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gnu / gcc / cd99b30c7cf1e68ef76ed2af7a41ac74c78116fe / . / gcc / rtlanal.c
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/* Analyze RTL for GNU compiler.
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "toplev.h"
#include "rtl.h"
#include "hard-reg-set.h"
#include "insn-config.h"
#include "recog.h"
#include "target.h"
#include "output.h"
#include "tm_p.h"
#include "flags.h"
#include "real.h"
#include "regs.h"
#include "function.h"
#include "df.h"
#include "tree.h"
/* Information about a subreg of a hard register. */
struct subreg_info
{
/* Offset of first hard register involved in the subreg. */
int offset;
/* Number of hard registers involved in the subreg. */
int nregs;
/* Whether this subreg can be represented as a hard reg with the new
mode. */
bool representable_p;
};
/* Forward declarations */
static void set_of_1 (rtx, const_rtx, void *);
static bool covers_regno_p (const_rtx, unsigned int);
static bool covers_regno_no_parallel_p (const_rtx, unsigned int);
static int rtx_referenced_p_1 (rtx *, void *);
static int computed_jump_p_1 (const_rtx);
static void parms_set (rtx, const_rtx, void *);
static void subreg_get_info (unsigned int, enum machine_mode,
unsigned int, enum machine_mode,
struct subreg_info *);
static unsigned HOST_WIDE_INT cached_nonzero_bits (const_rtx, enum machine_mode,
const_rtx, enum machine_mode,
unsigned HOST_WIDE_INT);
static unsigned HOST_WIDE_INT nonzero_bits1 (const_rtx, enum machine_mode,
const_rtx, enum machine_mode,
unsigned HOST_WIDE_INT);
static unsigned int cached_num_sign_bit_copies (const_rtx, enum machine_mode, const_rtx,
enum machine_mode,
unsigned int);
static unsigned int num_sign_bit_copies1 (const_rtx, enum machine_mode, const_rtx,
enum machine_mode, unsigned int);
/* Offset of the first 'e', 'E' or 'V' operand for each rtx code, or
-1 if a code has no such operand. */
static int non_rtx_starting_operands[NUM_RTX_CODE];
/* Bit flags that specify the machine subtype we are compiling for.
Bits are tested using macros TARGET_... defined in the tm.h file
and set by `-m...' switches. Must be defined in rtlanal.c. */
int target_flags;
/* Truncation narrows the mode from SOURCE mode to DESTINATION mode.
If TARGET_MODE_REP_EXTENDED (DESTINATION, DESTINATION_REP) is
SIGN_EXTEND then while narrowing we also have to enforce the
representation and sign-extend the value to mode DESTINATION_REP.
If the value is already sign-extended to DESTINATION_REP mode we
can just switch to DESTINATION mode on it. For each pair of
integral modes SOURCE and DESTINATION, when truncating from SOURCE
to DESTINATION, NUM_SIGN_BIT_COPIES_IN_REP[SOURCE][DESTINATION]
contains the number of high-order bits in SOURCE that have to be
copies of the sign-bit so that we can do this mode-switch to
DESTINATION. */
static unsigned int
num_sign_bit_copies_in_rep[MAX_MODE_INT + 1][MAX_MODE_INT + 1];
/* Return 1 if the value of X is unstable
(would be different at a different point in the program).
The frame pointer, arg pointer, etc. are considered stable
(within one function) and so is anything marked `unchanging'. */
int
rtx_unstable_p (const_rtx x)
{
const RTX_CODE code = GET_CODE (x);
int i;
const char *fmt;
switch (code)
{
case MEM:
return !MEM_READONLY_P (x) || rtx_unstable_p (XEXP (x, 0));
case CONST:
case CONST_INT:
case CONST_DOUBLE:
case CONST_FIXED:
case CONST_VECTOR:
case SYMBOL_REF:
case LABEL_REF:
return 0;
case REG:
/* As in rtx_varies_p, we have to use the actual rtx, not reg number. */
if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx
/* The arg pointer varies if it is not a fixed register. */
|| (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]))
return 0;
#ifndef PIC_OFFSET_TABLE_REG_CALL_CLOBBERED
/* ??? When call-clobbered, the value is stable modulo the restore
that must happen after a call. This currently screws up local-alloc
into believing that the restore is not needed. */
if (x == pic_offset_table_rtx)
return 0;
#endif
return 1;
case ASM_OPERANDS:
if (MEM_VOLATILE_P (x))
return 1;
/* Fall through. */
default:
break;
}
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
if (fmt[i] == 'e')
{
if (rtx_unstable_p (XEXP (x, i)))
return 1;
}
else if (fmt[i] == 'E')
{
int j;
for (j = 0; j < XVECLEN (x, i); j++)
if (rtx_unstable_p (XVECEXP (x, i, j)))
return 1;
}
return 0;
}
/* Return 1 if X has a value that can vary even between two
executions of the program. 0 means X can be compared reliably
against certain constants or near-constants.
FOR_ALIAS is nonzero if we are called from alias analysis; if it is
zero, we are slightly more conservative.
The frame pointer and the arg pointer are considered constant. */
bool
rtx_varies_p (const_rtx x, bool for_alias)
{
RTX_CODE code;
int i;
const char *fmt;
if (!x)
return 0;
code = GET_CODE (x);
switch (code)
{
case MEM:
return !MEM_READONLY_P (x) || rtx_varies_p (XEXP (x, 0), for_alias);
case CONST:
case CONST_INT:
case CONST_DOUBLE:
case CONST_FIXED:
case CONST_VECTOR:
case SYMBOL_REF:
case LABEL_REF:
return 0;
case REG:
/* Note that we have to test for the actual rtx used for the frame
and arg pointers and not just the register number in case we have
eliminated the frame and/or arg pointer and are using it
for pseudos. */
if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx
/* The arg pointer varies if it is not a fixed register. */
|| (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]))
return 0;
if (x == pic_offset_table_rtx
#ifdef PIC_OFFSET_TABLE_REG_CALL_CLOBBERED
/* ??? When call-clobbered, the value is stable modulo the restore
that must happen after a call. This currently screws up
local-alloc into believing that the restore is not needed, so we
must return 0 only if we are called from alias analysis. */
&& for_alias
#endif
)
return 0;
return 1;
case LO_SUM:
/* The operand 0 of a LO_SUM is considered constant
(in fact it is related specifically to operand 1)
during alias analysis. */
return (! for_alias && rtx_varies_p (XEXP (x, 0), for_alias))
|| rtx_varies_p (XEXP (x, 1), for_alias);
case ASM_OPERANDS:
if (MEM_VOLATILE_P (x))
return 1;
/* Fall through. */
default:
break;
}
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
if (fmt[i] == 'e')
{
if (rtx_varies_p (XEXP (x, i), for_alias))
return 1;
}
else if (fmt[i] == 'E')
{
int j;
for (j = 0; j < XVECLEN (x, i); j++)
if (rtx_varies_p (XVECEXP (x, i, j), for_alias))
return 1;
}
return 0;
}
/* Return nonzero if the use of X as an address in a MEM can cause a trap.
