+
if (flag_variable_expansion_in_unroller
&& can_apply)
- opt_info->insns_with_var_to_expand = htab_create (5 * loop->num_nodes,
- ve_info_hash, ve_info_eq, free);
-
+ {
+ opt_info->insns_with_var_to_expand = htab_create (5 * loop->num_nodes,
+ ve_info_hash,
+ ve_info_eq, free);
+ opt_info->var_to_expand_head = NULL;
+ opt_info->var_to_expand_tail = &opt_info->var_to_expand_head;
+ }
+
for (i = 0; i < loop->num_nodes; i++)
{
bb = body[i];
@@ -1764,29 +1909,35 @@ analyze_insns_in_loop (struct loop *loop)
{
if (!INSN_P (insn))
continue;
-
+
if (opt_info->insns_to_split)
ivts = analyze_iv_to_split_insn (insn);
-
+
if (ivts)
{
slot1 = htab_find_slot (opt_info->insns_to_split, ivts, INSERT);
+ gcc_assert (*slot1 == NULL);
*slot1 = ivts;
+ *opt_info->iv_to_split_tail = ivts;
+ opt_info->iv_to_split_tail = &ivts->next;
continue;
}
-
+
if (opt_info->insns_with_var_to_expand)
ves = analyze_insn_to_expand_var (loop, insn);
-
+
if (ves)
{
slot2 = htab_find_slot (opt_info->insns_with_var_to_expand, ves, INSERT);
+ gcc_assert (*slot2 == NULL);
*slot2 = ves;
+ *opt_info->var_to_expand_tail = ves;
+ opt_info->var_to_expand_tail = &ves->next;
}
}
}
-
- VEC_free (edge, heap, edges);
+
+ edges.release ();
free (body);
return opt_info;
}
@@ -1794,7 +1945,7 @@ analyze_insns_in_loop (struct loop *loop)
/* Called just before loop duplication. Records start of duplicated area
to OPT_INFO. */
-static void
+static void
opt_info_start_duplication (struct opt_info *opt_info)
{
if (opt_info)
@@ -1841,18 +1992,14 @@ get_ivts_expr (rtx expr, struct iv_to_split *ivts)
return ret;
}
-/* Allocate basic variable for the induction variable chain. Callback for
- htab_traverse. */
+/* Allocate basic variable for the induction variable chain. */
-static int
-allocate_basic_variable (void **slot, void *data ATTRIBUTE_UNUSED)
+static void
+allocate_basic_variable (struct iv_to_split *ivts)
{
- struct iv_to_split *ivts = *slot;
rtx expr = *get_ivts_expr (single_set (ivts->insn), ivts);
ivts->base_var = gen_reg_rtx (GET_MODE (expr));
-
- return 1;
}
/* Insert initialization of basic variable of IVTS before INSN, taking
@@ -1911,7 +2058,7 @@ split_iv (struct iv_to_split *ivts, rtx insn, unsigned delta)
seq = get_insns ();
end_sequence ();
emit_insn_before (seq, insn);
-
+
if (validate_change (insn, loc, var, 0))
return;
@@ -1929,7 +2076,7 @@ split_iv (struct iv_to_split *ivts, rtx insn, unsigned delta)
emit_move_insn (dest, src);
seq = get_insns ();
end_sequence ();
-
+
emit_insn_before (seq, insn);
delete_insn (insn);
}
@@ -1941,22 +2088,22 @@ static rtx
get_expansion (struct var_to_expand *ve)
{
rtx reg;
-
+
if (ve->reuse_expansion == 0)
reg = ve->reg;
else
- reg = VEC_index (rtx, ve->var_expansions, ve->reuse_expansion - 1);
-
- if (VEC_length (rtx, ve->var_expansions) == (unsigned) ve->reuse_expansion)
+ reg = ve->var_expansions[ve->reuse_expansion - 1];
+
+ if (ve->var_expansions.length () == (unsigned) ve->reuse_expansion)
ve->reuse_expansion = 0;
- else
+ else
ve->reuse_expansion++;
-
+
return reg;
}
-/* Given INSN replace the uses of the accumulator recorded in VE
+/* Given INSN replace the uses of the accumulator recorded in VE
with a new register. */
static void
@@ -1964,10 +2111,10 @@ expand_var_during_unrolling (struct var_to_expand *ve, rtx insn)
{
rtx new_reg, set;
bool really_new_expansion = false;
-
+
set = single_set (insn);
gcc_assert (set);
-
+
/* Generate a new register only if the expansion limit has not been
