d05c8ee724
From-SVN: r2415
1688 lines
48 KiB
C
1688 lines
48 KiB
C
/* Compute register class preferences for pseudo-registers.
|
||
Copyright (C) 1987, 1988, 1991, 1992 Free Software Foundation, Inc.
|
||
|
||
This file is part of GNU CC.
|
||
|
||
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.
|
||
|
||
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.
|
||
|
||
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, 675 Mass Ave, Cambridge, MA 02139, USA. */
|
||
|
||
|
||
/* This file contains two passes of the compiler: reg_scan and reg_class.
|
||
It also defines some tables of information about the hardware registers
|
||
and a function init_reg_sets to initialize the tables. */
|
||
|
||
#include "config.h"
|
||
#include "rtl.h"
|
||
#include "hard-reg-set.h"
|
||
#include "flags.h"
|
||
#include "basic-block.h"
|
||
#include "regs.h"
|
||
#include "insn-config.h"
|
||
#include "recog.h"
|
||
#include "reload.h"
|
||
#include "real.h"
|
||
|
||
#ifndef REGISTER_MOVE_COST
|
||
#define REGISTER_MOVE_COST(x, y) 2
|
||
#endif
|
||
|
||
#ifndef MEMORY_MOVE_COST
|
||
#define MEMORY_MOVE_COST(x) 4
|
||
#endif
|
||
|
||
/* If we have auto-increment or auto-decrement and we can have secondary
|
||
reloads, we are not allowed to use classes requiring secondary
|
||
reloads for psuedos auto-incremented since reload can't handle it. */
|
||
|
||
#ifdef AUTO_INC_DEC
|
||
#if defined(SECONARY_INPUT_RELOAD_CLASS) || defined(SECONDARY_OUTPUT_RELOAD_CLASS)
|
||
#define FORBIDDEN_INC_DEC_CLASSES
|
||
#endif
|
||
#endif
|
||
|
||
/* Register tables used by many passes. */
|
||
|
||
/* Indexed by hard register number, contains 1 for registers
|
||
that are fixed use (stack pointer, pc, frame pointer, etc.).
|
||
These are the registers that cannot be used to allocate
|
||
a pseudo reg whose life does not cross calls. */
|
||
|
||
char fixed_regs[FIRST_PSEUDO_REGISTER];
|
||
|
||
/* Same info as a HARD_REG_SET. */
|
||
|
||
HARD_REG_SET fixed_reg_set;
|
||
|
||
/* Data for initializing the above. */
|
||
|
||
static char initial_fixed_regs[] = FIXED_REGISTERS;
|
||
|
||
/* Indexed by hard register number, contains 1 for registers
|
||
that are fixed use or are clobbered by function calls.
|
||
These are the registers that cannot be used to allocate
|
||
a pseudo reg whose life crosses calls. */
|
||
|
||
char call_used_regs[FIRST_PSEUDO_REGISTER];
|
||
|
||
/* Same info as a HARD_REG_SET. */
|
||
|
||
HARD_REG_SET call_used_reg_set;
|
||
|
||
/* Data for initializing the above. */
|
||
|
||
static char initial_call_used_regs[] = CALL_USED_REGISTERS;
|
||
|
||
/* Indexed by hard register number, contains 1 for registers that are
|
||
fixed use -- i.e. in fixed_regs -- or a function value return register
|
||
or STRUCT_VALUE_REGNUM or STATIC_CHAIN_REGNUM. These are the
|
||
registers that cannot hold quantities across calls even if we are
|
||
willing to save and restore them. */
|
||
|
||
char call_fixed_regs[FIRST_PSEUDO_REGISTER];
|
||
|
||
/* The same info as a HARD_REG_SET. */
|
||
|
||
HARD_REG_SET call_fixed_reg_set;
|
||
|
||
/* Number of non-fixed registers. */
|
||
|
||
int n_non_fixed_regs;
|
||
|
||
/* Indexed by hard register number, contains 1 for registers
|
||
that are being used for global register decls.
|
||
These must be exempt from ordinary flow analysis
|
||
and are also considered fixed. */
|
||
|
||
char global_regs[FIRST_PSEUDO_REGISTER];
|
||
|
||
/* Table of register numbers in the order in which to try to use them. */
|
||
#ifdef REG_ALLOC_ORDER
|
||
int reg_alloc_order[FIRST_PSEUDO_REGISTER] = REG_ALLOC_ORDER;
|
||
#endif
|
||
|
||
/* For each reg class, a HARD_REG_SET saying which registers are in it. */
|
||
|
||
HARD_REG_SET reg_class_contents[N_REG_CLASSES];
|
||
|
||
/* The same information, but as an array of ints. We copy from these
|
||
ints to the table above. This is done so that the tm.h files do
|
||
not have to be aware of the wordsize for machines with <= 64 regs. */
|
||
|
||
#define N_REG_INTS \
|
||
((FIRST_PSEUDO_REGISTER + (HOST_BITS_PER_INT - 1)) / HOST_BITS_PER_INT)
|
||
|
||
static int int_reg_class_contents[N_REG_CLASSES][N_REG_INTS]
|
||
= REG_CLASS_CONTENTS;
|
||
|
||
/* For each reg class, number of regs it contains. */
|
||
|
||
int reg_class_size[N_REG_CLASSES];
|
||
|
||
/* For each reg class, table listing all the containing classes. */
|
||
|
||
enum reg_class reg_class_superclasses[N_REG_CLASSES][N_REG_CLASSES];
|
||
|
||
/* For each reg class, table listing all the classes contained in it. */
|
||
|
||
enum reg_class reg_class_subclasses[N_REG_CLASSES][N_REG_CLASSES];
|
||
|
||
/* For each pair of reg classes,
|
||
a largest reg class contained in their union. */
|
||
|
||
enum reg_class reg_class_subunion[N_REG_CLASSES][N_REG_CLASSES];
|
||
|
||
/* For each pair of reg classes,
|
||
the smallest reg class containing their union. */
|
||
|
||
enum reg_class reg_class_superunion[N_REG_CLASSES][N_REG_CLASSES];
|
||
|
||
/* Array containing all of the register names */
|
||
|
||
char *reg_names[] = REGISTER_NAMES;
|
||
|
||
/* Indexed by n, gives number of times (REG n) is set or clobbered.
|
||
This information remains valid for the rest of the compilation
|
||
of the current function; it is used to control register allocation.
|
||
|
||
This information applies to both hard registers and pseudo registers,
|
||
unlike much of the information above. */
|
||
|
||
short *reg_n_sets;
|
||
|
||
/* Maximum cost of moving from a register in one class to a register in
|
||
another class. Based on REGISTER_MOVE_COST. */
|
||
|
||
static int move_cost[N_REG_CLASSES][N_REG_CLASSES];
|
||
|
||
/* Similar, but here we don't have to move if the first index is a subset
|
||
of the second so in that case the cost is zero. */
|
||
|
||
static int may_move_cost[N_REG_CLASSES][N_REG_CLASSES];
|
||
|
||
#ifdef FORBIDDEN_INC_DEC_CLASSES
|
||
|
||
/* These are the classes that regs which are auto-incremented or decremented
|
||
cannot be put in. */
|
||
|
||
static int forbidden_inc_dec_class[N_REG_CLASSES];
|
||
|
||
/* Indexed by n, is non-zero if (REG n) is used in an auto-inc or auto-dec
|
||
context. */
|
||
|
||
static char *in_inc_dec;
|
||
|
||
#endif /* FORBIDDEN_INC_DEC_CLASSES */
|
||
|
||
/* Function called only once to initialize the above data on reg usage.
|
||
Once this is done, various switches may override. */
|
||
|
||
void
|
||
init_reg_sets ()
|
||
{
|
||
register int i, j;
|
||
|
||
/* First copy the register information from the initial int form into
|
||
the regsets. */
|
||
|
||
for (i = 0; i < N_REG_CLASSES; i++)
|
||
{
|
||
CLEAR_HARD_REG_SET (reg_class_contents[i]);
|
||
|
||
for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
|
||
if (int_reg_class_contents[i][j / HOST_BITS_PER_INT]
|
||
& (1 << (j % HOST_BITS_PER_INT)))
|
||
SET_HARD_REG_BIT (reg_class_contents[i], j);
|
||
}
|
||
|
||
bcopy (initial_fixed_regs, fixed_regs, sizeof fixed_regs);
|
||
bcopy (initial_call_used_regs, call_used_regs, sizeof call_used_regs);
|
||
bzero (global_regs, sizeof global_regs);
|
||
|
||
/* Compute number of hard regs in each class. */
|
||
|
||
bzero (reg_class_size, sizeof reg_class_size);
|
||
for (i = 0; i < N_REG_CLASSES; i++)
|
||
for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
|
||
if (TEST_HARD_REG_BIT (reg_class_contents[i], j))
|
||
reg_class_size[i]++;
|
||
|
||
/* Initialize the table of subunions.
