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/* Expands front end tree to back end RTL for GNU C-Compiler
Copyright (C) 1987, 88, 89, 91-97, 1998 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, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/* This file handles the generation of rtl code from tree structure
at the level of the function as a whole.
It creates the rtl expressions for parameters and auto variables
and has full responsibility for allocating stack slots.
`expand_function_start' is called at the beginning of a function,
before the function body is parsed, and `expand_function_end' is
called after parsing the body.
Call `assign_stack_local' to allocate a stack slot for a local variable.
This is usually done during the RTL generation for the function body,
but it can also be done in the reload pass when a pseudo-register does
not get a hard register.
Call `put_var_into_stack' when you learn, belatedly, that a variable
previously given a pseudo-register must in fact go in the stack.
This function changes the DECL_RTL to be a stack slot instead of a reg
then scans all the RTL instructions so far generated to correct them. */
#include "config.h"
#include <stdio.h>
#include "rtl.h"
#include "tree.h"
#include "flags.h"
#include "except.h"
#include "function.h"
#include "insn-flags.h"
#include "expr.h"
#include "insn-codes.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "insn-config.h"
#include "recog.h"
#include "output.h"
#include "basic-block.h"
#include "obstack.h"
#include "bytecode.h"
#include "bc-emit.h"
#ifndef TRAMPOLINE_ALIGNMENT
#define TRAMPOLINE_ALIGNMENT FUNCTION_BOUNDARY
#endif
/* Some systems use __main in a way incompatible with its use in gcc, in these
cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
give the same symbol without quotes for an alternative entry point. You
must define both, or neither. */
#ifndef NAME__MAIN
#define NAME__MAIN "__main"
#define SYMBOL__MAIN __main
#endif
/* Round a value to the lowest integer less than it that is a multiple of
the required alignment. Avoid using division in case the value is
negative. Assume the alignment is a power of two. */
#define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
/* Similar, but round to the next highest integer that meets the
alignment. */
#define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
/* NEED_SEPARATE_AP means that we cannot derive ap from the value of fp
during rtl generation. If they are different register numbers, this is
always true. It may also be true if
FIRST_PARM_OFFSET - STARTING_FRAME_OFFSET is not a constant during rtl
generation. See fix_lexical_addr for details. */
#if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
#define NEED_SEPARATE_AP
#endif
/* Number of bytes of args popped by function being compiled on its return.
Zero if no bytes are to be popped.
May affect compilation of return insn or of function epilogue. */
int current_function_pops_args;
/* Nonzero if function being compiled needs to be given an address
where the value should be stored. */
int current_function_returns_struct;
/* Nonzero if function being compiled needs to
return the address of where it has put a structure value. */
int current_function_returns_pcc_struct;
/* Nonzero if function being compiled needs to be passed a static chain. */
int current_function_needs_context;
/* Nonzero if function being compiled can call setjmp. */
int current_function_calls_setjmp;
/* Nonzero if function being compiled can call longjmp. */
int current_function_calls_longjmp;
/* Nonzero if function being compiled receives nonlocal gotos
from nested functions. */
int current_function_has_nonlocal_label;
/* Nonzero if function being compiled has nonlocal gotos to parent
function. */
int current_function_has_nonlocal_goto;
/* Nonzero if function being compiled contains nested functions. */
int current_function_contains_functions;
/* Nonzero if the current function is a thunk (a lightweight function that
just adjusts one of its arguments and forwards to another function), so
we should try to cut corners where we can. */
int current_function_is_thunk;
/* Nonzero if function being compiled can call alloca,
either as a subroutine or builtin. */
int current_function_calls_alloca;
/* Nonzero if the current function returns a pointer type */
int current_function_returns_pointer;
/* If some insns can be deferred to the delay slots of the epilogue, the
delay list for them is recorded here. */
rtx current_function_epilogue_delay_list;
/* If function's args have a fixed size, this is that size, in bytes.
Otherwise, it is -1.
May affect compilation of return insn or of function epilogue. */
int current_function_args_size;
/* # bytes the prologue should push and pretend that the caller pushed them.
The prologue must do this, but only if parms can be passed in registers. */
int current_function_pretend_args_size;
/* # of bytes of outgoing arguments. If ACCUMULATE_OUTGOING_ARGS is
defined, the needed space is pushed by the prologue. */
int current_function_outgoing_args_size;
/* This is the offset from the arg pointer to the place where the first
anonymous arg can be found, if there is one. */
rtx current_function_arg_offset_rtx;
/* Nonzero if current function uses varargs.h or equivalent.
Zero for functions that use stdarg.h. */
int current_function_varargs;
/* Nonzero if current function uses stdarg.h or equivalent.
Zero for functions that use varargs.h. */
int current_function_stdarg;
/* Quantities of various kinds of registers
used for the current function's args. */
CUMULATIVE_ARGS current_function_args_info;
/* Name of function now being compiled. */
char *current_function_name;
/* If non-zero, an RTL expression for the location at which the current
function returns its result. If the current function returns its
result in a register, current_function_return_rtx will always be
the hard register containing the result. */
rtx current_function_return_rtx;
/* Nonzero if the current function uses the constant pool. */
int current_function_uses_const_pool;
/* Nonzero if the current function uses pic_offset_table_rtx. */
int current_function_uses_pic_offset_table;
/* The arg pointer hard register, or the pseudo into which it was copied. */
rtx current_function_internal_arg_pointer;
/* The FUNCTION_DECL for an inline function currently being expanded. */
tree inline_function_decl;
/* Number of function calls seen so far in current function. */
int function_call_count;
/* List (chain of TREE_LIST) of LABEL_DECLs for all nonlocal labels
(labels to which there can be nonlocal gotos from nested functions)
in this function. */
tree nonlocal_labels;
/* RTX for stack slot that holds the current handler for nonlocal gotos.
Zero when function does not have nonlocal labels. */
rtx nonlocal_goto_handler_slot;
/* RTX for stack slot that holds the stack pointer value to restore
for a nonlocal goto.
Zero when function does not have nonlocal labels. */
rtx nonlocal_goto_stack_level;
/* Label that will go on parm cleanup code, if any.
Jumping to this label runs cleanup code for parameters, if
such code must be run. Following this code is the logical return label. */
rtx cleanup_label;
/* Label that will go on function epilogue.
Jumping to this label serves as a "return" instruction
on machines which require execution of the epilogue on all returns. */
rtx return_label;
/* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
So we can mark them all live at the end of the function, if nonopt. */
rtx save_expr_regs;
/* List (chain of EXPR_LISTs) of all stack slots in this function.
Made for the sake of unshare_all_rtl. */
rtx stack_slot_list;
/* Chain of all RTL_EXPRs that have insns in them. */
tree rtl_expr_chain;
/* Label to jump back to for tail recursion, or 0 if we have
not yet needed one for this function. */
rtx tail_recursion_label;
/* Place after which to insert the tail_recursion_label if we need one. */
rtx tail_recursion_reentry;
/* Location at which to save the argument pointer if it will need to be
referenced. There are two cases where this is done: if nonlocal gotos
exist, or if vars stored at an offset from the argument pointer will be
needed by inner routines. */
rtx arg_pointer_save_area;
/* Offset to end of allocated area of stack frame.
If stack grows down, this is the address of the last stack slot allocated.
If stack grows up, this is the address for the next slot. */
HOST_WIDE_INT frame_offset;
/* List (chain of TREE_LISTs) of static chains for containing functions.
Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
in an RTL_EXPR in the TREE_VALUE. */
static tree context_display;
/* List (chain of TREE_LISTs) of trampolines for nested functions.
The trampoline sets up the static chain and jumps to the function.
We supply the trampoline's address when the function's address is requested.
Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
in an RTL_EXPR in the TREE_VALUE. */
static tree trampoline_list;
/* Insn after which register parms and SAVE_EXPRs are born, if nonopt. */
static rtx parm_birth_insn;
#if 0
/* Nonzero if a stack slot has been generated whose address is not
actually valid. It means that the generated rtl must all be scanned
to detect and correct the invalid addresses where they occur. */
static int invalid_stack_slot;
#endif
/* Last insn of those whose job was to put parms into their nominal homes. */
static rtx last_parm_insn;
/* 1 + last pseudo register number possibly used for loading a copy
of a parameter of this function. */
int max_parm_reg;
/* Vector indexed by REGNO, containing location on stack in which
to put the parm which is nominally in pseudo register REGNO,
if we discover that that parm must go in the stack. The highest
element in this vector is one less than MAX_PARM_REG, above. */
rtx *parm_reg_stack_loc;
/* Nonzero once virtual register instantiation has been done.
assign_stack_local uses frame_pointer_rtx when this is nonzero. */
static int virtuals_instantiated;
/* These variables hold pointers to functions to
save and restore machine-specific data,
in push_function_context and pop_function_context. */
void (*save_machine_status) PROTO((struct function *));
void (*restore_machine_status) PROTO((struct function *));
/* Nonzero if we need to distinguish between the return value of this function
and the return value of a function called by this function. This helps
integrate.c */
extern int rtx_equal_function_value_matters;
extern tree sequence_rtl_expr;
/* In order to evaluate some expressions, such as function calls returning
structures in memory, we need to temporarily allocate stack locations.
We record each allocated temporary in the following structure.
Associated with each temporary slot is a nesting level. When we pop up
one level, all temporaries associated with the previous level are freed.
Normally, all temporaries are freed after the execution of the statement
in which they were created. However, if we are inside a ({...}) grouping,
the result may be in a temporary and hence must be preserved. If the
result could be in a temporary, we preserve it if we can determine which
one it is in. If we cannot determine which temporary may contain the
result, all temporaries are preserved. A temporary is preserved by
pretending it was allocated at the previous nesting level.
Automatic variables are also assigned temporary slots, at the nesting
level where they are defined. They are marked a "kept" so that
free_temp_slots will not free them. */
struct temp_slot
{
/* Points to next temporary slot. */
struct temp_slot *next;
/* The rtx to used to reference the slot. */
rtx slot;
/* The rtx used to represent the address if not the address of the
slot above. May be an EXPR_LIST if multiple addresses exist. */
rtx address;
/* The size, in units, of the slot. */
int size;
/* The value of `sequence_rtl_expr' when this temporary is allocated. */
tree rtl_expr;
/* Non-zero if this temporary is currently in use. */
char in_use;
/* Non-zero if this temporary has its address taken. */
char addr_taken;
/* Nesting level at which this slot is being used. */
int level;
/* Non-zero if this should survive a call to free_temp_slots. */
int keep;
/* The offset of the slot from the frame_pointer, including extra space
for alignment. This info is for combine_temp_slots. */
int base_offset;
/* The size of the slot, including extra space for alignment. This
info is for combine_temp_slots. */
int full_size;
};
/* List of all temporaries allocated, both available and in use. */
struct temp_slot *temp_slots;
/* Current nesting level for temporaries. */
int temp_slot_level;
/* The FUNCTION_DECL node for the current function. */
static tree this_function_decl;
/* Callinfo pointer for the current function. */
static rtx this_function_callinfo;
/* The label in the bytecode file of this function's actual bytecode.
