the accumulator. If REUSE_EXPANSION is 0 reuse
the original accumulator. Else use
var_expansions[REUSE_EXPANSION - 1]. */
+ unsigned accum_pos; /* The position in which the accumulator is placed in
+ the insn src. For example in x = x + something
+ accum_pos is 0 while in x = something + x accum_pos
+ is 1. */
};
/* Information about optimization applied in
basic_block loop_preheader; /* The loop preheader basic block. */
};
-static void decide_unrolling_and_peeling (struct loops *, int);
-static void peel_loops_completely (struct loops *, int);
+static void decide_unrolling_and_peeling (int);
+static void peel_loops_completely (int);
static void decide_peel_simple (struct loop *, int);
static void decide_peel_once_rolling (struct loop *, int);
static void decide_peel_completely (struct loop *, int);
static void decide_unroll_stupid (struct loop *, int);
static void decide_unroll_constant_iterations (struct loop *, int);
static void decide_unroll_runtime_iterations (struct loop *, int);
-static void peel_loop_simple (struct loops *, struct loop *);
-static void peel_loop_completely (struct loops *, struct loop *);
-static void unroll_loop_stupid (struct loops *, struct loop *);
-static void unroll_loop_constant_iterations (struct loops *, struct loop *);
-static void unroll_loop_runtime_iterations (struct loops *, struct loop *);
+static void peel_loop_simple (struct loop *);
+static void peel_loop_completely (struct loop *);
+static void unroll_loop_stupid (struct loop *);
+static void unroll_loop_constant_iterations (struct loop *);
+static void unroll_loop_runtime_iterations (struct loop *);
static struct opt_info *analyze_insns_in_loop (struct loop *);
static void opt_info_start_duplication (struct opt_info *);
static void apply_opt_in_copies (struct opt_info *, unsigned, bool, bool);
/* Unroll and/or peel (depending on FLAGS) LOOPS. */
void
-unroll_and_peel_loops (struct loops *loops, int flags)
+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). */
- peel_loops_completely (loops, flags);
+ peel_loops_completely (flags);
/* Now decide rest of unrolling and peeling. */
- decide_unrolling_and_peeling (loops, flags);
-
- loop = loops->tree_root;
- while (loop->inner)
- loop = loop->inner;
+ decide_unrolling_and_peeling (flags);
/* Scan the loops, inner ones first. */
- while (loop != 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)
/* Already done. */
gcc_unreachable ();
case LPT_PEEL_SIMPLE:
- peel_loop_simple (loops, loop);
+ peel_loop_simple (loop);
break;
case LPT_UNROLL_CONSTANT:
- unroll_loop_constant_iterations (loops, loop);
+ unroll_loop_constant_iterations (loop);
break;
case LPT_UNROLL_RUNTIME:
- unroll_loop_runtime_iterations (loops, loop);
+ unroll_loop_runtime_iterations (loop);
break;
case LPT_UNROLL_STUPID:
- unroll_loop_stupid (loops, loop);
+ unroll_loop_stupid (loop);
break;
case LPT_NONE:
check = false;
{
#ifdef ENABLE_CHECKING
verify_dominators (CDI_DOMINATORS);
- verify_loop_structure (loops);
+ verify_loop_structure ();
#endif
}
- loop = next;
}
iv_analysis_done ();
return true;
}
-/* Check whether to peel LOOPS (depending on FLAGS) completely and do so. */
+/* Depending on FLAGS, check whether to peel loops completely and do so. */
static void
-peel_loops_completely (struct loops *loops, int flags)
+peel_loops_completely (int flags)