MODE is the mode of the MEM (not that of X) and UNALIGNED_MEMS controls
whether nonzero is returned for unaligned memory accesses on strict
alignment machines. */
static int
rtx_addr_can_trap_p_1 (const_rtx x, HOST_WIDE_INT offset, HOST_WIDE_INT size,
enum machine_mode mode, bool unaligned_mems)
{
enum rtx_code code = GET_CODE (x);
if (STRICT_ALIGNMENT
&& unaligned_mems
&& GET_MODE_SIZE (mode) != 0)
{
HOST_WIDE_INT actual_offset = offset;
#ifdef SPARC_STACK_BOUNDARY_HACK
/* ??? The SPARC port may claim a STACK_BOUNDARY higher than
the real alignment of %sp. However, when it does this, the
alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
if (SPARC_STACK_BOUNDARY_HACK
&& (x == stack_pointer_rtx || x == hard_frame_pointer_rtx))
actual_offset -= STACK_POINTER_OFFSET;
#endif
if (actual_offset % GET_MODE_SIZE (mode) != 0)
return 1;
}
switch (code)
{
case SYMBOL_REF:
if (SYMBOL_REF_WEAK (x))
return 1;
if (!CONSTANT_POOL_ADDRESS_P (x))
{
tree decl;
HOST_WIDE_INT decl_size;
if (offset < 0)
return 1;
if (size == 0)
size = GET_MODE_SIZE (mode);
if (size == 0)
return offset != 0;
/* If the size of the access or of the symbol is unknown,
assume the worst. */
decl = SYMBOL_REF_DECL (x);
/* Else check that the access is in bounds. TODO: restructure
expr_size/lhd_expr_size/int_expr_size and just use the latter. */
if (!decl)
decl_size = -1;
else if (DECL_P (decl) && DECL_SIZE_UNIT (decl))
decl_size = (host_integerp (DECL_SIZE_UNIT (decl), 0)
? tree_low_cst (DECL_SIZE_UNIT (decl), 0)
: -1);
else if (TREE_CODE (decl) == STRING_CST)
decl_size = TREE_STRING_LENGTH (decl);
else if (TYPE_SIZE_UNIT (TREE_TYPE (decl)))
decl_size = int_size_in_bytes (TREE_TYPE (decl));
else
decl_size = -1;
return (decl_size <= 0 ? offset != 0 : offset + size > decl_size);
}
return 0;
case LABEL_REF:
return 0;
case REG:
/* As in rtx_varies_p, we have to use the actual rtx, not reg number. */
if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx
|| x == stack_pointer_rtx
/* The arg pointer varies if it is not a fixed register. */
|| (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]))
return 0;
/* All of the virtual frame registers are stack references. */
if (REGNO (x) >= FIRST_VIRTUAL_REGISTER
&& REGNO (x) <= LAST_VIRTUAL_REGISTER)
return 0;
return 1;
case CONST:
return rtx_addr_can_trap_p_1 (XEXP (x, 0), offset, size,
mode, unaligned_mems);
case PLUS:
/* An address is assumed not to trap if:
- it is the pic register plus a constant. */
if (XEXP (x, 0) == pic_offset_table_rtx && CONSTANT_P (XEXP (x, 1)))
return 0;
/* - or it is an address that can't trap plus a constant integer,
with the proper remainder modulo the mode size if we are
considering unaligned memory references. */
if (GET_CODE (XEXP (x, 1)) == CONST_INT
&& !rtx_addr_can_trap_p_1 (XEXP (x, 0), offset + INTVAL (XEXP (x, 1)),
size, mode, unaligned_mems))
return 0;
return 1;
case LO_SUM:
case PRE_MODIFY:
return rtx_addr_can_trap_p_1 (XEXP (x, 1), offset, size,
mode, unaligned_mems);
case PRE_DEC:
case PRE_INC:
case POST_DEC:
case POST_INC:
case POST_MODIFY:
return rtx_addr_can_trap_p_1 (XEXP (x, 0), offset, size,
mode, unaligned_mems);
default:
break;
}
/* If it isn't one of the case above, it can cause a trap. */
return 1;
}
/* Return nonzero if the use of X as an address in a MEM can cause a trap. */
int
rtx_addr_can_trap_p (const_rtx x)
{
return rtx_addr_can_trap_p_1 (x, 0, 0, VOIDmode, false);
}
/* Return true if X is an address that is known to not be zero. */
bool
nonzero_address_p (const_rtx x)
{
const enum rtx_code code = GET_CODE (x);
switch (code)
{
case SYMBOL_REF:
return !SYMBOL_REF_WEAK (x);
case LABEL_REF:
return true;
case REG:
/* As in rtx_varies_p, we have to use the actual rtx, not reg number. */
if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx
|| x == stack_pointer_rtx
|| (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]))
return true;
/* All of the virtual frame registers are stack references. */
if (REGNO (x) >= FIRST_VIRTUAL_REGISTER
&& REGNO (x) <= LAST_VIRTUAL_REGISTER)
return true;
return false;
case CONST:
return nonzero_address_p (XEXP (x, 0));
case PLUS:
if (GET_CODE (XEXP (x, 1)) == CONST_INT)
return nonzero_address_p (XEXP (x, 0));
/* Handle PIC references. */
else if (XEXP (x, 0) == pic_offset_table_rtx
&& CONSTANT_P (XEXP (x, 1)))
return true;
return false;
case PRE_MODIFY:
/* Similar to the above; allow positive offsets. Further, since
auto-inc is only allowed in memories, the register must be a
pointer. */
if (GET_CODE (XEXP (x, 1)) == CONST_INT
&& INTVAL (XEXP (x, 1)) > 0)
return true;
return nonzero_address_p (XEXP (x, 0));
case PRE_INC:
/* Similarly. Further, the offset is always positive. */
return true;
case PRE_DEC:
case POST_DEC:
case POST_INC:
case POST_MODIFY:
return nonzero_address_p (XEXP (x, 0));
case LO_SUM:
return nonzero_address_p (XEXP (x, 1));
default:
break;
}
/* If it isn't one of the case above, might be zero. */
return false;
}
/* Return 1 if X refers to a memory location whose address
cannot be compared reliably with constant addresses,
or if X refers to a BLKmode memory object.
FOR_ALIAS is nonzero if we are called from alias analysis; if it is
zero, we are slightly more conservative. */
bool
rtx_addr_varies_p (const_rtx x, bool for_alias)
{
enum rtx_code code;
int i;
const char *fmt;
if (x == 0)
return 0;
code = GET_CODE (x);
if (code == MEM)
return GET_MODE (x) == BLKmode || rtx_varies_p (XEXP (x, 0), for_alias);
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
if (fmt[i] == 'e')
{
if (rtx_addr_varies_p (XEXP (x, i), for_alias))
return 1;
}
else if (fmt[i] == 'E')
{
int j;
for (j = 0; j < XVECLEN (x, i); j++)
if (rtx_addr_varies_p (XVECEXP (x, i, j), for_alias))
return 1;
}
return 0;
}
/* Return the value of the integer term in X, if one is apparent;
otherwise return 0.
Only obvious integer terms are detected.
This is used in cse.c with the `related_value' field. */
HOST_WIDE_INT
get_integer_term (const_rtx x)
{
if (GET_CODE (x) == CONST)
x = XEXP (x, 0);
if (GET_CODE (x) == MINUS
&& GET_CODE (XEXP (x, 1)) == CONST_INT)
return - INTVAL (XEXP (x, 1));
if (GET_CODE (x) == PLUS
&& GET_CODE (XEXP (x, 1)) == CONST_INT)
return INTVAL (XEXP (x, 1));
return 0;
}
/* If X is a constant, return the value sans apparent integer term;
otherwise return 0.
Only obvious integer terms are detected. */
rtx
get_related_value (const_rtx x)
{
if (GET_CODE (x) != CONST)
return 0;
x = XEXP (x, 0);
if (GET_CODE (x) == PLUS
&& GET_CODE (XEXP (x, 1)) == CONST_INT)
return XEXP (x, 0);
else if (GET_CODE (x) == MINUS
&& GET_CODE (XEXP (x, 1)) == CONST_INT)
return XEXP (x, 0);
return 0;
}
/* Return true if SYMBOL is a SYMBOL_REF and OFFSET + SYMBOL points
to somewhere in the same object or object_block as SYMBOL. */
bool
offset_within_block_p (const_rtx symbol, HOST_WIDE_INT offset)
{
tree decl;
if (GET_CODE (symbol) != SYMBOL_REF)
return false;
if (offset == 0)
return true;
if (offset > 0)
{
if (CONSTANT_POOL_ADDRESS_P (symbol)
&& offset < (int) GET_MODE_SIZE (get_pool_mode (symbol)))
return true;
decl = SYMBOL_REF_DECL (symbol);
if (decl && offset < int_size_in_bytes (TREE_TYPE (decl)))
return true;
}
if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol)
&& SYMBOL_REF_BLOCK (symbol)
&& SYMBOL_REF_BLOCK_OFFSET (symbol) >= 0
&& ((unsigned HOST_WIDE_INT) offset + SYMBOL_REF_BLOCK_OFFSET (symbol)
< (unsigned HOST_WIDE_INT) SYMBOL_REF_BLOCK (symbol)->size))
return true;
return false;
}
/* Split X into a base and a constant offset, storing them in *BASE_OUT
and *OFFSET_OUT respectively. */
void
split_const (rtx x, rtx *base_out, rtx *offset_out)
{
if (GET_CODE (x) == CONST)
{
x = XEXP (x, 0);
if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == CONST_INT)
{
*base_out = XEXP (x, 0);
*offset_out = XEXP (x, 1);
return;
}
}
*base_out = x;
*offset_out = const0_rtx;
}
/* Return the number of places FIND appears within X. If COUNT_DEST is
zero, we do not count occurrences inside the destination of a SET. */
int
count_occurrences (const_rtx x, const_rtx find, int count_dest)
{
int i, j;
enum rtx_code code;
const char *format_ptr;
int count;
if (x == find)
return 1;
code = GET_CODE (x);
switch (code)
{
case REG:
case CONST_INT:
case CONST_DOUBLE:
case CONST_FIXED:
case CONST_VECTOR:
case SYMBOL_REF:
case CODE_LABEL:
case PC:
case CC0:
return 0;
case EXPR_LIST:
count = count_occurrences (XEXP (x, 0), find, count_dest);
if (XEXP (x, 1))
count += count_occurrences (XEXP (x, 1), find, count_dest);
return count;
case MEM:
if (MEM_P (find) && rtx_equal_p (x, find))
return 1;
break;
case SET:
if (SET_DEST (x) == find && ! count_dest)
return count_occurrences (SET_SRC (x), find, count_dest);
break;
default:
break;
}
format_ptr = GET_RTX_FORMAT (code);
count = 0;
for (i = 0; i < GET_RTX_LENGTH (code); i++)
{
switch (*format_ptr++)
{
case 'e':
count += count_occurrences (XEXP (x, i), find, count_dest);
break;
case 'E':
for (j = 0; j < XVECLEN (x, i); j++)
count += count_occurrences (XVECEXP (x, i, j), find, count_dest);
break;
}
}
return count;
}
/* Nonzero if register REG appears somewhere within IN.