Not an rtx. */
static char *this_function_bytecode;
/* The call description vector for the current function. */
static rtx this_function_calldesc;
/* Size of the local variables allocated for the current function. */
int local_vars_size;
/* Current depth of the bytecode evaluation stack. */
int stack_depth;
/* Maximum depth of the evaluation stack in this function. */
int max_stack_depth;
/* Current depth in statement expressions. */
static int stmt_expr_depth;
/* This structure is used to record MEMs or pseudos used to replace VAR, any
SUBREGs of VAR, and any MEMs containing VAR as an address. We need to
maintain this list in case two operands of an insn were required to match;
in that case we must ensure we use the same replacement. */
struct fixup_replacement
{
rtx old;
rtx new;
struct fixup_replacement *next;
};
/* Forward declarations. */
static struct temp_slot *find_temp_slot_from_address PROTO((rtx));
static void put_reg_into_stack PROTO((struct function *, rtx, tree,
enum machine_mode, enum machine_mode,
int, int));
static void fixup_var_refs PROTO((rtx, enum machine_mode, int));
static struct fixup_replacement
*find_fixup_replacement PROTO((struct fixup_replacement **, rtx));
static void fixup_var_refs_insns PROTO((rtx, enum machine_mode, int,
rtx, int));
static void fixup_var_refs_1 PROTO((rtx, enum machine_mode, rtx *, rtx,
struct fixup_replacement **));
static rtx fixup_memory_subreg PROTO((rtx, rtx, int));
static rtx walk_fixup_memory_subreg PROTO((rtx, rtx, int));
static rtx fixup_stack_1 PROTO((rtx, rtx));
static void optimize_bit_field PROTO((rtx, rtx, rtx *));
static void instantiate_decls PROTO((tree, int));
static void instantiate_decls_1 PROTO((tree, int));
static void instantiate_decl PROTO((rtx, int, int));
static int instantiate_virtual_regs_1 PROTO((rtx *, rtx, int));
static void delete_handlers PROTO((void));
static void pad_to_arg_alignment PROTO((struct args_size *, int));
static void pad_below PROTO((struct args_size *, enum machine_mode,
tree));
static tree round_down PROTO((tree, int));
static rtx round_trampoline_addr PROTO((rtx));
static tree blocks_nreverse PROTO((tree));
static int all_blocks PROTO((tree, tree *));
static int *record_insns PROTO((rtx));
static int contains PROTO((rtx, int *));
static void put_addressof_into_stack PROTO((rtx));
static void purge_addressof_1 PROTO((rtx *, rtx, int));
/* Pointer to chain of `struct function' for containing functions. */
struct function *outer_function_chain;
/* Given a function decl for a containing function,
return the `struct function' for it. */
struct function *
find_function_data (decl)
tree decl;
{
struct function *p;
for (p = outer_function_chain; p; p = p->next)
if (p->decl == decl)
return p;
abort ();
}
/* Save the current context for compilation of a nested function.
This is called from language-specific code.
The caller is responsible for saving any language-specific status,
since this function knows only about language-independent variables. */
void
push_function_context_to (context)
tree context;
{
struct function *p = (struct function *) xmalloc (sizeof (struct function));
p->next = outer_function_chain;
outer_function_chain = p;
p->name = current_function_name;
p->decl = current_function_decl;
p->pops_args = current_function_pops_args;
p->returns_struct = current_function_returns_struct;
p->returns_pcc_struct = current_function_returns_pcc_struct;
p->returns_pointer = current_function_returns_pointer;
p->needs_context = current_function_needs_context;
p->calls_setjmp = current_function_calls_setjmp;
p->calls_longjmp = current_function_calls_longjmp;
p->calls_alloca = current_function_calls_alloca;
p->has_nonlocal_label = current_function_has_nonlocal_label;
p->has_nonlocal_goto = current_function_has_nonlocal_goto;
p->contains_functions = current_function_contains_functions;
p->is_thunk = current_function_is_thunk;
p->args_size = current_function_args_size;
p->pretend_args_size = current_function_pretend_args_size;
p->arg_offset_rtx = current_function_arg_offset_rtx;
p->varargs = current_function_varargs;
p->stdarg = current_function_stdarg;
p->uses_const_pool = current_function_uses_const_pool;
p->uses_pic_offset_table = current_function_uses_pic_offset_table;
p->internal_arg_pointer = current_function_internal_arg_pointer;
p->max_parm_reg = max_parm_reg;
p->parm_reg_stack_loc = parm_reg_stack_loc;
p->outgoing_args_size = current_function_outgoing_args_size;
p->return_rtx = current_function_return_rtx;
p->nonlocal_goto_handler_slot = nonlocal_goto_handler_slot;
p->nonlocal_goto_stack_level = nonlocal_goto_stack_level;
p->nonlocal_labels = nonlocal_labels;
p->cleanup_label = cleanup_label;
p->return_label = return_label;
p->save_expr_regs = save_expr_regs;
p->stack_slot_list = stack_slot_list;
p->parm_birth_insn = parm_birth_insn;
p->frame_offset = frame_offset;
p->tail_recursion_label = tail_recursion_label;
p->tail_recursion_reentry = tail_recursion_reentry;
p->arg_pointer_save_area = arg_pointer_save_area;
p->rtl_expr_chain = rtl_expr_chain;
p->last_parm_insn = last_parm_insn;
p->context_display = context_display;
p->trampoline_list = trampoline_list;
p->function_call_count = function_call_count;
p->temp_slots = temp_slots;
p->temp_slot_level = temp_slot_level;
p->fixup_var_refs_queue = 0;
p->epilogue_delay_list = current_function_epilogue_delay_list;
p->args_info = current_function_args_info;
save_tree_status (p, context);
save_storage_status (p);
save_emit_status (p);
init_emit ();
save_expr_status (p);
save_stmt_status (p);
save_varasm_status (p, context);
if (save_machine_status)
(*save_machine_status) (p);
}
void
push_function_context ()
{
push_function_context_to (current_function_decl);
}
/* Restore the last saved context, at the end of a nested function.
This function is called from language-specific code. */
void
pop_function_context_from (context)
tree context;
{
struct function *p = outer_function_chain;
outer_function_chain = p->next;
current_function_contains_functions
= p->contains_functions || p->inline_obstacks
|| context == current_function_decl;
current_function_name = p->name;
current_function_decl = p->decl;
current_function_pops_args = p->pops_args;
current_function_returns_struct = p->returns_struct;
current_function_returns_pcc_struct = p->returns_pcc_struct;
current_function_returns_pointer = p->returns_pointer;
current_function_needs_context = p->needs_context;
current_function_calls_setjmp = p->calls_setjmp;
current_function_calls_longjmp = p->calls_longjmp;
current_function_calls_alloca = p->calls_alloca;
current_function_has_nonlocal_label = p->has_nonlocal_label;
current_function_has_nonlocal_goto = p->has_nonlocal_goto;
current_function_is_thunk = p->is_thunk;
current_function_args_size = p->args_size;
current_function_pretend_args_size = p->pretend_args_size;
current_function_arg_offset_rtx = p->arg_offset_rtx;
current_function_varargs = p->varargs;
current_function_stdarg = p->stdarg;
current_function_uses_const_pool = p->uses_const_pool;
current_function_uses_pic_offset_table = p->uses_pic_offset_table;
current_function_internal_arg_pointer = p->internal_arg_pointer;
max_parm_reg = p->max_parm_reg;
parm_reg_stack_loc = p->parm_reg_stack_loc;
current_function_outgoing_args_size = p->outgoing_args_size;
current_function_return_rtx = p->return_rtx;
nonlocal_goto_handler_slot = p->nonlocal_goto_handler_slot;
nonlocal_goto_stack_level = p->nonlocal_goto_stack_level;
nonlocal_labels = p->nonlocal_labels;
cleanup_label = p->cleanup_label;
return_label = p->return_label;
save_expr_regs = p->save_expr_regs;
stack_slot_list = p->stack_slot_list;
parm_birth_insn = p->parm_birth_insn;
frame_offset = p->frame_offset;
tail_recursion_label = p->tail_recursion_label;
tail_recursion_reentry = p->tail_recursion_reentry;
arg_pointer_save_area = p->arg_pointer_save_area;
rtl_expr_chain = p->rtl_expr_chain;
last_parm_insn = p->last_parm_insn;
context_display = p->context_display;
trampoline_list = p->trampoline_list;
function_call_count = p->function_call_count;
temp_slots = p->temp_slots;
temp_slot_level = p->temp_slot_level;
current_function_epilogue_delay_list = p->epilogue_delay_list;
reg_renumber = 0;
current_function_args_info = p->args_info;
restore_tree_status (p, context);
restore_storage_status (p);
restore_expr_status (p);
restore_emit_status (p);
restore_stmt_status (p);
restore_varasm_status (p);
if (restore_machine_status)
(*restore_machine_status) (p);
/* Finish doing put_var_into_stack for any of our variables
which became addressable during the nested function. */
{
struct var_refs_queue *queue = p->fixup_var_refs_queue;
for (; queue; queue = queue->next)
fixup_var_refs (queue->modified, queue->promoted_mode, queue->unsignedp);
}
free (p);
/* Reset variables that have known state during rtx generation. */
rtx_equal_function_value_matters = 1;
virtuals_instantiated = 0;
}
void pop_function_context ()
{
pop_function_context_from (current_function_decl);
}
/* Allocate fixed slots in the stack frame of the current function. */
/* Return size needed for stack frame based on slots so far allocated.
This size counts from zero. It is not rounded to STACK_BOUNDARY;
the caller may have to do that. */
HOST_WIDE_INT
get_frame_size ()
{
#ifdef FRAME_GROWS_DOWNWARD
return -frame_offset;
#else
return frame_offset;
#endif
}
/* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
with machine mode MODE.
ALIGN controls the amount of alignment for the address of the slot:
0 means according to MODE,
-1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
positive specifies alignment boundary in bits.
We do not round to stack_boundary here. */
rtx
assign_stack_local (mode, size, align)
enum machine_mode mode;
int size;
int align;
{
register rtx x, addr;
int bigend_correction = 0;
int alignment;
if (align == 0)
{
alignment = GET_MODE_ALIGNMENT (mode) / BITS_PER_UNIT;
if (mode == BLKmode)
alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
}
else if (align == -1)
{
alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
size = CEIL_ROUND (size, alignment);
}
else
alignment = align / BITS_PER_UNIT;
/* Round frame offset to that alignment.
We must be careful here, since FRAME_OFFSET might be negative and
division with a negative dividend isn't as well defined as we might
like. So we instead assume that ALIGNMENT is a power of two and
use logical operations which are unambiguous. */
#ifdef FRAME_GROWS_DOWNWARD
frame_offset = FLOOR_ROUND (frame_offset, alignment);
#else
frame_offset = CEIL_ROUND (frame_offset, alignment);
#endif
/* On a big-endian machine, if we are allocating more space than we will use,
use the least significant bytes of those that are allocated. */
if (BYTES_BIG_ENDIAN && mode != BLKmode)
bigend_correction = size - GET_MODE_SIZE (mode);
#ifdef FRAME_GROWS_DOWNWARD
frame_offset -= size;
#endif
/* If we have already instantiated virtual registers, return the actual
address relative to the frame pointer. */
if (virtuals_instantiated)
addr = plus_constant (frame_pointer_rtx,
(frame_offset + bigend_correction
+ STARTING_FRAME_OFFSET));
else
addr = plus_constant (virtual_stack_vars_rtx,
frame_offset + bigend_correction);
#ifndef FRAME_GROWS_DOWNWARD
frame_offset += size;
#endif
x = gen_rtx (MEM, mode, addr);
stack_slot_list = gen_rtx (EXPR_LIST, VOIDmode, x, stack_slot_list);
return x;
}
/* Assign a stack slot in a containing function.
First three arguments are same as in preceding function.
The last argument specifies the function to allocate in. */
rtx
assign_outer_stack_local (mode, size, align, function)
enum machine_mode mode;
int size;
int align;
struct function *function;
{
register rtx x, addr;
int bigend_correction = 0;
int alignment;
/* Allocate in the memory associated with the function in whose frame
we are assigning. */
push_obstacks (function->function_obstack,
function->function_maybepermanent_obstack);
if (align == 0)
{
alignment = GET_MODE_ALIGNMENT (mode) / BITS_PER_UNIT;
if (mode == BLKmode)
alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
}
else if (align == -1)
{
alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
size = CEIL_ROUND (size, alignment);
}
else
alignment = align / BITS_PER_UNIT;
/* Round frame offset to that alignment. */
#ifdef FRAME_GROWS_DOWNWARD
function->frame_offset = FLOOR_ROUND (function->frame_offset, alignment);
#else
function->frame_offset = CEIL_ROUND (function->frame_offset, alignment);
#endif
/* On a big-endian machine, if we are allocating more space than we will use,
use the least significant bytes of those that are allocated. */
if (BYTES_BIG_ENDIAN && mode != BLKmode)
bigend_correction = size - GET_MODE_SIZE (mode);
#ifdef FRAME_GROWS_DOWNWARD
function->frame_offset -= size;
#endif
addr = plus_constant (virtual_stack_vars_rtx,
function->frame_offset + bigend_correction);
#ifndef FRAME_GROWS_DOWNWARD
function->frame_offset += size;
#endif
x = gen_rtx (MEM, mode, addr);
function->stack_slot_list
= gen_rtx (EXPR_LIST, VOIDmode, x, function->stack_slot_list);
pop_obstacks ();
return x;
}
/* Allocate a temporary stack slot and record it for possible later
reuse.