{
- struct loop *loop, *next;
-
- loop = loops->tree_root;
- while (loop->inner)
- loop = loop->inner;
+ struct loop *loop;
+ loop_iterator li;
- while (loop != loops->tree_root)
+ /* Scan the loops, the inner ones first. */
+ 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)
if (loop->lpt_decision.decision == LPT_PEEL_COMPLETELY)
{
- peel_loop_completely (loops, loop);
+ peel_loop_completely (loop);
#ifdef ENABLE_CHECKING
verify_dominators (CDI_DOMINATORS);
- verify_loop_structure (loops);
+ verify_loop_structure ();
#endif
}
- loop = next;
}
}
-/* Decide whether unroll or peel LOOPS (depending on FLAGS) and how much. */
+/* Decide whether unroll or peel loops (depending on FLAGS) and how much. */
static void
-decide_unrolling_and_peeling (struct loops *loops, int flags)
+decide_unrolling_and_peeling (int flags)
{
- struct loop *loop = loops->tree_root, *next;
-
- while (loop->inner)
- loop = loop->inner;
+ struct loop *loop;
+ loop_iterator li;
/* Scan the loops, inner ones first. */
- while (loop != 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)
{
if (dump_file)
fprintf (dump_file, ";; Not considering loop, cold area\n");
- loop = next;
continue;
}
if (dump_file)
fprintf (dump_file,
";; Not considering loop, cannot duplicate\n");
- loop = next;
continue;
}
{
if (dump_file)
fprintf (dump_file, ";; Not considering loop, is not innermost\n");
- loop = next;
continue;
}
decide_unroll_stupid (loop, flags);
if (loop->lpt_decision.decision == LPT_NONE)
decide_peel_simple (loop, flags);
-
- loop = next;
}
}
body; i++;
*/
static void
-peel_loop_completely (struct loops *loops, struct loop *loop)
+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 (edge, heap) *remove_edges;
+ edge ein;
struct niter_desc *desc = get_simple_loop_desc (loop);
struct opt_info *opt_info = NULL;
if (desc->noloop_assumptions)
RESET_BIT (wont_exit, 1);
- remove_edges = XCNEWVEC (edge, npeel);
- n_remove_edges = 0;
+ remove_edges = NULL;
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),
- loops, npeel,
+ npeel,
wont_exit, desc->out_edge,
- remove_edges, &n_remove_edges,
+ &remove_edges,
DLTHE_FLAG_UPDATE_FREQ
| DLTHE_FLAG_COMPLETTE_PEEL
| (opt_info
}
/* Remove the exit edges. */
- for (i = 0; i < n_remove_edges; i++)
- remove_path (loops, remove_edges[i]);
- free (remove_edges);
+ for (i = 0; VEC_iterate (edge, remove_edges, i, ein); i++)
+ remove_path (ein);
+ VEC_free (edge, heap, remove_edges);
}
ein = desc->in_edge;
/* Now remove the unreachable part of the last iteration and cancel
the loop. */
- remove_path (loops, ein);
+ remove_path (ein);
if (dump_file)
fprintf (dump_file, ";; Peeled loop completely, %d times\n", (int) npeel);
}
*/
static void
-unroll_loop_constant_iterations (struct loops *loops, struct loop *loop)
+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 (edge, heap) *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);
wont_exit = sbitmap_alloc (max_unroll + 1);
sbitmap_ones (wont_exit);
- remove_edges = XCNEWVEC (edge, max_unroll + exit_mod + 1);
- n_remove_edges = 0;
+ remove_edges = NULL;
if (flag_split_ivs_in_unroller
|| flag_variable_expansion_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),
- loops, exit_mod,
+ 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
opt_info_start_duplication (opt_info);
ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
- loops, exit_mod + 1,
+ 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
opt_info_start_duplication (opt_info);
ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop),
- loops, max_unroll,
+ max_unroll,
wont_exit, desc->out_edge,
- remove_edges, &n_remove_edges,
+ &remove_edges,
DLTHE_FLAG_UPDATE_FREQ
| (opt_info
? DLTHE_RECORD_COPY_NUMBER
desc->niter_expr = GEN_INT (desc->niter);
/* Remove the edges. */
- for (i = 0; i < n_remove_edges; i++)
- remove_path (loops, remove_edges[i]);
- free (remove_edges);
+ for (i = 0; VEC_iterate (edge, remove_edges, i, e); i++)
+ remove_path (e);
+ VEC_free (edge, heap, remove_edges);
if (dump_file)
fprintf (dump_file,
loop->lpt_decision.times);
}
+/* Splits edge E and inserts the sequence of instructions INSNS on it, and
+ returns the newly created block. If INSNS is NULL_RTX, nothing is changed
+ and NULL is returned instead. */
+
+basic_block
+split_edge_and_insert (edge e, rtx insns)
+{
+ basic_block bb;
+
+ if (!insns)
+ return NULL;
+ bb = split_edge (e);
+ emit_insn_after (insns, BB_END (bb));
+
+ /* ??? 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 verify_flow_info call in loop_optimizer_finalize 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
extra care for case n < 0):
}
*/
static void
-unroll_loop_runtime_iterations (struct loops *loops, struct loop *loop)
+unroll_loop_runtime_iterations (struct loop *loop)
{
rtx old_niter, niter, init_code, branch_code, tmp;
unsigned i, j, p;
unsigned n_dom_bbs;
sbitmap wont_exit;
int may_exit_copy;
- unsigned n_peel, n_remove_edges;
- edge *remove_edges, e;
+ unsigned n_peel;
+ VEC (edge, heap) *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);
end_sequence ();
/* Precondition the loop. */
- loop_split_edge_with (loop_preheader_edge (loop), init_code);
+ 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 = NULL;
wont_exit = sbitmap_alloc (max_unroll + 2);
SET_BIT (wont_exit, 1);
ezc_swtch = loop_preheader_edge (loop)->src;
ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
- loops, 1,
- wont_exit, desc->out_edge,
- remove_edges, &n_remove_edges,
+ 1, wont_exit, desc->out_edge,
+ &remove_edges,
DLTHE_FLAG_UPDATE_FREQ);
gcc_assert (ok);
/* Record the place where switch will be built for preconditioning. */
- swtch = loop_split_edge_with (loop_preheader_edge (loop),
- NULL_RTX);
+ swtch = split_edge (loop_preheader_edge (loop));
for (i = 0; i < n_peel; i++)
{
if (i != n_peel - 1 || !last_may_exit)
SET_BIT (wont_exit, 1);
ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
- loops, 1,
- wont_exit, desc->out_edge,
- remove_edges, &n_remove_edges,
+ 1, wont_exit, desc->out_edge,
+ &remove_edges,
DLTHE_FLAG_UPDATE_FREQ);
gcc_assert (ok);
j = n_peel - i - (extra_zero_check ? 0 : 1);
p = REG_BR_PROB_BASE / (i + 2);
- preheader = loop_split_edge_with (loop_preheader_edge (loop), NULL_RTX);
+ preheader = split_edge (loop_preheader_edge (loop));
branch_code = compare_and_jump_seq (copy_rtx (niter), GEN_INT (j), EQ,
block_label (preheader), p,
NULL_RTX);
- swtch = loop_split_edge_with (single_pred_edge (swtch), branch_code);
+ /* We rely on the fact that the compare and jump cannot be optimized out,
+ and hence the cfg we create is correct. */
+ gcc_assert (branch_code != NULL_RTX);
+