Also works if REG is not a register; in this case it checks
for a subexpression of IN that is Lisp "equal" to REG. */
int
reg_mentioned_p (const_rtx reg, const_rtx in)
{
const char *fmt;
int i;
enum rtx_code code;
if (in == 0)
return 0;
if (reg == in)
return 1;
if (GET_CODE (in) == LABEL_REF)
return reg == XEXP (in, 0);
code = GET_CODE (in);
switch (code)
{
/* Compare registers by number. */
case REG:
return REG_P (reg) && REGNO (in) == REGNO (reg);
/* These codes have no constituent expressions
and are unique. */
case SCRATCH:
case CC0:
case PC:
return 0;
case CONST_INT:
case CONST_VECTOR:
case CONST_DOUBLE:
case CONST_FIXED:
/* These are kept unique for a given value. */
return 0;
default:
break;
}
if (GET_CODE (reg) == code && rtx_equal_p (reg, in))
return 1;
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'E')
{
int j;
for (j = XVECLEN (in, i) - 1; j >= 0; j--)
if (reg_mentioned_p (reg, XVECEXP (in, i, j)))
return 1;
}
else if (fmt[i] == 'e'
&& reg_mentioned_p (reg, XEXP (in, i)))
return 1;
}
return 0;
}
/* Return 1 if in between BEG and END, exclusive of BEG and END, there is
no CODE_LABEL insn. */
int
no_labels_between_p (const_rtx beg, const_rtx end)
{
rtx p;
if (beg == end)
return 0;
for (p = NEXT_INSN (beg); p != end; p = NEXT_INSN (p))
if (LABEL_P (p))
return 0;
return 1;
}
/* Nonzero if register REG is used in an insn between
FROM_INSN and TO_INSN (exclusive of those two). */
int
reg_used_between_p (const_rtx reg, const_rtx from_insn, const_rtx to_insn)
{
rtx insn;
if (from_insn == to_insn)
return 0;
for (insn = NEXT_INSN (from_insn); insn != to_insn; insn = NEXT_INSN (insn))
if (INSN_P (insn)
&& (reg_overlap_mentioned_p (reg, PATTERN (insn))
|| (CALL_P (insn) && find_reg_fusage (insn, USE, reg))))
return 1;
return 0;
}
/* Nonzero if the old value of X, a register, is referenced in BODY. If X
is entirely replaced by a new value and the only use is as a SET_DEST,
we do not consider it a reference. */
int
reg_referenced_p (const_rtx x, const_rtx body)
{
int i;
switch (GET_CODE (body))
{
case SET:
if (reg_overlap_mentioned_p (x, SET_SRC (body)))
return 1;
/* If the destination is anything other than CC0, PC, a REG or a SUBREG
of a REG that occupies all of the REG, the insn references X if
it is mentioned in the destination. */
if (GET_CODE (SET_DEST (body)) != CC0
&& GET_CODE (SET_DEST (body)) != PC
&& !REG_P (SET_DEST (body))
&& ! (GET_CODE (SET_DEST (body)) == SUBREG
&& REG_P (SUBREG_REG (SET_DEST (body)))
&& (((GET_MODE_SIZE (GET_MODE (SUBREG_REG (SET_DEST (body))))
+ (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
== ((GET_MODE_SIZE (GET_MODE (SET_DEST (body)))
+ (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)))
&& reg_overlap_mentioned_p (x, SET_DEST (body)))
return 1;
return 0;
case ASM_OPERANDS:
for (i = ASM_OPERANDS_INPUT_LENGTH (body) - 1; i >= 0; i--)
if (reg_overlap_mentioned_p (x, ASM_OPERANDS_INPUT (body, i)))
return 1;
return 0;
case CALL:
case USE:
case IF_THEN_ELSE:
return reg_overlap_mentioned_p (x, body);
case TRAP_IF:
return reg_overlap_mentioned_p (x, TRAP_CONDITION (body));
case PREFETCH:
return reg_overlap_mentioned_p (x, XEXP (body, 0));
case UNSPEC:
case UNSPEC_VOLATILE:
for (i = XVECLEN (body, 0) - 1; i >= 0; i--)
if (reg_overlap_mentioned_p (x, XVECEXP (body, 0, i)))
return 1;
return 0;
case PARALLEL:
for (i = XVECLEN (body, 0) - 1; i >= 0; i--)
if (reg_referenced_p (x, XVECEXP (body, 0, i)))
return 1;
return 0;
case CLOBBER:
if (MEM_P (XEXP (body, 0)))
if (reg_overlap_mentioned_p (x, XEXP (XEXP (body, 0), 0)))
return 1;
return 0;
case COND_EXEC:
if (reg_overlap_mentioned_p (x, COND_EXEC_TEST (body)))
return 1;
return reg_referenced_p (x, COND_EXEC_CODE (body));
default:
return 0;
}
}
/* Nonzero if register REG is set or clobbered in an insn between
FROM_INSN and TO_INSN (exclusive of those two). */
int
reg_set_between_p (const_rtx reg, const_rtx from_insn, const_rtx to_insn)
{
const_rtx insn;
if (from_insn == to_insn)
return 0;
for (insn = NEXT_INSN (from_insn); insn != to_insn; insn = NEXT_INSN (insn))
if (INSN_P (insn) && reg_set_p (reg, insn))
return 1;
return 0;
}
/* Internals of reg_set_between_p. */
int
reg_set_p (const_rtx reg, const_rtx insn)
{
/* We can be passed an insn or part of one. If we are passed an insn,
check if a side-effect of the insn clobbers REG. */
if (INSN_P (insn)
&& (FIND_REG_INC_NOTE (insn, reg)
|| (CALL_P (insn)
&& ((REG_P (reg)
&& REGNO (reg) < FIRST_PSEUDO_REGISTER
&& overlaps_hard_reg_set_p (regs_invalidated_by_call,
GET_MODE (reg), REGNO (reg)))
|| MEM_P (reg)
|| find_reg_fusage (insn, CLOBBER, reg)))))
return 1;
return set_of (reg, insn) != NULL_RTX;
}
/* Similar to reg_set_between_p, but check all registers in X. Return 0
only if none of them are modified between START and END. Return 1 if
X contains a MEM; this routine does use memory aliasing. */
int
modified_between_p (const_rtx x, const_rtx start, const_rtx end)
{
const enum rtx_code code = GET_CODE (x);
const char *fmt;
int i, j;
rtx insn;
if (start == end)
return 0;
switch (code)
{
case CONST_INT:
case CONST_DOUBLE:
case CONST_FIXED:
case CONST_VECTOR:
case CONST:
case SYMBOL_REF:
case LABEL_REF:
return 0;
case PC:
case CC0:
return 1;
case MEM:
if (modified_between_p (XEXP (x, 0), start, end))
return 1;
if (MEM_READONLY_P (x))
return 0;
for (insn = NEXT_INSN (start); insn != end; insn = NEXT_INSN (insn))
if (memory_modified_in_insn_p (x, insn))
return 1;
return 0;
break;
case REG:
return reg_set_between_p (x, start, end);
default:
break;
}
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e' && modified_between_p (XEXP (x, i), start, end))
return 1;
else if (fmt[i] == 'E')
for (j = XVECLEN (x, i) - 1; j >= 0; j--)
if (modified_between_p (XVECEXP (x, i, j), start, end))
return 1;
}
return 0;
}
/* Similar to reg_set_p, but check all registers in X. Return 0 only if none
of them are modified in INSN. Return 1 if X contains a MEM; this routine
does use memory aliasing. */
int
modified_in_p (const_rtx x, const_rtx insn)
{
const enum rtx_code code = GET_CODE (x);
const char *fmt;
int i, j;
switch (code)
{
case CONST_INT:
case CONST_DOUBLE:
case CONST_FIXED:
case CONST_VECTOR:
case CONST:
case SYMBOL_REF:
case LABEL_REF:
return 0;
case PC:
case CC0:
return 1;
case MEM:
if (modified_in_p (XEXP (x, 0), insn))
return 1;
if (MEM_READONLY_P (x))
return 0;
if (memory_modified_in_insn_p (x, insn))
return 1;
return 0;
break;
case REG:
return reg_set_p (x, insn);
default:
break;
}
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e' && modified_in_p (XEXP (x, i), insn))
return 1;
else if (fmt[i] == 'E')
for (j = XVECLEN (x, i) - 1; j >= 0; j--)
if (modified_in_p (XVECEXP (x, i, j), insn))
return 1;
}
return 0;
}
/* Helper function for set_of. */
struct set_of_data
{
const_rtx found;
const_rtx pat;
};
static void
set_of_1 (rtx x, const_rtx pat, void *data1)
{
struct set_of_data *const data = (struct set_of_data *) (data1);
if (rtx_equal_p (x, data->pat)
|| (!MEM_P (x) && reg_overlap_mentioned_p (data->pat, x)))
data->found = pat;
}
/* Give an INSN, return a SET or CLOBBER expression that does modify PAT
(either directly or via STRICT_LOW_PART and similar modifiers). */
const_rtx
set_of (const_rtx pat, const_rtx insn)
{
struct set_of_data data;
data.found = NULL_RTX;
data.pat = pat;
note_stores (INSN_P (insn) ? PATTERN (insn) : insn, set_of_1, &data);
return data.found;
}
/* Given an INSN, return a SET expression if this insn has only a single SET.
