/* Try to unroll loops, and split induction variables.
- Copyright (C) 1992, 93-95, 97-99, 2000 Free Software Foundation, Inc.
+ Copyright (C) 1992, 1993, 1994, 1995, 1997, 1998, 1999, 2000, 2001, 2002
+ Free Software Foundation, Inc.
Contributed by James E. Wilson, Cygnus Support/UC Berkeley.
-This file is part of GNU CC.
+This file is part of GCC.
-GNU CC 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 version.
+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
+version.
-GNU CC is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-GNU General Public License for more details.
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+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 GNU CC; see the file COPYING. If not, write to
-the Free Software Foundation, 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
+along with GCC; see the file COPYING. If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+02111-1307, USA. */
/* Try to unroll a loop, and split induction variables.
moving the insn back into the loop, or perhaps replicate the insn before
the loop, one copy for each time the loop is unrolled. */
-/* The prime factors looked for when trying to unroll a loop by some
- number which is modulo the total number of iterations. Just checking
- for these 4 prime factors will find at least one factor for 75% of
- all numbers theoretically. Practically speaking, this will succeed
- almost all of the time since loops are generally a multiple of 2
- and/or 5. */
-
-#define NUM_FACTORS 4
-
-struct _factor { int factor, count; } factors[NUM_FACTORS]
- = { {2, 0}, {3, 0}, {5, 0}, {7, 0}};
-
-/* Describes the different types of loop unrolling performed. */
-
-enum unroll_types { UNROLL_COMPLETELY, UNROLL_MODULO, UNROLL_NAIVE };
-
#include "config.h"
#include "system.h"
#include "rtl.h"
#include "expr.h"
#include "loop.h"
#include "toplev.h"
+#include "hard-reg-set.h"
+#include "basic-block.h"
+#include "predict.h"
+
+/* The prime factors looked for when trying to unroll a loop by some
+ number which is modulo the total number of iterations. Just checking
+ for these 4 prime factors will find at least one factor for 75% of
+ all numbers theoretically. Practically speaking, this will succeed
+ almost all of the time since loops are generally a multiple of 2
+ and/or 5. */
+
+#define NUM_FACTORS 4
+
+static struct _factor { const int factor; int count; }
+factors[NUM_FACTORS] = { {2, 0}, {3, 0}, {5, 0}, {7, 0}};
+
+/* Describes the different types of loop unrolling performed. */
+
+enum unroll_types
+{
+ UNROLL_COMPLETELY,
+ UNROLL_MODULO,
+ UNROLL_NAIVE
+};
/* This controls which loops are unrolled, and by how much we unroll
them. */
static rtx *splittable_regs;
/* Indexed by register number, if this is a splittable induction variable,
- this indicates if it was made from a derived giv. */
-static char *derived_regs;
-
-/* Indexed by register number, if this is a splittable induction variable,
then this will hold the number of instructions in the loop that modify
the induction variable. Used to ensure that only the last insn modifying
a split iv will update the original iv of the dest. */
/* Forward declarations. */
static void init_reg_map PARAMS ((struct inline_remap *, int));
-static rtx calculate_giv_inc PARAMS ((rtx, rtx, int));
+static rtx calculate_giv_inc PARAMS ((rtx, rtx, unsigned int));
static rtx initial_reg_note_copy PARAMS ((rtx, struct inline_remap *));
-static void final_reg_note_copy PARAMS ((rtx, struct inline_remap *));
-static void copy_loop_body PARAMS ((rtx, rtx, struct inline_remap *, rtx, int,
- enum unroll_types, rtx, rtx, rtx, rtx));
-static void iteration_info PARAMS ((rtx, rtx *, rtx *, rtx, rtx));
-static int find_splittable_regs PARAMS ((enum unroll_types, rtx, rtx, rtx, int,
- unsigned HOST_WIDE_INT));
-static int find_splittable_givs PARAMS ((struct iv_class *, enum unroll_types,
- rtx, rtx, rtx, int));
-static int reg_dead_after_loop PARAMS ((rtx, rtx, rtx));
+static void final_reg_note_copy PARAMS ((rtx *, struct inline_remap *));
+static void copy_loop_body PARAMS ((struct loop *, rtx, rtx,
+ struct inline_remap *, rtx, int,
+ enum unroll_types, rtx, rtx, rtx, rtx));
+static int find_splittable_regs PARAMS ((const struct loop *,
+ enum unroll_types, int));
+static int find_splittable_givs PARAMS ((const struct loop *,
+ struct iv_class *, enum unroll_types,
+ rtx, int));
+static int reg_dead_after_loop PARAMS ((const struct loop *, rtx));
static rtx fold_rtx_mult_add PARAMS ((rtx, rtx, rtx, enum machine_mode));
static int verify_addresses PARAMS ((struct induction *, rtx, int));
-static rtx remap_split_bivs PARAMS ((rtx));
+static rtx remap_split_bivs PARAMS ((struct loop *, rtx));
static rtx find_common_reg_term PARAMS ((rtx, rtx));
static rtx subtract_reg_term PARAMS ((rtx, rtx));
-static rtx loop_find_equiv_value PARAMS ((rtx, rtx));
+static rtx loop_find_equiv_value PARAMS ((const struct loop *, rtx));
+static rtx ujump_to_loop_cont PARAMS ((rtx, rtx));
/* Try to unroll one loop and split induction variables in the loop.
- The loop is described by the arguments LOOP_END, INSN_COUNT, and
- LOOP_START. END_INSERT_BEFORE indicates where insns should be added
- which need to be executed when the loop falls through. STRENGTH_REDUCTION_P
- indicates whether information generated in the strength reduction pass
- is available.
+ The loop is described by the arguments LOOP and INSN_COUNT.
+ STRENGTH_REDUCTION_P indicates whether information generated in the
+ strength reduction pass is available.
This function is intended to be called from within `strength_reduce'
in loop.c. */
void
-unroll_loop (loop, insn_count, end_insert_before, strength_reduce_p)
+unroll_loop (loop, insn_count, strength_reduce_p)
struct loop *loop;
int insn_count;
- rtx end_insert_before;
int strength_reduce_p;
{
+ struct loop_info *loop_info = LOOP_INFO (loop);
+ struct loop_ivs *ivs = LOOP_IVS (loop);
int i, j;
+ unsigned int r;
unsigned HOST_WIDE_INT temp;
int unroll_number = 1;
rtx copy_start, copy_end;
struct inline_remap *map;
char *local_label = NULL;
char *local_regno;
- int max_local_regnum;
- int maxregnum;
+ unsigned int max_local_regnum;
+ unsigned int maxregnum;
rtx exit_label = 0;
rtx start_label;
struct iv_class *bl;
int splitting_not_safe = 0;
- enum unroll_types unroll_type;
+ enum unroll_types unroll_type = UNROLL_NAIVE;
int loop_preconditioned = 0;
rtx safety_label;
/* This points to the last real insn in the loop, which should be either
rtx last_loop_insn;
rtx loop_start = loop->start;
rtx loop_end = loop->end;
- struct loop_info *loop_info = loop->info;
/* Don't bother unrolling huge loops. Since the minimum factor is
two, loops greater than one half of MAX_UNROLLED_INSNS will never
if (loop_info->n_iterations == 1)
{
+ /* Handle the case where the loop begins with an unconditional
+ jump to the loop condition. Make sure to delete the jump
+ insn, otherwise the loop body will never execute. */
+
+ rtx ujump = ujump_to_loop_cont (loop->start, loop->cont);
+ if (ujump)
+ delete_related_insns (ujump);
+
/* If number of iterations is exactly 1, then eliminate the compare and
branch at the end of the loop since they will never be taken.
Then return, since no other action is needed here. */
if (GET_CODE (last_loop_insn) == BARRIER)
{
/* Delete the jump insn. This will delete the barrier also. */
- delete_insn (PREV_INSN (last_loop_insn));
+ delete_related_insns (PREV_INSN (last_loop_insn));
}
else if (GET_CODE (last_loop_insn) == JUMP_INSN)
{
#ifdef HAVE_cc0
rtx prev = PREV_INSN (last_loop_insn);
#endif
- delete_insn (last_loop_insn);
+ delete_related_insns (last_loop_insn);
#ifdef HAVE_cc0
/* The immediately preceding insn may be a compare which must be
deleted. */
- if (sets_cc0_p (prev))
- delete_insn (prev);
+ if (only_sets_cc0_p (prev))
+ delete_related_insns (prev);
#endif
}
/* Remove the loop notes since this is no longer a loop. */
if (loop->vtop)
- delete_insn (loop->vtop);
+ delete_related_insns (loop->vtop);
if (loop->cont)
- delete_insn (loop->cont);
+ delete_related_insns (loop->cont);
if (loop_start)
- delete_insn (loop_start);
+ delete_related_insns (loop_start);
if (loop_end)
- delete_insn (loop_end);
+ delete_related_insns (loop_end);
return;
}
else if (loop_info->n_iterations > 0
+ /* Avoid overflow in the next expression. */
+ && loop_info->n_iterations < MAX_UNROLLED_INSNS
&& loop_info->n_iterations * insn_count < MAX_UNROLLED_INSNS)
{
unroll_number = loop_info->n_iterations;
if (unroll_number == 1)
{
if (loop_dump_stream)
- fprintf (loop_dump_stream,
- "Loop unrolling: No factors found.\n");
+ fprintf (loop_dump_stream, "Loop unrolling: No factors found.\n");
}
else
unroll_type = UNROLL_MODULO;
}
-
/* Default case, calculate number of times to unroll loop based on its
size. */
- if (unroll_number == 1)
+ if (unroll_type == UNROLL_NAIVE)
{
if (8 * insn_count < MAX_UNROLLED_INSNS)
unroll_number = 8;
unroll_number = 4;
else
unroll_number = 2;
-
- unroll_type = UNROLL_NAIVE;
}
/* Now we know how many times to unroll the loop. */
if (loop_dump_stream)
- fprintf (loop_dump_stream,
- "Unrolling loop %d times.\n", unroll_number);
-
+ fprintf (loop_dump_stream, "Unrolling loop %d times.\n", unroll_number);
if (unroll_type == UNROLL_COMPLETELY || unroll_type == UNROLL_MODULO)
{
for (i = 0; i < len; i++)
{
label = XEXP (XVECEXP (pat, diff_vec_p, i), 0);
- set_label_in_map (map,
- CODE_LABEL_NUMBER (label),
- label);
+ set_label_in_map (map, CODE_LABEL_NUMBER (label), label);
}
}
}
- else if ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)))
+ if ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)))
set_label_in_map (map, CODE_LABEL_NUMBER (XEXP (note, 0)),
XEXP (note, 0));
}
to access the splittable_regs[] and addr_combined_regs[] arrays. */
splittable_regs = (rtx *) xcalloc (maxregnum, sizeof (rtx));
- derived_regs = (char *) xcalloc (maxregnum, sizeof (char));
splittable_regs_updates = (int *) xcalloc (maxregnum, sizeof (int));
addr_combined_regs
= (struct induction **) xcalloc (maxregnum, sizeof (struct induction *));
/* If we have a target that uses cc0, then we also must not duplicate
the insn that sets cc0 before the jump insn, if one is present. */
#ifdef HAVE_cc0
- if (GET_CODE (copy_end) == JUMP_INSN && sets_cc0_p (PREV_INSN (copy_end)))
+ if (GET_CODE (copy_end) == JUMP_INSN
+ && sets_cc0_p (PREV_INSN (copy_end)))
copy_end_luid--;
#endif
results in better code. */
/* We must limit the generic test to max_reg_before_loop, because only
these pseudo registers have valid regno_first_uid info. */
- for (j = FIRST_PSEUDO_REGISTER; j < max_reg_before_loop; ++j)
- if (REGNO_FIRST_UID (j) > 0 && REGNO_FIRST_UID (j) <= max_uid_for_loop
- && uid_luid[REGNO_FIRST_UID (j)] >= copy_start_luid
- && REGNO_LAST_UID (j) > 0 && REGNO_LAST_UID (j) <= max_uid_for_loop
- && uid_luid[REGNO_LAST_UID (j)] <= copy_end_luid)
+ for (r = FIRST_PSEUDO_REGISTER; r < max_reg_before_loop; ++r)
+ if (REGNO_FIRST_UID (r) > 0 && REGNO_FIRST_UID (r) <= max_uid_for_loop
+ && REGNO_FIRST_LUID (r) >= copy_start_luid
+ && REGNO_LAST_UID (r) > 0 && REGNO_LAST_UID (r) <= max_uid_for_loop
+ && REGNO_LAST_LUID (r) <= copy_end_luid)
{
/* However, we must also check for loop-carried dependencies.