|
||
reg_class_subunion[I][J] gets the largest-numbered reg-class
|
||
that is contained in the union of classes I and J. */
|
||
|
||
for (i = 0; i < N_REG_CLASSES; i++)
|
||
{
|
||
for (j = 0; j < N_REG_CLASSES; j++)
|
||
{
|
||
#ifdef HARD_REG_SET
|
||
register /* Declare it register if it's a scalar. */
|
||
#endif
|
||
HARD_REG_SET c;
|
||
register int k;
|
||
|
||
COPY_HARD_REG_SET (c, reg_class_contents[i]);
|
||
IOR_HARD_REG_SET (c, reg_class_contents[j]);
|
||
for (k = 0; k < N_REG_CLASSES; k++)
|
||
{
|
||
GO_IF_HARD_REG_SUBSET (reg_class_contents[k], c,
|
||
subclass1);
|
||
continue;
|
||
|
||
subclass1:
|
||
/* keep the largest subclass */ /* SPEE 900308 */
|
||
GO_IF_HARD_REG_SUBSET (reg_class_contents[k],
|
||
reg_class_contents[(int) reg_class_subunion[i][j]],
|
||
subclass2);
|
||
reg_class_subunion[i][j] = (enum reg_class) k;
|
||
subclass2:
|
||
;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Initialize the table of superunions.
|
||
reg_class_superunion[I][J] gets the smallest-numbered reg-class
|
||
containing the union of classes I and J. */
|
||
|
||
for (i = 0; i < N_REG_CLASSES; i++)
|
||
{
|
||
for (j = 0; j < N_REG_CLASSES; j++)
|
||
{
|
||
#ifdef HARD_REG_SET
|
||
register /* Declare it register if it's a scalar. */
|
||
#endif
|
||
HARD_REG_SET c;
|
||
register int k;
|
||
|
||
COPY_HARD_REG_SET (c, reg_class_contents[i]);
|
||
IOR_HARD_REG_SET (c, reg_class_contents[j]);
|
||
for (k = 0; k < N_REG_CLASSES; k++)
|
||
GO_IF_HARD_REG_SUBSET (c, reg_class_contents[k], superclass);
|
||
|
||
superclass:
|
||
reg_class_superunion[i][j] = (enum reg_class) k;
|
||
}
|
||
}
|
||
|
||
/* Initialize the tables of subclasses and superclasses of each reg class.
|
||
First clear the whole table, then add the elements as they are found. */
|
||
|
||
for (i = 0; i < N_REG_CLASSES; i++)
|
||
{
|
||
for (j = 0; j < N_REG_CLASSES; j++)
|
||
{
|
||
reg_class_superclasses[i][j] = LIM_REG_CLASSES;
|
||
reg_class_subclasses[i][j] = LIM_REG_CLASSES;
|
||
}
|
||
}
|
||
|
||
for (i = 0; i < N_REG_CLASSES; i++)
|
||
{
|
||
if (i == (int) NO_REGS)
|
||
continue;
|
||
|
||
for (j = i + 1; j < N_REG_CLASSES; j++)
|
||
{
|
||
enum reg_class *p;
|
||
|
||
GO_IF_HARD_REG_SUBSET (reg_class_contents[i], reg_class_contents[j],
|
||
subclass);
|
||
continue;
|
||
subclass:
|
||
/* Reg class I is a subclass of J.
|
||
Add J to the table of superclasses of I. */
|
||
p = ®_class_superclasses[i][0];
|
||
while (*p != LIM_REG_CLASSES) p++;
|
||
*p = (enum reg_class) j;
|
||
/* Add I to the table of superclasses of J. */
|
||
p = ®_class_subclasses[j][0];
|
||
while (*p != LIM_REG_CLASSES) p++;
|
||
*p = (enum reg_class) i;
|
||
}
|
||
}
|
||
|
||
/* Initialize the move cost table. Find every subset of each class
|
||
and take the maximum cost of moving any subset to any other. */
|
||
|
||
for (i = 0; i < N_REG_CLASSES; i++)
|
||
for (j = 0; j < N_REG_CLASSES; j++)
|
||
{
|
||
int cost = i == j ? 2 : REGISTER_MOVE_COST (i, j);
|
||
enum reg_class *p1, *p2;
|
||
|
||
for (p2 = ®_class_subclasses[j][0]; *p2 != LIM_REG_CLASSES; p2++)
|
||
if (*p2 != i)
|
||
cost = MAX (cost, REGISTER_MOVE_COST (i, *p2));
|
||
|
||
for (p1 = ®_class_subclasses[i][0]; *p1 != LIM_REG_CLASSES; p1++)
|
||
{
|
||
if (*p1 != j)
|
||
cost = MAX (cost, REGISTER_MOVE_COST (*p1, j));
|
||
|
||
for (p2 = ®_class_subclasses[j][0];
|
||
*p2 != LIM_REG_CLASSES; p2++)
|
||
if (*p1 != *p2)
|
||
cost = MAX (cost, REGISTER_MOVE_COST (*p1, *p2));
|
||
}
|
||
|
||
move_cost[i][j] = cost;
|
||
|
||
if (reg_class_subset_p (i, j))
|
||
cost = 0;
|
||
|
||
may_move_cost[i][j] = cost;
|
||
}
|
||
}
|
||
|
||
/* After switches have been processed, which perhaps alter
|
||
`fixed_regs' and `call_used_regs', convert them to HARD_REG_SETs. */
|
||
|
||
void
|
||
init_reg_sets_1 ()
|
||
{
|
||
register int i;
|
||
|
||
/* This macro allows the fixed or call-used registers
|
||
to depend on target flags. */
|
||
|
||
#ifdef CONDITIONAL_REGISTER_USAGE
|
||
CONDITIONAL_REGISTER_USAGE;
|
||
#endif
|
||
|
||
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
|
||
if (global_regs[i])
|
||
{
|
||
if (call_used_regs[i] && ! fixed_regs[i])
|
||
warning ("call-clobbered register used for global register variable");
|
||
fixed_regs[i] = 1;
|
||
/* Prevent saving/restoring of this reg. */
|
||
call_used_regs[i] = 1;
|
||
}
|
||
|
||
/* Initialize "constant" tables. */
|
||
|
||
CLEAR_HARD_REG_SET (fixed_reg_set);
|
||
CLEAR_HARD_REG_SET (call_used_reg_set);
|
||
CLEAR_HARD_REG_SET (call_fixed_reg_set);
|
||
|
||
bcopy (fixed_regs, call_fixed_regs, sizeof call_fixed_regs);
|
||
#ifdef STRUCT_VALUE_REGNUM
|
||
call_fixed_regs[STRUCT_VALUE_REGNUM] = 1;
|
||
#endif
|
||
#ifdef STATIC_CHAIN_REGNUM
|
||
call_fixed_regs[STATIC_CHAIN_REGNUM] = 1;
|
||
#endif
|
||
|
||
n_non_fixed_regs = 0;
|
||
|
||
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
|
||
{
|
||
if (FUNCTION_VALUE_REGNO_P (i))
|
||
call_fixed_regs[i] = 1;
|
||
if (fixed_regs[i])
|
||
SET_HARD_REG_BIT (fixed_reg_set, i);
|
||
else
|
||
n_non_fixed_regs++;
|
||
|
||
if (call_used_regs[i])
|
||
SET_HARD_REG_BIT (call_used_reg_set, i);
|
||
if (call_fixed_regs[i])
|
||
SET_HARD_REG_BIT (call_fixed_reg_set, i);
|
||
}
|
||
}
|
||
|
||
/* Specify the usage characteristics of the register named NAME.