It may also have CLOBBERs, USEs, or SET whose output
will not be used, which we ignore. */
rtx
single_set_2 (const_rtx insn, const_rtx pat)
{
rtx set = NULL;
int set_verified = 1;
int i;
if (GET_CODE (pat) == PARALLEL)
{
for (i = 0; i < XVECLEN (pat, 0); i++)
{
rtx sub = XVECEXP (pat, 0, i);
switch (GET_CODE (sub))
{
case USE:
case CLOBBER:
break;
case SET:
/* We can consider insns having multiple sets, where all
but one are dead as single set insns. In common case
only single set is present in the pattern so we want
to avoid checking for REG_UNUSED notes unless necessary.
When we reach set first time, we just expect this is
the single set we are looking for and only when more
sets are found in the insn, we check them. */
if (!set_verified)
{
if (find_reg_note (insn, REG_UNUSED, SET_DEST (set))
&& !side_effects_p (set))
set = NULL;
else
set_verified = 1;
}
if (!set)
set = sub, set_verified = 0;
else if (!find_reg_note (insn, REG_UNUSED, SET_DEST (sub))
|| side_effects_p (sub))
return NULL_RTX;
break;
default:
return NULL_RTX;
}
}
}
return set;
}
/* Given an INSN, return nonzero if it has more than one SET, else return
zero. */
int
multiple_sets (const_rtx insn)
{
int found;
int i;
/* INSN must be an insn. */
if (! INSN_P (insn))
return 0;
/* Only a PARALLEL can have multiple SETs. */
if (GET_CODE (PATTERN (insn)) == PARALLEL)
{
for (i = 0, found = 0; i < XVECLEN (PATTERN (insn), 0); i++)
if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == SET)
{
/* If we have already found a SET, then return now. */
if (found)
return 1;
else
found = 1;
}
}
/* Either zero or one SET. */
return 0;
}
/* Return nonzero if the destination of SET equals the source
and there are no side effects. */
int
set_noop_p (const_rtx set)
{
rtx src = SET_SRC (set);
rtx dst = SET_DEST (set);
if (dst == pc_rtx && src == pc_rtx)
return 1;
if (MEM_P (dst) && MEM_P (src))
return rtx_equal_p (dst, src) && !side_effects_p (dst);
if (GET_CODE (dst) == ZERO_EXTRACT)
return rtx_equal_p (XEXP (dst, 0), src)
&& ! BYTES_BIG_ENDIAN && XEXP (dst, 2) == const0_rtx
&& !side_effects_p (src);
if (GET_CODE (dst) == STRICT_LOW_PART)
dst = XEXP (dst, 0);
if (GET_CODE (src) == SUBREG && GET_CODE (dst) == SUBREG)
{
if (SUBREG_BYTE (src) != SUBREG_BYTE (dst))
return 0;
src = SUBREG_REG (src);
dst = SUBREG_REG (dst);
}
return (REG_P (src) && REG_P (dst)
&& REGNO (src) == REGNO (dst));
}
/* Return nonzero if an insn consists only of SETs, each of which only sets a
value to itself. */
int
noop_move_p (const_rtx insn)
{
rtx pat = PATTERN (insn);
if (INSN_CODE (insn) == NOOP_MOVE_INSN_CODE)
return 1;
/* Insns carrying these notes are useful later on. */
if (find_reg_note (insn, REG_EQUAL, NULL_RTX))
return 0;
if (GET_CODE (pat) == SET && set_noop_p (pat))
return 1;
if (GET_CODE (pat) == PARALLEL)
{
int i;
/* If nothing but SETs of registers to themselves,
this insn can also be deleted. */
for (i = 0; i < XVECLEN (pat, 0); i++)
{
rtx tem = XVECEXP (pat, 0, i);
if (GET_CODE (tem) == USE
|| GET_CODE (tem) == CLOBBER)
continue;
if (GET_CODE (tem) != SET || ! set_noop_p (tem))
return 0;
}
return 1;
}
return 0;
}
/* Return the last thing that X was assigned from before *PINSN. If VALID_TO
is not NULL_RTX then verify that the object is not modified up to VALID_TO.
If the object was modified, if we hit a partial assignment to X, or hit a
CODE_LABEL first, return X. If we found an assignment, update *PINSN to
point to it. ALLOW_HWREG is set to 1 if hardware registers are allowed to
be the src. */
rtx
find_last_value (rtx x, rtx *pinsn, rtx valid_to, int allow_hwreg)
{
rtx p;
for (p = PREV_INSN (*pinsn); p && !LABEL_P (p);
p = PREV_INSN (p))
if (INSN_P (p))
{
rtx set = single_set (p);
rtx note = find_reg_note (p, REG_EQUAL, NULL_RTX);
if (set && rtx_equal_p (x, SET_DEST (set)))
{
rtx src = SET_SRC (set);
if (note && GET_CODE (XEXP (note, 0)) != EXPR_LIST)
src = XEXP (note, 0);
if ((valid_to == NULL_RTX
|| ! modified_between_p (src, PREV_INSN (p), valid_to))
/* Reject hard registers because we don't usually want
to use them; we'd rather use a pseudo. */
&& (! (REG_P (src)
&& REGNO (src) < FIRST_PSEUDO_REGISTER) || allow_hwreg))
{
*pinsn = p;
return src;
}
}
/* If set in non-simple way, we don't have a value. */
if (reg_set_p (x, p))
break;
}
return x;
}
/* Return nonzero if register in range [REGNO, ENDREGNO)
appears either explicitly or implicitly in X
other than being stored into.
References contained within the substructure at LOC do not count.