reached. Else reuse an already existing expansion. */
if (PARAM_VALUE (PARAM_MAX_VARIABLE_EXPANSIONS) > ve->expansion_count)
@@ -1978,118 +2125,174 @@ expand_var_during_unrolling (struct var_to_expand *ve, rtx insn)
else
new_reg = get_expansion (ve);
- validate_change (insn, &SET_DEST (set), new_reg, 1);
- validate_change (insn, &XEXP (SET_SRC (set), 0), new_reg, 1);
-
+ validate_replace_rtx_group (SET_DEST (set), new_reg, insn);
if (apply_change_group ())
if (really_new_expansion)
{
- VEC_safe_push (rtx, heap, ve->var_expansions, new_reg);
+ ve->var_expansions.safe_push (new_reg);
ve->expansion_count++;
}
}
-/* Initialize the variable expansions in loop preheader.
- Callbacks for htab_traverse. PLACE_P is the loop-preheader
- basic block where the initialization of the expansions
- should take place. */
+/* Initialize the variable expansions in loop preheader. PLACE is the
+ loop-preheader basic block where the initialization of the
+ expansions should take place. The expansions are initialized with
+ (-0) when the operation is plus or minus to honor sign zero. This
+ way we can prevent cases where the sign of the final result is
+ effected by the sign of the expansion. Here is an example to
+ demonstrate this:
-static int
-insert_var_expansion_initialization (void **slot, void *place_p)
+ for (i = 0 ; i < n; i++)
+ sum += something;
+
+ ==>
+
+ sum += something
+ ....
+ i = i+1;
+ sum1 += something
+ ....
+ i = i+1
+ sum2 += something;
+ ....
+
+ When SUM is initialized with -zero and SOMETHING is also -zero; the
+ final result of sum should be -zero thus the expansions sum1 and sum2
+ should be initialized with -zero as well (otherwise we will get +zero
+ as the final result). */
+
+static void
+insert_var_expansion_initialization (struct var_to_expand *ve,
+ basic_block place)
{
- struct var_to_expand *ve = *slot;
- basic_block place = (basic_block)place_p;
- rtx seq, var, zero_init, insn;
+ rtx seq, var, zero_init;
unsigned i;
-
- if (VEC_length (rtx, ve->var_expansions) == 0)
- return 1;
-
+ enum machine_mode mode = GET_MODE (ve->reg);
+ bool honor_signed_zero_p = HONOR_SIGNED_ZEROS (mode);
+
+ if (ve->var_expansions.length () == 0)
+ return;
+
start_sequence ();
- if (ve->op == PLUS || ve->op == MINUS)
- for (i = 0; VEC_iterate (rtx, ve->var_expansions, i, var); i++)
- {
- zero_init = CONST0_RTX (GET_MODE (var));
- emit_move_insn (var, zero_init);
- }
- else if (ve->op == MULT)
- for (i = 0; VEC_iterate (rtx, ve->var_expansions, i, var); i++)
- {
- zero_init = CONST1_RTX (GET_MODE (var));
- emit_move_insn (var, zero_init);
- }
-
+ switch (ve->op)
+ {
+ case FMA:
+ /* Note that we only accumulate FMA via the ADD operand. */
+ case PLUS:
+ case MINUS:
+ FOR_EACH_VEC_ELT (ve->var_expansions, i, var)
+ {
+ if (honor_signed_zero_p)
+ zero_init = simplify_gen_unary (NEG, mode, CONST0_RTX (mode), mode);
+ else
+ zero_init = CONST0_RTX (mode);
+ emit_move_insn (var, zero_init);
+ }
+ break;
+
+ case MULT:
+ FOR_EACH_VEC_ELT (ve->var_expansions, i, var)
+ {
+ zero_init = CONST1_RTX (GET_MODE (var));
+ emit_move_insn (var, zero_init);
+ }
+ break;
+
+ default:
+ gcc_unreachable ();
+ }
+
seq = get_insns ();
end_sequence ();
-
- insn = BB_HEAD (place);
- while (!NOTE_INSN_BASIC_BLOCK_P (insn))
- insn = NEXT_INSN (insn);
-
- emit_insn_after (seq, insn);
- /* Continue traversing the hash table. */
- return 1;
+
+ emit_insn_after (seq, BB_END (place));
}
-/* Combine the variable expansions at the loop exit.