If the value the pseudo has at the end of iteration X is
regno_last_uid. */
/* ??? This check is simplistic. We would get better code if
this check was more sophisticated. */
- if (set_dominates_use (j, REGNO_FIRST_UID (j), REGNO_LAST_UID (j),
+ if (set_dominates_use (r, REGNO_FIRST_UID (r), REGNO_LAST_UID (r),
copy_start, copy_end))
- local_regno[j] = 1;
+ local_regno[r] = 1;
if (loop_dump_stream)
{
- if (local_regno[j])
- fprintf (loop_dump_stream, "Marked reg %d as local\n", j);
+ if (local_regno[r])
+ fprintf (loop_dump_stream, "Marked reg %d as local\n", r);
else
fprintf (loop_dump_stream, "Did not mark reg %d as local\n",
- j);
+ r);
}
}
- /* Givs that have been created from multiple biv increments always have
- local registers. */
- for (j = first_increment_giv; j <= last_increment_giv; j++)
- {
- local_regno[j] = 1;
- if (loop_dump_stream)
- fprintf (loop_dump_stream, "Marked reg %d as local\n", j);
- }
}
/* If this loop requires exit tests when unrolled, check to see if we
rtx initial_value, final_value, increment;
enum machine_mode mode;
- if (precondition_loop_p (loop_start, loop_info,
+ if (precondition_loop_p (loop,
&initial_value, &final_value, &increment,
&mode))
{
- register rtx diff ;
+ rtx diff;
rtx *labels;
int abs_inc, neg_inc;
+ enum rtx_code cc = loop_info->comparison_code;
+ int less_p = (cc == LE || cc == LEU || cc == LT || cc == LTU);
+ int unsigned_p = (cc == LEU || cc == GEU || cc == LTU || cc == GTU);
map->reg_map = (rtx *) xmalloc (maxregnum * sizeof (rtx));
VARRAY_CONST_EQUIV_INIT (map->const_equiv_varray, maxregnum,
- "unroll_loop");
+ "unroll_loop_precondition");
global_const_equiv_varray = map->const_equiv_varray;
init_reg_map (map, maxregnum);
abs_inc = INTVAL (increment);
if (abs_inc < 0)
{
- abs_inc = - abs_inc;
+ abs_inc = -abs_inc;
neg_inc = 1;
}
start_sequence ();
+ /* Final value may have form of (PLUS val1 const1_rtx). We need
+ to convert it into general operand, so compute the real value. */
+
+ if (GET_CODE (final_value) == PLUS)
+ {
+ final_value = expand_simple_binop (mode, PLUS,
+ copy_rtx (XEXP (final_value, 0)),
+ copy_rtx (XEXP (final_value, 1)),
+ NULL_RTX, 0, OPTAB_LIB_WIDEN);
+ }
+ if (!nonmemory_operand (final_value, VOIDmode))
+ final_value = force_reg (mode, copy_rtx (final_value));
+
/* Calculate the difference between the final and initial values.
Final value may be a (plus (reg x) (const_int 1)) rtx.
Let the following cse pass simplify this if initial value is
a constant.
We must copy the final and initial values here to avoid
- improperly shared rtl. */
-
- diff = expand_binop (mode, sub_optab, copy_rtx (final_value),
- copy_rtx (initial_value), NULL_RTX, 0,
- OPTAB_LIB_WIDEN);
+ improperly shared rtl.
+
+ We have to deal with for (i = 0; --i < 6;) type loops.
+ For such loops the real final value is the first time the
+ loop variable overflows, so the diff we calculate is the
+ distance from the overflow value. This is 0 or ~0 for
+ unsigned loops depending on the direction, or INT_MAX,
+ INT_MAX+1 for signed loops. We really do not need the
+ exact value, since we are only interested in the diff
+ modulo the increment, and the increment is a power of 2,
+ so we can pretend that the overflow value is 0/~0. */
+
+ if (cc == NE || less_p != neg_inc)
+ diff = expand_simple_binop (mode, MINUS, final_value,
+ copy_rtx (initial_value), NULL_RTX, 0,
+ OPTAB_LIB_WIDEN);
+ else
+ diff = expand_simple_unop (mode, neg_inc ? NOT : NEG,
+ copy_rtx (initial_value), NULL_RTX, 0);
/* Now calculate (diff % (unroll * abs (increment))) by using an
and instruction. */
- diff = expand_binop (GET_MODE (diff), and_optab, diff,
- GEN_INT (unroll_number * abs_inc - 1),
- NULL_RTX, 0, OPTAB_LIB_WIDEN);
+ diff = expand_simple_binop (GET_MODE (diff), AND, diff,
+ GEN_INT (unroll_number * abs_inc - 1),
+ NULL_RTX, 0, OPTAB_LIB_WIDEN);
/* Now emit a sequence of branches to jump to the proper precond
loop entry point. */
case. This check does not apply if the loop has a NE
comparison at the end. */
- if (loop_info->comparison_code != NE)
+ if (cc != NE)
{
- emit_cmp_and_jump_insns (initial_value, final_value,
- neg_inc ? LE : GE,
- NULL_RTX, mode, 0, 0, labels[1]);
+ rtx incremented_initval;
+ incremented_initval = expand_simple_binop (mode, PLUS,
+ initial_value,
+ increment,
+ NULL_RTX, 0,
+ OPTAB_LIB_WIDEN);
+ emit_cmp_and_jump_insns (incremented_initval, final_value,
+ less_p ? GE : LE, NULL_RTX,
+ mode, unsigned_p, labels[1]);
+ predict_insn_def (get_last_insn (), PRED_LOOP_CONDITION,
+ TAKEN);
JUMP_LABEL (get_last_insn ()) = labels[1];
LABEL_NUSES (labels[1])++;
}
}
emit_cmp_and_jump_insns (diff, GEN_INT (abs_inc * cmp_const),
- cmp_code, NULL_RTX, mode, 0, 0,
- labels[i]);
+ cmp_code, NULL_RTX, mode, 0, labels[i]);
JUMP_LABEL (get_last_insn ()) = labels[i];
LABEL_NUSES (labels[i])++;
+ predict_insn (get_last_insn (), PRED_LOOP_PRECONDITIONING,
+ REG_BR_PROB_BASE / (unroll_number - i));
}
/* If the increment is greater than one, then we need another branch,
}
emit_cmp_and_jump_insns (diff, GEN_INT (cmp_const), cmp_code,
- NULL_RTX, mode, 0, 0, labels[0]);
+ NULL_RTX, mode, 0, labels[0]);
JUMP_LABEL (get_last_insn ()) = labels[0];
LABEL_NUSES (labels[0])++;
}
sequence = gen_sequence ();
end_sequence ();
- emit_insn_before (sequence, loop_start);
+ loop_insn_hoist (loop, sequence);
/* Only the last copy of the loop body here needs the exit
test, so set copy_end to exclude the compare/branch here,
{
copy_end = PREV_INSN (last_loop_insn);
#ifdef HAVE_cc0
- /* The immediately preceding insn may be a compare which we do not
- want to copy. */
+ /* The immediately preceding insn may be a compare which
+ we do not want to copy. */
if (sets_cc0_p (PREV_INSN (copy_end)))
copy_end = PREV_INSN (copy_end);
#endif
emit_label_after (labels[unroll_number - i],
PREV_INSN (loop_start));
- bzero ((char *) map->insn_map, max_insnno * sizeof (rtx));
- bzero ((char *) &VARRAY_CONST_EQUIV (map->const_equiv_varray, 0),
- (VARRAY_SIZE (map->const_equiv_varray)
- * sizeof (struct const_equiv_data)));
+ memset ((char *) map->insn_map, 0, max_insnno * sizeof (rtx));
+ memset ((char *) &VARRAY_CONST_EQUIV (map->const_equiv_varray, 0),
+ 0, (VARRAY_SIZE (map->const_equiv_varray)
+ * sizeof (struct const_equiv_data)));
map->const_age = 0;
for (j = 0; j < max_labelno; j++)
if (local_label[j])
set_label_in_map (map, j, gen_label_rtx ());
- for (j = FIRST_PSEUDO_REGISTER; j < max_local_regnum; j++)
- if (local_regno[j])
+ for (r = FIRST_PSEUDO_REGISTER; r < max_local_regnum; r++)
+ if (local_regno[r])
{
- map->reg_map[j] = gen_reg_rtx (GET_MODE (regno_reg_rtx[j]));
- record_base_value (REGNO (map->reg_map[j]),
- regno_reg_rtx[j], 0);
+ map->reg_map[r]
+ = gen_reg_rtx (GET_MODE (regno_reg_rtx[r]));
+ record_base_value (REGNO (map->reg_map[r]),
+ regno_reg_rtx[r], 0);
}
/* The last copy needs the compare/branch insns at the end,
so reset copy_end here if the loop ends with a conditional
/* None of the copies are the `last_iteration', so just
pass zero for that parameter. */
- copy_loop_body (copy_start, copy_end, map, exit_label, 0,
+ copy_loop_body (loop, copy_start, copy_end, map, exit_label, 0,
unroll_type, start_label, loop_end,
loop_start, copy_end);
}
{
insert_before = last_loop_insn;
#ifdef HAVE_cc0
- /* The instruction immediately before the JUMP_INSN may be a compare
- instruction which we do not want to copy or delete. */
+ /* The instruction immediately before the JUMP_INSN may
+ be a compare instruction which we do not want to copy
+ or delete. */
if (sets_cc0_p (PREV_INSN (insert_before)))
insert_before = PREV_INSN (insert_before);
#endif
if (unroll_type == UNROLL_NAIVE && ! flag_unroll_all_loops)
{
if (loop_dump_stream)
- fprintf (loop_dump_stream, "Unrolling failure: Naive unrolling not being done.\n");
+ fprintf (loop_dump_stream,
+ "Unrolling failure: Naive unrolling not being done.\n");
goto egress;
}
if (splitting_not_safe)
temp = 0;
else
- temp = find_splittable_regs (unroll_type, loop_start, loop_end,
- end_insert_before, unroll_number,
- loop_info->n_iterations);
+ temp = find_splittable_regs (loop, unroll_type, unroll_number);
/* find_splittable_regs may have created some new registers, so must
reallocate the reg_map with the new larger size, and must realloc
/* Search the list of bivs and givs to find ones which need to be remapped
when split, and set their reg_map entry appropriately. */
- for (bl = loop_iv_list; bl; bl = bl->next)
+ for (bl = ivs->list; bl; bl = bl->next)
{
if (REGNO (bl->biv->src_reg) != bl->regno)
map->reg_map[bl->regno] = bl->biv->src_reg;
}
/* Use our current register alignment and pointer flags. */
- map->regno_pointer_flag = cfun->emit->regno_pointer_flag;
map->regno_pointer_align = cfun->emit->regno_pointer_align;
+ map->x_regno_reg_rtx = cfun->emit->x_regno_reg_rtx;
/* If the loop is being partially unrolled, and the iteration variables
are being split, and are being renamed for the split, then must fix up
{
insn = NEXT_INSN (copy_end);
if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN)