MODE is the machine mode to be given to the returned rtx.
SIZE is the size in units of the space required. We do no rounding here
since assign_stack_local will do any required rounding.
KEEP is 1 if this slot is to be retained after a call to
free_temp_slots. Automatic variables for a block are allocated
with this flag. KEEP is 2, if we allocate a longer term temporary,
whose lifetime is controlled by CLEANUP_POINT_EXPRs. */
rtx
assign_stack_temp (mode, size, keep)
enum machine_mode mode;
int size;
int keep;
{
struct temp_slot *p, *best_p = 0;
/* If SIZE is -1 it means that somebody tried to allocate a temporary
of a variable size. */
if (size == -1)
abort ();
/* First try to find an available, already-allocated temporary that is the
exact size we require. */
for (p = temp_slots; p; p = p->next)
if (p->size == size && GET_MODE (p->slot) == mode && ! p->in_use)
break;
/* If we didn't find, one, try one that is larger than what we want. We
find the smallest such. */
if (p == 0)
for (p = temp_slots; p; p = p->next)
if (p->size > size && GET_MODE (p->slot) == mode && ! p->in_use
&& (best_p == 0 || best_p->size > p->size))
best_p = p;
/* Make our best, if any, the one to use. */
if (best_p)
{
/* If there are enough aligned bytes left over, make them into a new
temp_slot so that the extra bytes don't get wasted. Do this only
for BLKmode slots, so that we can be sure of the alignment. */
if (GET_MODE (best_p->slot) == BLKmode)
{
int alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
int rounded_size = CEIL_ROUND (size, alignment);
if (best_p->size - rounded_size >= alignment)
{
p = (struct temp_slot *) oballoc (sizeof (struct temp_slot));
p->in_use = p->addr_taken = 0;
p->size = best_p->size - rounded_size;
p->base_offset = best_p->base_offset + rounded_size;
p->full_size = best_p->full_size - rounded_size;
p->slot = gen_rtx (MEM, BLKmode,
plus_constant (XEXP (best_p->slot, 0),
rounded_size));
p->address = 0;
p->rtl_expr = 0;
p->next = temp_slots;
temp_slots = p;
stack_slot_list = gen_rtx (EXPR_LIST, VOIDmode, p->slot,
stack_slot_list);
best_p->size = rounded_size;
best_p->full_size = rounded_size;
}
}
p = best_p;
}
/* If we still didn't find one, make a new temporary. */
if (p == 0)
{
int frame_offset_old = frame_offset;
p = (struct temp_slot *) oballoc (sizeof (struct temp_slot));
/* If the temp slot mode doesn't indicate the alignment,
use the largest possible, so no one will be disappointed. */
p->slot = assign_stack_local (mode, size, mode == BLKmode ? -1 : 0);
/* The following slot size computation is necessary because we don't
know the actual size of the temporary slot until assign_stack_local
has performed all the frame alignment and size rounding for the
requested temporary. Note that extra space added for alignment
can be either above or below this stack slot depending on which
way the frame grows. We include the extra space if and only if it
is above this slot. */
#ifdef FRAME_GROWS_DOWNWARD
p->size = frame_offset_old - frame_offset;
#else
p->size = size;
#endif
/* Now define the fields used by combine_temp_slots. */
#ifdef FRAME_GROWS_DOWNWARD
p->base_offset = frame_offset;
p->full_size = frame_offset_old - frame_offset;
#else
p->base_offset = frame_offset_old;
p->full_size = frame_offset - frame_offset_old;
#endif
p->address = 0;
p->next = temp_slots;
temp_slots = p;
}
p->in_use = 1;
p->addr_taken = 0;
p->rtl_expr = sequence_rtl_expr;
if (keep == 2)
{
p->level = target_temp_slot_level;
p->keep = 0;
}
else
{
p->level = temp_slot_level;
p->keep = keep;
}
/* We may be reusing an old slot, so clear any MEM flags that may have been
set from before. */
RTX_UNCHANGING_P (p->slot) = 0;
MEM_IN_STRUCT_P (p->slot) = 0;
return p->slot;
}
/* Assign a temporary of given TYPE.
KEEP is as for assign_stack_temp.
MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
it is 0 if a register is OK.
DONT_PROMOTE is 1 if we should not promote values in register
to wider modes. */
rtx
assign_temp (type, keep, memory_required, dont_promote)
tree type;
int keep;
int memory_required;
int dont_promote;
{
enum machine_mode mode = TYPE_MODE (type);
int unsignedp = TREE_UNSIGNED (type);
if (mode == BLKmode || memory_required)
{
int size = int_size_in_bytes (type);
rtx tmp;
/* Unfortunately, we don't yet know how to allocate variable-sized
temporaries. However, sometimes we have a fixed upper limit on
the size (which is stored in TYPE_ARRAY_MAX_SIZE) and can use that
instead. This is the case for Chill variable-sized strings. */
if (size == -1 && TREE_CODE (type) == ARRAY_TYPE
&& TYPE_ARRAY_MAX_SIZE (type) != NULL_TREE
&& TREE_CODE (TYPE_ARRAY_MAX_SIZE (type)) == INTEGER_CST)
size = TREE_INT_CST_LOW (TYPE_ARRAY_MAX_SIZE (type));
tmp = assign_stack_temp (mode, size, keep);
MEM_IN_STRUCT_P (tmp) = AGGREGATE_TYPE_P (type);
return tmp;
}
#ifndef PROMOTE_FOR_CALL_ONLY
if (! dont_promote)
mode = promote_mode (type, mode, &unsignedp, 0);
#endif
return gen_reg_rtx (mode);
}
/* Combine temporary stack slots which are adjacent on the stack.
This allows for better use of already allocated stack space. This is only
done for BLKmode slots because we can be sure that we won't have alignment
problems in this case. */
void
combine_temp_slots ()
{
struct temp_slot *p, *q;
struct temp_slot *prev_p, *prev_q;
/* Determine where to free back to after this function. */
rtx free_pointer = rtx_alloc (CONST_INT);
for (p = temp_slots, prev_p = 0; p; p = prev_p ? prev_p->next : temp_slots)
{
int delete_p = 0;
if (! p->in_use && GET_MODE (p->slot) == BLKmode)
for (q = p->next, prev_q = p; q; q = prev_q->next)
{
int delete_q = 0;
if (! q->in_use && GET_MODE (q->slot) == BLKmode)
{
if (p->base_offset + p->full_size == q->base_offset)
{
/* Q comes after P; combine Q into P. */
p->size += q->size;
p->full_size += q->full_size;
delete_q = 1;
}
else if (q->base_offset + q->full_size == p->base_offset)
{
/* P comes after Q; combine P into Q. */
q->size += p->size;
q->full_size += p->full_size;
delete_p = 1;
break;
}
}
/* Either delete Q or advance past it. */
if (delete_q)
prev_q->next = q->next;
else
prev_q = q;
}
/* Either delete P or advance past it. */
if (delete_p)
{
if (prev_p)
prev_p->next = p->next;
else
temp_slots = p->next;
}
else
prev_p = p;
}
/* Free all the RTL made by plus_constant. */
rtx_free (free_pointer);
}
/* Find the temp slot corresponding to the object at address X. */
static struct temp_slot *
find_temp_slot_from_address (x)
rtx x;
{
struct temp_slot *p;
rtx next;
for (p = temp_slots; p; p = p->next)
{
if (! p->in_use)
continue;
else if (XEXP (p->slot, 0) == x
|| p->address == x
|| (GET_CODE (x) == PLUS
&& XEXP (x, 0) == virtual_stack_vars_rtx
&& GET_CODE (XEXP (x, 1)) == CONST_INT
&& INTVAL (XEXP (x, 1)) >= p->base_offset
&& INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size))
return p;
else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
for (next = p->address; next; next = XEXP (next, 1))
if (XEXP (next, 0) == x)
return p;
}
return 0;
}
/* Indicate that NEW is an alternate way of referring to the temp slot
that previous was known by OLD. */
void
update_temp_slot_address (old, new)
rtx old, new;
{
struct temp_slot *p = find_temp_slot_from_address (old);
/* If none, return. Else add NEW as an alias. */
if (p == 0)
return;
else if (p->address == 0)
p->address = new;
else
{
if (GET_CODE (p->address) != EXPR_LIST)
p->address = gen_rtx (EXPR_LIST, VOIDmode, p->address, NULL_RTX);
p->address = gen_rtx (EXPR_LIST, VOIDmode, new, p->address);
}
}
/* If X could be a reference to a temporary slot, mark the fact that its
address was taken. */
void
mark_temp_addr_taken (x)
rtx x;
{
struct temp_slot *p;
if (x == 0)
return;
/* If X is not in memory or is at a constant address, it cannot be in
a temporary slot. */
if (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
return;
p = find_temp_slot_from_address (XEXP (x, 0));
if (p != 0)
p->addr_taken = 1;
}
/* If X could be a reference to a temporary slot, mark that slot as
belonging to the to one level higher than the current level. If X
matched one of our slots, just mark that one. Otherwise, we can't
easily predict which it is, so upgrade all of them. Kept slots
need not be touched.
This is called when an ({...}) construct occurs and a statement
returns a value in memory. */
void
preserve_temp_slots (x)
rtx x;
{
struct temp_slot *p = 0;
/* If there is no result, we still might have some objects whose address
were taken, so we need to make sure they stay around. */
if (x == 0)
{
for (p = temp_slots; p; p = p->next)
if (p->in_use && p->level == temp_slot_level && p->addr_taken)
p->level--;
return;
}
/* If X is a register that is being used as a pointer, see if we have
a temporary slot we know it points to. To be consistent with
the code below, we really should preserve all non-kept slots
if we can't find a match, but that seems to be much too costly. */
if (GET_CODE (x) == REG && REGNO_POINTER_FLAG (REGNO (x)))
p = find_temp_slot_from_address (x);
/* If X is not in memory or is at a constant address, it cannot be in
a temporary slot, but it can contain something whose address was
taken. */
if (p == 0 && (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0))))
{
for (p = temp_slots; p; p = p->next)
if (p->in_use && p->level == temp_slot_level && p->addr_taken)
p->level--;
return;
}
/* First see if we can find a match. */
if (p == 0)
p = find_temp_slot_from_address (XEXP (x, 0));
if (p != 0)
{
/* Move everything at our level whose address was taken to our new
level in case we used its address. */
struct temp_slot *q;
if (p->level == temp_slot_level)
{
for (q = temp_slots; q; q = q->next)
if (q != p && q->addr_taken && q->level == p->level)
q->level--;
p->level--;
p->addr_taken = 0;
}
return;
}
/* Otherwise, preserve all non-kept slots at this level. */
for (p = temp_slots; p; p = p->next)
if (p->in_use && p->level == temp_slot_level && ! p->keep)
p->level--;
}
/* X is the result of an RTL_EXPR. If it is a temporary slot associated
with that RTL_EXPR, promote it into a temporary slot at the present
level so it will not be freed when we free slots made in the
RTL_EXPR. */
void
preserve_rtl_expr_result (x)
rtx x;
{
struct temp_slot *p;
/* If X is not in memory or is at a constant address, it cannot be in
a temporary slot. */
if (x == 0 || GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
return;
/* If we can find a match, move it to our level unless it is already at
an upper level. */
p = find_temp_slot_from_address (XEXP (x, 0));
if (p != 0)
{
p->level = MIN (p->level, temp_slot_level);
p->rtl_expr = 0;
}
return;
}
/* Free all temporaries used so far. This is normally called at the end
of generating code for a statement. Don't free any temporaries
currently in use for an RTL_EXPR that hasn't yet been emitted.
