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riscv-gcc-1
Commit 5e787f07 by Jan Hubicka Committed by Jan Hubicka
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loop.c (check_insn_for_bivs, [...]): Break out from ... 

	* loop.c (check_insn_for_bivs, for_every_insn_in_loop,
	check_insn_for_givs): Break out from ...
	(strength_reduce) ... here; use for_every_insn_in_loop to call
	check_insn_for_givs.
	* loop.h (for_every_insn_in_loop): Declare.
	(loop_insn_callback): New type.

From-SVN: r33250
parent 21c076f9
Showing with 266 additions and 338 deletions
gcc/ChangeLog
Wed Apr 19 12:02:37 MET DST 2000 Jan Hubicka <jh@suse.cz>
* loop.c (check_insn_for_bivs, for_every_insn_in_loop,
check_insn_for_givs): Break out from ...
(strength_reduce) ... here; use for_every_insn_in_loop to call
check_insn_for_givs.
* loop.h (for_every_insn_in_loop): Declare.
(loop_insn_callback): New type.
2000-04-18 Zack Weinberg <zack@wolery.cumb.org>
* cpplib.c (do_pragma_poison): Strings in the token buffer are
......
gcc/loop.c
......@@ -308,6 +308,8 @@ static int replace_loop_reg PARAMS ((rtx *, void *));
static void note_reg_stored PARAMS ((rtx, rtx, void *));
static void try_copy_prop PARAMS ((const struct loop *, rtx, unsigned int));
static int replace_label PARAMS ((rtx *, void *));
static void check_insn_for_givs PARAMS((struct loop *, rtx, int, int));
static void check_insn_for_bivs PARAMS((struct loop *, rtx, int, int));
typedef struct rtx_and_int {
rtx r;
......@@ -3694,127 +3696,47 @@ static rtx addr_placeholder;
was rerun in loop_optimize whenever a register was added or moved.
Also, some of the optimizations could be a little less conservative. */
/* Perform strength reduction and induction variable elimination.
Pseudo registers created during this function will be beyond the last
valid index in several tables including n_times_set and regno_last_uid.
This does not cause a problem here, because the added registers cannot be
givs outside of their loop, and hence will never be reconsidered.
But scan_loop must check regnos to make sure they are in bounds. */
static void
strength_reduce (loop, insn_count, unroll_p, bct_p)
/* Scan the loop body and call FNCALL for each insn. In the addition to the
LOOP and INSN parameters pass MAYBE_MULTIPLE and NOT_EVERY_ITERATION to the
callback.
NOT_EVERY_ITERATION if current insn is not executed at least once for every
loop iteration except for the last one.
MAYBE_MULTIPLE is 1 if current insn may be executed more than once for every
loop iteration.
*/
void
for_each_insn_in_loop (loop, fncall)
struct loop *loop;
int insn_count;
int unroll_p, bct_p ATTRIBUTE_UNUSED;
loop_insn_callback fncall;
{
rtx p;
rtx set;
rtx inc_val;
rtx mult_val;
rtx dest_reg;
rtx *location;
/* This is 1 if current insn is not executed at least once for every loop
iteration. */
int not_every_iteration = 0;