- PATTERN (insn) = remap_split_bivs (PATTERN (insn));
+ PATTERN (insn) = remap_split_bivs (loop, PATTERN (insn));
}
/* For unroll_number times, make a copy of each instruction
for (i = 0; i < unroll_number; i++)
{
- bzero ((char *) map->insn_map, max_insnno * sizeof (rtx));
- bzero ((char *) &VARRAY_CONST_EQUIV (map->const_equiv_varray, 0),
- VARRAY_SIZE (map->const_equiv_varray) * sizeof (struct const_equiv_data));
+ memset ((char *) map->insn_map, 0, max_insnno * sizeof (rtx));
+ memset ((char *) &VARRAY_CONST_EQUIV (map->const_equiv_varray, 0), 0,
+ VARRAY_SIZE (map->const_equiv_varray) * sizeof (struct const_equiv_data));
map->const_age = 0;
for (j = 0; j < max_labelno; j++)
if (local_label[j])
set_label_in_map (map, j, gen_label_rtx ());
- for (j = FIRST_PSEUDO_REGISTER; j < max_local_regnum; j++)
- if (local_regno[j])
+ for (r = FIRST_PSEUDO_REGISTER; r < max_local_regnum; r++)
+ if (local_regno[r])
{
- map->reg_map[j] = gen_reg_rtx (GET_MODE (regno_reg_rtx[j]));
- record_base_value (REGNO (map->reg_map[j]),
- regno_reg_rtx[j], 0);
+ map->reg_map[r] = gen_reg_rtx (GET_MODE (regno_reg_rtx[r]));
+ record_base_value (REGNO (map->reg_map[r]),
+ regno_reg_rtx[r], 0);
}
/* If loop starts with a branch to the test, then fix it so that
LABEL_NUSES (tem)++;
}
- copy_loop_body (copy_start, copy_end, map, exit_label,
+ copy_loop_body (loop, copy_start, copy_end, map, exit_label,
i == unroll_number - 1, unroll_type, start_label,
loop_end, insert_before, insert_before);
}
&& ! (GET_CODE (insn) == CODE_LABEL && LABEL_NAME (insn))
&& ! (GET_CODE (insn) == NOTE
&& NOTE_LINE_NUMBER (insn) == NOTE_INSN_DELETED_LABEL))
- insn = delete_insn (insn);
+ insn = delete_related_insns (insn);
else
insn = NEXT_INSN (insn);
}
/* Can now delete the 'safety' label emitted to protect us from runaway
- delete_insn calls. */
+ delete_related_insns calls. */
if (INSN_DELETED_P (safety_label))
abort ();
- delete_insn (safety_label);
+ delete_related_insns (safety_label);
/* If exit_label exists, emit it after the loop. Doing the emit here
forces it to have a higher INSN_UID than any insn in the unrolled loop.
{
/* Remove the loop notes since this is no longer a loop. */
if (loop->vtop)
- delete_insn (loop->vtop);
+ delete_related_insns (loop->vtop);
if (loop->cont)
- delete_insn (loop->cont);
+ delete_related_insns (loop->cont);
if (loop_start)
- delete_insn (loop_start);
+ delete_related_insns (loop_start);
if (loop_end)
- delete_insn (loop_end);
+ delete_related_insns (loop_end);
}
if (map->const_equiv_varray)
}
free (map->insn_map);
free (splittable_regs);
- free (derived_regs);
free (splittable_regs_updates);
free (addr_combined_regs);
free (local_regno);
reflected in RTX_COST. */
int
-precondition_loop_p (loop_start, loop_info,
- initial_value, final_value, increment, mode)
- rtx loop_start;
- struct loop_info *loop_info;
+precondition_loop_p (loop, initial_value, final_value, increment, mode)
+ const struct loop *loop;
rtx *initial_value, *final_value, *increment;
enum machine_mode *mode;
{
+ rtx loop_start = loop->start;
+ struct loop_info *loop_info = LOOP_INFO (loop);
if (loop_info->n_iterations > 0)
{
- *initial_value = const0_rtx;
- *increment = const1_rtx;
- *final_value = GEN_INT (loop_info->n_iterations);
+ if (INTVAL (loop_info->increment) > 0)
+ {
+ *initial_value = const0_rtx;
+ *increment = const1_rtx;
+ *final_value = GEN_INT (loop_info->n_iterations);
+ }
+ else
+ {
+ *initial_value = GEN_INT (loop_info->n_iterations);
+ *increment = constm1_rtx;
+ *final_value = const0_rtx;
+ }
*mode = word_mode;
if (loop_dump_stream)
return 1;
}
- if (loop_info->initial_value == 0)
+ if (loop_info->iteration_var == 0)
+ {
+ if (loop_dump_stream)
+ fprintf (loop_dump_stream,
+ "Preconditioning: Could not find iteration variable.\n");
+ return 0;
+ }
+ else if (loop_info->initial_value == 0)
{
if (loop_dump_stream)
fprintf (loop_dump_stream,
return 0;
}
else if ((exact_log2 (INTVAL (loop_info->increment)) < 0)
- && (exact_log2 (- INTVAL (loop_info->increment)) < 0))
+ && (exact_log2 (-INTVAL (loop_info->increment)) < 0))
{
if (loop_dump_stream)
fprintf (loop_dump_stream,
return 0;
}
- /* Must ensure that final_value is invariant, so call invariant_p to
- check. Before doing so, must check regno against max_reg_before_loop
- to make sure that the register is in the range covered by invariant_p.
- If it isn't, then it is most likely a biv/giv which by definition are
- not invariant. */
+ /* Must ensure that final_value is invariant, so call
+ loop_invariant_p to check. Before doing so, must check regno
+ against max_reg_before_loop to make sure that the register is in
+ the range covered by loop_invariant_p. If it isn't, then it is
+ most likely a biv/giv which by definition are not invariant. */
if ((GET_CODE (loop_info->final_value) == REG
&& REGNO (loop_info->final_value) >= max_reg_before_loop)
|| (GET_CODE (loop_info->final_value) == PLUS
&& REGNO (XEXP (loop_info->final_value, 0)) >= max_reg_before_loop)
- || ! invariant_p (loop_info->final_value))
+ || ! loop_invariant_p (loop, loop_info->final_value))
{
if (loop_dump_stream)
fprintf (loop_dump_stream,
/* Fail if loop_info->iteration_var is not live before loop_start,
since we need to test its value in the preconditioning code. */
- if (uid_luid[REGNO_FIRST_UID (REGNO (loop_info->iteration_var))]
+ if (REGNO_FIRST_LUID (REGNO (loop_info->iteration_var))
> INSN_LUID (loop_start))
{
if (loop_dump_stream)
return 0;
}
- /* Note that iteration_info biases the initial value for GIV iterators
+ /* Note that loop_iterations biases the initial value for GIV iterators
such as "while (i-- > 0)" so that we can calculate the number of
iterations just like for BIV iterators.
return 1;
}
-
/* All pseudo-registers must be mapped to themselves. Two hard registers
must be mapped, VIRTUAL_STACK_VARS_REGNUM and VIRTUAL_INCOMING_ARGS_
REGNUM, to avoid function-inlining specific conversions of these
static rtx
calculate_giv_inc (pattern, src_insn, regno)
rtx pattern, src_insn;
- int regno;
+ unsigned int regno;
{
rtx increment;
rtx increment_total = 0;
/* SR sometimes computes the new giv value in a temp, then copies it
to the new_reg. */
src_insn = PREV_INSN (src_insn);
- pattern = PATTERN (src_insn);
+ pattern = single_set (src_insn);
if (GET_CODE (SET_SRC (pattern)) != PLUS)
abort ();
/* The last insn emitted is not needed, so delete it to avoid confusing
the second cse pass. This insn sets the giv unnecessarily. */
- delete_insn (get_last_insn ());
+ delete_related_insns (get_last_insn ());
}
/* Verify that we have a constant as the second operand of the plus. */
{
/* SR sometimes puts the constant in a register, especially if it is
too big to be an add immed operand. */
- src_insn = PREV_INSN (src_insn);
- increment = SET_SRC (PATTERN (src_insn));
+ increment = find_last_value (increment, &src_insn, NULL_RTX, 0);
/* SR may have used LO_SUM to compute the constant if it is too large
for a load immed operand. In this case, the constant is in operand
rtx second_part = XEXP (increment, 1);
enum rtx_code code = GET_CODE (increment);
- src_insn = PREV_INSN (src_insn);
- increment = SET_SRC (PATTERN (src_insn));
+ increment = find_last_value (XEXP (increment, 0),
+ &src_insn, NULL_RTX, 0);
/* Don't need the last insn anymore. */
- delete_insn (get_last_insn ());
+ delete_related_insns (get_last_insn ());
if (GET_CODE (second_part) != CONST_INT
|| GET_CODE (increment) != CONST_INT)
/* The insn loading the constant into a register is no longer needed,
so delete it. */
- delete_insn (get_last_insn ());
+ delete_related_insns (get_last_insn ());
}
if (increment_total)
tries++;
src_insn = PREV_INSN (src_insn);
- pattern = PATTERN (src_insn);
+ pattern = single_set (src_insn);
- delete_insn (get_last_insn ());
+ delete_related_insns (get_last_insn ());
goto retry;
}
return 0;
copy = rtx_alloc (GET_CODE (notes));
- PUT_MODE (copy, GET_MODE (notes));
+ PUT_REG_NOTE_KIND (copy, REG_NOTE_KIND (notes));
if (GET_CODE (notes) == EXPR_LIST)
XEXP (copy, 0) = copy_rtx_and_substitute (XEXP (notes, 0), map, 0);
else if (GET_CODE (notes) == INSN_LIST)
/* Don't substitute for these yet. */
- XEXP (copy, 0) = XEXP (notes, 0);
+ XEXP (copy, 0) = copy_rtx (XEXP (notes, 0));
else
abort ();
/* Fixup insn references in copied REG_NOTES. */
static void
-final_reg_note_copy (notes, map)
- rtx notes;
+final_reg_note_copy (notesp, map)
+ rtx *notesp;
struct inline_remap *map;
{
- rtx note;
+ while (*notesp)
+ {
+ rtx note = *notesp;
+
+ if (GET_CODE (note) == INSN_LIST)
+ {
+ /* Sometimes, we have a REG_WAS_0 note that points to a
+ deleted instruction. In that case, we can just delete the
+ note. */
+ if (REG_NOTE_KIND (note) == REG_WAS_0)
+ {
+ *notesp = XEXP (note, 1);
+ continue;
+ }
+ else
+ {
+ rtx insn = map->insn_map[INSN_UID (XEXP (note, 0))];
- for (note = notes; note; note = XEXP (note, 1))
- if (GET_CODE (note) == INSN_LIST)
- XEXP (note, 0) = map->insn_map[INSN_UID (XEXP (note, 0))];
+ /* If we failed to remap the note, something is awry.