We could eventually do better than this since it can be reused while
generating the same RTL_EXPR, but this is complex and probably not
worthwhile. */
void
free_temp_slots ()
{
struct temp_slot *p;
for (p = temp_slots; p; p = p->next)
if (p->in_use && p->level == temp_slot_level && ! p->keep
&& p->rtl_expr == 0)
p->in_use = 0;
combine_temp_slots ();
}
/* Free all temporary slots used in T, an RTL_EXPR node. */
void
free_temps_for_rtl_expr (t)
tree t;
{
struct temp_slot *p;
for (p = temp_slots; p; p = p->next)
if (p->rtl_expr == t)
p->in_use = 0;
combine_temp_slots ();
}
/* Mark all temporaries ever allocated in this function as not suitable
for reuse until the current level is exited. */
void
mark_all_temps_used ()
{
struct temp_slot *p;
for (p = temp_slots; p; p = p->next)
{
p->in_use = p->keep = 1;
p->level = MIN (p->level, temp_slot_level);
}
}
/* Push deeper into the nesting level for stack temporaries. */
void
push_temp_slots ()
{
temp_slot_level++;
}
/* Pop a temporary nesting level. All slots in use in the current level
are freed. */
void
pop_temp_slots ()
{
struct temp_slot *p;
for (p = temp_slots; p; p = p->next)
if (p->in_use && p->level == temp_slot_level && p->rtl_expr == 0)
p->in_use = 0;
combine_temp_slots ();
temp_slot_level--;
}
/* Initialize temporary slots. */
void
init_temp_slots ()
{
/* We have not allocated any temporaries yet. */
temp_slots = 0;
temp_slot_level = 0;
target_temp_slot_level = 0;
}
/* Retroactively move an auto variable from a register to a stack slot.
This is done when an address-reference to the variable is seen. */
void
put_var_into_stack (decl)
tree decl;
{
register rtx reg;
enum machine_mode promoted_mode, decl_mode;
struct function *function = 0;
tree context;
int can_use_addressof;
if (output_bytecode)
return;
context = decl_function_context (decl);
/* Get the current rtl used for this object and it's original mode. */
reg = TREE_CODE (decl) == SAVE_EXPR ? SAVE_EXPR_RTL (decl) : DECL_RTL (decl);
/* No need to do anything if decl has no rtx yet
since in that case caller is setting TREE_ADDRESSABLE
and a stack slot will be assigned when the rtl is made. */
if (reg == 0)
return;
/* Get the declared mode for this object. */
decl_mode = (TREE_CODE (decl) == SAVE_EXPR ? TYPE_MODE (TREE_TYPE (decl))
: DECL_MODE (decl));
/* Get the mode it's actually stored in. */
promoted_mode = GET_MODE (reg);
/* If this variable comes from an outer function,
find that function's saved context. */
if (context != current_function_decl && context != inline_function_decl)
for (function = outer_function_chain; function; function = function->next)
if (function->decl == context)
break;
/* If this is a variable-size object with a pseudo to address it,
put that pseudo into the stack, if the var is nonlocal. */
if (DECL_NONLOCAL (decl)
&& GET_CODE (reg) == MEM
&& GET_CODE (XEXP (reg, 0)) == REG
&& REGNO (XEXP (reg, 0)) > LAST_VIRTUAL_REGISTER)
{
reg = XEXP (reg, 0);
decl_mode = promoted_mode = GET_MODE (reg);
}
can_use_addressof
= (function == 0
/* FIXME make it work for promoted modes too */
&& decl_mode == promoted_mode
#ifdef NON_SAVING_SETJMP
&& ! (NON_SAVING_SETJMP && current_function_calls_setjmp)
#endif
);
/* If we can't use ADDRESSOF, make sure we see through one we already
generated. */
if (! can_use_addressof && GET_CODE (reg) == MEM
&& GET_CODE (XEXP (reg, 0)) == ADDRESSOF)
reg = XEXP (XEXP (reg, 0), 0);
/* Now we should have a value that resides in one or more pseudo regs. */
if (GET_CODE (reg) == REG)
{
/* If this variable lives in the current function and we don't need
to put things in the stack for the sake of setjmp, try to keep it
in a register until we know we actually need the address. */
if (can_use_addressof)
gen_mem_addressof (reg, decl);
else
put_reg_into_stack (function, reg, TREE_TYPE (decl),
promoted_mode, decl_mode,
TREE_SIDE_EFFECTS (decl), 0);
}
else if (GET_CODE (reg) == CONCAT)
{
/* A CONCAT contains two pseudos; put them both in the stack.
We do it so they end up consecutive. */
enum machine_mode part_mode = GET_MODE (XEXP (reg, 0));
tree part_type = TREE_TYPE (TREE_TYPE (decl));
#ifdef FRAME_GROWS_DOWNWARD
/* Since part 0 should have a lower address, do it second. */
put_reg_into_stack (function, XEXP (reg, 1), part_type, part_mode,
part_mode, TREE_SIDE_EFFECTS (decl), 0);
put_reg_into_stack (function, XEXP (reg, 0), part_type, part_mode,
part_mode, TREE_SIDE_EFFECTS (decl), 0);
#else
put_reg_into_stack (function, XEXP (reg, 0), part_type, part_mode,
part_mode, TREE_SIDE_EFFECTS (decl), 0);
put_reg_into_stack (function, XEXP (reg, 1), part_type, part_mode,
part_mode, TREE_SIDE_EFFECTS (decl), 0);
#endif
/* Change the CONCAT into a combined MEM for both parts. */
PUT_CODE (reg, MEM);
MEM_VOLATILE_P (reg) = MEM_VOLATILE_P (XEXP (reg, 0));
/* The two parts are in memory order already.
Use the lower parts address as ours. */
XEXP (reg, 0) = XEXP (XEXP (reg, 0), 0);
/* Prevent sharing of rtl that might lose. */
if (GET_CODE (XEXP (reg, 0)) == PLUS)
XEXP (reg, 0) = copy_rtx (XEXP (reg, 0));
}
else
return;
if (flag_check_memory_usage)
emit_library_call (chkr_set_right_libfunc, 1, VOIDmode, 3,
XEXP (reg, 0), ptr_mode,
GEN_INT (GET_MODE_SIZE (GET_MODE (reg))),
TYPE_MODE (sizetype),
GEN_INT (MEMORY_USE_RW),
TYPE_MODE (integer_type_node));
}
/* Subroutine of put_var_into_stack. This puts a single pseudo reg REG
into the stack frame of FUNCTION (0 means the current function).
DECL_MODE is the machine mode of the user-level data type.
PROMOTED_MODE is the machine mode of the register.
VOLATILE_P is nonzero if this is for a "volatile" decl. */
static void
put_reg_into_stack (function, reg, type, promoted_mode, decl_mode, volatile_p,
original_regno)
struct function *function;
rtx reg;
tree type;
enum machine_mode promoted_mode, decl_mode;
int volatile_p;
int original_regno;
{
rtx new = 0;
int regno = original_regno;
if (regno == 0)
regno = REGNO (reg);
if (function)
{
if (regno < function->max_parm_reg)
new = function->parm_reg_stack_loc[regno];
if (new == 0)
new = assign_outer_stack_local (decl_mode, GET_MODE_SIZE (decl_mode),
0, function);
}
else
{
if (regno < max_parm_reg)
new = parm_reg_stack_loc[regno];
if (new == 0)
new = assign_stack_local (decl_mode, GET_MODE_SIZE (decl_mode), 0);
}
PUT_MODE (reg, decl_mode);
XEXP (reg, 0) = XEXP (new, 0);
/* `volatil' bit means one thing for MEMs, another entirely for REGs. */
MEM_VOLATILE_P (reg) = volatile_p;
PUT_CODE (reg, MEM);
/* If this is a memory ref that contains aggregate components,
mark it as such for cse and loop optimize. */
MEM_IN_STRUCT_P (reg) = AGGREGATE_TYPE_P (type);
/* Now make sure that all refs to the variable, previously made
when it was a register, are fixed up to be valid again. */
if (function)
{
struct var_refs_queue *temp;
/* Variable is inherited; fix it up when we get back to its function. */
push_obstacks (function->function_obstack,
function->function_maybepermanent_obstack);
/* See comment in restore_tree_status in tree.c for why this needs to be
on saveable obstack. */
temp
= (struct var_refs_queue *) savealloc (sizeof (struct var_refs_queue));
temp->modified = reg;
temp->promoted_mode = promoted_mode;
temp->unsignedp = TREE_UNSIGNED (type);
temp->next = function->fixup_var_refs_queue;
function->fixup_var_refs_queue = temp;
pop_obstacks ();
}
else
/* Variable is local; fix it up now. */
fixup_var_refs (reg, promoted_mode, TREE_UNSIGNED (type));
}
static void
fixup_var_refs (var, promoted_mode, unsignedp)
rtx var;
enum machine_mode promoted_mode;
int unsignedp;
{
tree pending;
rtx first_insn = get_insns ();
struct sequence_stack *stack = sequence_stack;
tree rtl_exps = rtl_expr_chain;
/* Must scan all insns for stack-refs that exceed the limit. */
fixup_var_refs_insns (var, promoted_mode, unsignedp, first_insn, stack == 0);
/* Scan all pending sequences too. */
for (; stack; stack = stack->next)
{
push_to_sequence (stack->first);
fixup_var_refs_insns (var, promoted_mode, unsignedp,
stack->first, stack->next != 0);
/* Update remembered end of sequence
in case we added an insn at the end. */
stack->last = get_last_insn ();
end_sequence ();
}
/* Scan all waiting RTL_EXPRs too. */
for (pending = rtl_exps; pending; pending = TREE_CHAIN (pending))
{
rtx seq = RTL_EXPR_SEQUENCE (TREE_VALUE (pending));
if (seq != const0_rtx && seq != 0)
{
push_to_sequence (seq);
fixup_var_refs_insns (var, promoted_mode, unsignedp, seq, 0);
end_sequence ();
}
}
}
/* REPLACEMENTS is a pointer to a list of the struct fixup_replacement and X is
some part of an insn. Return a struct fixup_replacement whose OLD
value is equal to X. Allocate a new structure if no such entry exists. */
static struct fixup_replacement *
find_fixup_replacement (replacements, x)
struct fixup_replacement **replacements;
rtx x;
{
struct fixup_replacement *p;
/* See if we have already replaced this. */
for (p = *replacements; p && p->old != x; p = p->next)
;
if (p == 0)
{
p = (struct fixup_replacement *) oballoc (sizeof (struct fixup_replacement));
p->old = x;
p->new = 0;
p->next = *replacements;
*replacements = p;
}
return p;
}
/* Scan the insn-chain starting with INSN for refs to VAR
and fix them up. TOPLEVEL is nonzero if this chain is the
main chain of insns for the current function. */
static void
fixup_var_refs_insns (var, promoted_mode, unsignedp, insn, toplevel)
rtx var;
enum machine_mode promoted_mode;
int unsignedp;
rtx insn;
int toplevel;
{
rtx call_dest = 0;
while (insn)
{
rtx next = NEXT_INSN (insn);
rtx note;
if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
{
/* If this is a CLOBBER of VAR, delete it.
If it has a REG_LIBCALL note, delete the REG_LIBCALL
and REG_RETVAL notes too. */
if (GET_CODE (PATTERN (insn)) == CLOBBER
&& XEXP (PATTERN (insn), 0) == var)
{
if ((note = find_reg_note (insn, REG_LIBCALL, NULL_RTX)) != 0)
/* The REG_LIBCALL note will go away since we are going to
turn INSN into a NOTE, so just delete the
corresponding REG_RETVAL note. */
remove_note (XEXP (note, 0),
find_reg_note (XEXP (note, 0), REG_RETVAL,
NULL_RTX));
/* In unoptimized compilation, we shouldn't call delete_insn
except in jump.c doing warnings. */
PUT_CODE (insn, NOTE);
NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
NOTE_SOURCE_FILE (insn) = 0;
}
/* The insn to load VAR from a home in the arglist
is now a no-op. When we see it, just delete it. */
else if (toplevel
&& GET_CODE (PATTERN (insn)) == SET
&& SET_DEST (PATTERN (insn)) == var
/* If this represents the result of an insn group,
don't delete the insn. */
&& find_reg_note (insn, REG_RETVAL, NULL_RTX) == 0
&& rtx_equal_p (SET_SRC (PATTERN (insn)), var))
{
/* In unoptimized compilation, we shouldn't call delete_insn
except in jump.c doing warnings. */
PUT_CODE (insn, NOTE);
NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
NOTE_SOURCE_FILE (insn) = 0;
if (insn == last_parm_insn)
last_parm_insn = PREV_INSN (next);
}
else
{
struct fixup_replacement *replacements = 0;
rtx next_insn = NEXT_INSN (insn);
if (SMALL_REGISTER_CLASSES)
{
/* If the insn that copies the results of a CALL_INSN
into a pseudo now references VAR, we have to use an
intermediate pseudo since we want the life of the
return value register to be only a single insn.