/* This is 1 if current insn may be executed more than once for every
loop iteration. */
int maybe_multiple = 0;
/* This is 1 if we have past a branch back to the top of the loop
(aka a loop latch). */
int past_loop_latch = 0;
/* Temporary list pointers for traversing loop_iv_list. */
struct iv_class *bl, **backbl;
struct loop_info *loop_info = LOOP_INFO (loop);
/* Ratio of extra register life span we can justify
for saving an instruction. More if loop doesn't call subroutines
since in that case saving an insn makes more difference
and more registers are available. */
/* ??? could set this to last value of threshold in move_movables */
int threshold = (loop_info->has_call ? 1 : 2) * (3 + n_non_fixed_regs);
/* Map of pseudo-register replacements. */
rtx *reg_map = NULL;
int reg_map_size;
int call_seen;
rtx test;
rtx end_insert_before;
int loop_depth = 0;
int n_extra_increment;
int unrolled_insn_copies = 0;
rtx loop_start = loop->start;
rtx loop_end = loop->end;
rtx loop_scan_start = loop->scan_start;
rtx loop_top = loop->top;
rtx loop_cont = loop->cont;
rtx p;
/* If loop_scan_start points to the loop exit test, we have to be wary of
subversive use of gotos inside expression statements. */
if (prev_nonnote_insn (loop_scan_start) != prev_nonnote_insn (loop_start))
maybe_multiple = back_branch_in_range_p (loop, loop_scan_start);
VARRAY_INT_INIT (reg_iv_type, max_reg_before_loop, "reg_iv_type");
VARRAY_GENERIC_PTR_INIT (reg_iv_info, max_reg_before_loop, "reg_iv_info");
reg_biv_class = (struct iv_class **)
xcalloc (max_reg_before_loop, sizeof (struct iv_class *));
loop_iv_list = 0;
addr_placeholder = gen_reg_rtx (Pmode);
/* Save insn immediately after the loop_end. Insns inserted after loop_end
must be put before this insn, so that they will appear in the right
order (i.e. loop order).
If loop_end is the end of the current function, then emit a
NOTE_INSN_DELETED after loop_end and set end_insert_before to the
dummy note insn. */
if (NEXT_INSN (loop_end) != 0)
end_insert_before = NEXT_INSN (loop_end);
else
end_insert_before = emit_note_after (NOTE_INSN_DELETED, loop_end);
if (prev_nonnote_insn (loop->scan_start) != prev_nonnote_insn (loop->start))
maybe_multiple = back_branch_in_range_p (loop, loop->scan_start);
/* Scan through loop to find all possible bivs. */
for (p = next_insn_in_loop (loop, loop_scan_start);
for (p = next_insn_in_loop (loop, loop->scan_start);
p != NULL_RTX;
p = next_insn_in_loop (loop, p))
{
if (GET_CODE (p) == INSN
&& (set = single_set (p))
&& GET_CODE (SET_DEST (set)) == REG)
{
dest_reg = SET_DEST (set);
if (REGNO (dest_reg) < max_reg_before_loop
&& REGNO (dest_reg) >= FIRST_PSEUDO_REGISTER
&& REG_IV_TYPE (REGNO (dest_reg)) != NOT_BASIC_INDUCT)
{
int multi_insn_incr = 0;
if (basic_induction_var (loop, SET_SRC (set),
GET_MODE (SET_SRC (set)),
dest_reg, p, &inc_val, &mult_val,
&location, &multi_insn_incr))
{
/* It is a possible basic induction variable.
