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riscv-gcc-1
Commit 09dd1133 by Bernd Schmidt Committed by Jeff Law
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reload1.c (reload): Break out some more pieces into separate functions. 

	* reload1.c (reload): Break out some more pieces into separate
	functions.
	(dump_needs): New function, broken out of reload.
	(set_initial_elim_offsets): Likewise.
	(init_elim_table): Likewise.
	(update_eliminables): Likewise.

From-SVN: r22752
parent 34f89b5f
Showing with 222 additions and 172 deletions
gcc/ChangeLog
Fri Oct 2 10:51:35 1998 Bernd Schmidt <crux@Pool.Informatik.RWTH-Aachen.DE> Fri Oct 2 10:51:35 1998 Bernd Schmidt <crux@Pool.Informatik.RWTH-Aachen.DE>
* reload1.c (reload): Break out some more pieces into separate
functions.
(dump_needs): New function, broken out of reload.
(set_initial_elim_offsets): Likewise.
(init_elim_table): Likewise.
(update_eliminables): Likewise.
* global.c (global_alloc): Delete code to manage the scratch_list. * global.c (global_alloc): Delete code to manage the scratch_list.
* local-alloc.c (qty_scratch_rtx): Delete. * local-alloc.c (qty_scratch_rtx): Delete.
(scratch_block): Delete. (scratch_block): Delete.
......
gcc/reload1.c
...@@ -348,6 +348,7 @@ static int num_labels; ...@@ -348,6 +348,7 @@ static int num_labels;
struct hard_reg_n_uses { int regno; int uses; }; struct hard_reg_n_uses { int regno; int uses; };
static void dump_needs PROTO((FILE *));
static int calculate_needs_all_insns PROTO((rtx, int)); static int calculate_needs_all_insns PROTO((rtx, int));
static int calculate_needs PROTO((int, rtx, rtx, int)); static int calculate_needs PROTO((int, rtx, rtx, int));
static int find_reload_regs PROTO((int, FILE *)); static int find_reload_regs PROTO((int, FILE *));
...@@ -367,6 +368,9 @@ static void alter_reg PROTO((int, int)); ...@@ -367,6 +368,9 @@ static void alter_reg PROTO((int, int));
static void set_label_offsets PROTO((rtx, rtx, int)); static void set_label_offsets PROTO((rtx, rtx, int));
static int eliminate_regs_in_insn PROTO((rtx, int)); static int eliminate_regs_in_insn PROTO((rtx, int));
static void mark_not_eliminable PROTO((rtx, rtx)); static void mark_not_eliminable PROTO((rtx, rtx));
static void set_initial_elim_offsets PROTO((void));
static void init_elim_table PROTO((void));
static void update_eliminables PROTO((HARD_REG_SET *));
static int spill_hard_reg PROTO((int, int, FILE *, int)); static int spill_hard_reg PROTO((int, int, FILE *, int));
static void scan_paradoxical_subregs PROTO((rtx)); static void scan_paradoxical_subregs PROTO((rtx));
static int hard_reg_use_compare PROTO((const GENERIC_PTR, const GENERIC_PTR)); static int hard_reg_use_compare PROTO((const GENERIC_PTR, const GENERIC_PTR));
...@@ -749,46 +753,7 @@ reload (first, global, dumpfile) ...@@ -749,46 +753,7 @@ reload (first, global, dumpfile)
scan_paradoxical_subregs (PATTERN (insn)); scan_paradoxical_subregs (PATTERN (insn));
} }
/* Does this function require a frame pointer? */ init_elim_table ();
frame_pointer_needed = (! flag_omit_frame_pointer
#ifdef EXIT_IGNORE_STACK
/* ?? If EXIT_IGNORE_STACK is set, we will not save
and restore sp for alloca. So we can't eliminate
the frame pointer in that case. At some point,
we should improve this by emitting the
sp-adjusting insns for this case. */
|| (current_function_calls_alloca
&& EXIT_IGNORE_STACK)
#endif
|| FRAME_POINTER_REQUIRED);
num_eliminable = 0;
/* Initialize the table of registers to eliminate. The way we do this
depends on how the eliminable registers were defined. */
#ifdef ELIMINABLE_REGS
for (ep = reg_eliminate; ep < &reg_eliminate[NUM_ELIMINABLE_REGS]; ep++)
{
ep->can_eliminate = ep->can_eliminate_previous
= (CAN_ELIMINATE (ep->from, ep->to)
&& ! (ep->to == STACK_POINTER_REGNUM && frame_pointer_needed));
}
#else
reg_eliminate[0].can_eliminate = reg_eliminate[0].can_eliminate_previous
= ! frame_pointer_needed;
#endif
/* Count the number of eliminable registers and build the FROM and TO
REG rtx's. Note that code in gen_rtx will cause, e.g.,
gen_rtx (REG, Pmode, STACK_POINTER_REGNUM) to equal stack_pointer_rtx.