|
||
It should be a fixed register if FIXED and a
|
||
call-used register if CALL_USED. */
|
||
|
||
void
|
||
fix_register (name, fixed, call_used)
|
||
char *name;
|
||
int fixed, call_used;
|
||
{
|
||
int i;
|
||
|
||
/* Decode the name and update the primary form of
|
||
the register info. */
|
||
|
||
if ((i = decode_reg_name (name)) >= 0)
|
||
{
|
||
fixed_regs[i] = fixed;
|
||
call_used_regs[i] = call_used;
|
||
}
|
||
else
|
||
{
|
||
warning ("unknown register name: %s", name);
|
||
}
|
||
}
|
||
|
||
/* Now the data and code for the `regclass' pass, which happens
|
||
just before local-alloc. */
|
||
|
||
/* The `costs' struct records the cost of using a hard register of each class
|
||
and of using memory for each pseudo. We use this data to set up
|
||
register class preferences. */
|
||
|
||
struct costs
|
||
{
|
||
int cost[N_REG_CLASSES];
|
||
int mem_cost;
|
||
};
|
||
|
||
/* Record the cost of each class for each pseudo. */
|
||
|
||
static struct costs *costs;
|
||
|
||
/* Record the same data by operand number, accumulated for each alternative
|
||
in an insn. The contribution to a pseudo is that of the minimum-cost
|
||
alternative. */
|
||
|
||
static struct costs op_costs[MAX_RECOG_OPERANDS];
|
||
|
||
/* (enum reg_class) prefclass[R] is the preferred class for pseudo number R.
|
||
This is available after `regclass' is run. */
|
||
|
||
static char *prefclass;
|
||
|
||
/* altclass[R] is a register class that we should use for allocating
|
||
pseudo number R if no register in the preferred class is available.
|
||
If no register in this class is available, memory is preferred.
|
||
|
||
It might appear to be more general to have a bitmask of classes here,
|
||
but since it is recommended that there be a class corresponding to the
|
||
union of most major pair of classes, that generality is not required.
|
||
|
||
This is available after `regclass' is run. */
|
||
|
||
static char *altclass;
|
||
|
||
/* Record the depth of loops that we are in. */
|
||
|
||
static int loop_depth;
|
||
|
||
/* Account for the fact that insns within a loop are executed very commonly,
|
||
but don't keep doing this as loops go too deep. */
|
||
|
||
static int loop_cost;
|
||
|
||
static int copy_cost ();
|
||
static void record_reg_classes ();
|
||
static void record_address_regs ();
|
||
|
||
|
||
/* Return the reg_class in which pseudo reg number REGNO is best allocated.
|
||
This function is sometimes called before the info has been computed.
|
||
When that happens, just return GENERAL_REGS, which is innocuous. */
|
||
|
||
enum reg_class
|
||
reg_preferred_class (regno)
|
||
int regno;
|
||
{
|
||
if (prefclass == 0)
|
||
return GENERAL_REGS;
|
||
return (enum reg_class) prefclass[regno];
|
||
}
|
||
|
||
enum reg_class
|
||
reg_alternate_class (regno)
|
||
{
|
||
if (prefclass == 0)
|
||
return ALL_REGS;
|
||
|
||
return (enum reg_class) altclass[regno];
|
||
}
|
||
|
||
/* This prevents dump_flow_info from losing if called
|
||
before regclass is run. */
|
||
|
||
void
|
||
regclass_init ()
|
||
{
|
||
prefclass = 0;
|
||
}
|
||
|
||
/* This is a pass of the compiler that scans all instructions
|
||
and calculates the preferred class for each pseudo-register.
|
||
This information can be accessed later by calling `reg_preferred_class'.
|
||
This pass comes just before local register allocation. */
|
||
|
||
void
|
||
regclass (f, nregs)
|
||
rtx f;
|
||
int nregs;
|
||
{
|
||
#ifdef REGISTER_CONSTRAINTS
|
||
register rtx insn;
|
||
register int i, j;
|
||
struct costs init_cost;
|
||
rtx set;
|
||
int pass;
|
||
|
||
init_recog ();
|
||
|
||
costs = (struct costs *) alloca (nregs * sizeof (struct costs));
|
||
|
||
#ifdef FORBIDDEN_INC_DEC_CLASSES
|
||
|
||
in_inc_dec = (char *) alloca (nregs);
|
||
|
||
/* Initialize information about which register classes can be used for
|
||
pseudos that are auto-incremented or auto-decremented. It would
|
||
seem better to put this in init_reg_sets, but we need to be able
|
||
to allocate rtx, which we can't do that early. */
|
||
|
||
for (i = 0; i < N_REG_CLASSES; i++)
|
||
{
|
||
rtx r = gen_rtx (REG, VOIDmode, 0);
|
||
enum machine_mode m;
|
||
|
||
for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
|
||
if (TEST_HARD_REG_BIT (reg_class_contents[i], j))
|
||
{
|
||
REGNO (r) = j;
|
||
|
||
for (m = VOIDmode; (int) m < (int) MAX_MACHINE_MODE;
|
||
m = (enum machine_mode) ((int) m) + 1)
|
||
if (HARD_REGNO_MODE_OK (j, m))
|
||
{
|
||
PUT_MODE (r, m);
|
||
if (0
|
||
#ifdef SECONDARY_INPUT_RELOAD_CLASS
|
||
|| (SECONDARY_INPUT_RELOAD_CLASS (BASE_REG_CLASS, m, r)
|
||
!= NO_REGS)
|
||
#endif
|
||
#ifdef SECONDARY_OUTPUT_RELOAD_CLASS
|
||
|| (SECONDARY_OUTPUT_RELOAD_CLASS (BASE_REG_CLASS, m, r)
|
||
!= NO_REGS)
|
||
#endif
|
||
)
|
||
forbidden_inc_dec_class[i] = 1;
|
||
}
|
||
}
|
||
}
|
||
#endif /* FORBIDDEN_INC_DEC_CLASSES */
|
||
|
||
init_cost.mem_cost = 10000;
|
||
for (i = 0; i < N_REG_CLASSES; i++)
|
||
init_cost.cost[i] = 10000;
|
||
|
||
/* Normally we scan the insns once and determine the best class to use for
|
||
each register. However, if -fexpensive_optimizations are on, we do so
|
||
twice, the second time using the tentative best classes to guide the
|
||
selection. */
|
||
|
||
for (pass = 0; pass <= flag_expensive_optimizations; pass++)
|
||
{
|
||
/* Zero out our accumulation of the cost of each class for each reg. */
|
||
|
||
bzero (costs, nregs * sizeof (struct costs));
|
||
|
||
#ifdef FORBIDDEN_INC_DEC_CLASSES
|
||
bzero (in_inc_dec, nregs);
|
||
#endif
|
||
|
||
loop_depth = 0, loop_cost = 1;
|
||
|
||
/* Scan the instructions and record each time it would
|
||
save code to put a certain register in a certain class. */
|
||
|
||
for (insn = f; insn; insn = NEXT_INSN (insn))
|
||
{
|
||
char *constraints[MAX_RECOG_OPERANDS];
|
||
enum machine_mode modes[MAX_RECOG_OPERANDS];
|
||
int nalternatives;
|
||
int noperands;
|
||
|
||
/* Show that an insn inside a loop is likely to be executed three
|
||
times more than insns outside a loop. This is much more agressive
|
||
than the assumptions made elsewhere and is being tried as an
|
||
experiment. */
|
||
|
||
if (GET_CODE (insn) == NOTE
|
||
&& NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
|
||
loop_depth++, loop_cost = 1 << (2 * MIN (loop_depth, 5));
|
||
else if (GET_CODE (insn) == NOTE
|
||
&& NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END)
|
||
loop_depth--, loop_cost = 1 << (2 * MIN (loop_depth, 5));
|
||
|
||
else if ((GET_CODE (insn) == INSN
|
||
&& GET_CODE (PATTERN (insn)) != USE
|
||
&& GET_CODE (PATTERN (insn)) != CLOBBER
|
||
&& GET_CODE (PATTERN (insn)) != ASM_INPUT)
|
||
|| (GET_CODE (insn) == JUMP_INSN
|
||
&& GET_CODE (PATTERN (insn)) != ADDR_VEC
|
||
&& GET_CODE (PATTERN (insn)) != ADDR_DIFF_VEC)
|
||
|| GET_CODE (insn) == CALL_INSN)
|
||
{
|
||
if (GET_CODE (insn) == INSN
|
||
&& (noperands = asm_noperands (PATTERN (insn))) >= 0)
|
||
{
|
||
decode_asm_operands (PATTERN (insn), recog_operand, NULL_PTR,
|
||
constraints, modes);
|
||
nalternatives = (noperands == 0 ? 0
|
||
: n_occurrences (',', constraints[0]) + 1);
|
||
}
|
||
else
|
||
{
|
||
int insn_code_number = recog_memoized (insn);
|
||
rtx note;
|
||
|
||
set = single_set (insn);
|
||
insn_extract (insn);
|
||
|
||
nalternatives = insn_n_alternatives[insn_code_number];
|
||
noperands = insn_n_operands[insn_code_number];
|
||
|
||
/* If this insn loads a parameter from its stack slot, then
|
||
it represents a savings, rather than a cost, if the
|
||
parameter is stored in memory. Record this fact. */
|
||
|
||
if (set != 0 && GET_CODE (SET_DEST (set)) == REG
|
||
&& GET_CODE (SET_SRC (set)) == MEM
|
||
&& (note = find_reg_note (insn, REG_EQUIV,
|
||
NULL_RTX)) != 0
|
||
&& GET_CODE (XEXP (note, 0)) == MEM)
|
||
{
|
||
costs[REGNO (SET_DEST (set))].mem_cost
|
||
-= (MEMORY_MOVE_COST (GET_MODE (SET_DEST (set)))
|
||
* loop_cost);
|
||
record_address_regs (XEXP (SET_SRC (set), 0),
|
||
BASE_REG_CLASS, loop_cost * 2);
|
||
continue;
|
||
}
|
||
|
||
/* Improve handling of two-address insns such as
|
||
(set X (ashift CONST Y)) where CONST must be made to
|
||
match X. Change it into two insns: (set X CONST)
|
||
(set X (ashift X Y)). If we left this for reloading, it
|
||
would probably get three insns because X and Y might go
|
||
in the same place. This prevents X and Y from receiving
|
||
the same hard reg.