+ swtch = split_edge_and_insert (single_pred_edge (swtch), branch_code);
set_immediate_dominator (CDI_DOMINATORS, preheader, swtch);
single_pred_edge (swtch)->probability = REG_BR_PROB_BASE - p;
e = make_edge (swtch, preheader,
/* Add branch for zero iterations. */
p = REG_BR_PROB_BASE / (max_unroll + 1);
swtch = ezc_swtch;
- preheader = loop_split_edge_with (loop_preheader_edge (loop), NULL_RTX);
+ preheader = split_edge (loop_preheader_edge (loop));
branch_code = compare_and_jump_seq (copy_rtx (niter), const0_rtx, EQ,
block_label (preheader), p,
NULL_RTX);
+ gcc_assert (branch_code != NULL_RTX);
- swtch = loop_split_edge_with (single_succ_edge (swtch), branch_code);
+ swtch = split_edge_and_insert (single_succ_edge (swtch), branch_code);
set_immediate_dominator (CDI_DOMINATORS, preheader, swtch);
single_succ_edge (swtch)->probability = REG_BR_PROB_BASE - p;
e = make_edge (swtch, preheader,
opt_info_start_duplication (opt_info);
ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop),
- loops, max_unroll,
+ max_unroll,
wont_exit, desc->out_edge,
- remove_edges, &n_remove_edges,
+ &remove_edges,
DLTHE_FLAG_UPDATE_FREQ
| (opt_info
? DLTHE_RECORD_COPY_NUMBER
}
/* Remove the edges. */
- for (i = 0; i < n_remove_edges; i++)
- remove_path (loops, remove_edges[i]);
- free (remove_edges);
+ for (i = 0; VEC_iterate (edge, remove_edges, i, e); i++)
+ remove_path (e);
+ VEC_free (edge, heap, remove_edges);
/* We must be careful when updating the number of iterations due to
preconditioning and the fact that the value must be valid at entry
end: ;
*/
static void
-peel_loop_simple (struct loops *loops, struct loop *loop)
+peel_loop_simple (struct loop *loop)
{
sbitmap wont_exit;
unsigned npeel = loop->lpt_decision.times;
opt_info_start_duplication (opt_info);
ok = duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
- loops, npeel, wont_exit,
- NULL, NULL,
+ npeel, wont_exit, NULL,
NULL, DLTHE_FLAG_UPDATE_FREQ
| (opt_info
? DLTHE_RECORD_COPY_NUMBER
}
*/
static void
-unroll_loop_stupid (struct loops *loops, struct loop *loop)
+unroll_loop_stupid (struct loop *loop)
{
sbitmap wont_exit;
unsigned nunroll = loop->lpt_decision.times;
opt_info_start_duplication (opt_info);
ok = duplicate_loop_to_header_edge (loop, loop_latch_edge (loop),
- loops, nunroll, wont_exit,
- NULL, NULL, NULL,
+ nunroll, wont_exit,
+ NULL, NULL,
DLTHE_FLAG_UPDATE_FREQ
| (opt_info
? DLTHE_RECORD_COPY_NUMBER
static hashval_t
si_info_hash (const void *ivts)
{
- return htab_hash_pointer (((struct iv_to_split *) ivts)->insn);
+ return (hashval_t) INSN_UID (((struct iv_to_split *) ivts)->insn);
}
/* An equality functions for information about insns to split. */
static hashval_t
ve_info_hash (const void *ves)
{
- return htab_hash_pointer (((struct var_to_expand *) ves)->insn);
+ return (hashval_t) INSN_UID (((struct var_to_expand *) ves)->insn);
}
/* Return true if IVTS1 and IVTS2 (which are really both of type
static struct var_to_expand *
analyze_insn_to_expand_var (struct loop *loop, rtx insn)
{
- rtx set, dest, src, op1;
+ rtx set, dest, src, op1, op2, something;
struct var_to_expand *ves;
enum machine_mode mode1, mode2;
-
+ unsigned accum_pos;
+
set = single_set (insn);
if (!set)
return NULL;
if (!have_insn_for (GET_CODE (src), GET_MODE (src)))
return NULL;
- if (!XEXP (src, 0))
- return NULL;
-
op1 = XEXP (src, 0);