+ Allow REG_LABEL as it may reference label outside
+ the unrolled loop. */
+ if (!insn)
+ {
+ if (REG_NOTE_KIND (note) != REG_LABEL)
+ abort ();
+ }
+ else
+ XEXP (note, 0) = insn;
+ }
+ }
+
+ notesp = &XEXP (note, 1);
+ }
}
/* Copy each instruction in the loop, substituting from map as appropriate.
This is very similar to a loop in expand_inline_function. */
static void
-copy_loop_body (copy_start, copy_end, map, exit_label, last_iteration,
+copy_loop_body (loop, copy_start, copy_end, map, exit_label, last_iteration,
unroll_type, start_label, loop_end, insert_before,
copy_notes_from)
+ struct loop *loop;
rtx copy_start, copy_end;
struct inline_remap *map;
rtx exit_label;
enum unroll_types unroll_type;
rtx start_label, loop_end, insert_before, copy_notes_from;
{
+ struct loop_ivs *ivs = LOOP_IVS (loop);
rtx insn, pattern;
rtx set, tem, copy = NULL_RTX;
int dest_reg_was_split, i;
if (! last_iteration)
{
final_label = gen_label_rtx ();
- set_label_in_map (map, CODE_LABEL_NUMBER (start_label),
- final_label);
+ set_label_in_map (map, CODE_LABEL_NUMBER (start_label), final_label);
}
else
set_label_in_map (map, CODE_LABEL_NUMBER (start_label), start_label);
{
struct iv_class *bl;
struct induction *v, *tv;
- int regno = REGNO (SET_DEST (set));
+ unsigned int regno = REGNO (SET_DEST (set));
v = addr_combined_regs[REGNO (SET_DEST (set))];
- bl = reg_biv_class[REGNO (v->src_reg)];
+ bl = REG_IV_CLASS (ivs, REGNO (v->src_reg));
/* Although the giv_inc amount is not needed here, we must call
calculate_giv_inc here since it might try to delete the
we might accidentally delete insns generated immediately
below by emit_unrolled_add. */
- if (! derived_regs[regno])
- giv_inc = calculate_giv_inc (set, insn, regno);
+ giv_inc = calculate_giv_inc (set, insn, regno);
/* Now find all address giv's that were combined with this
giv 'v'. */
We must subtract the const_adjust factor added in
above. */
tv->dest_reg = plus_constant (dest_reg,
- - tv->const_adjust);
+ -tv->const_adjust);
*tv->location = tv->dest_reg;
}
}
&& GET_CODE (SET_DEST (set)) == REG
&& splittable_regs[REGNO (SET_DEST (set))])
{
- int regno = REGNO (SET_DEST (set));
- int src_regno;
+ unsigned int regno = REGNO (SET_DEST (set));
+ unsigned int src_regno;
dest_reg_was_split = 1;
giv_dest_reg = SET_DEST (set);
- if (derived_regs[regno])
- {
- /* ??? This relies on SET_SRC (SET) to be of
- the form (plus (reg) (const_int)), and thus
- forces recombine_givs to restrict the kind
- of giv derivations it does before unrolling. */
- giv_src_reg = XEXP (SET_SRC (set), 0);
- giv_inc = XEXP (SET_SRC (set), 1);
- }
- else
- {
- giv_src_reg = giv_dest_reg;
- /* Compute the increment value for the giv, if it wasn't
- already computed above. */
- if (giv_inc == 0)
- giv_inc = calculate_giv_inc (set, insn, regno);
- }
+ giv_src_reg = giv_dest_reg;
+ /* Compute the increment value for the giv, if it wasn't
+ already computed above. */
+ if (giv_inc == 0)
+ giv_inc = calculate_giv_inc (set, insn, regno);
+
src_regno = REGNO (giv_src_reg);
if (unroll_type == UNROLL_COMPLETELY)
for the biv was stored in the biv's first struct
induction entry by find_splittable_regs. */
- if (regno < max_reg_before_loop
- && REG_IV_TYPE (regno) == BASIC_INDUCT)
+ if (regno < ivs->n_regs
+ && REG_IV_TYPE (ivs, regno) == BASIC_INDUCT)
{
- giv_src_reg = reg_biv_class[regno]->biv->src_reg;
+ giv_src_reg = REG_IV_CLASS (ivs, regno)->biv->src_reg;
giv_dest_reg = giv_src_reg;
}
#endif
splittable_regs[regno]
- = GEN_INT (INTVAL (giv_inc)
- + INTVAL (splittable_regs[src_regno]));
+ = simplify_gen_binary (PLUS, GET_MODE (giv_src_reg),
+ giv_inc,
+ splittable_regs[src_regno]);
giv_inc = splittable_regs[regno];
/* Now split the induction variable by changing the dest
copy = emit_jump_insn (pattern);
REG_NOTES (copy) = initial_reg_note_copy (REG_NOTES (insn), map);
+ if (JUMP_LABEL (insn))
+ {
+ JUMP_LABEL (copy) = get_label_from_map (map,
+ CODE_LABEL_NUMBER
+ (JUMP_LABEL (insn)));
+ LABEL_NUSES (JUMP_LABEL (copy))++;
+ }
if (JUMP_LABEL (insn) == start_label && insn == copy_end
&& ! last_iteration)
{
+
/* This is a branch to the beginning of the loop; this is the
last insn being copied; and this is not the last iteration.
In this case, we want to change the original fall through
case to be a branch past the end of the loop, and the
original jump label case to fall_through. */
- if (invert_exp (pattern, copy))
- {
- if (! redirect_exp (&pattern,
- get_label_from_map (map,
- CODE_LABEL_NUMBER
- (JUMP_LABEL (insn))),
- exit_label, copy))
- abort ();
- }
- else
+ if (!invert_jump (copy, exit_label, 0))
{
rtx jmp;
rtx lab = gen_label_rtx ();
jump_insn after COPY, and redirect the jump around
that. */
jmp = emit_jump_insn_after (gen_jump (exit_label), copy);
+ JUMP_LABEL (jmp) = exit_label;
+ LABEL_NUSES (exit_label)++;
jmp = emit_barrier_after (jmp);
emit_label_after (lab, jmp);
LABEL_NUSES (lab) = 0;
- if (! redirect_exp (&pattern,
- get_label_from_map (map,
- CODE_LABEL_NUMBER
- (JUMP_LABEL (insn))),
- lab, copy))
+ if (!redirect_jump (copy, lab, 0))
abort ();
}
}
/* If this used to be a conditional jump insn but whose branch
direction is now known, we must do something special. */
- if (condjump_p (insn) && !simplejump_p (insn) && map->last_pc_value)
+ if (any_condjump_p (insn) && onlyjump_p (insn) && map->last_pc_value)
{
#ifdef HAVE_cc0
/* If the previous insn set cc0 for us, delete it. */
- if (sets_cc0_p (PREV_INSN (copy)))
- delete_insn (PREV_INSN (copy));
+ if (only_sets_cc0_p (PREV_INSN (copy)))
+ delete_related_insns (PREV_INSN (copy));
#endif
/* If this is now a no-op, delete it. */
if (map->last_pc_value == pc_rtx)
{
- /* Don't let delete_insn delete the label referenced here,
- because we might possibly need it later for some other
- instruction in the loop. */
- if (JUMP_LABEL (copy))
- LABEL_NUSES (JUMP_LABEL (copy))++;
delete_insn (copy);
- if (JUMP_LABEL (copy))
- LABEL_NUSES (JUMP_LABEL (copy))--;
copy = 0;
}
else
/* VTOP and CONT notes are valid only before the loop exit test.
If placed anywhere else, loop may generate bad code. */
/* BASIC_BLOCK notes exist to stabilize basic block structures with
- the associated rtl. We do not want to share the structure in
+ the associated rtl. We do not want to share the structure in
this new block. */
if (NOTE_LINE_NUMBER (insn) != NOTE_INSN_DELETED
+ && NOTE_LINE_NUMBER (insn) != NOTE_INSN_DELETED_LABEL
&& NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK
&& ((NOTE_LINE_NUMBER (insn) != NOTE_INSN_LOOP_VTOP
&& NOTE_LINE_NUMBER (insn) != NOTE_INSN_LOOP_CONT)
if ((GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
|| GET_CODE (insn) == CALL_INSN)
&& map->insn_map[INSN_UID (insn)])
- final_reg_note_copy (REG_NOTES (map->insn_map[INSN_UID (insn)]), map);
+ final_reg_note_copy (®_NOTES (map->insn_map[INSN_UID (insn)]), map);
}
while (insn != copy_end);
tem = gen_sequence ();
end_sequence ();
- emit_insn_before (tem, insert_before);
+ loop_insn_emit_before (loop, 0, insert_before, tem);
}
\f
/* Emit an insn, using the expand_binop to ensure that a valid insn is
{
rtx result;
- result = expand_binop (GET_MODE (dest_reg), add_optab, src_reg, increment,
- dest_reg, 0, OPTAB_LIB_WIDEN);
+ result = expand_simple_binop (GET_MODE (dest_reg), PLUS, src_reg, increment,
+ dest_reg, 0, OPTAB_LIB_WIDEN);
if (dest_reg != result)
emit_move_insn (dest_reg, result);
}
\f
-/* Searches the insns between INSN and LOOP_END. Returns 1 if there
+/* Searches the insns between INSN and LOOP->END. Returns 1 if there
is a backward branch in that range that branches to somewhere between
- LOOP_START and INSN. Returns 0 otherwise. */
+ LOOP->START and INSN. Returns 0 otherwise. */
/* ??? This is quadratic algorithm. Could be rewritten to be linear.