We depend on this. */
for (ep = reg_eliminate; ep < &reg_eliminate[NUM_ELIMINABLE_REGS]; ep++)
{
num_eliminable += ep->can_eliminate;
ep->from_rtx = gen_rtx_REG (Pmode, ep->from);
ep->to_rtx = gen_rtx_REG (Pmode, ep->to);
}
num_labels = max_label_num () - get_first_label_num (); num_labels = max_label_num () - get_first_label_num ();
...@@ -903,12 +868,7 @@ reload (first, global, dumpfile) ...@@ -903,12 +868,7 @@ reload (first, global, dumpfile)
something_needs_elimination = 0; something_needs_elimination = 0;
while (something_changed) while (something_changed)
{ {
rtx x;
HOST_WIDE_INT starting_frame_size; HOST_WIDE_INT starting_frame_size;
#if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
int previous_frame_pointer_needed = frame_pointer_needed;
#endif
static char *reg_class_names[] = REG_CLASS_NAMES;
something_changed = 0; something_changed = 0;
bzero ((char *) max_needs, sizeof max_needs); bzero ((char *) max_needs, sizeof max_needs);
...@@ -929,39 +889,8 @@ reload (first, global, dumpfile) ...@@ -929,39 +889,8 @@ reload (first, global, dumpfile)
starting_frame_size = get_frame_size (); starting_frame_size = get_frame_size ();
/* Reset all offsets on eliminable registers to their initial values. */ set_initial_elim_offsets ();
#ifdef ELIMINABLE_REGS
for (ep = reg_eliminate; ep < &reg_eliminate[NUM_ELIMINABLE_REGS]; ep++)
{
INITIAL_ELIMINATION_OFFSET (ep->from, ep->to, ep->initial_offset);
ep->previous_offset = ep->offset
= ep->max_offset = ep->initial_offset;
}
#else
#ifdef INITIAL_FRAME_POINTER_OFFSET
INITIAL_FRAME_POINTER_OFFSET (reg_eliminate[0].initial_offset);
#else
if (!FRAME_POINTER_REQUIRED)
abort ();
reg_eliminate[0].initial_offset = 0;
#endif
reg_eliminate[0].previous_offset = reg_eliminate[0].max_offset
= reg_eliminate[0].offset = reg_eliminate[0].initial_offset;
#endif
num_not_at_initial_offset = 0;
bzero ((char *) &offsets_known_at[get_first_label_num ()], num_labels);
/* Set a known offset for each forced label to be at the initial offset
of each elimination. We do this because we assume that all
computed jumps occur from a location where each elimination is
at its initial offset. */
for (x = forced_labels; x; x = XEXP (x, 1))
if (XEXP (x, 0))
set_label_offsets (XEXP (x, 0), NULL_RTX, 1);
/* For each pseudo register that has an equivalent location defined, /* For each pseudo register that has an equivalent location defined,
try to eliminate any eliminable registers (such as the frame pointer) try to eliminate any eliminable registers (such as the frame pointer)
assuming initial offsets for the replacement register, which assuming initial offsets for the replacement register, which
...@@ -1040,25 +969,7 @@ reload (first, global, dumpfile) ...@@ -1040,25 +969,7 @@ reload (first, global, dumpfile)
something_changed = 1; something_changed = 1;
if (dumpfile) if (dumpfile)
for (i = 0; i < N_REG_CLASSES; i++) dump_needs (dumpfile);
{
if (max_needs[i] > 0)
fprintf (dumpfile,
";; Need %d reg%s of class %s (for insn %d).\n",
max_needs[i], max_needs[i] == 1 ? "" : "s",
reg_class_names[i], INSN_UID (max_needs_insn[i]));
if (max_nongroups[i] > 0)