LOC may be zero, meaning don't ignore anything. */
int
refers_to_regno_p (unsigned int regno, unsigned int endregno, const_rtx x,
rtx *loc)
{
int i;
unsigned int x_regno;
RTX_CODE code;
const char *fmt;
repeat:
/* The contents of a REG_NONNEG note is always zero, so we must come here
upon repeat in case the last REG_NOTE is a REG_NONNEG note. */
if (x == 0)
return 0;
code = GET_CODE (x);
switch (code)
{
case REG:
x_regno = REGNO (x);
/* If we modifying the stack, frame, or argument pointer, it will
clobber a virtual register. In fact, we could be more precise,
but it isn't worth it. */
if ((x_regno == STACK_POINTER_REGNUM
#if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
|| x_regno == ARG_POINTER_REGNUM
#endif
|| x_regno == FRAME_POINTER_REGNUM)
&& regno >= FIRST_VIRTUAL_REGISTER && regno <= LAST_VIRTUAL_REGISTER)
return 1;
return endregno > x_regno && regno < END_REGNO (x);
case SUBREG:
/* If this is a SUBREG of a hard reg, we can see exactly which
registers are being modified. Otherwise, handle normally. */
if (REG_P (SUBREG_REG (x))
&& REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER)
{
unsigned int inner_regno = subreg_regno (x);
unsigned int inner_endregno
= inner_regno + (inner_regno < FIRST_PSEUDO_REGISTER
? subreg_nregs (x) : 1);
return endregno > inner_regno && regno < inner_endregno;
}
break;
case CLOBBER:
case SET:
if (&SET_DEST (x) != loc
/* Note setting a SUBREG counts as referring to the REG it is in for
a pseudo but not for hard registers since we can
treat each word individually. */
&& ((GET_CODE (SET_DEST (x)) == SUBREG
&& loc != &SUBREG_REG (SET_DEST (x))
&& REG_P (SUBREG_REG (SET_DEST (x)))
&& REGNO (SUBREG_REG (SET_DEST (x))) >= FIRST_PSEUDO_REGISTER
&& refers_to_regno_p (regno, endregno,
SUBREG_REG (SET_DEST (x)), loc))
|| (!REG_P (SET_DEST (x))
&& refers_to_regno_p (regno, endregno, SET_DEST (x), loc))))
return 1;
if (code == CLOBBER || loc == &SET_SRC (x))
return 0;
x = SET_SRC (x);
goto repeat;
default:
break;
}
/* X does not match, so try its subexpressions. */
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e' && loc != &XEXP (x, i))
{
if (i == 0)
{
x = XEXP (x, 0);
goto repeat;
}
else
if (refers_to_regno_p (regno, endregno, XEXP (x, i), loc))
return 1;
}
else if (fmt[i] == 'E')
{
int j;
for (j = XVECLEN (x, i) - 1; j >= 0; j--)
if (loc != &XVECEXP (x, i, j)
&& refers_to_regno_p (regno, endregno, XVECEXP (x, i, j), loc))
return 1;
}
}
return 0;
}
/* Nonzero if modifying X will affect IN. If X is a register or a SUBREG,
we check if any register number in X conflicts with the relevant register
numbers. If X is a constant, return 0. If X is a MEM, return 1 iff IN
contains a MEM (we don't bother checking for memory addresses that can't
conflict because we expect this to be a rare case. */
int
reg_overlap_mentioned_p (const_rtx x, const_rtx in)
{
unsigned int regno, endregno;
/* If either argument is a constant, then modifying X can not
affect IN. Here we look at IN, we can profitably combine
CONSTANT_P (x) with the switch statement below. */
if (CONSTANT_P (in))
return 0;
recurse:
switch (GET_CODE (x))
{
case STRICT_LOW_PART:
case ZERO_EXTRACT:
case SIGN_EXTRACT:
/* Overly conservative. */
x = XEXP (x, 0);
goto recurse;
case SUBREG:
regno = REGNO (SUBREG_REG (x));
if (regno < FIRST_PSEUDO_REGISTER)
regno = subreg_regno (x);
endregno = regno + (regno < FIRST_PSEUDO_REGISTER
? subreg_nregs (x) : 1);
goto do_reg;
case REG:
regno = REGNO (x);
endregno = END_REGNO (x);
do_reg:
return refers_to_regno_p (regno, endregno, in, (rtx*) 0);
case MEM:
{
const char *fmt;
int i;
if (MEM_P (in))
return 1;
fmt = GET_RTX_FORMAT (GET_CODE (in));
for (i = GET_RTX_LENGTH (GET_CODE (in)) - 1; i >= 0; i--)
if (fmt[i] == 'e')
{
if (reg_overlap_mentioned_p (x, XEXP (in, i)))
return 1;
}
else if (fmt[i] == 'E')
{
int j;
for (j = XVECLEN (in, i) - 1; j >= 0; --j)
if (reg_overlap_mentioned_p (x, XVECEXP (in, i, j)))
return 1;
}
return 0;
}
case SCRATCH:
case PC:
case CC0:
return reg_mentioned_p (x, in);
case PARALLEL:
{
int i;
/* If any register in here refers to it we return true. */
for (i = XVECLEN (x, 0) - 1; i >= 0; i--)
if (XEXP (XVECEXP (x, 0, i), 0) != 0
&& reg_overlap_mentioned_p (XEXP (XVECEXP (x, 0, i), 0), in))
return 1;
return 0;
}
default:
gcc_assert (CONSTANT_P (x));
return 0;
}
}
/* Call FUN on each register or MEM that is stored into or clobbered by X.
(X would be the pattern of an insn). DATA is an arbitrary pointer,
ignored by note_stores, but passed to FUN.
FUN receives three arguments:
1. the REG, MEM, CC0 or PC being stored in or clobbered,
2. the SET or CLOBBER rtx that does the store,
3. the pointer DATA provided to note_stores.
If the item being stored in or clobbered is a SUBREG of a hard register,
the SUBREG will be passed. */
void
note_stores (const_rtx x, void (*fun) (rtx, const_rtx, void *), void *data)
{
int i;
if (GET_CODE (x) == COND_EXEC)
x = COND_EXEC_CODE (x);
if (GET_CODE (x) == SET || GET_CODE (x) == CLOBBER)
{
rtx dest = SET_DEST (x);
while ((GET_CODE (dest) == SUBREG
&& (!REG_P (SUBREG_REG (dest))
|| REGNO (SUBREG_REG (dest)) >= FIRST_PSEUDO_REGISTER))
|| GET_CODE (dest) == ZERO_EXTRACT
|| GET_CODE (dest) == STRICT_LOW_PART)
dest = XEXP (dest, 0);
/* If we have a PARALLEL, SET_DEST is a list of EXPR_LIST expressions,
each of whose first operand is a register. */
if (GET_CODE (dest) == PARALLEL)
{
for (i = XVECLEN (dest, 0) - 1; i >= 0; i--)
if (XEXP (XVECEXP (dest, 0, i), 0) != 0)
(*fun) (XEXP (XVECEXP (dest, 0, i), 0), x, data);
}
else
(*fun) (dest, x, data);
}
else if (GET_CODE (x) == PARALLEL)
for (i = XVECLEN (x, 0) - 1; i >= 0; i--)
note_stores (XVECEXP (x, 0, i), fun, data);
}
/* Like notes_stores, but call FUN for each expression that is being
referenced in PBODY, a pointer to the PATTERN of an insn. We only call
FUN for each expression, not any interior subexpressions. FUN receives a
pointer to the expression and the DATA passed to this function.
Note that this is not quite the same test as that done in reg_referenced_p
since that considers something as being referenced if it is being
partially set, while we do not. */
void
note_uses (rtx *pbody, void (*fun) (rtx *, void *), void *data)
{
rtx body = *pbody;
int i;
switch (GET_CODE (body))
{
case COND_EXEC:
(*fun) (&COND_EXEC_TEST (body), data);
note_uses (&COND_EXEC_CODE (body), fun, data);
return;
case PARALLEL:
for (i = XVECLEN (body, 0) - 1; i >= 0; i--)
note_uses (&XVECEXP (body, 0, i), fun, data);
return;
case SEQUENCE:
for (i = XVECLEN (body, 0) - 1; i >= 0; i--)
note_uses (&PATTERN (XVECEXP (body, 0, i)), fun, data);
return;
case USE:
(*fun) (&XEXP (body, 0), data);
return;
case ASM_OPERANDS:
for (i = ASM_OPERANDS_INPUT_LENGTH (body) - 1; i >= 0; i--)
(*fun) (&ASM_OPERANDS_INPUT (body, i), data);
return;
case TRAP_IF:
(*fun) (&TRAP_CONDITION (body), data);
return;
case PREFETCH:
(*fun) (&XEXP (body, 0), data);
return;
case UNSPEC:
case UNSPEC_VOLATILE:
for (i = XVECLEN (body, 0) - 1; i >= 0; i--)
(*fun) (&XVECEXP (body, 0, i), data);
return;
case CLOBBER:
if (MEM_P (XEXP (body, 0)))
(*fun) (&XEXP (XEXP (body, 0), 0), data);
return;
case SET:
{
rtx dest = SET_DEST (body);
/* For sets we replace everything in source plus registers in memory
expression in store and operands of a ZERO_EXTRACT. */
(*fun) (&SET_SRC (body), data);
if (GET_CODE (dest) == ZERO_EXTRACT)
{
(*fun) (&XEXP (dest, 1), data);
(*fun) (&XEXP (dest, 2), data);
}
while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART)
dest = XEXP (dest, 0);
if (MEM_P (dest))
(*fun) (&XEXP (dest, 0), data);
}
return;
default:
/* All the other possibilities never store. */
(*fun) (pbody, data);
return;
}
}
/* Return nonzero if X's old contents don't survive after INSN.