- Callbacks for htab_traverse. PLACE_P is the loop exit
- basic block where the summation of the expansions should
- take place. */
+/* Combine the variable expansions at the loop exit. PLACE is the
+ loop exit basic block where the summation of the expansions should
+ take place. */
-static int
-combine_var_copies_in_loop_exit (void **slot, void *place_p)
+static void
+combine_var_copies_in_loop_exit (struct var_to_expand *ve, basic_block place)
{
- struct var_to_expand *ve = *slot;
- basic_block place = (basic_block)place_p;
rtx sum = ve->reg;
rtx expr, seq, var, insn;
unsigned i;
- if (VEC_length (rtx, ve->var_expansions) == 0)
- return 1;
-
+ if (ve->var_expansions.length () == 0)
+ return;
+
start_sequence ();
- if (ve->op == PLUS || ve->op == MINUS)
- for (i = 0; VEC_iterate (rtx, ve->var_expansions, i, var); i++)
- {
- sum = simplify_gen_binary (PLUS, GET_MODE (ve->reg),
- var, sum);
- }
- else if (ve->op == MULT)
- for (i = 0; VEC_iterate (rtx, ve->var_expansions, i, var); i++)
- {
- sum = simplify_gen_binary (MULT, GET_MODE (ve->reg),
- var, sum);
- }
-
+ switch (ve->op)
+ {
+ case FMA:
+ /* Note that we only accumulate FMA via the ADD operand. */
+ case PLUS:
+ case MINUS:
+ FOR_EACH_VEC_ELT (ve->var_expansions, i, var)
+ sum = simplify_gen_binary (PLUS, GET_MODE (ve->reg), var, sum);
+ break;
+
+ case MULT:
+ FOR_EACH_VEC_ELT (ve->var_expansions, i, var)
+ sum = simplify_gen_binary (MULT, GET_MODE (ve->reg), var, sum);
+ break;
+
+ default:
+ gcc_unreachable ();
+ }
+
expr = force_operand (sum, ve->reg);
if (expr != ve->reg)
emit_move_insn (ve->reg, expr);
seq = get_insns ();
end_sequence ();
-
+
insn = BB_HEAD (place);
while (!NOTE_INSN_BASIC_BLOCK_P (insn))
insn = NEXT_INSN (insn);
emit_insn_after (seq, insn);
-
- /* Continue traversing the hash table. */
- return 1;
}
-/* Apply loop optimizations in loop copies using the
- data which gathered during the unrolling. Structure
+/* Strip away REG_EQUAL notes for IVs we're splitting.
+
+ Updating REG_EQUAL notes for IVs we split is tricky: We
+ cannot tell until after unrolling, DF-rescanning, and liveness
+ updating, whether an EQ_USE is reached by the split IV while
+ the IV reg is still live. See PR55006.