fprintf (dumpfile,
";; Need %d nongroup reg%s of class %s (for insn %d).\n",
max_nongroups[i], max_nongroups[i] == 1 ? "" : "s",
reg_class_names[i], INSN_UID (max_nongroups_insn[i]));
if (max_groups[i] > 0)
fprintf (dumpfile,
";; Need %d group%s (%smode) of class %s (for insn %d).\n",
max_groups[i], max_groups[i] == 1 ? "" : "s",
mode_name[(int) group_mode[i]],
reg_class_names[i], INSN_UID (max_groups_insn[i]));
}
/* If we have caller-saves, set up the save areas and see if caller-save /* If we have caller-saves, set up the save areas and see if caller-save
will need a spill register. */ will need a spill register. */
...@@ -1086,84 +997,17 @@ reload (first, global, dumpfile) ...@@ -1086,84 +997,17 @@ reload (first, global, dumpfile)
} }
} }
/* See if anything that happened changes which eliminations are valid. {
For example, on the Sparc, whether or not the frame pointer can HARD_REG_SET to_spill;
be eliminated can depend on what registers have been used. We need CLEAR_HARD_REG_SET (to_spill);
not check some conditions again (such as flag_omit_frame_pointer) update_eliminables (&to_spill);
since they can't have changed. */ for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
if (TEST_HARD_REG_BIT (to_spill, i))
for (ep = reg_eliminate; ep < &reg_eliminate[NUM_ELIMINABLE_REGS]; ep++)
if ((ep->from == HARD_FRAME_POINTER_REGNUM && FRAME_POINTER_REQUIRED)
#ifdef ELIMINABLE_REGS
|| ! CAN_ELIMINATE (ep->from, ep->to)
#endif
)
ep->can_eliminate = 0;
/* Look for the case where we have discovered that we can't replace
register A with register B and that means that we will now be
trying to replace register A with register C. This means we can
no longer replace register C with register B and we need to disable
such an elimination, if it exists. This occurs often with A == ap,
B == sp, and C == fp. */
for (ep = reg_eliminate; ep < &reg_eliminate[NUM_ELIMINABLE_REGS]; ep++)
{
struct elim_table *op;
register int new_to = -1;
if (! ep->can_eliminate && ep->can_eliminate_previous)
{
/* Find the current elimination for ep->from, if there is a
new one. */
for (op = reg_eliminate;
op < &reg_eliminate[NUM_ELIMINABLE_REGS]; op++)
if (op->from == ep->from && op->can_eliminate)
{
new_to = op->to;
break;
}
/* See if there is an elimination of NEW_TO -> EP->TO. If so,
disable it. */
for (op = reg_eliminate;
op < &reg_eliminate[NUM_ELIMINABLE_REGS]; op++)
if (op->from == new_to && op->to == ep->to)
op->can_eliminate = 0;
}
}
/* See if any registers that we thought we could eliminate the previous
time are no longer eliminable. If so, something has changed and we
must spill the register. Also, recompute the number of eliminable
registers and see if the frame pointer is needed; it is if there is
no elimination of the frame pointer that we can perform. */
frame_pointer_needed = 1;
for (ep = reg_eliminate; ep < &reg_eliminate[NUM_ELIMINABLE_REGS]; ep++)
{
if (ep->can_eliminate && ep->from == FRAME_POINTER_REGNUM
&& ep->to != HARD_FRAME_POINTER_REGNUM)
frame_pointer_needed = 0;
if (! ep->can_eliminate && ep->can_eliminate_previous)
{ {
ep->can_eliminate_previous = 0; spill_hard_reg (i, global, dumpfile, 1);