Create and initialize an induction structure for it. */
struct induction *v
= (struct induction *) alloca (sizeof (struct induction));
record_biv (v, p, dest_reg, inc_val, mult_val, location,
not_every_iteration, maybe_multiple,
multi_insn_incr);
REG_IV_TYPE (REGNO (dest_reg)) = BASIC_INDUCT;
}
else if (REGNO (dest_reg) < max_reg_before_loop)
REG_IV_TYPE (REGNO (dest_reg)) = NOT_BASIC_INDUCT;
}
}
fncall (loop, p, maybe_multiple, not_every_iteration);
/* Past CODE_LABEL, we get to insns that may be executed multiple
times. The only way we can be sure that they can't is if every
jump insn between here and the end of the loop either
returns, exits the loop, is a jump to a location that is still
behind the label, or is a jump to the loop start. */
times. The only way we can be sure that they can't is if every
jump insn between here and the end of the loop either
returns, exits the loop, is a jump to a location that is still
behind the label, or is a jump to the loop start. */
if (GET_CODE (p) == CODE_LABEL)
{
......@@ -3825,24 +3747,24 @@ strength_reduce (loop, insn_count, unroll_p, bct_p)
while (1)
{
insn = NEXT_INSN (insn);
if (insn == loop_scan_start)
if (insn == loop->scan_start)
break;
if (insn == loop_end)
if (insn == loop->end)
{
if (loop_top != 0)
insn = loop_top;
if (loop->top != 0)
insn = loop->top;
else
break;
if (insn == loop_scan_start)
if (insn == loop->scan_start)
break;
}
if (GET_CODE (insn) == JUMP_INSN
&& GET_CODE (PATTERN (insn)) != RETURN
&& (! condjump_p (insn)
&& (!condjump_p (insn)
|| (JUMP_LABEL (insn) != 0
&& JUMP_LABEL (insn) != loop_scan_start
&& ! loop_insn_first_p (p, JUMP_LABEL (insn)))))
&& JUMP_LABEL (insn) != loop->scan_start
&& !loop_insn_first_p (p, JUMP_LABEL (insn)))))
{
maybe_multiple = 1;
break;
......@@ -3851,29 +3773,29 @@ strength_reduce (loop, insn_count, unroll_p, bct_p)
}
/* Past a jump, we get to insns for which we can't count
on whether they will be executed during each iteration. */
on whether they will be executed during each iteration. */
/* This code appears twice in strength_reduce. There is also similar
code in scan_loop. */
code in scan_loop. */
if (GET_CODE (p) == JUMP_INSN
/* If we enter the loop in the middle, and scan around to the
beginning, don't set not_every_iteration for that.
This can be any kind of jump, since we want to know if insns
will be executed if the loop is executed. */
&& ! (JUMP_LABEL (p) == loop_top
&& ((NEXT_INSN (NEXT_INSN (p)) == loop_end && simplejump_p (p))
|| (NEXT_INSN (p) == loop_end && condjump_p (p)))))
/* If we enter the loop in the middle, and scan around to the
beginning, don't set not_every_iteration for that.
This can be any kind of jump, since we want to know if insns
will be executed if the loop is executed. */
&& !(JUMP_LABEL (p) == loop->top
&& ((NEXT_INSN (NEXT_INSN (p)) == loop->end && simplejump_p (p))
|| (NEXT_INSN (p) == loop->end && condjump_p (p)))))
{
rtx label = 0;
/* If this is a jump outside the loop, then it also doesn't
matter. Check to see if the target of this branch is on the
loop->exits_labels list. */
for (label = loop->exit_labels; label; label = LABEL_NEXTREF (label))
if (XEXP (label, 0) == JUMP_LABEL (p))
break;
if (! label)
if (!label)
not_every_iteration = 1;
}
......@@ -3896,34 +3818,93 @@ strength_reduce (loop, insn_count, unroll_p, bct_p)
}
/* Note if we pass a loop latch. If we do, then we can not clear
NOT_EVERY_ITERATION below when we pass the last CODE_LABEL in
a loop since a jump before the last CODE_LABEL may have started
a new loop iteration.
Note that LOOP_TOP is only set for rotated loops and we need
this check for all loops, so compare against the CODE_LABEL
which immediately follows LOOP_START. */
if (GET_CODE (p) == JUMP_INSN
&& JUMP_LABEL (p) == NEXT_INSN (loop_start))
NOT_EVERY_ITERATION below when we pass the last CODE_LABEL in
a loop since a jump before the last CODE_LABEL may have started
a new loop iteration.
Note that LOOP_TOP is only set for rotated loops and we need
this check for all loops, so compare against the CODE_LABEL
which immediately follows LOOP_START. */
if (GET_CODE (p) == JUMP_INSN
&& JUMP_LABEL (p) == NEXT_INSN (loop->start))
past_loop_latch = 1;
/* Unlike in the code motion pass where MAYBE_NEVER indicates that
an insn may never be executed, NOT_EVERY_ITERATION indicates whether
or not an insn is known to be executed each iteration of the
loop, whether or not any iterations are known to occur.
an insn may never be executed, NOT_EVERY_ITERATION indicates whether
or not an insn is known to be executed each iteration of the
loop, whether or not any iterations are known to occur.