If we don't use an intermediate pseudo, such things as
address computations to make the address of VAR valid
if it is not can be placed between the CALL_INSN and INSN.
To make sure this doesn't happen, we record the destination
of the CALL_INSN and see if the next insn uses both that
and VAR. */
if (call_dest != 0 && GET_CODE (insn) == INSN
&& reg_mentioned_p (var, PATTERN (insn))
&& reg_mentioned_p (call_dest, PATTERN (insn)))
{
rtx temp = gen_reg_rtx (GET_MODE (call_dest));
emit_insn_before (gen_move_insn (temp, call_dest), insn);
PATTERN (insn) = replace_rtx (PATTERN (insn),
call_dest, temp);
}
if (GET_CODE (insn) == CALL_INSN
&& GET_CODE (PATTERN (insn)) == SET)
call_dest = SET_DEST (PATTERN (insn));
else if (GET_CODE (insn) == CALL_INSN
&& GET_CODE (PATTERN (insn)) == PARALLEL
&& GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == SET)
call_dest = SET_DEST (XVECEXP (PATTERN (insn), 0, 0));
else
call_dest = 0;
}
/* See if we have to do anything to INSN now that VAR is in
memory. If it needs to be loaded into a pseudo, use a single
pseudo for the entire insn in case there is a MATCH_DUP
between two operands. We pass a pointer to the head of
a list of struct fixup_replacements. If fixup_var_refs_1
needs to allocate pseudos or replacement MEMs (for SUBREGs),
it will record them in this list.
If it allocated a pseudo for any replacement, we copy into
it here. */
fixup_var_refs_1 (var, promoted_mode, &PATTERN (insn), insn,
&replacements);
/* If this is last_parm_insn, and any instructions were output
after it to fix it up, then we must set last_parm_insn to
the last such instruction emitted. */
if (insn == last_parm_insn)
last_parm_insn = PREV_INSN (next_insn);
while (replacements)
{
if (GET_CODE (replacements->new) == REG)
{
rtx insert_before;
rtx seq;
/* OLD might be a (subreg (mem)). */
if (GET_CODE (replacements->old) == SUBREG)
replacements->old
= fixup_memory_subreg (replacements->old, insn, 0);
else
replacements->old
= fixup_stack_1 (replacements->old, insn);
insert_before = insn;
/* If we are changing the mode, do a conversion.
This might be wasteful, but combine.c will
eliminate much of the waste. */
if (GET_MODE (replacements->new)
!= GET_MODE (replacements->old))
{
start_sequence ();
convert_move (replacements->new,
replacements->old, unsignedp);
seq = gen_sequence ();
end_sequence ();
}
else
seq = gen_move_insn (replacements->new,
replacements->old);
emit_insn_before (seq, insert_before);
}
replacements = replacements->next;
}
}
/* Also fix up any invalid exprs in the REG_NOTES of this insn.
But don't touch other insns referred to by reg-notes;
we will get them elsewhere. */
for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
if (GET_CODE (note) != INSN_LIST)
XEXP (note, 0)
= walk_fixup_memory_subreg (XEXP (note, 0), insn, 1);
}
insn = next;
}
}
/* VAR is a MEM that used to be a pseudo register with mode PROMOTED_MODE.
See if the rtx expression at *LOC in INSN needs to be changed.
REPLACEMENTS is a pointer to a list head that starts out zero, but may
contain a list of original rtx's and replacements. If we find that we need
to modify this insn by replacing a memory reference with a pseudo or by
making a new MEM to implement a SUBREG, we consult that list to see if
we have already chosen a replacement. If none has already been allocated,
we allocate it and update the list. fixup_var_refs_insns will copy VAR
or the SUBREG, as appropriate, to the pseudo. */
static void
fixup_var_refs_1 (var, promoted_mode, loc, insn, replacements)
register rtx var;
enum machine_mode promoted_mode;
register rtx *loc;
rtx insn;
struct fixup_replacement **replacements;
{
register int i;
register rtx x = *loc;
RTX_CODE code = GET_CODE (x);
register char *fmt;
register rtx tem, tem1;
struct fixup_replacement *replacement;
switch (code)
{
case ADDRESSOF:
if (XEXP (x, 0) == var)
{
/* Prevent sharing of rtl that might lose. */
rtx sub = copy_rtx (XEXP (var, 0));
start_sequence ();
if (! validate_change (insn, loc, sub, 0))
{
rtx y = force_operand (sub, NULL_RTX);
if (! validate_change (insn, loc, y, 0))
*loc = copy_to_reg (y);
}
emit_insn_before (gen_sequence (), insn);
end_sequence ();
}
return;
case MEM:
if (var == x)
{
/* If we already have a replacement, use it. Otherwise,
try to fix up this address in case it is invalid. */
replacement = find_fixup_replacement (replacements, var);
if (replacement->new)
{
*loc = replacement->new;
return;
}
*loc = replacement->new = x = fixup_stack_1 (x, insn);
/* Unless we are forcing memory to register or we changed the mode,
we can leave things the way they are if the insn is valid. */
INSN_CODE (insn) = -1;
if (! flag_force_mem && GET_MODE (x) == promoted_mode
&& recog_memoized (insn) >= 0)
return;
*loc = replacement->new = gen_reg_rtx (promoted_mode);
return;
}
/* If X contains VAR, we need to unshare it here so that we update
each occurrence separately. But all identical MEMs in one insn
must be replaced with the same rtx because of the possibility of
MATCH_DUPs. */
if (reg_mentioned_p (var, x))
{
replacement = find_fixup_replacement (replacements, x);
if (replacement->new == 0)
replacement->new = copy_most_rtx (x, var);
*loc = x = replacement->new;
}
break;
case REG:
case CC0:
case PC:
case CONST_INT:
case CONST:
case SYMBOL_REF:
case LABEL_REF:
case CONST_DOUBLE:
return;
case SIGN_EXTRACT:
case ZERO_EXTRACT:
/* Note that in some cases those types of expressions are altered
by optimize_bit_field, and do not survive to get here. */
if (XEXP (x, 0) == var
|| (GET_CODE (XEXP (x, 0)) == SUBREG
&& SUBREG_REG (XEXP (x, 0)) == var))
{
/* Get TEM as a valid MEM in the mode presently in the insn.
We don't worry about the possibility of MATCH_DUP here; it
is highly unlikely and would be tricky to handle. */
tem = XEXP (x, 0);
if (GET_CODE (tem) == SUBREG)
{
if (GET_MODE_BITSIZE (GET_MODE (tem))
> GET_MODE_BITSIZE (GET_MODE (var)))
{
replacement = find_fixup_replacement (replacements, var);
if (replacement->new == 0)
replacement->new = gen_reg_rtx (GET_MODE (var));
SUBREG_REG (tem) = replacement->new;
}
else
tem = fixup_memory_subreg (tem, insn, 0);
}
else
tem = fixup_stack_1 (tem, insn);
/* Unless we want to load from memory, get TEM into the proper mode
for an extract from memory. This can only be done if the
extract is at a constant position and length. */
if (! flag_force_mem && GET_CODE (XEXP (x, 1)) == CONST_INT
&& GET_CODE (XEXP (x, 2)) == CONST_INT
&& ! mode_dependent_address_p (XEXP (tem, 0))
&& ! MEM_VOLATILE_P (tem))
{
enum machine_mode wanted_mode = VOIDmode;
enum machine_mode is_mode = GET_MODE (tem);
int width = INTVAL (XEXP (x, 1));
int pos = INTVAL (XEXP (x, 2));
#ifdef HAVE_extzv
if (GET_CODE (x) == ZERO_EXTRACT)
wanted_mode = insn_operand_mode[(int) CODE_FOR_extzv][1];
#endif
#ifdef HAVE_extv
if (GET_CODE (x) == SIGN_EXTRACT)
wanted_mode = insn_operand_mode[(int) CODE_FOR_extv][1];
#endif
/* If we have a narrower mode, we can do something. */
if (wanted_mode != VOIDmode
&& GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
{
int offset = pos / BITS_PER_UNIT;
rtx old_pos = XEXP (x, 2);
rtx newmem;
/* If the bytes and bits are counted differently, we
must adjust the offset. */
if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
offset = (GET_MODE_SIZE (is_mode)
- GET_MODE_SIZE (wanted_mode) - offset);
pos %= GET_MODE_BITSIZE (wanted_mode);
newmem = gen_rtx (MEM, wanted_mode,
plus_constant (XEXP (tem, 0), offset));
RTX_UNCHANGING_P (newmem) = RTX_UNCHANGING_P (tem);
MEM_VOLATILE_P (newmem) = MEM_VOLATILE_P (tem);
MEM_IN_STRUCT_P (newmem) = MEM_IN_STRUCT_P (tem);
/* Make the change and see if the insn remains valid. */
INSN_CODE (insn) = -1;
XEXP (x, 0) = newmem;
XEXP (x, 2) = GEN_INT (pos);
if (recog_memoized (insn) >= 0)
return;
/* Otherwise, restore old position. XEXP (x, 0) will be
restored later. */
XEXP (x, 2) = old_pos;
}
}
/* If we get here, the bitfield extract insn can't accept a memory
reference. Copy the input into a register. */
tem1 = gen_reg_rtx (GET_MODE (tem));
emit_insn_before (gen_move_insn (tem1, tem), insn);
XEXP (x, 0) = tem1;
return;
}
break;
case SUBREG:
if (SUBREG_REG (x) == var)
{
/* If this is a special SUBREG made because VAR was promoted
from a wider mode, replace it with VAR and call ourself
recursively, this time saying that the object previously
had its current mode (by virtue of the SUBREG). */
if (SUBREG_PROMOTED_VAR_P (x))
{
*loc = var;
fixup_var_refs_1 (var, GET_MODE (var), loc, insn, replacements);
return;
}
/* If this SUBREG makes VAR wider, it has become a paradoxical
SUBREG with VAR in memory, but these aren't allowed at this
stage of the compilation. So load VAR into a pseudo and take
a SUBREG of that pseudo. */
if (GET_MODE_SIZE (GET_MODE (x)) > GET_MODE_SIZE (GET_MODE (var)))
{
replacement = find_fixup_replacement (replacements, var);
if (replacement->new == 0)
replacement->new = gen_reg_rtx (GET_MODE (var));
SUBREG_REG (x) = replacement->new;
return;
}
/* See if we have already found a replacement for this SUBREG.
If so, use it. Otherwise, make a MEM and see if the insn
is recognized. If not, or if we should force MEM into a register,
make a pseudo for this SUBREG. */
replacement = find_fixup_replacement (replacements, x);
if (replacement->new)
{
*loc = replacement->new;
return;
}
replacement->new = *loc = fixup_memory_subreg (x, insn, 0);
INSN_CODE (insn) = -1;
if (! flag_force_mem && recog_memoized (insn) >= 0)
return;
*loc = replacement->new = gen_reg_rtx (GET_MODE (x));
return;
}
break;
case SET:
/* First do special simplification of bit-field references. */
if (GET_CODE (SET_DEST (x)) == SIGN_EXTRACT
|| GET_CODE (SET_DEST (x)) == ZERO_EXTRACT)
optimize_bit_field (x, insn, 0);
if (GET_CODE (SET_SRC (x)) == SIGN_EXTRACT
|| GET_CODE (SET_SRC (x)) == ZERO_EXTRACT)
optimize_bit_field (x, insn, NULL_PTR);
/* For a paradoxical SUBREG inside a ZERO_EXTRACT, load the object
into a register and then store it back out. */
if (GET_CODE (SET_DEST (x)) == ZERO_EXTRACT
&& GET_CODE (XEXP (SET_DEST (x), 0)) == SUBREG
&& SUBREG_REG (XEXP (SET_DEST (x), 0)) == var
&& (GET_MODE_SIZE (GET_MODE (XEXP (SET_DEST (x), 0)))
> GET_MODE_SIZE (GET_MODE (var))))
{
replacement = find_fixup_replacement (replacements, var);
if (replacement->new == 0)
replacement->new = gen_reg_rtx (GET_MODE (var));
SUBREG_REG (XEXP (SET_DEST (x), 0)) = replacement->new;
emit_insn_after (gen_move_insn (var, replacement->new), insn);
}
/* If SET_DEST is now a paradoxical SUBREG, put the result of this
insn into a pseudo and store the low part of the pseudo into VAR. */
if (GET_CODE (SET_DEST (x)) == SUBREG
&& SUBREG_REG (SET_DEST (x)) == var
&& (GET_MODE_SIZE (GET_MODE (SET_DEST (x)))
> GET_MODE_SIZE (GET_MODE (var))))
{
SET_DEST (x) = tem = gen_reg_rtx (GET_MODE (SET_DEST (x)));
emit_insn_after (gen_move_insn (var, gen_lowpart (GET_MODE (var),
tem)),
insn);
break;
}
{
rtx dest = SET_DEST (x);
rtx src = SET_SRC (x);
rtx outerdest = dest;
while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
|| GET_CODE (dest) == SIGN_EXTRACT
|| GET_CODE (dest) == ZERO_EXTRACT)
dest = XEXP (dest, 0);
if (GET_CODE (src) == SUBREG)
src = XEXP (src, 0);
/* If VAR does not appear at the top level of the SET
just scan the lower levels of the tree. */
if (src != var && dest != var)
break;
/* We will need to rerecognize this insn. */
INSN_CODE (insn) = -1;
#ifdef HAVE_insv
if (GET_CODE (outerdest) == ZERO_EXTRACT && dest == var)
{
/* Since this case will return, ensure we fixup all the
operands here. */
fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 1),
insn, replacements);
fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 2),
insn, replacements);
fixup_var_refs_1 (var, promoted_mode, &SET_SRC (x),
insn, replacements);
tem = XEXP (outerdest, 0);
/* Clean up (SUBREG:SI (MEM:mode ...) 0)
that may appear inside a ZERO_EXTRACT.