spill_hard_reg (ep->from, global, dumpfile, 1);
something_changed = 1; something_changed = 1;
num_eliminable--;
} }
} }
#if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
/* If we didn't need a frame pointer last time, but we do now, spill
the hard frame pointer. */
if (frame_pointer_needed && ! previous_frame_pointer_needed)
{
spill_hard_reg (HARD_FRAME_POINTER_REGNUM, global, dumpfile, 1);
something_changed = 1;
}
#endif
/* If all needs are met, we win. */ /* If all needs are met, we win. */
...@@ -2253,6 +2097,33 @@ find_reload_regs (global, dumpfile) ...@@ -2253,6 +2097,33 @@ find_reload_regs (global, dumpfile)
return something_changed; return something_changed;
} }
static void
dump_needs (dumpfile)
FILE *dumpfile;
{
static char *reg_class_names[] = REG_CLASS_NAMES;
int i;
for (i = 0; i < N_REG_CLASSES; i++)
{
if (max_needs[i] > 0)
fprintf (dumpfile,
";; Need %d reg%s of class %s (for insn %d).\n",
max_needs[i], max_needs[i] == 1 ? "" : "s",
reg_class_names[i], INSN_UID (max_needs_insn[i]));
if (max_nongroups[i] > 0)
fprintf (dumpfile,
";; Need %d nongroup reg%s of class %s (for insn %d).\n",
max_nongroups[i], max_nongroups[i] == 1 ? "" : "s",
reg_class_names[i], INSN_UID (max_nongroups_insn[i]));
if (max_groups[i] > 0)
fprintf (dumpfile,
";; Need %d group%s (%smode) of class %s (for insn %d).\n",
max_groups[i], max_groups[i] == 1 ? "" : "s",
mode_name[(int) group_mode[i]],
reg_class_names[i], INSN_UID (max_groups_insn[i]));
}
}
/* Nonzero if, after spilling reg REGNO for non-groups, /* Nonzero if, after spilling reg REGNO for non-groups,
it will still be possible to find a group if we still need one. */ it will still be possible to find a group if we still need one. */
...@@ -3720,6 +3591,178 @@ mark_not_eliminable (dest, x) ...@@ -3720,6 +3591,178 @@ mark_not_eliminable (dest, x)
num_eliminable--; num_eliminable--;
} }
} }
/* Reset all offsets on eliminable registers to their initial values. */
static void
set_initial_elim_offsets ()
{
rtx x;
#ifdef ELIMINABLE_REGS
struct elim_table *ep;
for (ep = reg_eliminate; ep < &reg_eliminate[NUM_ELIMINABLE_REGS]; ep++)
{
INITIAL_ELIMINATION_OFFSET (ep->from, ep->to, ep->initial_offset);
ep->previous_offset = ep->offset
= ep->max_offset = ep->initial_offset;
}
#else
#ifdef INITIAL_FRAME_POINTER_OFFSET
INITIAL_FRAME_POINTER_OFFSET (reg_eliminate[0].initial_offset);
#else
if (!FRAME_POINTER_REQUIRED)
abort ();
reg_eliminate[0].initial_offset = 0;
#endif
reg_eliminate[0].previous_offset = reg_eliminate[0].max_offset
= reg_eliminate[0].offset = reg_eliminate[0].initial_offset;
#endif
num_not_at_initial_offset = 0;
bzero ((char *) &offsets_known_at[get_first_label_num ()], num_labels);
/* Set a known offset for each forced label to be at the initial offset
of each elimination. We do this because we assume that all
computed jumps occur from a location where each elimination is
at its initial offset. */
for (x = forced_labels; x; x = XEXP (x, 1))
if (XEXP (x, 0))
set_label_offsets (XEXP (x, 0), NULL_RTX, 1);
}
/* See if anything that happened changes which eliminations are valid.