|
||
|
||
We can only do this if the modes of operands 0 and 1
|
||
(which might not be the same) are tieable and we only need
|
||
do this during our first pass. */
|
||
|
||
if (pass == 0 && optimize
|
||
&& noperands >= 3
|
||
&& insn_operand_constraint[insn_code_number][1][0] == '0'
|
||
&& insn_operand_constraint[insn_code_number][1][1] == 0
|
||
&& CONSTANT_P (recog_operand[1])
|
||
&& ! rtx_equal_p (recog_operand[0], recog_operand[1])
|
||
&& ! rtx_equal_p (recog_operand[0], recog_operand[2])
|
||
&& GET_CODE (recog_operand[0]) == REG
|
||
&& MODES_TIEABLE_P (GET_MODE (recog_operand[0]),
|
||
insn_operand_mode[insn_code_number][1]))
|
||
{
|
||
rtx previnsn = prev_real_insn (insn);
|
||
rtx dest
|
||
= gen_lowpart (insn_operand_mode[insn_code_number][1],
|
||
recog_operand[0]);
|
||
rtx newinsn
|
||
= emit_insn_before (gen_move_insn (dest,
|
||
recog_operand[1]),
|
||
insn);
|
||
|
||
/* If this insn was the start of a basic block,
|
||
include the new insn in that block.
|
||
We need not check for code_label here;
|
||
while a basic block can start with a code_label,
|
||
INSN could not be at the beginning of that block. */
|
||
if (previnsn == 0 || GET_CODE (previnsn) == JUMP_INSN)
|
||
{
|
||
int b;
|
||
for (b = 0; b < n_basic_blocks; b++)
|
||
if (insn == basic_block_head[b])
|
||
basic_block_head[b] = newinsn;
|
||
}
|
||
|
||
/* This makes one more setting of new insns's dest. */
|
||
reg_n_sets[REGNO (recog_operand[0])]++;
|
||
|
||
*recog_operand_loc[1] = recog_operand[0];
|
||
for (i = insn_n_dups[insn_code_number] - 1; i >= 0; i--)
|
||
if (recog_dup_num[i] == 1)
|
||
*recog_dup_loc[i] = recog_operand[0];
|
||
|
||
insn = PREV_INSN (newinsn);
|
||
continue;
|
||
}
|
||
|
||
/* If this is setting a pseudo from another pseudo or the
|
||
sum of a pseudo and a constant integer and the other
|
||
pseudo is known to be a pointer, set the destination to
|
||
be a pointer as well.
|
||
|
||
Likewise if it is setting the destination from an address
|
||
or from a value equivalent to an address or to the sum of
|
||
an address and something else.
|
||
|
||
But don't do any of this if the pseudo corresponds to
|
||
a user variable since it should have already been set
|
||
as a pointer based on the type.
|
||
|
||
There is no point in doing this during our second
|
||
pass since not enough should have changed. */
|
||
|
||
if (pass == 0 && set != 0 && GET_CODE (SET_DEST (set)) == REG
|
||
&& REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER
|
||
&& ! REG_USERVAR_P (SET_DEST (set))
|
||
&& ! REGNO_POINTER_FLAG (REGNO (SET_DEST (set)))
|
||
&& ((GET_CODE (SET_SRC (set)) == REG
|
||
&& REGNO_POINTER_FLAG (REGNO (SET_SRC (set))))
|
||
|| ((GET_CODE (SET_SRC (set)) == PLUS
|
||
|| GET_CODE (SET_SRC (set)) == LO_SUM)
|
||
&& (GET_CODE (XEXP (SET_SRC (set), 1))
|
||
== CONST_INT)
|
||
&& GET_CODE (XEXP (SET_SRC (set), 0)) == REG
|
||
&& REGNO_POINTER_FLAG (REGNO (XEXP (SET_SRC (set), 0))))
|
||
|| GET_CODE (SET_SRC (set)) == CONST
|
||
|| GET_CODE (SET_SRC (set)) == SYMBOL_REF
|
||
|| GET_CODE (SET_SRC (set)) == LABEL_REF
|
||
|| (GET_CODE (SET_SRC (set)) == HIGH
|
||
&& (GET_CODE (XEXP (SET_SRC (set), 0)) == CONST
|
||
|| (GET_CODE (XEXP (SET_SRC (set), 0))
|
||
== SYMBOL_REF)
|
||
|| (GET_CODE (XEXP (SET_SRC (set), 0))
|
||
== LABEL_REF)))
|
||
|| ((GET_CODE (SET_SRC (set)) == PLUS
|
||
|| GET_CODE (SET_SRC (set)) == LO_SUM)
|
||
&& (GET_CODE (XEXP (SET_SRC (set), 1)) == CONST
|
||
|| (GET_CODE (XEXP (SET_SRC (set), 1))
|
||
== SYMBOL_REF)
|
||
|| (GET_CODE (XEXP (SET_SRC (set), 1))
|
||
== LABEL_REF)))
|
||
|| ((note = find_reg_note (insn, REG_EQUAL, 0)) != 0
|
||
&& (GET_CODE (XEXP (note, 0)) == CONST
|
||
|| GET_CODE (XEXP (note, 0)) == SYMBOL_REF
|
||
|| GET_CODE (XEXP (note, 0)) == LABEL_REF))))
|
||
REGNO_POINTER_FLAG (REGNO (SET_DEST (set))) = 1;
|
||
|
||
for (i = 0; i < noperands; i++)
|
||
{
|
||
constraints[i]
|
||
= insn_operand_constraint[insn_code_number][i];
|
||
modes[i] = insn_operand_mode[insn_code_number][i];
|
||
}
|
||
}
|
||
|
||
/* If we get here, we are set up to record the costs of all the
|
||
operands for this insn. Start by initializing the costs.
|
||
Then handle any address registers. Finally record the desired
|
||
classes for any pseudos, doing it twice if some pair of
|
||
operands are commutative. */
|
||
|
||
for (i = 0; i < noperands; i++)
|
||
{
|
||
op_costs[i] = init_cost;
|
||
|
||
if (GET_CODE (recog_operand[i]) == SUBREG)
|
||
recog_operand[i] = SUBREG_REG (recog_operand[i]);
|
||
|
||
if (GET_CODE (recog_operand[i]) == MEM)
|
||
record_address_regs (XEXP (recog_operand[i], 0),
|
||
BASE_REG_CLASS, loop_cost * 2);
|
||
else if (constraints[i][0] == 'p')
|
||
record_address_regs (recog_operand[i],
|
||
BASE_REG_CLASS, loop_cost * 2);
|
||
}
|
||
|
||
/* Check for commutative in a separate loop so everything will
|
||
have been initialized. Don't bother doing anything if the
|
||
second operand is a constant since that is the case
|
||
for which the constraints should have been written. */
|
||
|
||
for (i = 0; i < noperands - 1; i++)
|
||
if (constraints[i][0] == '%'
|
||
&& ! CONSTANT_P (recog_operand[i+1]))
|
||
{
|
||
char *xconstraints[MAX_RECOG_OPERANDS];
|
||
int j;
|
||
|
||
/* Handle commutative operands by swapping the constraints.