In practice, this is not a problem, because this function is seldom called,
and uses a negligible amount of CPU time on average. */
int
-back_branch_in_range_p (insn, loop_start, loop_end)
+back_branch_in_range_p (loop, insn)
+ const struct loop *loop;
rtx insn;
- rtx loop_start, loop_end;
{
rtx p, q, target_insn;
- rtx orig_loop_end = loop_end;
+ rtx loop_start = loop->start;
+ rtx loop_end = loop->end;
+ rtx orig_loop_end = loop->end;
/* Stop before we get to the backward branch at the end of the loop. */
loop_end = prev_nonnote_insn (loop_end);
if it can be calculated. Otherwise, returns 0. */
rtx
-biv_total_increment (bl, loop_start, loop_end)
- struct iv_class *bl;
- rtx loop_start ATTRIBUTE_UNUSED, loop_end ATTRIBUTE_UNUSED;
+biv_total_increment (bl)
+ const struct iv_class *bl;
{
struct induction *v;
rtx result;
return result;
}
-/* Determine the initial value of the iteration variable, and the amount
- that it is incremented each loop. Use the tables constructed by
- the strength reduction pass to calculate these values.
-
- Initial_value and/or increment are set to zero if their values could not
- be calculated. */
-
-static void
-iteration_info (iteration_var, initial_value, increment, loop_start, loop_end)
- rtx iteration_var, *initial_value, *increment;
- rtx loop_start, loop_end;
-{
- struct iv_class *bl;
-#if 0
- struct induction *v;
-#endif
-
- /* Clear the result values, in case no answer can be found. */
- *initial_value = 0;
- *increment = 0;
-
- /* The iteration variable can be either a giv or a biv. Check to see
- which it is, and compute the variable's initial value, and increment
- value if possible. */
-
- /* If this is a new register, can't handle it since we don't have any
- reg_iv_type entry for it. */
- if ((unsigned) REGNO (iteration_var) >= reg_iv_type->num_elements)
- {
- if (loop_dump_stream)
- fprintf (loop_dump_stream,
- "Loop unrolling: No reg_iv_type entry for iteration var.\n");
- return;
- }
-
- /* Reject iteration variables larger than the host wide int size, since they
- could result in a number of iterations greater than the range of our
- `unsigned HOST_WIDE_INT' variable loop_info->n_iterations. */
- else if ((GET_MODE_BITSIZE (GET_MODE (iteration_var))
- > HOST_BITS_PER_WIDE_INT))
- {
- if (loop_dump_stream)
- fprintf (loop_dump_stream,
- "Loop unrolling: Iteration var rejected because mode too large.\n");
- return;
- }
- else if (GET_MODE_CLASS (GET_MODE (iteration_var)) != MODE_INT)
- {
- if (loop_dump_stream)
- fprintf (loop_dump_stream,
- "Loop unrolling: Iteration var not an integer.\n");
- return;
- }
- else if (REG_IV_TYPE (REGNO (iteration_var)) == BASIC_INDUCT)
- {
- /* When reg_iv_type / reg_iv_info is resized for biv increments
- that are turned into givs, reg_biv_class is not resized.
- So check here that we don't make an out-of-bounds access. */
- if (REGNO (iteration_var) >= max_reg_before_loop)
- abort ();
-
- /* Grab initial value, only useful if it is a constant. */
- bl = reg_biv_class[REGNO (iteration_var)];
- *initial_value = bl->initial_value;
-
- *increment = biv_total_increment (bl, loop_start, loop_end);
- }
- else if (REG_IV_TYPE (REGNO (iteration_var)) == GENERAL_INDUCT)
- {
- HOST_WIDE_INT offset = 0;
- struct induction *v = REG_IV_INFO (REGNO (iteration_var));
-
- if (REGNO (v->src_reg) >= max_reg_before_loop)
- abort ();
-
- bl = reg_biv_class[REGNO (v->src_reg)];
-
- /* Increment value is mult_val times the increment value of the biv. */
-
- *increment = biv_total_increment (bl, loop_start, loop_end);
- if (*increment)
- {
- struct induction *biv_inc;
-
- *increment
- = fold_rtx_mult_add (v->mult_val, *increment, const0_rtx, v->mode);
- /* The caller assumes that one full increment has occured at the
- first loop test. But that's not true when the biv is incremented
- after the giv is set (which is the usual case), e.g.:
- i = 6; do {;} while (i++ < 9) .
- Therefore, we bias the initial value by subtracting the amount of
- the increment that occurs between the giv set and the giv test. */
- for (biv_inc = bl->biv; biv_inc; biv_inc = biv_inc->next_iv)
- {
- if (loop_insn_first_p (v->insn, biv_inc->insn))
- offset -= INTVAL (biv_inc->add_val);
- }
- offset *= INTVAL (v->mult_val);
- }
- if (loop_dump_stream)
- fprintf (loop_dump_stream,
- "Loop unrolling: Giv iterator, initial value bias %ld.\n",
- (long) offset);
- /* Initial value is mult_val times the biv's initial value plus
- add_val. Only useful if it is a constant. */
- *initial_value
- = fold_rtx_mult_add (v->mult_val,
- plus_constant (bl->initial_value, offset),
- v->add_val, v->mode);
- }
- else
- {
- if (loop_dump_stream)
- fprintf (loop_dump_stream,
- "Loop unrolling: Not basic or general induction var.\n");
- return;
- }
-}
-
-
/* For each biv and giv, determine whether it can be safely split into
a different variable for each unrolled copy of the loop body. If it
is safe to split, then indicate that by saving some useful info
times, since multiplies by small integers (1,2,3,4) are very cheap. */
static int
-find_splittable_regs (unroll_type, loop_start, loop_end, end_insert_before,
- unroll_number, n_iterations)
+find_splittable_regs (loop, unroll_type, unroll_number)
+ const struct loop *loop;
enum unroll_types unroll_type;
- rtx loop_start, loop_end;
- rtx end_insert_before;
int unroll_number;
- unsigned HOST_WIDE_INT n_iterations;
{
+ struct loop_ivs *ivs = LOOP_IVS (loop);
struct iv_class *bl;
struct induction *v;
rtx increment, tem;
int biv_splittable;
int result = 0;
- for (bl = loop_iv_list; bl; bl = bl->next)
+ for (bl = ivs->list; bl; bl = bl->next)
{
/* Biv_total_increment must return a constant value,
otherwise we can not calculate the split values. */
- increment = biv_total_increment (bl, loop_start, loop_end);
+ increment = biv_total_increment (bl);
if (! increment || GET_CODE (increment) != CONST_INT)
continue;
biv_splittable = 1;
biv_final_value = 0;
if (unroll_type != UNROLL_COMPLETELY
- && (uid_loop[INSN_UID (loop_start)]->exit_count
- || unroll_type == UNROLL_NAIVE)
- && (uid_luid[REGNO_LAST_UID (bl->regno)] >= INSN_LUID (loop_end)
+ && (loop->exit_count || unroll_type == UNROLL_NAIVE)
+ && (REGNO_LAST_LUID (bl->regno) >= INSN_LUID (loop->end)
|| ! bl->init_insn
|| INSN_UID (bl->init_insn) >= max_uid_for_loop
- || (uid_luid[REGNO_FIRST_UID (bl->regno)]
+ || (REGNO_FIRST_LUID (bl->regno)
< INSN_LUID (bl->init_insn))
|| reg_mentioned_p (bl->biv->dest_reg, SET_SRC (bl->init_set)))
- && ! (biv_final_value = final_biv_value (bl, loop_start, loop_end,
- n_iterations)))
+ && ! (biv_final_value = final_biv_value (loop, bl)))
biv_splittable = 0;
/* If any of the insns setting the BIV don't do so with a simple
if (GET_CODE (bl->initial_value) == REG
&& (REGNO (bl->initial_value) == bl->regno
|| REGNO (bl->initial_value) < FIRST_PSEUDO_REGISTER
- || ! invariant_p (bl->initial_value)))
+ || ! loop_invariant_p (loop, bl->initial_value)))
{
rtx tem = gen_reg_rtx (bl->biv->mode);
record_base_value (REGNO (tem), bl->biv->add_val, 0);
- emit_insn_before (gen_move_insn (tem, bl->biv->src_reg),
- loop_start);
+ loop_insn_hoist (loop,
+ gen_move_insn (tem, bl->biv->src_reg));
if (loop_dump_stream)
- fprintf (loop_dump_stream, "Biv %d initial value remapped to %d.\n",
+ fprintf (loop_dump_stream,
+ "Biv %d initial value remapped to %d.\n",
bl->regno, REGNO (tem));
splittable_regs[bl->regno] = tem;
depend on it may be splittable if the biv is live outside the
loop, and the givs aren't. */
- result += find_splittable_givs (bl, unroll_type, loop_start, loop_end,
- increment, unroll_number);
+ result += find_splittable_givs (loop, bl, unroll_type, increment,
+ unroll_number);
/* If final value is non-zero, then must emit an instruction which sets
the value of the biv to the proper value. This is done after
loop to ensure that it will always be executed no matter
how the loop exits. Otherwise emit the insn after the loop,
since this is slightly more efficient. */
- if (! uid_loop[INSN_UID (loop_start)]->exit_count)
- emit_insn_before (gen_move_insn (bl->biv->src_reg,
- biv_final_value),
- end_insert_before);
+ if (! loop->exit_count)
+ loop_insn_sink (loop, gen_move_insn (bl->biv->src_reg,
+ biv_final_value));
else
{
/* Create a new register to hold the value of the biv, and then
rtx tem = gen_reg_rtx (bl->biv->mode);
record_base_value (REGNO (tem), bl->biv->add_val, 0);
- emit_insn_before (gen_move_insn (tem, bl->biv->src_reg),
- loop_start);
- emit_insn_before (gen_move_insn (bl->biv->src_reg,
- biv_final_value),
- loop_start);
+ loop_insn_hoist (loop, gen_move_insn (tem, bl->biv->src_reg));
+ loop_insn_hoist (loop, gen_move_insn (bl->biv->src_reg,
+ biv_final_value));
if (loop_dump_stream)
fprintf (loop_dump_stream, "Biv %d mapped to %d for split.\n",
Return the number of instructions that set splittable registers. */
static int
-find_splittable_givs (bl, unroll_type, loop_start, loop_end, increment,
- unroll_number)
+find_splittable_givs (loop, bl, unroll_type, increment, unroll_number)
+ const struct loop *loop;
struct iv_class *bl;
enum unroll_types unroll_type;
- rtx loop_start, loop_end;
rtx increment;
int unroll_number;
{
+ struct loop_ivs *ivs = LOOP_IVS (loop);
struct induction *v, *v2;
rtx final_value;
rtx tem;
won't reach here if they aren't. */
if (v->giv_type != DEST_ADDR
&& (! v->always_computable
- || back_branch_in_range_p (v->insn, loop_start, loop_end)))
+ || back_branch_in_range_p (loop, v->insn)))
continue;
/* The giv increment value must be a constant. */
final_value = 0;
if (unroll_type != UNROLL_COMPLETELY
- && (uid_loop[INSN_UID (loop_start)]->exit_count
- || unroll_type == UNROLL_NAIVE)
+ && (loop->exit_count || unroll_type == UNROLL_NAIVE)
&& v->giv_type != DEST_ADDR
/* The next part is true if the pseudo is used outside the loop.