+ op2 = XEXP (src, 1);
if (!REG_P (dest)
&& !(GET_CODE (dest) == SUBREG
&& REG_P (SUBREG_REG (dest))))
return NULL;
- if (!rtx_equal_p (dest, op1))
- return NULL;
-
+ if (rtx_equal_p (dest, op1))
+ accum_pos = 0;
+ else if (rtx_equal_p (dest, op2))
+ accum_pos = 1;
+ else
+ return NULL;
+
+ /* 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 (accum_pos == 1
+ && GET_CODE (src) == MINUS)
+ return NULL;
+
+ something = (accum_pos == 0)? op2 : op1;
+
if (!referenced_in_one_insn_in_loop_p (loop, dest))
return NULL;
- if (rtx_referenced_p (dest, XEXP (src, 1)))
+ if (rtx_referenced_p (dest, something))
return NULL;
mode1 = GET_MODE (dest);
- mode2 = GET_MODE (XEXP (src, 1));
+ mode2 = GET_MODE (something);
if ((FLOAT_MODE_P (mode1)
|| FLOAT_MODE_P (mode2))
&& !flag_unsafe_math_optimizations)
return NULL;
-
+
+ if (dump_file)
+ {
+ fprintf (dump_file,
+ "\n;; Expanding Accumulator ");
+ print_rtl (dump_file, dest);
+ fprintf (dump_file, "\n");
+ }
+
/* Record the accumulator to expand. */
ves = XNEW (struct var_to_expand);
ves->insn = insn;
ves->op = GET_CODE (src);
ves->expansion_count = 0;
ves->reuse_expansion = 0;
+ ves->accum_pos = accum_pos;
return ves;
}
return NULL;
ok = iv_analyze_result (insn, dest, &iv);
- gcc_assert (ok);
+
+ /* This used to be an assert under the assumption that if biv_p returns
+ true that iv_analyze_result must also return true. However, that
+ assumption is not strictly correct as evidenced by pr25569.
+
+ Returning NULL when iv_analyze_result returns false is safe and
+ avoids the problems in pr25569 until the iv_analyze_* routines
+ can be fixed, which is apparently hard and time consuming
+ according to their author. */
+ if (! ok)
+ return NULL;
if (iv.step == const0_rtx
|| iv.mode != iv.extend_mode)
analyze_insns_in_loop (struct loop *loop)
{
basic_block *body, bb;
- unsigned i, num_edges = 0;
+ unsigned i;
struct opt_info *opt_info = XCNEW (struct opt_info);
rtx insn;
struct iv_to_split *ivts = NULL;
struct var_to_expand *ves = NULL;
PTR *slot1;
PTR *slot2;
- edge *edges = get_loop_exit_edges (loop, &num_edges);
+ VEC (edge, heap) *edges = get_loop_exit_edges (loop);
+ edge exit;
bool can_apply = false;
iv_analysis_loop_init (loop);
si_info_hash, si_info_eq, free);
/* Record the loop exit bb and loop preheader before the unrolling. */
- if (!loop_preheader_edge (loop)->src)
- {
- loop_split_edge_with (loop_preheader_edge (loop), NULL_RTX);
- opt_info->loop_preheader = loop_split_edge_with (loop_preheader_edge (loop), NULL_RTX);
- }
- else
- opt_info->loop_preheader = loop_preheader_edge (loop)->src;
+ opt_info->loop_preheader = loop_preheader_edge (loop)->src;
- if (num_edges == 1
- && !(edges[0]->flags & EDGE_COMPLEX))
+ if (VEC_length (edge, edges) == 1)
{
- opt_info->loop_exit = loop_split_edge_with (edges[0], NULL_RTX);
- can_apply = true;
+ exit = VEC_index (edge, edges, 0);
+ if (!(exit->flags & EDGE_COMPLEX))
+ {
+ opt_info->loop_exit = split_edge (exit);
+ can_apply = true;
+ }
}
if (flag_variable_expansion_in_unroller
}
}
- free (edges);
+ VEC_free (edge, heap, edges);
free (body);
return opt_info;
}
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_change (insn, &XEXP (SET_SRC (set), ve->accum_pos), new_reg, 1);
if (apply_change_group ())
if (really_new_expansion)
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