Therefore, if we have just passed a label and have no more labels
between here and the test insn of the loop, and we have not passed
a jump to the top of the loop, then we know these insns will be
executed each iteration. */
Therefore, if we have just passed a label and have no more labels
between here and the test insn of the loop, and we have not passed
a jump to the top of the loop, then we know these insns will be
executed each iteration. */
if (not_every_iteration
&& ! past_loop_latch
if (not_every_iteration
&& !past_loop_latch
&& GET_CODE (p) == CODE_LABEL
&& no_labels_between_p (p, loop_end)
&& loop_insn_first_p (p, loop_cont))
&& no_labels_between_p (p, loop->end)
&& loop_insn_first_p (p, loop->cont))
not_every_iteration = 0;
}
}
/* Perform strength reduction and induction variable elimination.
Pseudo registers created during this function will be beyond the last
valid index in several tables including n_times_set and regno_last_uid.
This does not cause a problem here, because the added registers cannot be
givs outside of their loop, and hence will never be reconsidered.
But scan_loop must check regnos to make sure they are in bounds. */
static void
strength_reduce (loop, insn_count, unroll_p, bct_p)
struct loop *loop;
int insn_count;
int unroll_p, bct_p ATTRIBUTE_UNUSED;
{
rtx p;
/* Temporary list pointers for traversing loop_iv_list. */
struct iv_class *bl, **backbl;
struct loop_info *loop_info = LOOP_INFO (loop);
/* Ratio of extra register life span we can justify
for saving an instruction. More if loop doesn't call subroutines
since in that case saving an insn makes more difference
and more registers are available. */
/* ??? could set this to last value of threshold in move_movables */
int threshold = (loop_info->has_call ? 1 : 2) * (3 + n_non_fixed_regs);
/* Map of pseudo-register replacements. */
rtx *reg_map = NULL;
int reg_map_size;
int call_seen;
rtx test;
rtx end_insert_before;
int n_extra_increment;
int unrolled_insn_copies = 0;
rtx loop_start = loop->start;
rtx loop_end = loop->end;
rtx loop_scan_start = loop->scan_start;
VARRAY_INT_INIT (reg_iv_type, max_reg_before_loop, "reg_iv_type");
VARRAY_GENERIC_PTR_INIT (reg_iv_info, max_reg_before_loop, "reg_iv_info");
reg_biv_class = (struct iv_class **)
xcalloc (max_reg_before_loop, sizeof (struct iv_class *));
loop_iv_list = 0;
addr_placeholder = gen_reg_rtx (Pmode);
/* Save insn immediately after the loop_end. Insns inserted after loop_end
must be put before this insn, so that they will appear in the right
order (i.e. loop order).
If loop_end is the end of the current function, then emit a
NOTE_INSN_DELETED after loop_end and set end_insert_before to the
dummy note insn. */
if (NEXT_INSN (loop_end) != 0)
end_insert_before = NEXT_INSN (loop_end);
else
end_insert_before = emit_note_after (NOTE_INSN_DELETED, loop_end);
for_each_insn_in_loop (loop, check_insn_for_bivs);
/* Scan loop_iv_list to remove all regs that proved not to be bivs.
Make a sanity check against n_times_set. */
......@@ -4430,203 +4411,7 @@ strength_reduce (loop, insn_count, unroll_p, bct_p)
/* Search the loop for general induction variables. */
/* A register is a giv if: it is only set once, it is a function of a
biv and a constant (or invariant), and it is not a biv. */
not_every_iteration = 0;
loop_depth = 0;
maybe_multiple = 0;
p = loop_scan_start;
while (1)
{
p = NEXT_INSN (p);
/* At end of a straight-in loop, we are done.