We assume that this is true for any pseudo created after loop
|| (REGNO_FIRST_UID (REGNO (v->dest_reg))
!= INSN_UID (XEXP (tem, 0)))))
/* Line above always fails if INSN was moved by loop opt. */
- || (uid_luid[REGNO_LAST_UID (REGNO (v->dest_reg))]
- >= INSN_LUID (loop_end)))
- /* Givs made from biv increments are missed by the above test, so
- test explicitly for them. */
- && (REGNO (v->dest_reg) < first_increment_giv
- || REGNO (v->dest_reg) > last_increment_giv)
+ || (REGNO_LAST_LUID (REGNO (v->dest_reg))
+ >= INSN_LUID (loop->end)))
&& ! (final_value = v->final_value))
continue;
to its final value before loop start to ensure that this insn
will always be executed, no matter how we exit. */
tem = gen_reg_rtx (v->mode);
- emit_insn_before (gen_move_insn (tem, v->dest_reg), loop_start);
- emit_insn_before (gen_move_insn (v->dest_reg, final_value),
- loop_start);
+ loop_insn_hoist (loop, gen_move_insn (tem, v->dest_reg));
+ loop_insn_hoist (loop, gen_move_insn (v->dest_reg, final_value));
if (loop_dump_stream)
fprintf (loop_dump_stream, "Giv %d mapped to %d for split.\n",
rtx tem = gen_reg_rtx (bl->biv->mode);
record_base_value (REGNO (tem), bl->biv->add_val, 0);
- emit_insn_before (gen_move_insn (tem, bl->biv->src_reg),
- loop_start);
+ loop_insn_hoist (loop, gen_move_insn (tem, bl->biv->src_reg));
biv_initial_value = tem;
}
+ biv_initial_value = extend_value_for_giv (v, biv_initial_value);
value = fold_rtx_mult_add (v->mult_val, biv_initial_value,
v->add_val, v->mode);
}
{
rtx tem = gen_reg_rtx (v->mode);
record_base_value (REGNO (tem), v->add_val, 0);
- emit_iv_add_mult (bl->initial_value, v->mult_val,
- v->add_val, tem, loop_start);
+ loop_iv_add_mult_hoist (loop, bl->initial_value, v->mult_val,
+ v->add_val, tem);
value = tem;
}
splittable_regs[REGNO (v->new_reg)] = value;
- derived_regs[REGNO (v->new_reg)] = v->derived_from != 0;
}
else
{
rtx new_reg = v->new_reg;
record_base_value (REGNO (tem), v->add_val, 0);
- if (same && same->derived_from)
- {
- /* calculate_giv_inc doesn't work for derived givs.
- copy_loop_body works around the problem for the
- DEST_REG givs themselves, but it can't handle
- DEST_ADDR givs that have been combined with
- a derived DEST_REG giv.
- So Handle V as if the giv from which V->SAME has
- been derived has been combined with V.
- recombine_givs only derives givs from givs that
- are reduced the ordinary, so we need not worry
- about same->derived_from being in turn derived. */
-
- same = same->derived_from;
- new_reg = express_from (same, v);
- new_reg = replace_rtx (new_reg, same->dest_reg,
- same->new_reg);
- }
-
/* If the address giv has a constant in its new_reg value,
then this constant can be pulled out and put in value,
instead of being part of the initialization code. */
/* Save the negative of the eliminated const, so
that we can calculate the dest_reg's increment
value later. */
- v->const_adjust = - INTVAL (XEXP (new_reg, 1));
+ v->const_adjust = -INTVAL (XEXP (new_reg, 1));
new_reg = XEXP (new_reg, 0);
if (loop_dump_stream)
instruction on machines with complex addressing modes.
If we can't recognize it, then delete it and emit insns
to calculate the value from scratch. */
- emit_insn_before (gen_rtx_SET (VOIDmode, tem,
- copy_rtx (v->new_reg)),
- loop_start);
- if (recog_memoized (PREV_INSN (loop_start)) < 0)
+ loop_insn_hoist (loop, gen_rtx_SET (VOIDmode, tem,
+ copy_rtx (v->new_reg)));
+ if (recog_memoized (PREV_INSN (loop->start)) < 0)
{
rtx sequence, ret;
/* We can't use bl->initial_value to compute the initial
value, because the loop may have been preconditioned.
- We must calculate it from NEW_REG. Try using
- force_operand instead of emit_iv_add_mult. */
- delete_insn (PREV_INSN (loop_start));
+ We must calculate it from NEW_REG. */
+ delete_related_insns (PREV_INSN (loop->start));
start_sequence ();
ret = force_operand (v->new_reg, tem);
emit_move_insn (tem, ret);
sequence = gen_sequence ();
end_sequence ();
- emit_insn_before (sequence, loop_start);
+ loop_insn_hoist (loop, sequence);
if (loop_dump_stream)
fprintf (loop_dump_stream,
INSN_UID (v->insn));
continue;
}
- if (v->same && v->same->derived_from)
- {
- /* Handle V as if the giv from which V->SAME has
- been derived has been combined with V. */
-
- v->same = v->same->derived_from;
- v->new_reg = express_from (v->same, v);
- v->new_reg = replace_rtx (v->new_reg, v->same->dest_reg,
- v->same->new_reg);
- }
-
}
/* Store the value of dest_reg into the insn. This sharing
Make sure that it's giv is marked as splittable here. */
splittable_regs[REGNO (v->new_reg)] = value;
- derived_regs[REGNO (v->new_reg)] = v->derived_from != 0;
/* Make it appear to depend upon itself, so that the
giv will be properly split in the main loop above. */
{
int count = 1;
if (! v->ignore)
- count = reg_biv_class[REGNO (v->src_reg)]->biv_count;
-
- if (count > 1 && v->derived_from)
- /* In this case, there is one set where the giv insn was and one
- set each after each biv increment. (Most are likely dead.) */
- count++;
+ count = REG_IV_CLASS (ivs, REGNO (v->src_reg))->biv_count;
splittable_regs_updates[REGNO (v->new_reg)] = count;
}
it can search past if statements and other similar structures. */
static int
-reg_dead_after_loop (reg, loop_start, loop_end)
- rtx reg, loop_start, loop_end;
+reg_dead_after_loop (loop, reg)
+ const struct loop *loop;
+ rtx reg;
{
rtx insn, label;
enum rtx_code code;
int jump_count = 0;
int label_count = 0;
- struct loop *loop = uid_loop[INSN_UID (loop_start)];
/* In addition to checking all exits of this loop, we must also check
all exits of inner nested loops that would exit this loop. We don't
return 0;
/* HACK: Must also search the loop fall through exit, create a label_ref
- here which points to the loop_end, and append the loop_number_exit_labels
+ here which points to the loop->end, and append the loop_number_exit_labels
list to it. */
- label = gen_rtx_LABEL_REF (VOIDmode, loop_end);
+ label = gen_rtx_LABEL_REF (VOIDmode, loop->end);
LABEL_NEXTREF (label) = loop->exit_labels;
- for ( ; label; label = LABEL_NEXTREF (label))
+ for (; label; label = LABEL_NEXTREF (label))
{
/* Succeed if find an insn which sets the biv or if reach end of
function. Fail if find an insn that uses the biv, or if come to
{
if (GET_CODE (PATTERN (insn)) == RETURN)
break;
- else if (! simplejump_p (insn)
+ else if (!any_uncondjump_p (insn)
/* Prevent infinite loop following infinite loops. */
|| jump_count++ > 20)
return 0;
the end of the loop. If we can do it, return that value. */
rtx
-final_biv_value (bl, loop_start, loop_end, n_iterations)
+final_biv_value (loop, bl)
+ const struct loop *loop;
struct iv_class *bl;
- rtx loop_start, loop_end;
- unsigned HOST_WIDE_INT n_iterations;
{
+ unsigned HOST_WIDE_INT n_iterations = LOOP_INFO (loop)->n_iterations;
rtx increment, tem;
/* ??? This only works for MODE_INT biv's. Reject all others for now. */
return 0;
/* The final value for reversed bivs must be calculated differently than
- for ordinary bivs. In this case, there is already an insn after the
+ for ordinary bivs. In this case, there is already an insn after the
loop which sets this biv's final value (if necessary), and there are
no other loop exits, so we can return any value. */
if (bl->reversed)
value of the biv must be invariant. */
if (n_iterations != 0
- && ! uid_loop[INSN_UID (loop_start)]->exit_count
- && invariant_p (bl->initial_value))
+ && ! loop->exit_count
+ && loop_invariant_p (loop, bl->initial_value))
{
- increment = biv_total_increment (bl, loop_start, loop_end);
+ increment = biv_total_increment (bl);
- if (increment && invariant_p (increment))
+ if (increment && loop_invariant_p (loop, increment))
{
/* Can calculate the loop exit value, emit insns after loop
end to calculate this value into a temporary register in
tem = gen_reg_rtx (bl->biv->mode);
record_base_value (REGNO (tem), bl->biv->add_val, 0);
- /* Make sure loop_end is not the last insn. */
- if (NEXT_INSN (loop_end) == 0)
- emit_note_after (NOTE_INSN_DELETED, loop_end);
- emit_iv_add_mult (increment, GEN_INT (n_iterations),
- bl->initial_value, tem, NEXT_INSN (loop_end));
+ loop_iv_add_mult_sink (loop, increment, GEN_INT (n_iterations),
+ bl->initial_value, tem);
if (loop_dump_stream)
fprintf (loop_dump_stream,
}
/* Check to see if the biv is dead at all loop exits. */
- if (reg_dead_after_loop (bl->biv->src_reg, loop_start, loop_end))
+ if (reg_dead_after_loop (loop, bl->biv->src_reg))
{
if (loop_dump_stream)
fprintf (loop_dump_stream,
the end of the loop. If we can do it, return that value. */
rtx
-final_giv_value (v, loop_start, loop_end, n_iterations)
+final_giv_value (loop, v)
+ const struct loop *loop;
struct induction *v;
- rtx loop_start, loop_end;
- unsigned HOST_WIDE_INT n_iterations;
{
+ struct loop_ivs *ivs = LOOP_IVS (loop);
struct iv_class *bl;
rtx insn;
rtx increment, tem;
- rtx insert_before, seq;
+ rtx seq;
+ rtx loop_end = loop->end;
+ unsigned HOST_WIDE_INT n_iterations = LOOP_INFO (loop)->n_iterations;
- bl = reg_biv_class[REGNO (v->src_reg)];
+ bl = REG_IV_CLASS (ivs, REGNO (v->src_reg));
/* The final value for givs which depend on reversed bivs must be calculated
differently than for ordinary givs. In this case, there is already an
to be known. */
if (n_iterations != 0
- && ! uid_loop[INSN_UID (loop_start)]->exit_count)
+ && ! loop->exit_count)
{
/* ?? It is tempting to use the biv's value here since these insns will
