#include "cselib.h"
#include "except.h"
#include "toplev.h"
+#include "predict.h"
#define LOOP_REG_LIFETIME(LOOP, REGNO) \
((REGNO_LAST_LUID (REGNO) - REGNO_FIRST_LUID (REGNO)))
static void force_movables PARAMS ((struct loop_movables *));
static void combine_movables PARAMS ((struct loop_movables *,
struct loop_regs *));
+static int num_unmoved_movables PARAMS ((const struct loop *));
static int regs_match_p PARAMS ((rtx, rtx, struct loop_movables *));
static int rtx_equal_for_loop_p PARAMS ((rtx, rtx, struct loop_movables *,
struct loop_regs *));
static void loop_givs_rescan PARAMS((struct loop *, struct iv_class *,
rtx *));
static void loop_ivs_free PARAMS((struct loop *));
-static void strength_reduce PARAMS ((struct loop *, int, int));
+static void strength_reduce PARAMS ((struct loop *, int));
static void find_single_use_in_loop PARAMS ((struct loop_regs *, rtx, rtx));
static int valid_initial_value_p PARAMS ((rtx, rtx, int, rtx));
static void find_mem_givs PARAMS ((const struct loop *, rtx, rtx, int, int));
static void record_initial PARAMS ((rtx, rtx, void *));
static void update_reg_last_use PARAMS ((rtx, rtx));
static rtx next_insn_in_loop PARAMS ((const struct loop *, rtx));
-static void loop_regs_scan PARAMS ((const struct loop*, int, int *));
+static void loop_regs_scan PARAMS ((const struct loop *, int));
+static int count_insns_in_loop PARAMS ((const struct loop *));
static void load_mems PARAMS ((const struct loop *));
static int insert_loop_mem PARAMS ((rtx *, void *));
static int replace_loop_mem PARAMS ((rtx *, void *));
static rtx loop_insn_sink_or_swim PARAMS((const struct loop *, rtx));
static void loop_dump_aux PARAMS ((const struct loop *, FILE *, int));
+static void loop_delete_insns PARAMS ((rtx, rtx));
void debug_ivs PARAMS ((const struct loop *));
void debug_iv_class PARAMS ((const struct iv_class *));
void debug_biv PARAMS ((const struct induction *));
movables->head = 0;
movables->last = 0;
- movables->num = 0;
/* Determine whether this loop starts with a jump down to a test at
the end. This will occur for a small number of loops with a test
/* Allocate extra space for REGs that might be created by load_mems.
We allocate a little extra slop as well, in the hopes that we
won't have to reallocate the regs array. */
- loop_regs_scan (loop, loop_info->mems_idx + 16, &insn_count);
+ loop_regs_scan (loop, loop_info->mems_idx + 16);
+ insn_count = count_insns_in_loop (loop);
if (loop_dump_stream)
{
&& (REGNO_LAST_UID (regno)
== INSN_UID (regs->array[regno].single_usage))
&& regs->array[regno].set_in_loop == 1
+ && GET_CODE (SET_SRC (set)) != ASM_OPERANDS
&& ! side_effects_p (SET_SRC (set))
&& ! find_reg_note (p, REG_RETVAL, NULL_RTX)
&& (! SMALL_REGISTER_CLASSES
/* Recalculate regs->array if load_mems has created new registers. */
if (max_reg_num () > regs->num)
- loop_regs_scan (loop, 0, &insn_count);
+ loop_regs_scan (loop, 0);
for (update_start = loop_start;
PREV_INSN (update_start)
/* Ensure our label doesn't go away. */
LABEL_NUSES (update_end)++;
- strength_reduce (loop, insn_count, flags);
+ strength_reduce (loop, flags);
reg_scan_update (update_start, update_end, loop_max_reg);
loop_max_reg = max_reg_num ();
/* Clean up. */
free (matched_regs);
}
+
+/* Returns the number of movable instructions in LOOP that were not
+ moved outside the loop. */
+
+static int
+num_unmoved_movables (loop)
+ const struct loop *loop;
+{
+ int num = 0;
+ struct movable *m;
+
+ for (m = LOOP_MOVABLES (loop)->head; m; m = m->next)
+ if (!m->done)
+ ++num;
+
+ return num;
+}
+
\f
/* Return 1 if regs X and Y will become the same if moved. */
rtx *reg_map = (rtx *) xcalloc (nregs, sizeof (rtx));
char *already_moved = (char *) xcalloc (nregs, sizeof (char));
- movables->num = 0;
-
for (m = movables->head; m; m = m->next)
{
/* Describe this movable insn. */
INSN_UID (m->forces->insn));
}
- /* Count movables. Value used in heuristics in strength_reduce. */
- movables->num++;
-
/* Ignore the insn if it's already done (it matched something else).