For example, on the Sparc, whether or not the frame pointer can
be eliminated can depend on what registers have been used. We need
not check some conditions again (such as flag_omit_frame_pointer)
since they can't have changed. */
static void
update_eliminables (pset)
HARD_REG_SET *pset;
{
#if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
int previous_frame_pointer_needed = frame_pointer_needed;
#endif
struct elim_table *ep;
for (ep = reg_eliminate; ep < &reg_eliminate[NUM_ELIMINABLE_REGS]; ep++)
if ((ep->from == HARD_FRAME_POINTER_REGNUM && FRAME_POINTER_REQUIRED)
#ifdef ELIMINABLE_REGS
|| ! CAN_ELIMINATE (ep->from, ep->to)
#endif
)
ep->can_eliminate = 0;
/* Look for the case where we have discovered that we can't replace
register A with register B and that means that we will now be
trying to replace register A with register C. This means we can
no longer replace register C with register B and we need to disable
such an elimination, if it exists. This occurs often with A == ap,
B == sp, and C == fp. */
for (ep = reg_eliminate; ep < &reg_eliminate[NUM_ELIMINABLE_REGS]; ep++)
{
struct elim_table *op;
register int new_to = -1;
if (! ep->can_eliminate && ep->can_eliminate_previous)
{
/* Find the current elimination for ep->from, if there is a
new one. */
for (op = reg_eliminate;
op < &reg_eliminate[NUM_ELIMINABLE_REGS]; op++)
if (op->from == ep->from && op->can_eliminate)
{
new_to = op->to;
break;
}
/* See if there is an elimination of NEW_TO -> EP->TO. If so,
disable it. */
for (op = reg_eliminate;
op < &reg_eliminate[NUM_ELIMINABLE_REGS]; op++)
if (op->from == new_to && op->to == ep->to)
op->can_eliminate = 0;
}
}
/* See if any registers that we thought we could eliminate the previous
time are no longer eliminable. If so, something has changed and we
must spill the register. Also, recompute the number of eliminable
registers and see if the frame pointer is needed; it is if there is
no elimination of the frame pointer that we can perform. */
frame_pointer_needed = 1;
for (ep = reg_eliminate; ep < &reg_eliminate[NUM_ELIMINABLE_REGS]; ep++)
{
if (ep->can_eliminate && ep->from == FRAME_POINTER_REGNUM
&& ep->to != HARD_FRAME_POINTER_REGNUM)
frame_pointer_needed = 0;
if (! ep->can_eliminate && ep->can_eliminate_previous)
{
ep->can_eliminate_previous = 0;
SET_HARD_REG_BIT (*pset, ep->from);
num_eliminable--;
}
}
#if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
/* If we didn't need a frame pointer last time, but we do now, spill
the hard frame pointer. */
if (frame_pointer_needed && ! previous_frame_pointer_needed)
SET_HARD_REG_BIT (*pset, HARD_FRAME_POINTER_REGNUM);
#endif
}
/* Initialize the table of registers to eliminate. */
static void
init_elim_table ()
{
struct elim_table *ep;
/* Does this function require a frame pointer? */
frame_pointer_needed = (! flag_omit_frame_pointer
#ifdef EXIT_IGNORE_STACK
/* ?? If EXIT_IGNORE_STACK is set, we will not save
and restore sp for alloca. So we can't eliminate
the frame pointer in that case. At some point,
we should improve this by emitting the
sp-adjusting insns for this case. */
|| (current_function_calls_alloca
&& EXIT_IGNORE_STACK)
#endif
|| FRAME_POINTER_REQUIRED);
num_eliminable = 0;
#ifdef ELIMINABLE_REGS
for (ep = reg_eliminate; ep < &reg_eliminate[NUM_ELIMINABLE_REGS]; ep++)
{
ep->can_eliminate = ep->can_eliminate_previous
= (CAN_ELIMINATE (ep->from, ep->to)
&& ! (ep->to == STACK_POINTER_REGNUM && frame_pointer_needed));
}
#else
reg_eliminate[0].can_eliminate = reg_eliminate[0].can_eliminate_previous
= ! frame_pointer_needed;
#endif
/* Count the number of eliminable registers and build the FROM and TO
REG rtx's. Note that code in gen_rtx will cause, e.g.,
gen_rtx (REG, Pmode, STACK_POINTER_REGNUM) to equal stack_pointer_rtx.
We depend on this. */
for (ep = reg_eliminate; ep < &reg_eliminate[NUM_ELIMINABLE_REGS]; ep++)
{
num_eliminable += ep->can_eliminate;
ep->from_rtx = gen_rtx_REG (Pmode, ep->from);
ep->to_rtx = gen_rtx_REG (Pmode, ep->to);
}
}
/* Kick all pseudos out of hard register REGNO. /* Kick all pseudos out of hard register REGNO.
If GLOBAL is nonzero, try to find someplace else to put them. If GLOBAL is nonzero, try to find someplace else to put them.
......
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