be put after the loop, and hence the biv will have its final value
sure that bl->initial_value is still valid then. It will still
be valid if it is invariant. */
- increment = biv_total_increment (bl, loop_start, loop_end);
+ increment = biv_total_increment (bl);
- if (increment && invariant_p (increment)
- && invariant_p (bl->initial_value))
+ if (increment && loop_invariant_p (loop, increment)
+ && loop_invariant_p (loop, bl->initial_value))
{
/* Can calculate the loop exit value of its biv as
(n_iterations * increment) + initial_value */
We must search from the insn that sets the giv to the end
of the loop to calculate this value. */
- insert_before = NEXT_INSN (loop_end);
-
/* Put the final biv value in tem. */
- tem = gen_reg_rtx (bl->biv->mode);
+ tem = gen_reg_rtx (v->mode);
record_base_value (REGNO (tem), bl->biv->add_val, 0);
- emit_iv_add_mult (increment, GEN_INT (n_iterations),
- bl->initial_value, tem, insert_before);
+ loop_iv_add_mult_sink (loop, extend_value_for_giv (v, increment),
+ GEN_INT (n_iterations),
+ extend_value_for_giv (v, bl->initial_value),
+ tem);
/* Subtract off extra increments as we find them. */
for (insn = NEXT_INSN (v->insn); insn != loop_end;
if (biv->insn == insn)
{
start_sequence ();
- tem = expand_binop (GET_MODE (tem), sub_optab, tem,
- biv->add_val, NULL_RTX, 0,
- OPTAB_LIB_WIDEN);
+ tem = expand_simple_binop (GET_MODE (tem), MINUS, tem,
+ biv->add_val, NULL_RTX, 0,
+ OPTAB_LIB_WIDEN);
seq = gen_sequence ();
end_sequence ();
- emit_insn_before (seq, insert_before);
+ loop_insn_sink (loop, seq);
}
}
/* Now calculate the giv's final value. */
- emit_iv_add_mult (tem, v->mult_val, v->add_val, tem,
- insert_before);
+ loop_iv_add_mult_sink (loop, tem, v->mult_val, v->add_val, tem);
if (loop_dump_stream)
fprintf (loop_dump_stream,
abort ();
/* Check to see if the biv is dead at all loop exits. */
- if (reg_dead_after_loop (v->dest_reg, loop_start, loop_end))
+ if (reg_dead_after_loop (loop, v->dest_reg))
{
if (loop_dump_stream)
fprintf (loop_dump_stream,
return 0;
}
-
-/* Look back before LOOP_START for then insn that sets REG and return
+/* Look back before LOOP->START for the insn that sets REG and return
the equivalent constant if there is a REG_EQUAL note otherwise just
the SET_SRC of REG. */
static rtx
-loop_find_equiv_value (loop_start, reg)
- rtx loop_start;
+loop_find_equiv_value (loop, reg)
+ const struct loop *loop;
rtx reg;
{
+ rtx loop_start = loop->start;
rtx insn, set;
rtx ret;
ret = reg;
- for (insn = PREV_INSN (loop_start); insn ; insn = PREV_INSN (insn))
+ for (insn = PREV_INSN (loop_start); insn; insn = PREV_INSN (insn))
{
if (GET_CODE (insn) == CODE_LABEL)
break;
- else if (GET_RTX_CLASS (GET_CODE (insn)) == 'i'
- && reg_set_p (reg, insn))
+ else if (INSN_P (insn) && reg_set_p (reg, insn))
{
/* We found the last insn before the loop that sets the register.
If it sets the entire register, and has a REG_EQUAL note,
then use the value of the REG_EQUAL note. */
if ((set = single_set (insn))
- && (SET_DEST (set) == reg))
+ && (SET_DEST (set) == reg))
{
rtx note = find_reg_note (insn, REG_EQUAL, NULL_RTX);
ret = XEXP (note, 0);
else
ret = SET_SRC (set);
+
+ /* We cannot do this if it changes between the
+ assignment and loop start though. */
+ if (modified_between_p (ret, insn, loop_start))
+ ret = reg;
}
break;
}
abort ();
}
-
/* Find and return register term common to both expressions OP0 and
OP1 or NULL_RTX if no such term exists. Each expression must be a
REG or a PLUS of a REG. */
return NULL_RTX;
}
-/* Calculate the number of loop iterations. Returns the exact number of loop
- iterations if it can be calculated, otherwise returns zero. */
+/* Determine the loop iterator and calculate the number of loop
+ iterations. Returns the exact number of loop iterations if it can
+ be calculated, otherwise returns zero. */
unsigned HOST_WIDE_INT
loop_iterations (loop)
struct loop *loop;
{
+ struct loop_info *loop_info = LOOP_INFO (loop);
+ struct loop_ivs *ivs = LOOP_IVS (loop);
rtx comparison, comparison_value;
rtx iteration_var, initial_value, increment, final_value;
enum rtx_code comparison_code;
- HOST_WIDE_INT abs_inc;
+ HOST_WIDE_INT inc;
+ unsigned HOST_WIDE_INT abs_inc;
unsigned HOST_WIDE_INT abs_diff;
int off_by_one;
int increment_dir;
int unsigned_p, compare_dir, final_larger;
rtx last_loop_insn;
rtx reg_term;
- struct loop_info *loop_info = loop->info;
+ struct iv_class *bl;
loop_info->n_iterations = 0;
loop_info->initial_value = 0;
loop_info->increment = 0;
loop_info->iteration_var = 0;
loop_info->unroll_number = 1;
+ loop_info->iv = 0;
/* We used to use prev_nonnote_insn here, but that fails because it might
accidentally get the branch for a contained loop if the branch for this
return 0;
}
+ /* If there are multiple conditionalized loop exit tests, they may jump
+ back to differing CODE_LABELs. */
+ if (loop->top && loop->cont)
+ {
+ rtx temp = PREV_INSN (last_loop_insn);
+
+ do
+ {
+ if (GET_CODE (temp) == JUMP_INSN)
+ {
+ /* There are some kinds of jumps we can't deal with easily. */
+ if (JUMP_LABEL (temp) == 0)
+ {
+ if (loop_dump_stream)
+ fprintf
+ (loop_dump_stream,
+ "Loop iterations: Jump insn has null JUMP_LABEL.\n");
+ return 0;
+ }
+
+ if (/* Previous unrolling may have generated new insns not
+ covered by the uid_luid array. */
+ INSN_UID (JUMP_LABEL (temp)) < max_uid_for_loop
+ /* Check if we jump back into the loop body. */
+ && INSN_LUID (JUMP_LABEL (temp)) > INSN_LUID (loop->top)
+ && INSN_LUID (JUMP_LABEL (temp)) < INSN_LUID (loop->cont))
+ {
+ if (loop_dump_stream)
+ fprintf
+ (loop_dump_stream,
+ "Loop iterations: Loop has multiple back edges.\n");
+ return 0;
+ }
+ }
+ }
+ while ((temp = PREV_INSN (temp)) != loop->cont);
+ }
+
/* Find the iteration variable. If the last insn is a conditional
branch, and the insn before tests a register value, make that the
iteration variable. */
- comparison = get_condition_for_loop (last_loop_insn);
+ comparison = get_condition_for_loop (loop, last_loop_insn);
if (comparison == 0)
{
if (loop_dump_stream)
will propagate a new pseudo into the old iteration register but
this will be marked by having the REG_USERVAR_P bit set. */
- if ((unsigned) REGNO (iteration_var) >= reg_iv_type->num_elements
+ if ((unsigned) REGNO (iteration_var) >= ivs->n_regs
&& ! REG_USERVAR_P (iteration_var))
abort ();
- iteration_info (iteration_var, &initial_value, &increment,
- loop->start, loop->end);
+ /* Determine the initial value of the iteration variable, and the amount
+ that it is incremented each loop. Use the tables constructed by
+ the strength reduction pass to calculate these values. */
+
+ /* Clear the result values, in case no answer can be found. */
+ initial_value = 0;
+ increment = 0;
+
+ /* The iteration variable can be either a giv or a biv. Check to see
+ which it is, and compute the variable's initial value, and increment
+ value if possible. */
+
+ /* If this is a new register, can't handle it since we don't have any
+ reg_iv_type entry for it. */
+ if ((unsigned) REGNO (iteration_var) >= ivs->n_regs)
+ {
+ if (loop_dump_stream)
+ fprintf (loop_dump_stream,
+ "Loop iterations: No reg_iv_type entry for iteration var.\n");
+ return 0;
+ }
+
+ /* Reject iteration variables larger than the host wide int size, since they
+ could result in a number of iterations greater than the range of our
+ `unsigned HOST_WIDE_INT' variable loop_info->n_iterations. */
+ else if ((GET_MODE_BITSIZE (GET_MODE (iteration_var))
+ > HOST_BITS_PER_WIDE_INT))
+ {
+ if (loop_dump_stream)
+ fprintf (loop_dump_stream,
+ "Loop iterations: Iteration var rejected because mode too large.\n");
+ return 0;
+ }
+ else if (GET_MODE_CLASS (GET_MODE (iteration_var)) != MODE_INT)
+ {
+ if (loop_dump_stream)
+ fprintf (loop_dump_stream,
+ "Loop iterations: Iteration var not an integer.\n");
+ return 0;
+ }
+ else if (REG_IV_TYPE (ivs, REGNO (iteration_var)) == BASIC_INDUCT)
+ {
+ if (REGNO (iteration_var) >= ivs->n_regs)
+ abort ();
+
+ /* Grab initial value, only useful if it is a constant. */
+ bl = REG_IV_CLASS (ivs, REGNO (iteration_var));
+ initial_value = bl->initial_value;
+ if (!bl->biv->always_executed || bl->biv->maybe_multiple)
+ {
+ if (loop_dump_stream)
+ fprintf (loop_dump_stream,
+ "Loop iterations: Basic induction var not set once in each iteration.\n");
+ return 0;
+ }
+
+ increment = biv_total_increment (bl);
+ }
+ else if (REG_IV_TYPE (ivs, REGNO (iteration_var)) == GENERAL_INDUCT)
+ {
+ HOST_WIDE_INT offset = 0;
+ struct induction *v = REG_IV_INFO (ivs, REGNO (iteration_var));
+ rtx biv_initial_value;
+
+ if (REGNO (v->src_reg) >= ivs->n_regs)
+ abort ();
+
+ if (!v->always_executed || v->maybe_multiple)
+ {
+ if (loop_dump_stream)
+ fprintf (loop_dump_stream,
+ "Loop iterations: General induction var not set once in each iteration.\n");
+ return 0;
+ }
+
+ bl = REG_IV_CLASS (ivs, REGNO (v->src_reg));
+
+ /* Increment value is mult_val times the increment value of the biv. */
+
+ increment = biv_total_increment (bl);
+ if (increment)
+ {
+ struct induction *biv_inc;
+
+ increment = fold_rtx_mult_add (v->mult_val,
+ extend_value_for_giv (v, increment),
+ const0_rtx, v->mode);
+ /* The caller assumes that one full increment has occurred at the
+ first loop test. But that's not true when the biv is incremented
+ after the giv is set (which is the usual case), e.g.:
+ i = 6; do {;} while (i++ < 9) .