Otherwise, see if it is now safe to move. */
must check regnos to make sure they are in bounds. */
static void
-strength_reduce (loop, insn_count, flags)
+strength_reduce (loop, flags)
struct loop *loop;
- int insn_count;
int flags;
{
struct loop_info *loop_info = LOOP_INFO (loop);
int reg_map_size;
int unrolled_insn_copies = 0;
rtx test_reg = gen_rtx_REG (word_mode, LAST_VIRTUAL_REGISTER + 1);
+ int insn_count = count_insns_in_loop (loop);
addr_placeholder = gen_reg_rtx (Pmode);
provided all givs are reduced. */
bl->eliminable = loop_biv_eliminable_p (loop, bl, threshold, insn_count);
+ /* This will be true at the end, if all givs which depend on this
+ biv have been strength reduced.
+ We can't (currently) eliminate the biv unless this is so. */
+ bl->all_reduced = 1;
+
/* Check each extension dependent giv in this class to see if its
root biv is safe from wrapping in the interior mode. */
check_ext_dependant_givs (bl, loop_info);
/* Combine all giv's for this iv_class. */
combine_givs (regs, bl);
- /* This will be true at the end, if all givs which depend on this
- biv have been strength reduced.
- We can't (currently) eliminate the biv unless this is so. */
- bl->all_reduced = 1;
-
for (v = bl->giv; v; v = v->next_iv)
{
struct induction *tv;
doloop_optimize (loop);
#endif /* HAVE_doloop_end */
+ /* In case number of iterations is known, drop branch prediction note
+ in the branch. Do that only in second loop pass, as loop unrolling
+ may change the number of iterations performed. */
+ if ((flags & LOOP_BCT)
+ && loop_info->n_iterations / loop_info->unroll_number > 1)
+ {
+ int n = loop_info->n_iterations / loop_info->unroll_number;
+ predict_insn (PREV_INSN (loop->end),
+ PRED_LOOP_ITERATIONS,
+ REG_BR_PROB_BASE - REG_BR_PROB_BASE / n);
+ }
+
if (loop_dump_stream)
fprintf (loop_dump_stream, "\n");
record_giv (loop, v, p, src_reg, dest_reg, mult_val, add_val,
ext_val, benefit, DEST_REG, not_every_iteration,
- maybe_multiple, NULL_PTR);
+ maybe_multiple, (rtx*)0);
}
}
INSN_UID (v->insn), why);
}
v->ignore = 1;
+ bl->all_reduced = 0;
}
}
}
{
struct induction *v;
- reversible_mem_store
- = (! loop_info->unknown_address_altered
- && ! loop_info->unknown_constant_address_altered
- && ! loop_invariant_p (loop,
- XEXP (XEXP (loop_info->store_mems, 0),
- 0)));
+ /* If we could prove that each of the memory locations
+ written to was different, then we could reverse the
+ store -- but we don't presently have any way of
+ knowing that. */
+ reversible_mem_store = 0;
/* If the store depends on a register that is set after the
store, it depends on the initial value, and is thus not
&& ! loop_info->has_volatile
&& reversible_mem_store
&& (bl->giv_count + bl->biv_count + loop_info->num_mem_sets
- + LOOP_MOVABLES (loop)->num + compare_and_branch == insn_count)
+ + num_unmoved_movables (loop) + compare_and_branch == insn_count)
&& (bl == ivs->list && bl->next == 0))
|| no_use_except_counting)
{
const struct loop *loop;
rtx x;
{
- rtx comparison = get_condition (x, NULL_PTR);
+ rtx comparison = get_condition (x, (rtx*)0);
if (comparison == 0
|| ! loop_invariant_p (loop, XEXP (comparison, 0))
parameter may be zero, in which case this processing is not done.