At end of a loop entered at the bottom, scan the top. */
if (p == loop_scan_start)
break;
if (p == loop_end)
{
if (loop_top != 0)
p = loop_top;
else
break;
if (p == loop_scan_start)
break;
}
/* Look for a general induction variable in a register. */
if (GET_CODE (p) == INSN
&& (set = single_set (p))
&& GET_CODE (SET_DEST (set)) == REG
&& ! VARRAY_CHAR (may_not_optimize, REGNO (SET_DEST (set))))
{
rtx src_reg;
rtx add_val;
rtx mult_val;
int benefit;
rtx regnote = 0;
rtx last_consec_insn;
dest_reg = SET_DEST (set);
if (REGNO (dest_reg) < FIRST_PSEUDO_REGISTER)
continue;
if (/* SET_SRC is a giv. */
(general_induction_var (loop, SET_SRC (set), &src_reg, &add_val,
&mult_val, 0, &benefit)
/* Equivalent expression is a giv. */
|| ((regnote = find_reg_note (p, REG_EQUAL, NULL_RTX))
&& general_induction_var (loop, XEXP (regnote, 0), &src_reg,
&add_val, &mult_val, 0,
&benefit)))
/* Don't try to handle any regs made by loop optimization.
We have nothing on them in regno_first_uid, etc. */
&& REGNO (dest_reg) < max_reg_before_loop
/* Don't recognize a BASIC_INDUCT_VAR here. */
&& dest_reg != src_reg
/* This must be the only place where the register is set. */
&& (VARRAY_INT (n_times_set, REGNO (dest_reg)) == 1
/* or all sets must be consecutive and make a giv. */
|| (benefit = consec_sets_giv (loop, benefit, p,
src_reg, dest_reg,
&add_val, &mult_val,
&last_consec_insn))))
{
struct induction *v
= (struct induction *) alloca (sizeof (struct induction));
/* If this is a library call, increase benefit. */
if (find_reg_note (p, REG_RETVAL, NULL_RTX))
benefit += libcall_benefit (p);
/* Skip the consecutive insns, if there are any. */
if (VARRAY_INT (n_times_set, REGNO (dest_reg)) != 1)
p = last_consec_insn;
record_giv (loop, v, p, src_reg, dest_reg, mult_val, add_val,
benefit, DEST_REG, not_every_iteration,
maybe_multiple, NULL_PTR);
}
}
#ifndef DONT_REDUCE_ADDR
/* Look for givs which are memory addresses. */
/* This resulted in worse code on a VAX 8600. I wonder if it
still does. */
if (GET_CODE (p) == INSN)
find_mem_givs (loop, PATTERN (p), p, not_every_iteration,
maybe_multiple);
#endif
/* Update the status of whether giv can derive other givs. This can
change when we pass a label or an insn that updates a biv. */
if (GET_CODE (p) == INSN || GET_CODE (p) == JUMP_INSN
|| GET_CODE (p) == CODE_LABEL)
update_giv_derive (loop, p);
/* Past CODE_LABEL, we get to insns that may be executed multiple
times. The only way we can be sure that they can't is if every
every jump insn between here and the end of the loop either
returns, exits the loop, is a forward jump, or is a jump
to the loop start. */
if (GET_CODE (p) == CODE_LABEL)
{
rtx insn = p;
maybe_multiple = 0;
while (1)
{
insn = NEXT_INSN (insn);
if (insn == loop_scan_start)
break;
if (insn == loop_end)
{
if (loop_top != 0)
insn = loop_top;
else
break;
if (insn == loop_scan_start)
break;
}
if (GET_CODE (insn) == JUMP_INSN
&& GET_CODE (PATTERN (insn)) != RETURN
&& (! condjump_p (insn)
|| (JUMP_LABEL (insn) != 0
&& JUMP_LABEL (insn) != loop_scan_start
&& (INSN_UID (JUMP_LABEL (insn)) >= max_uid_for_loop
|| INSN_UID (insn) >= max_uid_for_loop
|| (INSN_LUID (JUMP_LABEL (insn))
< INSN_LUID (insn))))))
{
maybe_multiple = 1;
break;
}
}
}
/* Past a jump, we get to insns for which we can't count
on whether they will be executed during each iteration. */
/* This code appears twice in strength_reduce. There is also similar
code in scan_loop. */
if (GET_CODE (p) == JUMP_INSN
/* If we enter the loop in the middle, and scan around to the
beginning, don't set not_every_iteration for that.