This will be true if X is (cc0) or if X is a register and
X dies in INSN or because INSN entirely sets X.
"Entirely set" means set directly and not through a SUBREG, or
ZERO_EXTRACT, so no trace of the old contents remains.
Likewise, REG_INC does not count.
REG may be a hard or pseudo reg. Renumbering is not taken into account,
but for this use that makes no difference, since regs don't overlap
during their lifetimes. Therefore, this function may be used
at any time after deaths have been computed.
If REG is a hard reg that occupies multiple machine registers, this
function will only return 1 if each of those registers will be replaced
by INSN. */
int
dead_or_set_p (const_rtx insn, const_rtx x)
{
unsigned int regno, end_regno;
unsigned int i;
/* Can't use cc0_rtx below since this file is used by genattrtab.c. */
if (GET_CODE (x) == CC0)
return 1;
gcc_assert (REG_P (x));
regno = REGNO (x);
end_regno = END_REGNO (x);
for (i = regno; i < end_regno; i++)
if (! dead_or_set_regno_p (insn, i))
return 0;
return 1;
}
/* Return TRUE iff DEST is a register or subreg of a register and
doesn't change the number of words of the inner register, and any
part of the register is TEST_REGNO. */
static bool
covers_regno_no_parallel_p (const_rtx dest, unsigned int test_regno)
{
unsigned int regno, endregno;
if (GET_CODE (dest) == SUBREG
&& (((GET_MODE_SIZE (GET_MODE (dest))
+ UNITS_PER_WORD - 1) / UNITS_PER_WORD)
== ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))
+ UNITS_PER_WORD - 1) / UNITS_PER_WORD)))
dest = SUBREG_REG (dest);
if (!REG_P (dest))
return false;
regno = REGNO (dest);
endregno = END_REGNO (dest);
return (test_regno >= regno && test_regno < endregno);
}
/* Like covers_regno_no_parallel_p, but also handles PARALLELs where
any member matches the covers_regno_no_parallel_p criteria. */
static bool
covers_regno_p (const_rtx dest, unsigned int test_regno)
{
if (GET_CODE (dest) == PARALLEL)
{
/* Some targets place small structures in registers for return
values of functions, and those registers are wrapped in
PARALLELs that we may see as the destination of a SET. */
int i;
for (i = XVECLEN (dest, 0) - 1; i >= 0; i--)
{
rtx inner = XEXP (XVECEXP (dest, 0, i), 0);
if (inner != NULL_RTX
&& covers_regno_no_parallel_p (inner, test_regno))
return true;
}
return false;
}
else
return covers_regno_no_parallel_p (dest, test_regno);
}
/* Utility function for dead_or_set_p to check an individual register. */
int
dead_or_set_regno_p (const_rtx insn, unsigned int test_regno)
{
const_rtx pattern;
/* See if there is a death note for something that includes TEST_REGNO. */
if (find_regno_note (insn, REG_DEAD, test_regno))
return 1;
if (CALL_P (insn)
&& find_regno_fusage (insn, CLOBBER, test_regno))
return 1;
pattern = PATTERN (insn);
if (GET_CODE (pattern) == COND_EXEC)
pattern = COND_EXEC_CODE (pattern);
if (GET_CODE (pattern) == SET)
return covers_regno_p (SET_DEST (pattern), test_regno);
else if (GET_CODE (pattern) == PARALLEL)
{
int i;
for (i = XVECLEN (pattern, 0) - 1; i >= 0; i--)
{
rtx body = XVECEXP (pattern, 0, i);
if (GET_CODE (body) == COND_EXEC)
body = COND_EXEC_CODE (body);
if ((GET_CODE (body) == SET || GET_CODE (body) == CLOBBER)
&& covers_regno_p (SET_DEST (body), test_regno))
return 1;
}
}
return 0;
}
/* Return the reg-note of kind KIND in insn INSN, if there is one.
If DATUM is nonzero, look for one whose datum is DATUM. */
rtx
find_reg_note (const_rtx insn, enum reg_note kind, const_rtx datum)
{
rtx link;
gcc_assert (insn);
/* Ignore anything that is not an INSN, JUMP_INSN or CALL_INSN. */
if (! INSN_P (insn))
return 0;
if (datum == 0)
{
for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
if (REG_NOTE_KIND (link) == kind)
return link;
return 0;
}
for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
if (REG_NOTE_KIND (link) == kind && datum == XEXP (link, 0))
return link;
return 0;
}
/* Return the reg-note of kind KIND in insn INSN which applies to register
number REGNO, if any. Return 0 if there is no such reg-note. Note that
the REGNO of this NOTE need not be REGNO if REGNO is a hard register;
it might be the case that the note overlaps REGNO. */
rtx
find_regno_note (const_rtx insn, enum reg_note kind, unsigned int regno)
{
rtx link;
/* Ignore anything that is not an INSN, JUMP_INSN or CALL_INSN. */
if (! INSN_P (insn))
return 0;
for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
if (REG_NOTE_KIND (link) == kind
/* Verify that it is a register, so that scratch and MEM won't cause a
problem here. */
&& REG_P (XEXP (link, 0))
&& REGNO (XEXP (link, 0)) <= regno
&& END_REGNO (XEXP (link, 0)) > regno)
return link;
return 0;
}
/* Return a REG_EQUIV or REG_EQUAL note if insn has only a single set and
has such a note. */
rtx
find_reg_equal_equiv_note (const_rtx insn)
{
rtx link;
if (!INSN_P (insn))
return 0;
for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
if (REG_NOTE_KIND (link) == REG_EQUAL
|| REG_NOTE_KIND (link) == REG_EQUIV)
{
/* FIXME: We should never have REG_EQUAL/REG_EQUIV notes on
insns that have multiple sets. Checking single_set to
make sure of this is not the proper check, as explained
in the comment in set_unique_reg_note.