|
||
We assume the modes are the same. */
|
||
|
||
for (j = 0; j < noperands; j++)
|
||
xconstraints[j] = constraints[j];
|
||
|
||
xconstraints[i] = constraints[i+1];
|
||
xconstraints[i+1] = constraints[i];
|
||
record_reg_classes (nalternatives, noperands,
|
||
recog_operand, modes, xconstraints,
|
||
insn);
|
||
}
|
||
|
||
record_reg_classes (nalternatives, noperands, recog_operand,
|
||
modes, constraints, insn);
|
||
|
||
/* Now add the cost for each operand to the total costs for
|
||
its register. */
|
||
|
||
for (i = 0; i < noperands; i++)
|
||
if (GET_CODE (recog_operand[i]) == REG
|
||
&& REGNO (recog_operand[i]) >= FIRST_PSEUDO_REGISTER)
|
||
{
|
||
int regno = REGNO (recog_operand[i]);
|
||
struct costs *p = &costs[regno], *q = &op_costs[i];
|
||
|
||
p->mem_cost += q->mem_cost * loop_cost;
|
||
for (j = 0; j < N_REG_CLASSES; j++)
|
||
p->cost[j] += q->cost[j] * loop_cost;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Now for each register look at how desirable each class is
|
||
and find which class is preferred. Store that in
|
||
`prefclass[REGNO]'. Record in `altclass[REGNO]' the largest register
|
||
class any of whose registers is better than memory. */
|
||
|
||
if (pass == 0)
|
||
{
|
||
prefclass = (char *) oballoc (nregs);
|
||
altclass = (char *) oballoc (nregs);
|
||
}
|
||
|
||
for (i = FIRST_PSEUDO_REGISTER; i < nregs; i++)
|
||
{
|
||
register int best_cost = (1 << (HOST_BITS_PER_INT - 2)) - 1;
|
||
enum reg_class best = ALL_REGS, alt = NO_REGS;
|
||
/* This is an enum reg_class, but we call it an int
|
||
to save lots of casts. */
|
||
register int class;
|
||
register struct costs *p = &costs[i];
|
||
|
||
for (class = (int) ALL_REGS - 1; class > 0; class--)
|
||
{
|
||
/* Ignore classes that are too small for this operand or
|
||
invalid for a operand that was auto-incremented. */
|
||
if (CLASS_MAX_NREGS (class, PSEUDO_REGNO_MODE (i))
|
||
> reg_class_size[class]
|
||
#ifdef FORBIDDEN_INC_DEC_CLASSES
|
||
|| (in_inc_dec[i] && forbidden_inc_dec_class[class])
|
||
#endif
|
||
)
|
||
;
|
||
else if (p->cost[class] < best_cost)
|
||
{
|
||
best_cost = p->cost[class];
|
||
best = (enum reg_class) class;
|
||
}
|
||
else if (p->cost[class] == best_cost)
|
||
best = reg_class_subunion[(int)best][class];
|
||
}
|
||
|
||
/* Record the alternate register class; i.e., a class for which
|
||
every register in it is better than using memory. If adding a
|
||
class would make a smaller class (i.e., no union of just those
|
||
classes exists), skip that class. The major unions of classes
|
||
should be provided as a register class. Don't do this if we
|
||
will be doing it again later. */
|
||
|
||
if (pass == 1 || ! flag_expensive_optimizations)
|
||
for (class = 0; class < N_REG_CLASSES; class++)
|
||
if (p->cost[class] < p->mem_cost
|
||
&& (reg_class_size[reg_class_subunion[(int) alt][class]]
|
||
> reg_class_size[(int) alt])
|
||
#ifdef FORBIDDEN_INC_DEC_CLASSES
|
||
&& ! (in_inc_dec[i] && forbidden_inc_dec_class[class])
|
||
#endif
|
||
)
|
||
alt = reg_class_subunion[(int) alt][class];
|
||
|
||
/* If we don't add any classes, nothing to try. */
|
||
if (alt == best)
|
||
alt = (int) NO_REGS;
|
||
|
||
/* We cast to (int) because (char) hits bugs in some compilers. */
|
||
prefclass[i] = (int) best;
|
||
altclass[i] = (int) alt;
|
||
}
|
||
}
|
||
#endif /* REGISTER_CONSTRAINTS */
|
||
}
|
||
|
||
#ifdef REGISTER_CONSTRAINTS
|
||
|
||
/* Record the cost of using memory or registers of various classes for
|
||
the operands in INSN.
|
||
|
||
N_ALTS is the number of alternatives.
|
||
|
||
N_OPS is the number of operands.
|
||
|
||
OPS is an array of the operands.
|
||
|
||
MODES are the modes of the operands, in case any are VOIDmode.
|
||
|
||
CONSTRAINTS are the constraints to use for the operands. This array
|
||
is modified by this procedure.
|
||
|
||
This procedure works alternative by alternative. For each alternative
|
||
we assume that we will be able to allocate all pseudos to their ideal
|
||
register class and calculate the cost of using that alternative. Then
|
||
we compute for each operand that is a pseudo-register, the cost of
|
||
having the pseudo allocated to each register class and using it in that
|
||
alternative. To this cost is added the cost of the alternative.
|
||
|
||
The cost of each class for this insn is its lowest cost among all the
|
||
alternatives. */
|
||
|
||
static void
|
||
record_reg_classes (n_alts, n_ops, ops, modes, constraints, insn)
|
||
int n_alts;
|
||
int n_ops;
|
||
rtx *ops;
|
||
enum machine_mode *modes;
|
||
char **constraints;
|
||
rtx insn;
|
||
{
|
||
int alt;
|
||
enum op_type {OP_READ, OP_WRITE, OP_READ_WRITE} op_types[MAX_RECOG_OPERANDS];
|
||
int i, j;
|
||
|
||
/* By default, each operand is an input operand. */
|
||
|
||
for (i = 0; i < n_ops; i++)
|
||
op_types[i] = OP_READ;
|
||
|
||
/* Process each alternative, each time minimizing an operand's cost with
|
||
the cost for each operand in that alternative. */
|
||
|
||
for (alt = 0; alt < n_alts; alt++)
|
||
{
|
||
struct costs this_op_costs[MAX_RECOG_OPERANDS];
|
||
int alt_fail = 0;
|
||
int alt_cost = 0;
|
||
enum reg_class classes[MAX_RECOG_OPERANDS];
|
||
int class;
|
||
|
||
for (i = 0; i < n_ops; i++)
|
||
{
|
||
char *p = constraints[i];
|
||
rtx op = ops[i];
|
||
enum machine_mode mode = modes[i];
|
||
int allows_mem = 0;
|
||
int win = 0;
|
||
char c;
|
||
|
||
/* If this operand has no constraints at all, we can conclude
|
||
nothing about it since anything is valid. */
|
||
|
||
if (*p == 0)
|
||
{
|
||
if (GET_CODE (op) == REG && REGNO (op) >= FIRST_PSEUDO_REGISTER)
|
||
bzero ((char *) &this_op_costs[i], sizeof this_op_costs[i]);
|
||
|
||
continue;
|
||
}
|
||
|
||
if (*p == '%')
|
||
p++;
|
||
|
||
/* If this alternative is only relevant when this operand
|
||
matches a previous operand, we do different things depending
|
||
on whether this operand is a pseudo-reg or not. */
|
||
|
||
if (p[0] >= '0' && p[0] <= '0' + i && (p[1] == ',' || p[1] == 0))
|
||
{
|
||
j = p[0] - '0';
|
||
classes[i] = classes[j];
|
||
|
||
if (GET_CODE (op) != REG || REGNO (op) < FIRST_PSEUDO_REGISTER)
|
||
{
|
||
/* If this matches the other operand, we have no added
|
||
cost. */
|
||
if (rtx_equal_p (ops[j], op))
|
||
;
|
||
|
||
/* If we can't put the other operand into a register, this
|
||
alternative can't be used. */
|
||
|
||
else if (classes[j] == NO_REGS)
|
||
alt_fail = 1;
|
||
|
||
/* Otherwise, add to the cost of this alternative the cost
|
||
to copy this operand to the register used for the other
|
||
operand. */
|
||
|
||
else
|
||
alt_cost += copy_cost (op, mode, classes[j], 1);
|
||
}
|
||
else if (GET_CODE (ops[j]) != REG
|
||
|| REGNO (ops[j]) < FIRST_PSEUDO_REGISTER)
|
||
{
|
||
/* This op is a pseudo but the one it matches is not. */
|
||
|
||
/* If we can't put the other operand into a register, this
|
||
alternative can't be used. */
|
||
|