This can be any kind of jump, since we want to know if insns
will be executed if the loop is executed. */
&& ! (JUMP_LABEL (p) == loop_top
&& ((NEXT_INSN (NEXT_INSN (p)) == loop_end && simplejump_p (p))
|| (NEXT_INSN (p) == loop_end && condjump_p (p)))))
{
rtx label = 0;
/* If this is a jump outside the loop, then it also doesn't
matter. Check to see if the target of this branch is on the
loop->exits_labels list. */
for (label = loop->exit_labels; label; label = LABEL_NEXTREF (label))
if (XEXP (label, 0) == JUMP_LABEL (p))
break;
if (! label)
not_every_iteration = 1;
}
else if (GET_CODE (p) == NOTE)
{
/* At the virtual top of a converted loop, insns are again known to
be executed each iteration: logically, the loop begins here
even though the exit code has been duplicated.
Insns are also again known to be executed each iteration at
the LOOP_CONT note. */
if ((NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_VTOP
|| NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_CONT)
&& loop_depth == 0)
not_every_iteration = 0;
else if (NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_BEG)
loop_depth++;
else if (NOTE_LINE_NUMBER (p) == NOTE_INSN_LOOP_END)
loop_depth--;
}
/* Unlike in the code motion pass where MAYBE_NEVER indicates that
an insn may never be executed, NOT_EVERY_ITERATION indicates whether
or not an insn is known to be executed each iteration of the
loop, whether or not any iterations are known to occur.
Therefore, if we have just passed a label and have no more labels
between here and the test insn of the loop, we know these insns
will be executed each iteration. */
if (not_every_iteration && GET_CODE (p) == CODE_LABEL
&& no_labels_between_p (p, loop_end)
&& loop_insn_first_p (p, loop_cont))
not_every_iteration = 0;
}
for_each_insn_in_loop (loop, check_insn_for_givs);
/* Try to calculate and save the number of loop iterations. This is
set to zero if the actual number can not be calculated. This must
......@@ -5282,6 +5067,138 @@ egress:
free (reg_map);
}
/*Record all basic induction variables calculated in the insn. */
static void
check_insn_for_bivs (loop, p, not_every_iteration, maybe_multiple)
struct loop *loop;
rtx p;
int not_every_iteration;
int maybe_multiple;
{
rtx set;
rtx dest_reg;
rtx inc_val;
rtx mult_val;
rtx *location;
if (GET_CODE (p) == INSN
&& (set = single_set (p))
&& GET_CODE (SET_DEST (set)) == REG)
{
dest_reg = SET_DEST (set);
if (REGNO (dest_reg) < max_reg_before_loop
&& REGNO (dest_reg) >= FIRST_PSEUDO_REGISTER
&& REG_IV_TYPE (REGNO (dest_reg)) != NOT_BASIC_INDUCT)
{
int multi_insn_incr = 0;
if (basic_induction_var (loop, SET_SRC (set),
GET_MODE (SET_SRC (set)),
dest_reg, p, &inc_val, &mult_val,
&location, &multi_insn_incr))
{
/* It is a possible basic induction variable.
Create and initialize an induction structure for it. */
struct induction *v
= (struct induction *) oballoc (sizeof (struct induction));
record_biv (v, p, dest_reg, inc_val, mult_val, location,
not_every_iteration, maybe_multiple,
multi_insn_incr);
REG_IV_TYPE (REGNO (dest_reg)) = BASIC_INDUCT;
}
else if (REGNO (dest_reg) < max_reg_before_loop)
REG_IV_TYPE (REGNO (dest_reg)) = NOT_BASIC_INDUCT;
}
}
}
/* Record all givs calculated in the insn.