This should be changed into an assert. */
if (GET_CODE (PATTERN (insn)) == PARALLEL && multiple_sets (insn))
return 0;
return link;
}
return NULL;
}
/* Check whether INSN is a single_set whose source is known to be
equivalent to a constant. Return that constant if so, otherwise
return null. */
rtx
find_constant_src (const_rtx insn)
{
rtx note, set, x;
set = single_set (insn);
if (set)
{
x = avoid_constant_pool_reference (SET_SRC (set));
if (CONSTANT_P (x))
return x;
}
note = find_reg_equal_equiv_note (insn);
if (note && CONSTANT_P (XEXP (note, 0)))
return XEXP (note, 0);
return NULL_RTX;
}
/* Return true if DATUM, or any overlap of DATUM, of kind CODE is found
in the CALL_INSN_FUNCTION_USAGE information of INSN. */
int
find_reg_fusage (const_rtx insn, enum rtx_code code, const_rtx datum)
{
/* If it's not a CALL_INSN, it can't possibly have a
CALL_INSN_FUNCTION_USAGE field, so don't bother checking. */
if (!CALL_P (insn))
return 0;
gcc_assert (datum);
if (!REG_P (datum))
{
rtx link;
for (link = CALL_INSN_FUNCTION_USAGE (insn);
link;
link = XEXP (link, 1))
if (GET_CODE (XEXP (link, 0)) == code
&& rtx_equal_p (datum, XEXP (XEXP (link, 0), 0)))
return 1;
}
else
{
unsigned int regno = REGNO (datum);
/* CALL_INSN_FUNCTION_USAGE information cannot contain references
to pseudo registers, so don't bother checking. */
if (regno < FIRST_PSEUDO_REGISTER)
{
unsigned int end_regno = END_HARD_REGNO (datum);
unsigned int i;
for (i = regno; i < end_regno; i++)
if (find_regno_fusage (insn, code, i))
return 1;
}
}
return 0;
}
/* Return true if REGNO, or any overlap of REGNO, of kind CODE is found
in the CALL_INSN_FUNCTION_USAGE information of INSN. */
int
find_regno_fusage (const_rtx insn, enum rtx_code code, unsigned int regno)
{
rtx link;
/* CALL_INSN_FUNCTION_USAGE information cannot contain references
to pseudo registers, so don't bother checking. */
if (regno >= FIRST_PSEUDO_REGISTER
|| !CALL_P (insn) )
return 0;
for (link = CALL_INSN_FUNCTION_USAGE (insn); link; link = XEXP (link, 1))
{
rtx op, reg;
if (GET_CODE (op = XEXP (link, 0)) == code
&& REG_P (reg = XEXP (op, 0))
&& REGNO (reg) <= regno
&& END_HARD_REGNO (reg) > regno)
return 1;
}
return 0;
}
/* Add register note with kind KIND and datum DATUM to INSN. */
void
add_reg_note (rtx insn, enum reg_note kind, rtx datum)
{
rtx note;
switch (kind)
{
case REG_CC_SETTER:
case REG_CC_USER:
case REG_LABEL_TARGET:
case REG_LABEL_OPERAND:
/* These types of register notes use an INSN_LIST rather than an
EXPR_LIST, so that copying is done right and dumps look
better. */
note = alloc_INSN_LIST (datum, REG_NOTES (insn));
PUT_REG_NOTE_KIND (note, kind);
break;
default:
note = alloc_EXPR_LIST (kind, datum, REG_NOTES (insn));
break;
}
REG_NOTES (insn) = note;
}
/* Remove register note NOTE from the REG_NOTES of INSN. */
void
remove_note (rtx insn, const_rtx note)
{
rtx link;
if (note == NULL_RTX)
return;
if (REG_NOTES (insn) == note)
REG_NOTES (insn) = XEXP (note, 1);
else
for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
if (XEXP (link, 1) == note)
{
XEXP (link, 1) = XEXP (note, 1);
break;
}
switch (REG_NOTE_KIND (note))
{
case REG_EQUAL:
case REG_EQUIV:
df_notes_rescan (insn);
break;
default:
break;
}
}
/* Remove REG_EQUAL and/or REG_EQUIV notes if INSN has such notes. */
void
remove_reg_equal_equiv_notes (rtx insn)
{
rtx *loc;
loc = &REG_NOTES (insn);
while (*loc)
{
enum reg_note kind = REG_NOTE_KIND (*loc);
if (kind == REG_EQUAL || kind == REG_EQUIV)
*loc = XEXP (*loc, 1);
else
loc = &XEXP (*loc, 1);
}
}
/* Search LISTP (an EXPR_LIST) for an entry whose first operand is NODE and
return 1 if it is found. A simple equality test is used to determine if
NODE matches. */
int
in_expr_list_p (const_rtx listp, const_rtx node)
{
const_rtx x;
for (x = listp; x; x = XEXP (x, 1))
if (node == XEXP (x, 0))
return 1;
return 0;
}
/* Search LISTP (an EXPR_LIST) for an entry whose first operand is NODE and
remove that entry from the list if it is found.
A simple equality test is used to determine if NODE matches. */
void
remove_node_from_expr_list (const_rtx node, rtx *listp)
{
rtx temp = *listp;
rtx prev = NULL_RTX;
while (temp)
{
if (node == XEXP (temp, 0))
{
/* Splice the node out of the list. */
if (prev)
XEXP (prev, 1) = XEXP (temp, 1);
else
*listp = XEXP (temp, 1);
return;
}
prev = temp;
temp = XEXP (temp, 1);
}
}
/* Nonzero if X contains any volatile instructions. These are instructions
which may cause unpredictable machine state instructions, and thus no
instructions should be moved or combined across them. This includes
only volatile asms and UNSPEC_VOLATILE instructions. */
int
volatile_insn_p (const_rtx x)
{
const RTX_CODE code = GET_CODE (x);
switch (code)
{
case LABEL_REF:
case SYMBOL_REF:
case CONST_INT:
case CONST:
case CONST_DOUBLE:
case CONST_FIXED:
case CONST_VECTOR:
case CC0:
case PC:
case REG:
case SCRATCH:
case CLOBBER:
case ADDR_VEC:
case ADDR_DIFF_VEC:
case CALL:
case MEM:
return 0;
case UNSPEC_VOLATILE:
/* case TRAP_IF: This isn't clear yet. */
return 1;
case ASM_INPUT:
case ASM_OPERANDS:
if (MEM_VOLATILE_P (x))
return 1;
default:
break;
}
/* Recursively scan the operands of this expression. */
{
const char *const fmt = GET_RTX_FORMAT (code);
int i;
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e')
{
if (volatile_insn_p (XEXP (x, i)))
return 1;
}
else if (fmt[i] == 'E')
{
int j;
for (j = 0; j < XVECLEN (x, i); j++)
if (volatile_insn_p (XVECEXP (x, i, j)))
return 1;
}
}
}
return 0;
}
/* Nonzero if X contains any volatile memory references
UNSPEC_VOLATILE operations or volatile ASM_OPERANDS expressions. */
int
volatile_refs_p (const_rtx x)
{
const RTX_CODE code = GET_CODE (x);
switch (code)
{
case LABEL_REF:
case SYMBOL_REF:
case CONST_INT:
case CONST:
case CONST_DOUBLE:
case CONST_FIXED:
case CONST_VECTOR:
case CC0:
case PC:
case REG:
case SCRATCH:
case CLOBBER:
case ADDR_VEC:
case ADDR_DIFF_VEC:
return 0;
case UNSPEC_VOLATILE:
return 1;
case MEM:
case ASM_INPUT:
case ASM_OPERANDS:
if (MEM_VOLATILE_P (x))
return 1;
default:
break;
}
/* Recursively scan the operands of this expression. */
{
const char *const fmt = GET_RTX_FORMAT (code);
int i;
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e')
{
if (volatile_refs_p (XEXP (x, i)))
return 1;
}
else if (fmt[i] == 'E')
{
int j;
for (j = 0; j < XVECLEN (x, i); j++)
if (volatile_refs_p (XVECEXP (x, i, j)))
return 1;
}
}
}
return 0;
}
/* Similar to above, except that it also rejects register pre- and post-
incrementing. */
int
side_effects_p (const_rtx x)
{
const RTX_CODE code = GET_CODE (x);
switch (code)
{
case LABEL_REF:
case SYMBOL_REF:
case CONST_INT:
case CONST:
case CONST_DOUBLE:
case CONST_FIXED:
case CONST_VECTOR:
case CC0:
case PC:
case REG:
case SCRATCH:
case ADDR_VEC:
case ADDR_DIFF_VEC:
return 0;
case CLOBBER:
/* Reject CLOBBER with a non-VOID mode. These are made by combine.c
when some combination can't be done. If we see one, don't think
that we can simplify the expression. */
return (GET_MODE (x) != VOIDmode);
case PRE_INC:
case PRE_DEC:
case POST_INC:
case POST_DEC:
case PRE_MODIFY:
case POST_MODIFY:
case CALL:
case UNSPEC_VOLATILE:
/* case TRAP_IF: This isn't clear yet. */
return 1;
case MEM:
case ASM_INPUT:
case ASM_OPERANDS:
if (MEM_VOLATILE_P (x))
return 1;
default:
break;
}
/* Recursively scan the operands of this expression. */
{
const char *fmt = GET_RTX_FORMAT (code);
int i;
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e')
{
if (side_effects_p (XEXP (x, i)))
return 1;
}
else if (fmt[i] == 'E')
{
int j;
for (j = 0; j < XVECLEN (x, i); j++)
if (side_effects_p (XVECEXP (x, i, j)))
return 1;
}
}
}
return 0;
}
/* Return nonzero if evaluating rtx X might cause a trap.
FLAGS controls how to consider MEMs. A nonzero means the context
of the access may have changed from the original, such that the
address may have become invalid. */
int
may_trap_p_1 (const_rtx x, unsigned flags)
{
int i;
enum rtx_code code;
const char *fmt;
/* We make no distinction currently, but this function is part of
the internal target-hooks ABI so we keep the parameter as
"unsigned flags". */
bool code_changed = flags != 0;
if (x == 0)
return 0;
code = GET_CODE (x);
switch (code)
{
/* Handle these cases quickly. */
case CONST_INT:
case CONST_DOUBLE:
case CONST_FIXED:
case CONST_VECTOR:
case SYMBOL_REF:
case LABEL_REF:
case CONST:
case PC:
case CC0:
case REG:
case SCRATCH:
return 0;
case UNSPEC:
case UNSPEC_VOLATILE:
return targetm.unspec_may_trap_p (x, flags);
case ASM_INPUT:
case TRAP_IF:
return 1;
case ASM_OPERANDS:
return MEM_VOLATILE_P (x);
/* Memory ref can trap unless it's a static var or a stack slot. */
case MEM:
if (/* MEM_NOTRAP_P only relates to the actual position of the memory
reference; moving it out of context such as when moving code
when optimizing, might cause its address to become invalid. */
code_changed
|| !MEM_NOTRAP_P (x))
{
HOST_WIDE_INT size = MEM_SIZE (x) ? INTVAL (MEM_SIZE (x)) : 0;
return rtx_addr_can_trap_p_1 (XEXP (x, 0), 0, size,
GET_MODE (x), code_changed);
}
return 0;
/* Division by a non-constant might trap. */
case DIV:
case MOD:
case UDIV:
case UMOD:
if (HONOR_SNANS (GET_MODE (x)))
return 1;
if (SCALAR_FLOAT_MODE_P (GET_MODE (x)))
return flag_trapping_math;
if (!CONSTANT_P (XEXP (x, 1)) || (XEXP (x, 1) == const0_rtx))
return 1;
break;
case EXPR_LIST:
/* An EXPR_LIST is used to represent a function call. This
certainly may trap. */
return 1;
case GE:
case GT:
case LE:
case LT:
case LTGT:
case COMPARE:
/* Some floating point comparisons may trap. */
if (!flag_trapping_math)
break;
/* ??? There is no machine independent way to check for tests that trap
when COMPARE is used, though many targets do make this distinction.