+
+ ??? We cannot use remove_reg_equal_equiv_notes_for_regno,
+ because RTL loop-iv requires us to defer rescanning insns and
+ any notes attached to them. So resort to old techniques... */
+
+static void
+maybe_strip_eq_note_for_split_iv (struct opt_info *opt_info, rtx insn)
+{
+ struct iv_to_split *ivts;
+ rtx note = find_reg_equal_equiv_note (insn);
+ if (! note)
+ return;
+ for (ivts = opt_info->iv_to_split_head; ivts; ivts = ivts->next)
+ if (reg_mentioned_p (ivts->orig_var, note))
+ {
+ remove_note (insn, note);
+ return;
+ }
+}
+
+/* Apply loop optimizations in loop copies using the
+ data which gathered during the unrolling. Structure
OPT_INFO record that data.
-
+
UNROLLING is true if we unrolled (not peeled) the loop.
REWRITE_ORIGINAL_BODY is true if we should also rewrite the original body of
the loop (as it should happen in complete unrolling, but not in ordinary
peeling of the loop). */
static void
-apply_opt_in_copies (struct opt_info *opt_info,
- unsigned n_copies, bool unrolling,
+apply_opt_in_copies (struct opt_info *opt_info,
+ unsigned n_copies, bool unrolling,
bool rewrite_original_loop)
{
unsigned i, delta;
@@ -2097,48 +2300,56 @@ apply_opt_in_copies (struct opt_info *opt_info,
rtx insn, orig_insn, next;
struct iv_to_split ivts_templ, *ivts;
struct var_to_expand ve_templ, *ves;
-
+
/* Sanity check -- we need to put initialization in the original loop
body. */
gcc_assert (!unrolling || rewrite_original_loop);
-
+
/* Allocate the basic variables (i0). */
if (opt_info->insns_to_split)
- htab_traverse (opt_info->insns_to_split, allocate_basic_variable, NULL);
-
+ for (ivts = opt_info->iv_to_split_head; ivts; ivts = ivts->next)
+ allocate_basic_variable (ivts);
+
for (i = opt_info->first_new_block; i < (unsigned) last_basic_block; i++)
{
bb = BASIC_BLOCK (i);
orig_bb = get_bb_original (bb);
-
+
/* bb->aux holds position in copy sequence initialized by
duplicate_loop_to_header_edge. */
delta = determine_split_iv_delta ((size_t)bb->aux, n_copies,
unrolling);
bb->aux = 0;
orig_insn = BB_HEAD (orig_bb);
- for (insn = BB_HEAD (bb); insn != NEXT_INSN (BB_END (bb)); insn = next)
+ FOR_BB_INSNS_SAFE (bb, insn, next)
{
- next = NEXT_INSN (insn);
- if (!INSN_P (insn))
+ if (!INSN_P (insn)
+ || (DEBUG_INSN_P (insn)
+ && TREE_CODE (INSN_VAR_LOCATION_DECL (insn)) == LABEL_DECL))
continue;
-
- while (!INSN_P (orig_insn))
+
+ while (!INSN_P (orig_insn)
+ || (DEBUG_INSN_P (orig_insn)
+ && (TREE_CODE (INSN_VAR_LOCATION_DECL (orig_insn))
+ == LABEL_DECL)))
orig_insn = NEXT_INSN (orig_insn);
-
+
ivts_templ.insn = orig_insn;
ve_templ.insn = orig_insn;
-
+
/* Apply splitting iv optimization. */
if (opt_info->insns_to_split)
{
- ivts = htab_find (opt_info->insns_to_split, &ivts_templ);
-
+ maybe_strip_eq_note_for_split_iv (opt_info, insn);
+
+ ivts = (struct iv_to_split *)
+ htab_find (opt_info->insns_to_split, &ivts_templ);
+
if (ivts)
{
gcc_assert (GET_CODE (PATTERN (insn))
== GET_CODE (PATTERN (orig_insn)));
-
+
if (!delta)
insert_base_initialization (ivts, insn);
split_iv (ivts, insn, delta);