This was legitimate when the MEM was a REG. */
if (GET_CODE (tem) == SUBREG
&& SUBREG_REG (tem) == var)
tem = fixup_memory_subreg (tem, insn, 0);
else
tem = fixup_stack_1 (tem, insn);
if (GET_CODE (XEXP (outerdest, 1)) == CONST_INT
&& GET_CODE (XEXP (outerdest, 2)) == CONST_INT
&& ! mode_dependent_address_p (XEXP (tem, 0))
&& ! MEM_VOLATILE_P (tem))
{
enum machine_mode wanted_mode
= insn_operand_mode[(int) CODE_FOR_insv][0];
enum machine_mode is_mode = GET_MODE (tem);
int width = INTVAL (XEXP (outerdest, 1));
int pos = INTVAL (XEXP (outerdest, 2));
/* If we have a narrower mode, we can do something. */
if (GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
{
int offset = pos / BITS_PER_UNIT;
rtx old_pos = XEXP (outerdest, 2);
rtx newmem;
if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
offset = (GET_MODE_SIZE (is_mode)
- GET_MODE_SIZE (wanted_mode) - offset);
pos %= GET_MODE_BITSIZE (wanted_mode);
newmem = gen_rtx (MEM, wanted_mode,
plus_constant (XEXP (tem, 0), offset));
RTX_UNCHANGING_P (newmem) = RTX_UNCHANGING_P (tem);
MEM_VOLATILE_P (newmem) = MEM_VOLATILE_P (tem);
MEM_IN_STRUCT_P (newmem) = MEM_IN_STRUCT_P (tem);
/* Make the change and see if the insn remains valid. */
INSN_CODE (insn) = -1;
XEXP (outerdest, 0) = newmem;
XEXP (outerdest, 2) = GEN_INT (pos);
if (recog_memoized (insn) >= 0)
return;
/* Otherwise, restore old position. XEXP (x, 0) will be
restored later. */
XEXP (outerdest, 2) = old_pos;
}
}
/* If we get here, the bit-field store doesn't allow memory
or isn't located at a constant position. Load the value into
a register, do the store, and put it back into memory. */
tem1 = gen_reg_rtx (GET_MODE (tem));
emit_insn_before (gen_move_insn (tem1, tem), insn);
emit_insn_after (gen_move_insn (tem, tem1), insn);
XEXP (outerdest, 0) = tem1;
return;
}
#endif
/* STRICT_LOW_PART is a no-op on memory references
and it can cause combinations to be unrecognizable,
so eliminate it. */
if (dest == var && GET_CODE (SET_DEST (x)) == STRICT_LOW_PART)
SET_DEST (x) = XEXP (SET_DEST (x), 0);
/* A valid insn to copy VAR into or out of a register
must be left alone, to avoid an infinite loop here.
If the reference to VAR is by a subreg, fix that up,
since SUBREG is not valid for a memref.
Also fix up the address of the stack slot.
Note that we must not try to recognize the insn until
after we know that we have valid addresses and no
(subreg (mem ...) ...) constructs, since these interfere
with determining the validity of the insn. */
if ((SET_SRC (x) == var
|| (GET_CODE (SET_SRC (x)) == SUBREG
&& SUBREG_REG (SET_SRC (x)) == var))
&& (GET_CODE (SET_DEST (x)) == REG
|| (GET_CODE (SET_DEST (x)) == SUBREG
&& GET_CODE (SUBREG_REG (SET_DEST (x))) == REG))
&& GET_MODE (var) == promoted_mode
&& x == single_set (insn))
{
rtx pat;
replacement = find_fixup_replacement (replacements, SET_SRC (x));
if (replacement->new)
SET_SRC (x) = replacement->new;
else if (GET_CODE (SET_SRC (x)) == SUBREG)
SET_SRC (x) = replacement->new
= fixup_memory_subreg (SET_SRC (x), insn, 0);
else
SET_SRC (x) = replacement->new
= fixup_stack_1 (SET_SRC (x), insn);
if (recog_memoized (insn) >= 0)
return;
/* INSN is not valid, but we know that we want to
copy SET_SRC (x) to SET_DEST (x) in some way. So
we generate the move and see whether it requires more
than one insn. If it does, we emit those insns and
delete INSN. Otherwise, we an just replace the pattern
of INSN; we have already verified above that INSN has
no other function that to do X. */
pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
if (GET_CODE (pat) == SEQUENCE)
{
emit_insn_after (pat, insn);
PUT_CODE (insn, NOTE);
NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
NOTE_SOURCE_FILE (insn) = 0;
}
else
PATTERN (insn) = pat;
return;
}
if ((SET_DEST (x) == var
|| (GET_CODE (SET_DEST (x)) == SUBREG
&& SUBREG_REG (SET_DEST (x)) == var))
&& (GET_CODE (SET_SRC (x)) == REG
|| (GET_CODE (SET_SRC (x)) == SUBREG
&& GET_CODE (SUBREG_REG (SET_SRC (x))) == REG))
&& GET_MODE (var) == promoted_mode
&& x == single_set (insn))
{
rtx pat;
if (GET_CODE (SET_DEST (x)) == SUBREG)
SET_DEST (x) = fixup_memory_subreg (SET_DEST (x), insn, 0);
else
SET_DEST (x) = fixup_stack_1 (SET_DEST (x), insn);
if (recog_memoized (insn) >= 0)
return;
pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
if (GET_CODE (pat) == SEQUENCE)
{
emit_insn_after (pat, insn);
PUT_CODE (insn, NOTE);
NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
NOTE_SOURCE_FILE (insn) = 0;
}
else
PATTERN (insn) = pat;
return;
}
/* Otherwise, storing into VAR must be handled specially
by storing into a temporary and copying that into VAR
with a new insn after this one. Note that this case
will be used when storing into a promoted scalar since
the insn will now have different modes on the input
and output and hence will be invalid (except for the case
of setting it to a constant, which does not need any
change if it is valid). We generate extra code in that case,
but combine.c will eliminate it. */
if (dest == var)
{
rtx temp;
rtx fixeddest = SET_DEST (x);
/* STRICT_LOW_PART can be discarded, around a MEM. */
if (GET_CODE (fixeddest) == STRICT_LOW_PART)
fixeddest = XEXP (fixeddest, 0);
/* Convert (SUBREG (MEM)) to a MEM in a changed mode. */
if (GET_CODE (fixeddest) == SUBREG)
{
fixeddest = fixup_memory_subreg (fixeddest, insn, 0);
promoted_mode = GET_MODE (fixeddest);
}
else
fixeddest = fixup_stack_1 (fixeddest, insn);
temp = gen_reg_rtx (promoted_mode);
emit_insn_after (gen_move_insn (fixeddest,
gen_lowpart (GET_MODE (fixeddest),
temp)),
insn);
SET_DEST (x) = temp;
}
}
default:
break;
}
/* Nothing special about this RTX; fix its operands. */
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e')
fixup_var_refs_1 (var, promoted_mode, &XEXP (x, i), insn, replacements);
if (fmt[i] == 'E')
{
register int j;
for (j = 0; j < XVECLEN (x, i); j++)
fixup_var_refs_1 (var, promoted_mode, &XVECEXP (x, i, j),
insn, replacements);
}
}
}
/* Given X, an rtx of the form (SUBREG:m1 (MEM:m2 addr)),
return an rtx (MEM:m1 newaddr) which is equivalent.
If any insns must be emitted to compute NEWADDR, put them before INSN.
UNCRITICAL nonzero means accept paradoxical subregs.
This is used for subregs found inside REG_NOTES. */
static rtx
fixup_memory_subreg (x, insn, uncritical)
rtx x;
rtx insn;
int uncritical;
{
int offset = SUBREG_WORD (x) * UNITS_PER_WORD;
rtx addr = XEXP (SUBREG_REG (x), 0);
enum machine_mode mode = GET_MODE (x);
rtx saved, result;
/* Paradoxical SUBREGs are usually invalid during RTL generation. */
if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))
&& ! uncritical)
abort ();
if (BYTES_BIG_ENDIAN)
offset += (MIN (UNITS_PER_WORD, GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
- MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode)));
addr = plus_constant (addr, offset);
if (!flag_force_addr && memory_address_p (mode, addr))
/* Shortcut if no insns need be emitted. */
return change_address (SUBREG_REG (x), mode, addr);
start_sequence ();
result = change_address (SUBREG_REG (x), mode, addr);
emit_insn_before (gen_sequence (), insn);
end_sequence ();
return result;
}
/* Do fixup_memory_subreg on all (SUBREG (MEM ...) ...) contained in X.
Replace subexpressions of X in place.
If X itself is a (SUBREG (MEM ...) ...), return the replacement expression.
Otherwise return X, with its contents possibly altered.
If any insns must be emitted to compute NEWADDR, put them before INSN.
UNCRITICAL is as in fixup_memory_subreg. */
static rtx
walk_fixup_memory_subreg (x, insn, uncritical)
register rtx x;
rtx insn;
int uncritical;
{
register enum rtx_code code;
register char *fmt;
register int i;
if (x == 0)
return 0;
code = GET_CODE (x);
if (code == SUBREG && GET_CODE (SUBREG_REG (x)) == MEM)
return fixup_memory_subreg (x, insn, uncritical);
/* Nothing special about this RTX; fix its operands. */
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e')
XEXP (x, i) = walk_fixup_memory_subreg (XEXP (x, i), insn, uncritical);
if (fmt[i] == 'E')
{
register int j;
for (j = 0; j < XVECLEN (x, i); j++)
XVECEXP (x, i, j)
= walk_fixup_memory_subreg (XVECEXP (x, i, j), insn, uncritical);
}
}
return x;
}
/* For each memory ref within X, if it refers to a stack slot
with an out of range displacement, put the address in a temp register
(emitting new insns before INSN to load these registers)
and alter the memory ref to use that register.