||
if (classes[j] == NO_REGS)
|
||
alt_fail = 1;
|
||
|
||
/* Otherwise, add to the cost of this alternative the cost
|
||
to copy the other operand to the register used for this
|
||
operand. */
|
||
|
||
else
|
||
alt_cost += copy_cost (ops[j], mode, classes[j], 1);
|
||
}
|
||
else
|
||
{
|
||
/* The costs of this operand are the same as that of the
|
||
other operand. However, if we cannot tie them, this
|
||
alternative needs to do a copy, which is one
|
||
instruction. */
|
||
|
||
this_op_costs[i] = this_op_costs[j];
|
||
if (! find_reg_note (insn, REG_DEAD, op))
|
||
alt_cost += 2;
|
||
|
||
/* This is in place of ordinary cost computation
|
||
for this operand. */
|
||
continue;
|
||
}
|
||
}
|
||
|
||
/* Scan all the constraint letters. See if the operand matches
|
||
any of the constraints. Collect the valid register classes
|
||
and see if this operand accepts memory. */
|
||
|
||
classes[i] = NO_REGS;
|
||
while (*p && (c = *p++) != ',')
|
||
switch (c)
|
||
{
|
||
case '=':
|
||
op_types[i] = OP_WRITE;
|
||
break;
|
||
|
||
case '+':
|
||
op_types[i] = OP_READ_WRITE;
|
||
break;
|
||
|
||
case '*':
|
||
/* Ignore the next letter for this pass. */
|
||
p++;
|
||
break;
|
||
|
||
case '%':
|
||
case '?': case '!': case '#':
|
||
case '&':
|
||
case '0': case '1': case '2': case '3': case '4':
|
||
case 'p':
|
||
break;
|
||
|
||
case 'm': case 'o': case 'V':
|
||
/* It doesn't seem worth distingishing between offsettable
|
||
and non-offsettable addresses here. */
|
||
allows_mem = 1;
|
||
if (GET_CODE (op) == MEM)
|
||
win = 1;
|
||
break;
|
||
|
||
case '<':
|
||
if (GET_CODE (op) == MEM
|
||
&& (GET_CODE (XEXP (op, 0)) == PRE_DEC
|
||
|| GET_CODE (XEXP (op, 0)) == POST_DEC))
|
||
win = 1;
|
||
break;
|
||
|
||
case '>':
|
||
if (GET_CODE (op) == MEM
|
||
&& (GET_CODE (XEXP (op, 0)) == PRE_INC
|
||
|| GET_CODE (XEXP (op, 0)) == POST_INC))
|
||
win = 1;
|
||
break;
|
||
|
||
case 'E':
|
||
/* Match any floating double constant, but only if
|
||
we can examine the bits of it reliably. */
|
||
if ((HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT
|
||
|| HOST_BITS_PER_WIDE_INT != BITS_PER_WORD)
|
||
&& GET_MODE (op) != VOIDmode && ! flag_pretend_float)
|
||
break;
|
||
if (GET_CODE (op) == CONST_DOUBLE)
|
||
win = 1;
|
||
break;
|
||
|
||
case 'F':
|
||
if (GET_CODE (op) == CONST_DOUBLE)
|
||
win = 1;
|
||
break;
|
||
|
||
case 'G':
|
||
case 'H':
|
||
if (GET_CODE (op) == CONST_DOUBLE
|
||
&& CONST_DOUBLE_OK_FOR_LETTER_P (op, c))
|
||
win = 1;
|
||
break;
|
||
|
||
case 's':
|
||
if (GET_CODE (op) == CONST_INT
|
||
|| (GET_CODE (op) == CONST_DOUBLE
|
||
&& GET_MODE (op) == VOIDmode))
|
||
break;
|
||
case 'i':
|
||
if (CONSTANT_P (op)
|
||
#ifdef LEGITIMATE_PIC_OPERAND_P
|
||
&& (! flag_pic || LEGITIMATE_PIC_OPERAND_P (op))
|
||
#endif
|
||
)
|
||
win = 1;
|
||
break;
|
||
|
||
case 'n':
|
||
if (GET_CODE (op) == CONST_INT
|
||
|| (GET_CODE (op) == CONST_DOUBLE
|
||
&& GET_MODE (op) == VOIDmode))
|
||
win = 1;
|
||
break;
|
||
|
||
case 'I':
|
||
case 'J':
|
||
case 'K':
|
||
case 'L':
|
||
case 'M':
|
||
case 'N':
|
||
case 'O':
|
||
case 'P':
|
||
if (GET_CODE (op) == CONST_INT
|
||
&& CONST_OK_FOR_LETTER_P (INTVAL (op), c))
|
||
win = 1;
|
||
break;
|
||
|
||
case 'X':
|
||
win = 1;
|
||
break;
|
||
|
||
#ifdef EXTRA_CONSTRAINT
|
||
case 'Q':
|
||
case 'R':
|
||
case 'S':
|
||
case 'T':
|
||
case 'U':
|
||
if (EXTRA_CONSTRAINT (op, c))
|
||
win = 1;
|
||
break;
|
||
#endif
|
||
|
||
case 'g':
|
||
if (GET_CODE (op) == MEM
|
||
|| (CONSTANT_P (op)
|
||
#ifdef LEGITIMATE_PIC_OPERAND_P
|
||
&& (! flag_pic || LEGITIMATE_PIC_OPERAND_P (op))
|
||
#endif
|
||
))
|
||
win = 1;
|
||
allows_mem = 1;
|
||
case 'r':
|
||
classes[i]
|
||
= reg_class_subunion[(int) classes[i]][(int) GENERAL_REGS];
|
||
break;
|
||
|
||
default:
|
||
classes[i]
|
||
= reg_class_subunion[(int) classes[i]]
|
||
[(int) REG_CLASS_FROM_LETTER (c)];
|
||
}
|
||
|
||
constraints[i] = p;
|
||
|
||
/* How we account for this operand now depends on whether it is a
|
||
pseudo register or not. If it is, we first check if any
|
||
register classes are valid. If not, we ignore this alternative,
|
||
since we want to assume that all pseudos get allocated for
|
||
register preferencing. If some register class is valid, compute
|
||
the costs of moving the pseudo into that class. */
|
||
|
||
if (GET_CODE (op) == REG && REGNO (op) >= FIRST_PSEUDO_REGISTER)
|
||
{
|
||
if (classes[i] == NO_REGS)
|
||
alt_fail = 1;
|
||
else
|
||
{
|
||
struct costs *pp = &this_op_costs[i];
|
||
|
||
for (class = 0; class < N_REG_CLASSES; class++)
|
||
pp->cost[class] = may_move_cost[class][(int) classes[i]];
|
||
|
||
/* If the alternative actually allows memory, make things
|
||
a bit cheaper since we won't need an extra insn to
|
||
load it. */
|
||
|
||
pp->mem_cost = MEMORY_MOVE_COST (mode) - allows_mem;
|
||
|
||
/* If we have assigned a class to this register in our
|
||
first pass, add a cost to this alternative corresponding
|
||
to what we would add if this register were not in the
|
||
appropriate class. */
|
||
|
||
if (prefclass)
|
||
alt_cost
|
||
+= may_move_cost[prefclass[REGNO (op)]][(int) classes[i]];
|
||
}
|
||
}
|
||
|
||
/* Otherwise, if this alternative wins, either because we
|
||
have already determined that or if we have a hard register of
|
||
the proper class, there is no cost for this alternative. */
|
||
|
||
else if (win
|
||
|| (GET_CODE (op) == REG
|
||
&& reg_fits_class_p (op, classes[i], 0, GET_MODE (op))))
|
||
;
|
||
|
||
/* If registers are valid, the cost of this alternative includes
|
||
copying the object to and/or from a register. */
|
||
|
||
else if (classes[i] != NO_REGS)
|
||
{
|
||
if (op_types[i] != OP_WRITE)
|
||
alt_cost += copy_cost (op, mode, classes[i], 1);
|
||
|
||
if (op_types[i] != OP_READ)
|
||
alt_cost += copy_cost (op, mode, classes[i], 0);
|
||
}
|
||
|
||
/* The only other way this alternative can be used is if this is a
|
||
constant that could be placed into memory. */
|
||
|
||
else if (CONSTANT_P (op) && allows_mem)
|
||
alt_cost += MEMORY_MOVE_COST (mode);
|
||
else
|
||
alt_fail = 1;
|
||
}
|
||
|
||
if (alt_fail)
|
||
continue;
|
||
|
||
/* Finally, update the costs with the information we've calculated
|
||
about this alternative. */
|
||
|
||
for (i = 0; i < n_ops; i++)
|
||
if (GET_CODE (ops[i]) == REG
|
||
&& REGNO (ops[i]) >= FIRST_PSEUDO_REGISTER)
|
||
{
|
||
struct costs *pp = &op_costs[i], *qq = &this_op_costs[i];
|
||
int scale = 1 + (op_types[i] == OP_READ_WRITE);
|
||
|
||
pp->mem_cost = MIN (pp->mem_cost,
|
||
(qq->mem_cost + alt_cost) * scale);
|
||
|
||
for (class = 0; class < N_REG_CLASSES; class++)
|
||
pp->cost[class] = MIN (pp->cost[class],
|
||
(qq->cost[class] + alt_cost) * scale);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Compute the cost of loading X into (if TO_P is non-zero) or from (if
|
||
TO_P is zero) a register of class CLASS in mode MODE.