@@ -2147,9 +2358,10 @@ apply_opt_in_copies (struct opt_info *opt_info,
/* Apply variable expansion optimization. */
if (unrolling && opt_info->insns_with_var_to_expand)
{
- ves = htab_find (opt_info->insns_with_var_to_expand, &ve_templ);
+ ves = (struct var_to_expand *)
+ htab_find (opt_info->insns_with_var_to_expand, &ve_templ);
if (ves)
- {
+ {
gcc_assert (GET_CODE (PATTERN (insn))
== GET_CODE (PATTERN (orig_insn)));
expand_var_during_unrolling (ves, insn);
@@ -2161,19 +2373,17 @@ apply_opt_in_copies (struct opt_info *opt_info,
if (!rewrite_original_loop)
return;
-
+
/* Initialize the variable expansions in the loop preheader
- and take care of combining them at the loop exit. */
+ and take care of combining them at the loop exit. */
if (opt_info->insns_with_var_to_expand)
{
- htab_traverse (opt_info->insns_with_var_to_expand,
- insert_var_expansion_initialization,
- opt_info->loop_preheader);
- htab_traverse (opt_info->insns_with_var_to_expand,
- combine_var_copies_in_loop_exit,
- opt_info->loop_exit);
+ for (ves = opt_info->var_to_expand_head; ves; ves = ves->next)
+ insert_var_expansion_initialization (ves, opt_info->loop_preheader);
+ for (ves = opt_info->var_to_expand_head; ves; ves = ves->next)
+ combine_var_copies_in_loop_exit (ves, opt_info->loop_exit);
}
-
+
/* Rewrite also the original loop body. Find them as originals of the blocks
in the last copied iteration, i.e. those that have
get_bb_copy (get_bb_original (bb)) == bb. */
@@ -2183,21 +2393,24 @@ apply_opt_in_copies (struct opt_info *opt_info,
orig_bb = get_bb_original (bb);
if (get_bb_copy (orig_bb) != bb)
continue;
-
+
delta = determine_split_iv_delta (0, n_copies, unrolling);
for (orig_insn = BB_HEAD (orig_bb);
orig_insn != NEXT_INSN (BB_END (bb));
orig_insn = next)
{
next = NEXT_INSN (orig_insn);
-
+
if (!INSN_P (orig_insn))
continue;
-
+
ivts_templ.insn = orig_insn;
if (opt_info->insns_to_split)
{
- ivts = htab_find (opt_info->insns_to_split, &ivts_templ);
+ maybe_strip_eq_note_for_split_iv (opt_info, orig_insn);
+
+ ivts = (struct iv_to_split *)
+ htab_find (opt_info->insns_to_split, &ivts_templ);
if (ivts)
{
if (!delta)
@@ -2206,25 +2419,11 @@ apply_opt_in_copies (struct opt_info *opt_info,
continue;
}
}
-
+
}
}
}
-/* Release the data structures used for the variable expansion
- optimization. Callbacks for htab_traverse. */
-
-static int
-release_var_copies (void **slot, void *data ATTRIBUTE_UNUSED)
-{
- struct var_to_expand *ve = *slot;
-
- VEC_free (rtx, heap, ve->var_expansions);
-
- /* Continue traversing the hash table. */
- return 1;
-}
-
/* Release OPT_INFO. */
static void
@@ -2234,8 +2433,10 @@ free_opt_info (struct opt_info *opt_info)
htab_delete (opt_info->insns_to_split);
if (opt_info->insns_with_var_to_expand)
{
- htab_traverse (opt_info->insns_with_var_to_expand,
- release_var_copies, NULL);
+ struct var_to_expand *ves;
+
+ for (ves = opt_info->var_to_expand_head; ves; ves = ves->next)
+ ves->var_expansions.release ();
htab_delete (opt_info->insns_with_var_to_expand);
}
free (opt_info);