Replace each such MEM rtx with a copy, to avoid clobberage. */
static rtx
fixup_stack_1 (x, insn)
rtx x;
rtx insn;
{
register int i;
register RTX_CODE code = GET_CODE (x);
register char *fmt;
if (code == MEM)
{
register rtx ad = XEXP (x, 0);
/* If we have address of a stack slot but it's not valid
(displacement is too large), compute the sum in a register. */
if (GET_CODE (ad) == PLUS
&& GET_CODE (XEXP (ad, 0)) == REG
&& ((REGNO (XEXP (ad, 0)) >= FIRST_VIRTUAL_REGISTER
&& REGNO (XEXP (ad, 0)) <= LAST_VIRTUAL_REGISTER)
|| REGNO (XEXP (ad, 0)) == FRAME_POINTER_REGNUM
#if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
|| REGNO (XEXP (ad, 0)) == HARD_FRAME_POINTER_REGNUM
#endif
|| REGNO (XEXP (ad, 0)) == STACK_POINTER_REGNUM
|| REGNO (XEXP (ad, 0)) == ARG_POINTER_REGNUM
|| XEXP (ad, 0) == current_function_internal_arg_pointer)
&& GET_CODE (XEXP (ad, 1)) == CONST_INT)
{
rtx temp, seq;
if (memory_address_p (GET_MODE (x), ad))
return x;
start_sequence ();
temp = copy_to_reg (ad);
seq = gen_sequence ();
end_sequence ();
emit_insn_before (seq, insn);
return change_address (x, VOIDmode, temp);
}
return x;
}
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e')
XEXP (x, i) = fixup_stack_1 (XEXP (x, i), insn);
if (fmt[i] == 'E')
{
register int j;
for (j = 0; j < XVECLEN (x, i); j++)
XVECEXP (x, i, j) = fixup_stack_1 (XVECEXP (x, i, j), insn);
}
}
return x;
}
/* Optimization: a bit-field instruction whose field
happens to be a byte or halfword in memory
can be changed to a move instruction.
We call here when INSN is an insn to examine or store into a bit-field.
BODY is the SET-rtx to be altered.
EQUIV_MEM is the table `reg_equiv_mem' if that is available; else 0.
(Currently this is called only from function.c, and EQUIV_MEM
is always 0.) */
static void
optimize_bit_field (body, insn, equiv_mem)
rtx body;
rtx insn;
rtx *equiv_mem;
{
register rtx bitfield;
int destflag;
rtx seq = 0;
enum machine_mode mode;
if (GET_CODE (SET_DEST (body)) == SIGN_EXTRACT
|| GET_CODE (SET_DEST (body)) == ZERO_EXTRACT)
bitfield = SET_DEST (body), destflag = 1;
else
bitfield = SET_SRC (body), destflag = 0;
/* First check that the field being stored has constant size and position
and is in fact a byte or halfword suitably aligned. */
if (GET_CODE (XEXP (bitfield, 1)) == CONST_INT
&& GET_CODE (XEXP (bitfield, 2)) == CONST_INT
&& ((mode = mode_for_size (INTVAL (XEXP (bitfield, 1)), MODE_INT, 1))
!= BLKmode)
&& INTVAL (XEXP (bitfield, 2)) % INTVAL (XEXP (bitfield, 1)) == 0)
{
register rtx memref = 0;
/* Now check that the containing word is memory, not a register,
and that it is safe to change the machine mode. */
if (GET_CODE (XEXP (bitfield, 0)) == MEM)
memref = XEXP (bitfield, 0);
else if (GET_CODE (XEXP (bitfield, 0)) == REG
&& equiv_mem != 0)
memref = equiv_mem[REGNO (XEXP (bitfield, 0))];
else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
&& GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == MEM)
memref = SUBREG_REG (XEXP (bitfield, 0));
else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
&& equiv_mem != 0
&& GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == REG)
memref = equiv_mem[REGNO (SUBREG_REG (XEXP (bitfield, 0)))];
if (memref
&& ! mode_dependent_address_p (XEXP (memref, 0))
&& ! MEM_VOLATILE_P (memref))
{
/* Now adjust the address, first for any subreg'ing
that we are now getting rid of,
and then for which byte of the word is wanted. */
register int offset = INTVAL (XEXP (bitfield, 2));
rtx insns;
/* Adjust OFFSET to count bits from low-address byte. */
if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
offset = (GET_MODE_BITSIZE (GET_MODE (XEXP (bitfield, 0)))
- offset - INTVAL (XEXP (bitfield, 1)));
/* Adjust OFFSET to count bytes from low-address byte. */
offset /= BITS_PER_UNIT;
if (GET_CODE (XEXP (bitfield, 0)) == SUBREG)
{
offset += SUBREG_WORD (XEXP (bitfield, 0)) * UNITS_PER_WORD;
if (BYTES_BIG_ENDIAN)
offset -= (MIN (UNITS_PER_WORD,
GET_MODE_SIZE (GET_MODE (XEXP (bitfield, 0))))
- MIN (UNITS_PER_WORD,
GET_MODE_SIZE (GET_MODE (memref))));
}
start_sequence ();
memref = change_address (memref, mode,
plus_constant (XEXP (memref, 0), offset));
insns = get_insns ();
end_sequence ();
emit_insns_before (insns, insn);
/* Store this memory reference where
we found the bit field reference. */
if (destflag)
{
validate_change (insn, &SET_DEST (body), memref, 1);
if (! CONSTANT_ADDRESS_P (SET_SRC (body)))
{
rtx src = SET_SRC (body);
while (GET_CODE (src) == SUBREG
&& SUBREG_WORD (src) == 0)
src = SUBREG_REG (src);
if (GET_MODE (src) != GET_MODE (memref))
src = gen_lowpart (GET_MODE (memref), SET_SRC (body));
validate_change (insn, &SET_SRC (body), src, 1);
}
else if (GET_MODE (SET_SRC (body)) != VOIDmode
&& GET_MODE (SET_SRC (body)) != GET_MODE (memref))
/* This shouldn't happen because anything that didn't have
one of these modes should have got converted explicitly
and then referenced through a subreg.
This is so because the original bit-field was
handled by agg_mode and so its tree structure had
the same mode that memref now has. */
abort ();
}
else
{
rtx dest = SET_DEST (body);
while (GET_CODE (dest) == SUBREG
&& SUBREG_WORD (dest) == 0
&& (GET_MODE_CLASS (GET_MODE (dest))
== GET_MODE_CLASS (GET_MODE (SUBREG_REG (dest)))))
dest = SUBREG_REG (dest);
validate_change (insn, &SET_DEST (body), dest, 1);
if (GET_MODE (dest) == GET_MODE (memref))
validate_change (insn, &SET_SRC (body), memref, 1);
else
{
/* Convert the mem ref to the destination mode. */
rtx newreg = gen_reg_rtx (GET_MODE (dest));
start_sequence ();
convert_move (newreg, memref,
GET_CODE (SET_SRC (body)) == ZERO_EXTRACT);
seq = get_insns ();
end_sequence ();
validate_change (insn, &SET_SRC (body), newreg, 1);
}
}
/* See if we can convert this extraction or insertion into
a simple move insn. We might not be able to do so if this
was, for example, part of a PARALLEL.
If we succeed, write out any needed conversions. If we fail,
it is hard to guess why we failed, so don't do anything
special; just let the optimization be suppressed. */
if (apply_change_group () && seq)
emit_insns_before (seq, insn);
}
}
}
/* These routines are responsible for converting virtual register references
to the actual hard register references once RTL generation is complete.
The following four variables are used for communication between the
routines. They contain the offsets of the virtual registers from their
respective hard registers. */
static int in_arg_offset;
static int var_offset;
static int dynamic_offset;
static int out_arg_offset;
/* In most machines, the stack pointer register is equivalent to the bottom
of the stack. */
#ifndef STACK_POINTER_OFFSET
#define STACK_POINTER_OFFSET 0
#endif
/* If not defined, pick an appropriate default for the offset of dynamically
allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
#ifndef STACK_DYNAMIC_OFFSET
#ifdef ACCUMULATE_OUTGOING_ARGS
/* The bottom of the stack points to the actual arguments. If
REG_PARM_STACK_SPACE is defined, this includes the space for the register
parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
stack space for register parameters is not pushed by the caller, but
rather part of the fixed stack areas and hence not included in
`current_function_outgoing_args_size'. Nevertheless, we must allow
for it when allocating stack dynamic objects. */
#if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
#define STACK_DYNAMIC_OFFSET(FNDECL) \
(current_function_outgoing_args_size \
+ REG_PARM_STACK_SPACE (FNDECL) + (STACK_POINTER_OFFSET))
#else
#define STACK_DYNAMIC_OFFSET(FNDECL) \
(current_function_outgoing_args_size + (STACK_POINTER_OFFSET))
#endif
#else
#define STACK_DYNAMIC_OFFSET(FNDECL) STACK_POINTER_OFFSET
#endif
#endif
/* Build up a (MEM (ADDRESSOF (REG))) rtx for a register REG that just had
its address taken. DECL is the decl for the object stored in the
register, for later use if we do need to force REG into the stack.
REG is overwritten by the MEM like in put_reg_into_stack. */
rtx
gen_mem_addressof (reg, decl)
rtx reg;
tree decl;
{
tree type = TREE_TYPE (decl);
rtx r = gen_rtx (ADDRESSOF, Pmode, gen_reg_rtx (GET_MODE (reg)));
ADDRESSOF_REGNO (r) = REGNO (reg);
SET_ADDRESSOF_DECL (r, decl);
XEXP (reg, 0) = r;
PUT_CODE (reg, MEM);
PUT_MODE (reg, DECL_MODE (decl));
MEM_VOLATILE_P (reg) = TREE_SIDE_EFFECTS (decl);
MEM_IN_STRUCT_P (reg) = AGGREGATE_TYPE_P (type);
fixup_var_refs (reg, GET_MODE (reg), TREE_UNSIGNED (type));
return reg;
}
/* If DECL has an RTL that is an ADDRESSOF rtx, put it into the stack. */
void
flush_addressof (decl)
tree decl;
{
if ((TREE_CODE (decl) == PARM_DECL || TREE_CODE (decl) == VAR_DECL)
&& DECL_RTL (decl) != 0
&& GET_CODE (DECL_RTL (decl)) == MEM
&& GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF
&& GET_CODE (XEXP (XEXP (DECL_RTL (decl), 0), 0)) == REG)
put_addressof_into_stack (XEXP (DECL_RTL (decl), 0));
}
/* Force the register pointed to by R, an ADDRESSOF rtx, into the stack. */
static void
put_addressof_into_stack (r)
rtx r;
{
tree decl = ADDRESSOF_DECL (r);
rtx reg = XEXP (r, 0);
if (GET_CODE (reg) != REG)
abort ();
put_reg_into_stack (0, reg, TREE_TYPE (decl), GET_MODE (reg),
DECL_MODE (decl), TREE_SIDE_EFFECTS (decl),
ADDRESSOF_REGNO (r));
}
/* Helper function for purge_addressof. See if the rtx expression at *LOC
in INSN needs to be changed. If FORCE, always put any ADDRESSOFs into
the stack. */
static void
purge_addressof_1 (loc, insn, force)
rtx *loc;
rtx insn;
int force;
{
rtx x;
RTX_CODE code;
int i, j;
char *fmt;
/* Re-start here to avoid recursion in common cases. */
restart:
x = *loc;
if (x == 0)
return;
code = GET_CODE (x);
if (code == ADDRESSOF && GET_CODE (XEXP (x, 0)) == MEM)
{
rtx insns;
/* We must create a copy of the rtx because it was created by
overwriting a REG rtx which is always shared. */
rtx sub = copy_rtx (XEXP (XEXP (x, 0), 0));
if (validate_change (insn, loc, sub, 0))
return;
start_sequence ();
if (! validate_change (insn, loc,
force_operand (sub, NULL_RTX),
0))
abort ();
insns = get_insns ();
end_sequence ();
emit_insns_before (insns, insn);
return;
}
else if (code == MEM && GET_CODE (XEXP (x, 0)) == ADDRESSOF && ! force)
{
rtx sub = XEXP (XEXP (x, 0), 0);
if (GET_CODE (sub) == MEM)
sub = gen_rtx (MEM, GET_MODE (x), copy_rtx (XEXP (sub, 0)));
if (GET_CODE (sub) == REG && GET_MODE (x) != GET_MODE (sub))
{
if (! BYTES_BIG_ENDIAN && ! WORDS_BIG_ENDIAN)
{
rtx sub2 = gen_rtx (SUBREG, GET_MODE (x), sub, 0);
if (validate_change (insn, loc, sub2, 0))
goto restart;
}
}
else if (validate_change (insn, loc, sub, 0))
goto restart;
/* else give up and put it into the stack */
}
else if (code == ADDRESSOF)
{
put_addressof_into_stack (x);
return;
}
/* Scan all subexpressions. */
fmt = GET_RTX_FORMAT (code);
for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
{
if (*fmt == 'e')
purge_addressof_1 (&XEXP (x, i), insn, force);
else if (*fmt == 'E')
for (j = 0; j < XVECLEN (x, i); j++)
purge_addressof_1 (&XVECEXP (x, i, j), insn, force);
}
}
/* Eliminate all occurrences of ADDRESSOF from INSNS. Elide any remaining
(MEM (ADDRESSOF)) patterns, and force any needed registers into the
stack. */
void
purge_addressof (insns)
rtx insns;
{
rtx insn;
for (insn = insns; insn; insn = NEXT_INSN (insn))
if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
|| GET_CODE (insn) == CALL_INSN)
{
purge_addressof_1 (&PATTERN (insn), insn,
asm_noperands (PATTERN (insn)) > 0);
purge_addressof_1 (&REG_NOTES (insn), NULL_RTX, 0);
}
}
/* Pass through the INSNS of function FNDECL and convert virtual register
references to hard register references. */
void
instantiate_virtual_regs (fndecl, insns)
tree fndecl;
rtx insns;
{
rtx insn;
int i;
/* Compute the offsets to use for this function. */
in_arg_offset = FIRST_PARM_OFFSET (fndecl);
var_offset = STARTING_FRAME_OFFSET;
dynamic_offset = STACK_DYNAMIC_OFFSET (fndecl);
out_arg_offset = STACK_POINTER_OFFSET;
/* Scan all variables and parameters of this function. For each that is
in memory, instantiate all virtual registers if the result is a valid
address. If not, we do it later. That will handle most uses of virtual
regs on many machines. */
instantiate_decls (fndecl, 1);
/* Initialize recognition, indicating that volatile is OK. */
init_recog ();
/* Scan through all the insns, instantiating every virtual register still
present. */
for (insn = insns; insn; insn = NEXT_INSN (insn))
if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
|| GET_CODE (insn) == CALL_INSN)
{
instantiate_virtual_regs_1 (&PATTERN (insn), insn, 1);
instantiate_virtual_regs_1 (&REG_NOTES (insn), NULL_RTX, 0);
}
/* Instantiate the stack slots for the parm registers, for later use in
addressof elimination. */
for (i = 0; i < max_parm_reg; ++i)
if (parm_reg_stack_loc[i])
instantiate_virtual_regs_1 (&parm_reg_stack_loc[i], NULL_RTX, 0);
/* Now instantiate the remaining register equivalences for debugging info.