+ Therefore, we bias the initial value by subtracting the amount of
+ the increment that occurs between the giv set and the giv test. */
+ for (biv_inc = bl->biv; biv_inc; biv_inc = biv_inc->next_iv)
+ {
+ if (loop_insn_first_p (v->insn, biv_inc->insn))
+ offset -= INTVAL (biv_inc->add_val);
+ }
+ }
+ if (loop_dump_stream)
+ fprintf (loop_dump_stream,
+ "Loop iterations: Giv iterator, initial value bias %ld.\n",
+ (long) offset);
+
+ /* Initial value is mult_val times the biv's initial value plus
+ add_val. Only useful if it is a constant. */
+ biv_initial_value = extend_value_for_giv (v, bl->initial_value);
+ initial_value
+ = fold_rtx_mult_add (v->mult_val,
+ plus_constant (biv_initial_value, offset),
+ v->add_val, v->mode);
+ }
+ else
+ {
+ if (loop_dump_stream)
+ fprintf (loop_dump_stream,
+ "Loop iterations: Not basic or general induction var.\n");
+ return 0;
+ }
+
if (initial_value == 0)
- /* iteration_info already printed a message. */
return 0;
unsigned_p = 0;
its value from the insns before the start of the loop. */
final_value = comparison_value;
- if (GET_CODE (comparison_value) == REG && invariant_p (comparison_value))
+ if (GET_CODE (comparison_value) == REG
+ && loop_invariant_p (loop, comparison_value))
{
- final_value = loop_find_equiv_value (loop->start, comparison_value);
+ final_value = loop_find_equiv_value (loop, comparison_value);
+
/* If we don't get an invariant final value, we are better
off with the original register. */
- if (!invariant_p (final_value))
+ if (! loop_invariant_p (loop, final_value))
final_value = comparison_value;
}
loop_info->increment = increment;
loop_info->iteration_var = iteration_var;
loop_info->comparison_code = comparison_code;
+ loop_info->iv = bl;
/* Try to determine the iteration count for loops such
as (for i = init; i < init + const; i++). When running the
/* Find what reg1 is equivalent to. Hopefully it will
either be reg2 or reg2 plus a constant. */
- temp = loop_find_equiv_value (loop->start, reg1);
+ temp = loop_find_equiv_value (loop, reg1);
+
if (find_common_reg_term (temp, reg2))
initial_value = temp;
else
/* Find what reg2 is equivalent to. Hopefully it will
either be reg1 or reg1 plus a constant. Let's ignore
the latter case for now since it is not so common. */
- temp = loop_find_equiv_value (loop->start, reg2);
+ temp = loop_find_equiv_value (loop, reg2);
+
if (temp == loop_info->iteration_var)
temp = initial_value;
if (temp == reg1)
{
rtx temp;
- /* When running the loop optimizer twice, check_dbra_loop
- further obfuscates reversible loops of the form:
- for (i = init; i < init + const; i++). We often end up with
- final_value = 0, initial_value = temp, temp = temp2 - init,
- where temp2 = init + const. If the loop has a vtop we
- can replace initial_value with const. */
+ /* When running the loop optimizer twice, check_dbra_loop
+ further obfuscates reversible loops of the form:
+ for (i = init; i < init + const; i++). We often end up with
+ final_value = 0, initial_value = temp, temp = temp2 - init,
+ where temp2 = init + const. If the loop has a vtop we
+ can replace initial_value with const. */
+
+ temp = loop_find_equiv_value (loop, reg1);
- temp = loop_find_equiv_value (loop->start, reg1);
if (GET_CODE (temp) == MINUS && REG_P (XEXP (temp, 0)))
{
- rtx temp2 = loop_find_equiv_value (loop->start, XEXP (temp, 0));
+ rtx temp2 = loop_find_equiv_value (loop, XEXP (temp, 0));
+
if (GET_CODE (temp2) == PLUS
&& XEXP (temp2, 0) == XEXP (temp, 1))
initial_value = XEXP (temp2, 1);
Check this now so that we won't leave an invalid value if we
return early for any other reason. */
if (comparison_code == EQ)
- loop_info->final_equiv_value = loop_info->final_value = 0;
+ loop_info->final_equiv_value = loop_info->final_value = 0;
if (increment == 0)
{
/* ??? Other RTL, such as (neg (reg)) is possible here, but it isn't
clear if it is worthwhile to try to handle such RTL. */
if (GET_CODE (increment) == REG || GET_CODE (increment) == SUBREG)
- increment = loop_find_equiv_value (loop->start, increment);
+ increment = loop_find_equiv_value (loop, increment);
if (GET_CODE (increment) != CONST_INT)
{
{
fprintf (loop_dump_stream,
"Loop iterations: Increment value not constant ");
- print_rtl (loop_dump_stream, increment);
+ print_simple_rtl (loop_dump_stream, increment);
fprintf (loop_dump_stream, ".\n");
}
return 0;
{
fprintf (loop_dump_stream,
"Loop iterations: Initial value not constant ");
- print_rtl (loop_dump_stream, initial_value);
+ print_simple_rtl (loop_dump_stream, initial_value);
fprintf (loop_dump_stream, ".\n");
}
return 0;
else if (comparison_code == EQ)
{
if (loop_dump_stream)
- fprintf (loop_dump_stream,
- "Loop iterations: EQ comparison loop.\n");
+ fprintf (loop_dump_stream, "Loop iterations: EQ comparison loop.\n");
return 0;
}
else if (GET_CODE (final_value) != CONST_INT)
{
fprintf (loop_dump_stream,
"Loop iterations: Final value not constant ");
- print_rtl (loop_dump_stream, final_value);
+ print_simple_rtl (loop_dump_stream, final_value);
fprintf (loop_dump_stream, ".\n");
}
return 0;
else
{
if (loop_dump_stream)
- fprintf (loop_dump_stream,
- "Loop iterations: Not normal loop.\n");
+ fprintf (loop_dump_stream, "Loop iterations: Not normal loop.\n");
return 0;
}
so correct for that. Note that abs_diff and n_iterations are
unsigned, because they can be as large as 2^n - 1. */
- abs_inc = INTVAL (increment);
- if (abs_inc > 0)
- abs_diff = INTVAL (final_value) - INTVAL (initial_value);
- else if (abs_inc < 0)
+ inc = INTVAL (increment);
+ if (inc > 0)
+ {
+ abs_diff = INTVAL (final_value) - INTVAL (initial_value);
+ abs_inc = inc;
+ }
+ else if (inc < 0)
{
abs_diff = INTVAL (initial_value) - INTVAL (final_value);
- abs_inc = -abs_inc;
+ abs_inc = -inc;
}
else
abort ();
+ /* Given that iteration_var is going to iterate over its own mode,
+ not HOST_WIDE_INT, disregard higher bits that might have come
+ into the picture due to sign extension of initial and final
+ values. */
+ abs_diff &= ((unsigned HOST_WIDE_INT) 1
+ << (GET_MODE_BITSIZE (GET_MODE (iteration_var)) - 1)
+ << 1) - 1;
+
/* For NE tests, make sure that the iteration variable won't miss
the final value. If abs_diff mod abs_incr is not zero, then the
iteration variable will overflow before the loop exits, and we
return loop_info->n_iterations;
}
-
/* Replace uses of split bivs with their split pseudo register. This is
for original instructions which remain after loop unrolling without
copying. */
static rtx
-remap_split_bivs (x)
+remap_split_bivs (loop, x)
+ struct loop *loop;
rtx x;
{
- register enum rtx_code code;
- register int i;
- register const char *fmt;
+ struct loop_ivs *ivs = LOOP_IVS (loop);
+ enum rtx_code code;
+ int i;
+ const char *fmt;
if (x == 0)
return x;
/* If non-reduced/final-value givs were split, then this would also
have to remap those givs also. */
#endif
- if (REGNO (x) < max_reg_before_loop
- && REG_IV_TYPE (REGNO (x)) == BASIC_INDUCT)
- return reg_biv_class[REGNO (x)]->biv->src_reg;
+ if (REGNO (x) < ivs->n_regs
+ && REG_IV_TYPE (ivs, REGNO (x)) == BASIC_INDUCT)
+ return REG_IV_CLASS (ivs, REGNO (x))->biv->src_reg;
break;
default:
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e')
- XEXP (x, i) = remap_split_bivs (XEXP (x, i));
+ XEXP (x, i) = remap_split_bivs (loop, XEXP (x, i));
else if (fmt[i] == 'E')
{
- register int j;
+ int j;
for (j = 0; j < XVECLEN (x, i); j++)
- XVECEXP (x, i, j) = remap_split_bivs (XVECEXP (x, i, j));
+ XVECEXP (x, i, j) = remap_split_bivs (loop, XVECEXP (x, i, j));
}
}
return x;
while (INSN_UID (p) != first_uid)
{
if (GET_CODE (p) == JUMP_INSN)
- passed_jump= 1;
+ passed_jump = 1;
/* Could not find FIRST_UID. */
if (p == copy_end)
return 0;
}
/* Verify that FIRST_UID is an insn that entirely sets REGNO. */
- if (GET_RTX_CLASS (GET_CODE (p)) != 'i'
- || ! dead_or_set_regno_p (p, regno))
+ if (! INSN_P (p) || ! dead_or_set_regno_p (p, regno))
return 0;
/* FIRST_UID is always executed. */
/* FIRST_UID is always executed if LAST_UID is executed. */
return 1;
}
+
+/* This routine is called when the number of iterations for the unrolled
+ loop is one. The goal is to identify a loop that begins with an
+ unconditional branch to the loop continuation note (or a label just after).
+ In this case, the unconditional branch that starts the loop needs to be
+ deleted so that we execute the single iteration. */
+
+static rtx
+ujump_to_loop_cont (loop_start, loop_cont)
+ rtx loop_start;
+ rtx loop_cont;
+{
+ rtx x, label, label_ref;
+
+ /* See if loop start, or the next insn is an unconditional jump. */
+ loop_start = next_nonnote_insn (loop_start);
+
+ x = pc_set (loop_start);
+ if (!x)
+ return NULL_RTX;
+
+ label_ref = SET_SRC (x);
+ if (!label_ref)
+ return NULL_RTX;
+
+ /* Examine insn after loop continuation note. Return if not a label. */
+ label = next_nonnote_insn (loop_cont);
+ if (label == 0 || GET_CODE (label) != CODE_LABEL)
+ return NULL_RTX;
+
+ /* Return the loop start if the branch label matches the code label. */
+ if (CODE_LABEL_NUMBER (label) == CODE_LABEL_NUMBER (XEXP (label_ref, 0)))
+ return loop_start;
+ else
+ return NULL_RTX;
+}
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