Set REGS->ARRAY[I].MAY_NOT_OPTIMIZE nonzero if we should not
- optimize register I.
-
- Store in *COUNT_PTR the number of actual instructions
- in the loop. We use this to decide what is worth moving out. */
+ optimize register I. */
static void
-loop_regs_scan (loop, extra_size, count_ptr)
+loop_regs_scan (loop, extra_size)
const struct loop *loop;
int extra_size;
- int *count_ptr;
{
struct loop_regs *regs = LOOP_REGS (loop);
int old_nregs;
basic block. In that case, it is the insn that last set reg n. */
rtx *last_set;
rtx insn;
- int count = 0;
int i;
old_nregs = regs->num;
{
if (INSN_P (insn))
{
- ++count;
-
/* Record registers that have exactly one use. */
find_single_use_in_loop (regs, insn, PATTERN (insn));
regs->array[i].n_times_set = regs->array[i].set_in_loop;
free (last_set);
- *count_ptr = count;
}
+/* Returns the number of real INSNs in the LOOP. */
+
+static int
+count_insns_in_loop (loop)
+ const struct loop *loop;
+{
+ int count = 0;
+ rtx insn;
+
+ for (insn = loop->top ? loop->top : loop->start; insn != loop->end;
+ insn = NEXT_INSN (insn))
+ if (INSN_P (insn))
+ ++count;
+
+ return count;
+}
/* Move MEMs into registers for the duration of the loop. */
fprintf (loop_dump_stream, " Replaced reg %d", regno);
if (store_is_first && replaced_last)
{
- PUT_CODE (init_insn, NOTE);
- NOTE_LINE_NUMBER (init_insn) = NOTE_INSN_DELETED;
- if (loop_dump_stream)
- fprintf (loop_dump_stream, ", deleting init_insn (%d)",
- INSN_UID (init_insn));
+ rtx first;
+ rtx retval_note;
+
+ /* Assume we're just deleting INIT_INSN. */
+ first = init_insn;
+ /* Look for REG_RETVAL note. If we're deleting the end of
+ the libcall sequence, the whole sequence can go. */
+ retval_note = find_reg_note (init_insn, REG_RETVAL, NULL_RTX);
+ /* If we found a REG_RETVAL note, find the first instruction
+ in the sequence. */
+ if (retval_note)
+ first = XEXP (retval_note, 0);
+
+ /* Delete the instructions. */
+ loop_delete_insns (first, init_insn);
}
if (loop_dump_stream)
fprintf (loop_dump_stream, ".\n");
}
}
+/* Replace all the instructions from FIRST up to and including LAST
+ with NOTE_INSN_DELETED notes. */
+
+static void
+loop_delete_insns (first, last)
+ rtx first;
+ rtx last;
+{
+ while (1)
+ {
+ PUT_CODE (first, NOTE);
+ NOTE_LINE_NUMBER (first) = NOTE_INSN_DELETED;
+ if (loop_dump_stream)
+ fprintf (loop_dump_stream, ", deleting init_insn (%d)",
+ INSN_UID (first));
+
+ /* If this was the LAST instructions we're supposed to delete,
+ we're done. */
+ if (first == last)
+ break;
+
+ first = NEXT_INSN (first);
+ }
+}
+
/* Try to replace occurrences of pseudo REGNO with REPLACEMENT within
loop LOOP if the order of the sets of these registers can be
swapped. There must be exactly one insn within the loop that sets
break;
}
- if (set)
+ if (insn != NULL_RTX)
{
rtx prev_insn;
rtx prev_set;
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