These will not be valid addresses. */
instantiate_decls (fndecl, 0);
/* Indicate that, from now on, assign_stack_local should use
frame_pointer_rtx. */
virtuals_instantiated = 1;
}
/* Scan all decls in FNDECL (both variables and parameters) and instantiate
all virtual registers in their DECL_RTL's.
If VALID_ONLY, do this only if the resulting address is still valid.
Otherwise, always do it. */
static void
instantiate_decls (fndecl, valid_only)
tree fndecl;
int valid_only;
{
tree decl;
if (DECL_SAVED_INSNS (fndecl))
/* When compiling an inline function, the obstack used for
rtl allocation is the maybepermanent_obstack. Calling
`resume_temporary_allocation' switches us back to that
obstack while we process this function's parameters. */
resume_temporary_allocation ();
/* Process all parameters of the function. */
for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
{
int size = int_size_in_bytes (TREE_TYPE (decl));
instantiate_decl (DECL_RTL (decl), size, valid_only);
/* If the parameter was promoted, then the incoming RTL mode may be
larger than the declared type size. We must use the larger of
the two sizes. */
size = MAX (GET_MODE_SIZE (GET_MODE (DECL_INCOMING_RTL (decl))), size);
instantiate_decl (DECL_INCOMING_RTL (decl), size, valid_only);
}
/* Now process all variables defined in the function or its subblocks. */
instantiate_decls_1 (DECL_INITIAL (fndecl), valid_only);
if (DECL_INLINE (fndecl) || DECL_DEFER_OUTPUT (fndecl))
{
/* Save all rtl allocated for this function by raising the
high-water mark on the maybepermanent_obstack. */
preserve_data ();
/* All further rtl allocation is now done in the current_obstack. */
rtl_in_current_obstack ();
}
}
/* Subroutine of instantiate_decls: Process all decls in the given
BLOCK node and all its subblocks. */
static void
instantiate_decls_1 (let, valid_only)
tree let;
int valid_only;
{
tree t;
for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
instantiate_decl (DECL_RTL (t), int_size_in_bytes (TREE_TYPE (t)),
valid_only);
/* Process all subblocks. */
for (t = BLOCK_SUBBLOCKS (let); t; t = TREE_CHAIN (t))
instantiate_decls_1 (t, valid_only);
}
/* Subroutine of the preceding procedures: Given RTL representing a
decl and the size of the object, do any instantiation required.
If VALID_ONLY is non-zero, it means that the RTL should only be
changed if the new address is valid. */
static void
instantiate_decl (x, size, valid_only)
rtx x;
int size;
int valid_only;
{
enum machine_mode mode;
rtx addr;
/* If this is not a MEM, no need to do anything. Similarly if the
address is a constant or a register that is not a virtual register. */
if (x == 0 || GET_CODE (x) != MEM)
return;
addr = XEXP (x, 0);
if (CONSTANT_P (addr)
|| (GET_CODE (addr) == ADDRESSOF && GET_CODE (XEXP (addr, 0)) == REG)
|| (GET_CODE (addr) == REG
&& (REGNO (addr) < FIRST_VIRTUAL_REGISTER
|| REGNO (addr) > LAST_VIRTUAL_REGISTER)))
return;
/* If we should only do this if the address is valid, copy the address.
We need to do this so we can undo any changes that might make the
address invalid. This copy is unfortunate, but probably can't be
avoided. */
if (valid_only)
addr = copy_rtx (addr);
instantiate_virtual_regs_1 (&addr, NULL_RTX, 0);
if (valid_only)
{
/* Now verify that the resulting address is valid for every integer or
floating-point mode up to and including SIZE bytes long. We do this
since the object might be accessed in any mode and frame addresses
are shared. */
for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
mode != VOIDmode && GET_MODE_SIZE (mode) <= size;
mode = GET_MODE_WIDER_MODE (mode))
if (! memory_address_p (mode, addr))
return;
for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
mode != VOIDmode && GET_MODE_SIZE (mode) <= size;
mode = GET_MODE_WIDER_MODE (mode))
if (! memory_address_p (mode, addr))
return;
}
/* Put back the address now that we have updated it and we either know
it is valid or we don't care whether it is valid. */
XEXP (x, 0) = addr;
}
/* Given a pointer to a piece of rtx and an optional pointer to the
containing object, instantiate any virtual registers present in it.
If EXTRA_INSNS, we always do the replacement and generate
any extra insns before OBJECT. If it zero, we do nothing if replacement
is not valid.
Return 1 if we either had nothing to do or if we were able to do the
needed replacement. Return 0 otherwise; we only return zero if
EXTRA_INSNS is zero.
We first try some simple transformations to avoid the creation of extra
pseudos. */
static int
instantiate_virtual_regs_1 (loc, object, extra_insns)
rtx *loc;
rtx object;
int extra_insns;
{
rtx x;
RTX_CODE code;
rtx new = 0;
int offset;
rtx temp;
rtx seq;
int i, j;
char *fmt;
/* Re-start here to avoid recursion in common cases. */
restart:
x = *loc;
if (x == 0)
return 1;
code = GET_CODE (x);
/* Check for some special cases. */
switch (code)
{
case CONST_INT:
case CONST_DOUBLE:
case CONST:
case SYMBOL_REF:
case CODE_LABEL:
case PC:
case CC0:
case ASM_INPUT:
case ADDR_VEC:
case ADDR_DIFF_VEC:
case RETURN:
return 1;
case SET:
/* We are allowed to set the virtual registers. This means that
that the actual register should receive the source minus the
appropriate offset. This is used, for example, in the handling
of non-local gotos. */
if (SET_DEST (x) == virtual_incoming_args_rtx)
new = arg_pointer_rtx, offset = - in_arg_offset;
else if (SET_DEST (x) == virtual_stack_vars_rtx)
new = frame_pointer_rtx, offset = - var_offset;
else if (SET_DEST (x) == virtual_stack_dynamic_rtx)
new = stack_pointer_rtx, offset = - dynamic_offset;
else if (SET_DEST (x) == virtual_outgoing_args_rtx)
new = stack_pointer_rtx, offset = - out_arg_offset;
if (new)
{
/* The only valid sources here are PLUS or REG. Just do
the simplest possible thing to handle them. */
if (GET_CODE (SET_SRC (x)) != REG
&& GET_CODE (SET_SRC (x)) != PLUS)
abort ();
start_sequence ();
if (GET_CODE (SET_SRC (x)) != REG)
temp = force_operand (SET_SRC (x), NULL_RTX);
else
temp = SET_SRC (x);
temp = force_operand (plus_constant (temp, offset), NULL_RTX);
seq = get_insns ();
end_sequence ();
emit_insns_before (seq, object);
SET_DEST (x) = new;
if (! validate_change (object, &SET_SRC (x), temp, 0)
|| ! extra_insns)
abort ();
return 1;
}
instantiate_virtual_regs_1 (&SET_DEST (x), object, extra_insns);
loc = &SET_SRC (x);
goto restart;
case PLUS:
/* Handle special case of virtual register plus constant. */
if (CONSTANT_P (XEXP (x, 1)))
{
rtx old, new_offset;
/* Check for (plus (plus VIRT foo) (const_int)) first. */
if (GET_CODE (XEXP (x, 0)) == PLUS)
{
rtx inner = XEXP (XEXP (x, 0), 0);
if (inner == virtual_incoming_args_rtx)
new = arg_pointer_rtx, offset = in_arg_offset;
else if (inner == virtual_stack_vars_rtx)
new = frame_pointer_rtx, offset = var_offset;
else if (inner == virtual_stack_dynamic_rtx)
new = stack_pointer_rtx, offset = dynamic_offset;
else if (inner == virtual_outgoing_args_rtx)
new = stack_pointer_rtx, offset = out_arg_offset;
else
{
loc = &XEXP (x, 0);
goto restart;
}
instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 1), object,
extra_insns);
new = gen_rtx (PLUS, Pmode, new, XEXP (XEXP (x, 0), 1));
}
else if (XEXP (x, 0) == virtual_incoming_args_rtx)
new = arg_pointer_rtx, offset = in_arg_offset;
else if (XEXP (x, 0) == virtual_stack_vars_rtx)
new = frame_pointer_rtx, offset = var_offset;
else if (XEXP (x, 0) == virtual_stack_dynamic_rtx)
new = stack_pointer_rtx, offset = dynamic_offset;
else if (XEXP (x, 0) == virtual_outgoing_args_rtx)
new = stack_pointer_rtx, offset = out_arg_offset;
else
{
/* We know the second operand is a constant. Unless the
first operand is a REG (which has been already checked),
it needs to be checked. */
if (GET_CODE (XEXP (x, 0)) != REG)
{
loc = &XEXP (x, 0);
goto restart;
}
return 1;
}
new_offset = plus_constant (XEXP (x, 1), offset);
/* If the new constant is zero, try to replace the sum with just
the register. */
if (new_offset == const0_rtx
&& validate_change (object, loc, new, 0))
return 1;
/* Next try to replace the register and new offset.
There are two changes to validate here and we can't assume that
in the case of old offset equals new just changing the register
will yield a valid insn. In the interests of a little efficiency,
however, we only call validate change once (we don't queue up the
changes and then call apply_change_group). */
old = XEXP (x, 0);
if (offset == 0
? ! validate_change (object, &XEXP (x, 0), new, 0)
: (XEXP (x, 0) = new,
! validate_change (object, &XEXP (x, 1), new_offset, 0)))
{
if (! extra_insns)
{
XEXP (x, 0) = old;
return 0;
}
/* Otherwise copy the new constant into a register and replace
constant with that register. */
temp = gen_reg_rtx (Pmode);
XEXP (x, 0) = new;
if (validate_change (object, &XEXP (x, 1), temp, 0))
emit_insn_before (gen_move_insn (temp, new_offset), object);
else
{
/* If that didn't work, replace this expression with a
register containing the sum. */
XEXP (x, 0) = old;
new = gen_rtx (PLUS, Pmode, new, new_offset);
start_sequence ();
temp = force_operand (new, NULL_RTX);
seq = get_insns ();
end_sequence ();
emit_insns_before (seq, object);
if (! validate_change (object, loc, temp, 0)
&& ! validate_replace_rtx (x, temp, object))
abort ();
}
}
return