|
||
|
||
X must not be a pseudo. */
|
||
|
||
static int
|
||
copy_cost (x, mode, class, to_p)
|
||
rtx x;
|
||
enum machine_mode mode;
|
||
enum reg_class class;
|
||
int to_p;
|
||
{
|
||
enum reg_class secondary_class = NO_REGS;
|
||
|
||
/* If X is a SCRATCH, there is actually nothing to move since we are
|
||
assuming optimal allocation. */
|
||
|
||
if (GET_CODE (x) == SCRATCH)
|
||
return 0;
|
||
|
||
/* Get the class we will actually use for a reload. */
|
||
class = PREFERRED_RELOAD_CLASS (x, class);
|
||
|
||
#ifdef HAVE_SECONDARY_RELOADS
|
||
/* If we need a secondary reload (we assume here that we are using
|
||
the secondary reload as an intermediate, not a scratch register), the
|
||
cost is that to load the input into the intermediate register, then
|
||
to copy them. We use a special value of TO_P to avoid recursion. */
|
||
|
||
#ifdef SECONDARY_INPUT_RELOAD_CLASS
|
||
if (to_p == 1)
|
||
secondary_class = SECONDARY_INPUT_RELOAD_CLASS (class, mode, x);
|
||
#endif
|
||
|
||
#ifdef SECONARY_OUTPUT_RELOAD_CLASS
|
||
if (! to_p)
|
||
secondary_class = SECONDARY_OUTPUT_RELOAD_CLASS (class, mode, x);
|
||
#endif
|
||
|
||
if (secondary_class != NO_REGS)
|
||
return (move_cost[(int) secondary_class][(int) class]
|
||
+ copy_cost (x, mode, secondary_class, 2));
|
||
#endif /* HAVE_SECONARY_RELOADS */
|
||
|
||
/* For memory, use the memory move cost, for (hard) registers, use the
|
||
cost to move between the register classes, and use 2 for everything
|
||
else (constants). */
|
||
|
||
if (GET_CODE (x) == MEM || class == NO_REGS)
|
||
return MEMORY_MOVE_COST (mode);
|
||
|
||
else if (GET_CODE (x) == REG)
|
||
return move_cost[(int) REGNO_REG_CLASS (REGNO (x))][(int) class];
|
||
|
||
else
|
||
/* If this is a constant, we may eventually want to call rtx_cost here. */
|
||
return 2;
|
||
}
|
||
|
||
/* Record the pseudo registers we must reload into hard registers
|
||
in a subexpression of a memory address, X.
|
||
|
||
CLASS is the class that the register needs to be in and is either
|
||
BASE_REG_CLASS or INDEX_REG_CLASS.
|
||
|
||
SCALE is twice the amount to multiply the cost by (it is twice so we
|
||
can represent half-cost adjustments). */
|
||
|
||
static void
|
||
record_address_regs (x, class, scale)
|
||
rtx x;
|
||
enum reg_class class;
|
||
int scale;
|
||
{
|
||
register enum rtx_code code = GET_CODE (x);
|
||
|
||
switch (code)
|
||
{
|
||
case CONST_INT:
|
||
case CONST:
|
||
case CC0:
|
||
case PC:
|
||
case SYMBOL_REF:
|
||
case LABEL_REF:
|
||
return;
|
||
|
||
case PLUS:
|
||
/* When we have an address that is a sum,
|
||
we must determine whether registers are "base" or "index" regs.
|
||
If there is a sum of two registers, we must choose one to be
|
||
the "base". Luckily, we can use the REGNO_POINTER_FLAG
|
||
to make a good choice most of the time. We only need to do this
|
||
on machines that can have two registers in an address and where
|
||
the base and index register classes are different.
|
||
|
||
??? This code used to set REGNO_POINTER_FLAG in some cases, but
|
||
that seems bogus since it should only be set when we are sure
|
||
the register is being used as a pointer. */
|
||
|
||
{
|
||
rtx arg0 = XEXP (x, 0);
|
||
rtx arg1 = XEXP (x, 1);
|
||
register enum rtx_code code0 = GET_CODE (arg0);
|
||
register enum rtx_code code1 = GET_CODE (arg1);
|
||
|
||
/* Look inside subregs. */
|
||
if (code0 == SUBREG)
|
||
arg0 = SUBREG_REG (arg0), code0 = GET_CODE (arg0);
|
||
if (code1 == SUBREG)
|
||
arg1 = SUBREG_REG (arg1), code1 = GET_CODE (arg1);
|
||
|
||
/* If this machine only allows one register per address, it must
|
||
be in the first operand. */
|
||
|
||
if (MAX_REGS_PER_ADDRESS == 1)
|
||
record_address_regs (arg0, class, scale);
|
||
|
||
/* If index and base registers are the same on this machine, just
|
||
record registers in any non-constant operands. We assume here,
|
||
as well as in the tests below, that all addresses are in
|
||
canonical form. */
|
||
|
||
else if (INDEX_REG_CLASS == BASE_REG_CLASS)
|
||
{
|
||
record_address_regs (arg0, class, scale);
|
||
if (! CONSTANT_P (arg1))
|
||
record_address_regs (arg1, class, scale);
|
||
}
|
||
|
||
/* If the second operand is a constant integer, it doesn't change
|
||
what class the first operand must be. */
|
||
|
||
else if (code1 == CONST_INT || code1 == CONST_DOUBLE)
|
||
record_address_regs (arg0, class, scale);
|
||
|
||
/* If the second operand is a symbolic constant, the first operand
|
||
must be an index register. */
|
||
|
||
else if (code1 == SYMBOL_REF || code1 == CONST || code1 == LABEL_REF)
|
||
record_address_regs (arg0, INDEX_REG_CLASS, scale);
|
||
|
||
/* If this the sum of two registers where the first is known to be a
|
||
pointer, it must be a base register with the second an index. */
|
||
|
||
else if (code0 == REG && code1 == REG
|
||
&& REGNO_POINTER_FLAG (REGNO (arg0)))
|
||
{
|
||
record_address_regs (arg0, BASE_REG_CLASS, scale);
|
||
record_address_regs (arg1, INDEX_REG_CLASS, scale);
|
||
}
|
||
|
||
/* If this is the sum of two registers and neither is known to
|
||
be a pointer, count equal chances that each might be a base
|
||
or index register. This case should be rare. */
|
||
|
||
else if (code0 == REG && code1 == REG
|
||
&& ! REGNO_POINTER_FLAG (REGNO (arg0))
|
||
&& ! REGNO_POINTER_FLAG (REGNO (arg1)))
|
||
{
|
||
record_address_regs (arg0, BASE_REG_CLASS, scale / 2);
|
||
record_address_regs (arg0, INDEX_REG_CLASS, scale / 2);
|
||
record_address_regs (arg1, BASE_REG_CLASS, scale / 2);
|
||
record_address_regs (arg1, INDEX_REG_CLASS, scale / 2);
|
||
}
|
||
|
||
/* In all other cases, the first operand is an index and the
|
||
second is the base. */
|
||
|
||
else
|
||
{
|
||
record_address_regs (arg0, INDEX_REG_CLASS, scale);
|
||
record_address_regs (arg1, BASE_REG_CLASS, scale);
|
||
}
|
||
}
|
||
break;
|
||
|
||
case POST_INC:
|
||
case PRE_INC:
|
||
case POST_DEC:
|
||
case PRE_DEC:
|
||
/* Double the importance of a pseudo register that is incremented
|
||
or decremented, since it would take two extra insns
|
||
if it ends up in the wrong place. If the operand is a pseudo,
|
||
show it is being used in an INC_DEC context. */
|
||
|
||
#ifdef FORBIDDEN_INC_DEC_CLASSES
|
||
if (GET_CODE (XEXP (x, 0)) == REG
|
||
&& REGNO (XEXP (x, 0)) >= FIRST_PSEUDO_REGISTER)
|
||
in_inc_dec[REGNO (XEXP (x, 0))] = 1;
|
||
#endif
|
||
|
||
record_address_regs (XEXP (x, 0), class, 2 * scale);
|
||
break;
|
||
|
||
case REG:
|
||
{
|
||
register struct costs *pp = &costs[REGNO (x)];
|
||
register int i;
|
||
|
||
pp->mem_cost += (MEMORY_MOVE_COST (Pmode) * scale) / 2;
|
||
|
||
for (i = 0; i < N_REG_CLASSES; i++)
|
||
pp->cost[i] += (may_move_cost[i][(int) class] * scale) / 2;
|
||
}
|
||
break;
|
||
|
||
default:
|
||
{
|
||
register char *fmt = GET_RTX_FORMAT (code);
|
||
register int i;
|
||
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
|
||
if (fmt[i] == 'e')
|
||
record_address_regs (XEXP (x, i), class, scale);
|
||
}
|
||
}
|
||
}
|
||
#endif /* REGISTER_CONSTRAINTS */
|
||
|
||
/* This is the `regscan' pass of the compiler, run just before cse
|
||
and again just before loop.