A register is a giv if: it is only set once, it is a function of a
biv and a constant (or invariant), and it is not a biv. */
static void
check_insn_for_givs (loop, p, not_every_iteration, maybe_multiple)
struct loop *loop;
rtx p;
int not_every_iteration;
int maybe_multiple;
{
rtx set;
/* Look for a general induction variable in a register. */
if (GET_CODE (p) == INSN
&& (set = single_set (p))
&& GET_CODE (SET_DEST (set)) == REG
&& ! VARRAY_CHAR (may_not_optimize, REGNO (SET_DEST (set))))
{
rtx src_reg;
rtx dest_reg;
rtx add_val;
rtx mult_val;
int benefit;
rtx regnote = 0;
rtx last_consec_insn;
dest_reg = SET_DEST (set);
if (REGNO (dest_reg) < FIRST_PSEUDO_REGISTER)
return;
if (/* SET_SRC is a giv. */
(general_induction_var (loop, SET_SRC (set), &src_reg, &add_val,
&mult_val, 0, &benefit)
/* Equivalent expression is a giv. */
|| ((regnote = find_reg_note (p, REG_EQUAL, NULL_RTX))
&& general_induction_var (loop, XEXP (regnote, 0), &src_reg,
&add_val, &mult_val, 0,
&benefit)))
/* Don't try to handle any regs made by loop optimization.
We have nothing on them in regno_first_uid, etc. */
&& REGNO (dest_reg) < max_reg_before_loop
/* Don't recognize a BASIC_INDUCT_VAR here. */
&& dest_reg != src_reg
/* This must be the only place where the register is set. */
&& (VARRAY_INT (n_times_set, REGNO (dest_reg)) == 1
/* or all sets must be consecutive and make a giv. */
|| (benefit = consec_sets_giv (loop, benefit, p,
src_reg, dest_reg,
&add_val, &mult_val,
&last_consec_insn))))
{
struct induction *v
= (struct induction *) oballoc (sizeof (struct induction));
/* If this is a library call, increase benefit. */
if (find_reg_note (p, REG_RETVAL, NULL_RTX))
benefit += libcall_benefit (p);
/* Skip the consecutive insns, if there are any. */
if (VARRAY_INT (n_times_set, REGNO (dest_reg)) != 1)
p = last_consec_insn;
record_giv (loop, v, p, src_reg, dest_reg, mult_val, add_val,
benefit, DEST_REG, not_every_iteration,
maybe_multiple, NULL_PTR);
}
}
#ifndef DONT_REDUCE_ADDR
/* Look for givs which are memory addresses. */
/* This resulted in worse code on a VAX 8600. I wonder if it
still does. */
if (GET_CODE (p) == INSN)
find_mem_givs (loop, PATTERN (p), p, not_every_iteration,
maybe_multiple);
#endif
/* Update the status of whether giv can derive other givs. This can
change when we pass a label or an insn that updates a biv. */
if (GET_CODE (p) == INSN || GET_CODE (p) == JUMP_INSN
|| GET_CODE (p) == CODE_LABEL)
update_giv_derive (loop, p);
}
/* Return 1 if X is a valid source for an initial value (or as value being
compared against in an initial test).
......
gcc/loop.h
......@@ -247,4 +247,6 @@ void emit_unrolled_add PARAMS ((rtx, rtx, rtx));
int back_branch_in_range_p PARAMS ((const struct loop *, rtx));
int loop_insn_first_p PARAMS ((rtx, rtx));
typedef void (*loop_insn_callback ) PARAMS ((struct loop *, rtx, int, int));
void for_each_insn_in_loop PARAMS ((struct loop *, loop_insn_callback));
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