/* Loop unrolling and peeling.
- Copyright (C) 2002, 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008
+ Free Software Foundation, Inc.
This file is part of GCC.
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
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. */
+ 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. */
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. */
static bool referenced_in_one_insn_in_loop_p (struct loop *, rtx);
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. */
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");
}
/* 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");
/* 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 = VEC_alloc (rtx, heap, 1);
+ ves->next = NULL;
ves->op = GET_CODE (src);
ves->expansion_count = 0;
ves->reuse_expansion = 0;
ivts->insn = insn;
ivts->base_var = NULL_RTX;
ivts->step = iv.step;
+ ivts->next = NULL;
ivts->n_loc = 1;
ivts->loc[0] = 1;
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 (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++)
{
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 (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;
}
}
}
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 = (struct iv_to_split *) *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
}
}
-/* 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. 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:
+/* 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:
for (i = 0 ; i < n; i++)
sum += something;
should be initialized with -zero as well (otherwise we will get +zero
as the final result). */
-static int
-insert_var_expansion_initialization (void **slot, void *place_p)
+static void
+insert_var_expansion_initialization (struct var_to_expand *ve,
+ basic_block place)
{
- struct var_to_expand *ve = (struct var_to_expand *) *slot;
- basic_block place = (basic_block)place_p;
rtx seq, var, zero_init, insn;
unsigned i;
enum machine_mode mode = GET_MODE (ve->reg);
bool honor_signed_zero_p = HONOR_SIGNED_ZEROS (mode);
if (VEC_length (rtx, ve->var_expansions) == 0)
- return 1;
+ return;
start_sequence ();
if (ve->op == PLUS || ve->op == MINUS)
insn = NEXT_INSN (insn);
emit_insn_after (seq, insn);
- /* Continue traversing the hash table. */
- return 1;
}
-/* 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 = (struct var_to_expand *) *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;
+ return;
start_sequence ();
if (ve->op == PLUS || ve->op == MINUS)
insn = NEXT_INSN (insn);
emit_insn_after (seq, insn);
-
- /* Continue traversing the hash table. */
- return 1;
}
/* Apply loop optimizations in loop copies using the
/* 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++)
{
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
}
}
-/* 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 = (struct var_to_expand *) *slot;
-
- VEC_free (rtx, heap, ve->var_expansions);
-
- /* Continue traversing the hash table. */
- return 1;
-}
-
/* Release OPT_INFO. */
static void
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)
+ VEC_free (rtx, heap, ves->var_expansions);
htab_delete (opt_info->insns_with_var_to_expand);
}
free (opt_info);
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