|
||
|
||
It finds the first and last use of each pseudo-register
|
||
and records them in the vectors regno_first_uid, regno_last_uid
|
||
and counts the number of sets in the vector reg_n_sets.
|
||
|
||
REPEAT is nonzero the second time this is called. */
|
||
|
||
/* Indexed by pseudo register number, gives uid of first insn using the reg
|
||
(as of the time reg_scan is called). */
|
||
|
||
int *regno_first_uid;
|
||
|
||
/* Indexed by pseudo register number, gives uid of last insn using the reg
|
||
(as of the time reg_scan is called). */
|
||
|
||
int *regno_last_uid;
|
||
|
||
/* Record the number of registers we used when we allocated the above two
|
||
tables. If we are called again with more than this, we must re-allocate
|
||
the tables. */
|
||
|
||
static int highest_regno_in_uid_map;
|
||
|
||
/* Maximum number of parallel sets and clobbers in any insn in this fn.
|
||
Always at least 3, since the combiner could put that many togetherm
|
||
and we want this to remain correct for all the remaining passes. */
|
||
|
||
int max_parallel;
|
||
|
||
void reg_scan_mark_refs ();
|
||
|
||
void
|
||
reg_scan (f, nregs, repeat)
|
||
rtx f;
|
||
int nregs;
|
||
int repeat;
|
||
{
|
||
register rtx insn;
|
||
|
||
if (!repeat || nregs > highest_regno_in_uid_map)
|
||
{
|
||
/* Leave some spare space in case more regs are allocated. */
|
||
highest_regno_in_uid_map = nregs + nregs / 20;
|
||
regno_first_uid
|
||
= (int *) oballoc (highest_regno_in_uid_map * sizeof (int));
|
||
regno_last_uid
|
||
= (int *) oballoc (highest_regno_in_uid_map * sizeof (int));
|
||
reg_n_sets
|
||
= (short *) oballoc (highest_regno_in_uid_map * sizeof (short));
|
||
}
|
||
|
||
bzero (regno_first_uid, highest_regno_in_uid_map * sizeof (int));
|
||
bzero (regno_last_uid, highest_regno_in_uid_map * sizeof (int));
|
||
bzero (reg_n_sets, highest_regno_in_uid_map * sizeof (short));
|
||
|
||
max_parallel = 3;
|
||
|
||
for (insn = f; insn; insn = NEXT_INSN (insn))
|
||
if (GET_CODE (insn) == INSN
|
||
|| GET_CODE (insn) == CALL_INSN
|
||
|| GET_CODE (insn) == JUMP_INSN)
|
||
{
|
||
if (GET_CODE (PATTERN (insn)) == PARALLEL
|
||
&& XVECLEN (PATTERN (insn), 0) > max_parallel)
|
||
max_parallel = XVECLEN (PATTERN (insn), 0);
|
||
reg_scan_mark_refs (PATTERN (insn), INSN_UID (insn));
|
||
}
|
||
}
|
||
|
||
void
|
||
reg_scan_mark_refs (x, uid)
|
||
rtx x;
|
||
int uid;
|
||
{
|
||
register enum rtx_code code = GET_CODE (x);
|
||
register rtx dest;
|
||
|
||
switch (code)
|
||
{
|
||
case CONST_INT:
|
||
case CONST:
|
||
case CONST_DOUBLE:
|
||
case CC0:
|
||
case PC:
|
||
case SYMBOL_REF:
|
||
case LABEL_REF:
|
||
case ADDR_VEC:
|
||
case ADDR_DIFF_VEC:
|
||
return;
|
||
|
||
case REG:
|
||
{
|
||
register int regno = REGNO (x);
|
||
|
||
regno_last_uid[regno] = uid;
|
||
if (regno_first_uid[regno] == 0)
|
||
regno_first_uid[regno] = uid;
|
||
}
|
||
break;
|
||
|
||
case SET:
|
||
/* Count a set of the destination if it is a register. */
|
||
for (dest = SET_DEST (x);
|
||
GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
|
||
|| GET_CODE (dest) == ZERO_EXTEND;
|
||
dest = XEXP (dest, 0))
|
||
;
|
||
|
||
if (GET_CODE (dest) == REG)
|
||
reg_n_sets[REGNO (dest)]++;
|
||
|
||
/* ... fall through ... */
|
||
|
||
default:
|
||
{
|
||
register char *fmt = GET_RTX_FORMAT (code);
|
||
register int i;
|
||
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
|
||
{
|
||
if (fmt[i] == 'e')
|
||
reg_scan_mark_refs (XEXP (x, i), uid);
|
||
else if (fmt[i] == 'E' && XVEC (x, i) != 0)
|
||
{
|
||
register int j;
|
||
for (j = XVECLEN (x, i) - 1; j >= 0; j--)
|
||
reg_scan_mark_refs (XVECEXP (x, i, j), uid);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Return nonzero if C1 is a subset of C2, i.e., if every register in C1
|
||
is also in C2. */
|
||
|
||
int
|
||
reg_class_subset_p (c1, c2)
|
||
register enum reg_class c1;
|
||
register enum reg_class c2;
|
||
{
|
||
if (c1 == c2) return 1;
|
||
|
||
if (c2 == ALL_REGS)
|
||
win:
|
||
return 1;
|
||
GO_IF_HARD_REG_SUBSET (reg_class_contents[(int)c1],
|
||
reg_class_contents[(int)c2],
|
||
win);
|
||
return 0;
|
||
}
|
||
|
||
/* Return nonzero if there is a register that is in both C1 and C2. */
|
||
|
||
int
|
||
reg_classes_intersect_p (c1, c2)
|
||
register enum reg_class c1;
|
||
register enum reg_class c2;
|
||
{
|
||
#ifdef HARD_REG_SET
|
||
register
|
||
#endif
|
||
HARD_REG_SET c;
|
||
|
||
if (c1 == c2) return 1;
|
||
|
||
if (c1 == ALL_REGS || c2 == ALL_REGS)
|
||
return 1;
|
||
|
||
COPY_HARD_REG_SET (c, reg_class_contents[(int) c1]);
|
||
AND_HARD_REG_SET (c, reg_class_contents[(int) c2]);
|
||
|
||
GO_IF_HARD_REG_SUBSET (c, reg_class_contents[(int) NO_REGS], lose);
|
||
return 1;
|
||
|
||
lose:
|
||
return 0;
|
||
}
|
||
|