For instance, sparc uses CCFPE for compares which generate exceptions
and CCFP for compares which do not generate exceptions. */
if (HONOR_NANS (GET_MODE (x)))
return 1;
/* But often the compare has some CC mode, so check operand
modes as well. */
if (HONOR_NANS (GET_MODE (XEXP (x, 0)))
|| HONOR_NANS (GET_MODE (XEXP (x, 1))))
return 1;
break;
case EQ:
case NE:
if (HONOR_SNANS (GET_MODE (x)))
return 1;
/* Often comparison is CC mode, so check operand modes. */
if (HONOR_SNANS (GET_MODE (XEXP (x, 0)))
|| HONOR_SNANS (GET_MODE (XEXP (x, 1))))
return 1;
break;
case FIX:
/* Conversion of floating point might trap. */
if (flag_trapping_math && HONOR_NANS (GET_MODE (XEXP (x, 0))))
return 1;
break;
case NEG:
case ABS:
case SUBREG:
/* These operations don't trap even with floating point. */
break;
default:
/* Any floating arithmetic may trap. */
if (SCALAR_FLOAT_MODE_P (GET_MODE (x))
&& flag_trapping_math)
return 1;
}
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e')
{
if (may_trap_p_1 (XEXP (x, i), flags))
return 1;
}
else if (fmt[i] == 'E')
{
int j;
for (j = 0; j < XVECLEN (x, i); j++)
if (may_trap_p_1 (XVECEXP (x, i, j), flags))
return 1;
}
}
return 0;
}
/* Return nonzero if evaluating rtx X might cause a trap. */
int
may_trap_p (const_rtx x)
{
return may_trap_p_1 (x, 0);
}
/* Same as above, but additionally return nonzero if evaluating rtx X might
cause a fault. We define a fault for the purpose of this function as a
erroneous execution condition that cannot be encountered during the normal
execution of a valid program; the typical example is an unaligned memory
access on a strict alignment machine. The compiler guarantees that it
doesn't generate code that will fault from a valid program, but this
guarantee doesn't mean anything for individual instructions. Consider
the following example:
struct S { int d; union { char *cp; int *ip; }; };
int foo(struct S *s)
{
if (s->d == 1)
return *s->ip;
else
return *s->cp;
}
on a strict alignment machine. In a valid program, foo will never be
invoked on a structure for which d is equal to 1 and the underlying
unique field of the union not aligned on a 4-byte boundary, but the
expression *s->ip might cause a fault if considered individually.
At the RTL level, potentially problematic expressions will almost always
verify may_trap_p; for example, the above dereference can be emitted as
(mem:SI (reg:P)) and this expression is may_trap_p for a generic register.
However, suppose that foo is inlined in a caller that causes s->cp to
point to a local character variable and guarantees that s->d is not set
to 1; foo may have been effectively translated into pseudo-RTL as:
if ((reg:SI) == 1)
(set (reg:SI) (mem:SI (%fp - 7)))
else
(set (reg:QI) (mem:QI (%fp - 7)))
Now (mem:SI (%fp - 7)) is considered as not may_trap_p since it is a
memory reference to a stack slot, but it will certainly cause a fault
on a strict alignment machine. */
int
may_trap_or_fault_p (const_rtx x)
{
return may_trap_p_1 (x, 1);
}
/* Return nonzero if X contains a comparison that is not either EQ or NE,
i.e., an inequality. */
int
inequality_comparisons_p (const_rtx x)
{
const char *fmt;
int len, i;
const enum rtx_code code = GET_CODE (x);
switch (code)
{
case REG:
case SCRATCH:
case PC:
case CC0:
case CONST_INT:
case CONST_DOUBLE:
case CONST_FIXED:
case CONST_VECTOR:
case CONST:
case LABEL_REF:
case SYMBOL_REF:
return 0;
case LT:
case LTU:
case GT:
case GTU:
case LE:
case LEU:
case GE:
case GEU:
return 1;
default:
break;
}
len = GET_RTX_LENGTH (code);
fmt = GET_RTX_FORMAT (code);
for (i = 0; i < len; i++)
{
if (fmt[i] == 'e')
{
if (inequality_comparisons_p (XEXP (x, i)))
return 1;
}
else if (fmt[i] == 'E')
{
int j;
for (j = XVECLEN (x, i) - 1; j >= 0; j--)
if (inequality_comparisons_p (XVECEXP (x, i, j)))
return 1;
}
}
return 0;
}
/* Replace any occurrence of FROM in X with TO. The function does
not enter into CONST_DOUBLE for the replace.
Note that copying is not done so X must not be shared unless all copies
are to be modified. */
rtx
replace_rtx (rtx x, rtx from, rtx to)
{
int i, j;
const char *fmt;
/* The following prevents loops occurrence when we change MEM in
CONST_DOUBLE onto the same CONST_DOUBLE. */
if (x != 0 && GET_CODE (x) == CONST_DOUBLE)
return x;
if (x == from)
return to;
/* Allow this function to make replacements in EXPR_LISTs. */
if (x == 0)
return 0;
if (GET_CODE (x) == SUBREG)
{
rtx new_rtx = replace_rtx (SUBREG_REG (x), from, to);
if (GET_CODE (new_rtx) == CONST_INT)
{
x = simplify_subreg (GET_MODE (x), new_rtx,
GET_MODE (SUBREG_REG (x)),
SUBREG_BYTE (x));
gcc_assert (x);
}
else
SUBREG_REG (x) = new_rtx;
return x;
}
else if (GET_CODE (x) == ZERO_EXTEND)
{
rtx new_rtx = replace_rtx (XEXP (x, 0), from, to);
if (GET_CODE (new_rtx) == CONST_INT)
{
x = simplify_unary_operation (ZERO_EXTEND, GET_MODE (x),
new_rtx, GET_MODE (XEXP (x, 0)));
gcc_assert (x);
}
else
XEXP (x, 0) = new_rtx;
return x;
}
fmt = GET_RTX_FORMAT (GET_CODE (x));
for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
{
if (fmt[i] == 'e')
XEXP (x, i) = replace_rtx (XEXP (x, i), from, to);
else if (fmt[i] == 'E')
for (j = XVECLEN (x, i) - 1; j >= 0; j--)
XVECEXP (x, i, j) = replace_rtx (XVECEXP (x, i, j), from, to);
}
return x;
}
/* Replace occurrences of the old label in *X with the new one.
DATA is a REPLACE_LABEL_DATA containing the old and new labels. */
int
replace_label (rtx *x, void *data)
{
rtx l = *x;
rtx old_label = ((replace_label_data *) data)->r1;
rtx new_label = ((replace_label_data *) data)->r2;
bool update_label_nuses = ((replace_label_data *) data)->update_label_nuses;
if (l == NULL_RTX)
return 0;
if (GET_CODE (l) == SYMBOL_REF
&& CONSTANT_POOL_ADDRESS_P (l))
{
rtx c = get_pool_constant (l);
if (rtx_referenced_p (old_label, c))
{
rtx new_c, new_l;
replace_label_data *d = (replace_label_data *) data;
/* Create a copy of constant C; replace the label inside
but do not update LABEL_NUSES because uses in constant pool
are not counted. */
new_c = copy_rtx (c);
d->update_label_nuses = false;
for_each_rtx (&new_c, replace_label, data);
d->update_label_nuses = update_label_nuses;
/* Add the new constant NEW_C to constant pool and replace
the old reference to constant by new reference. */
new_l = XEXP (force_const_mem (get_pool_mode (l), new_c), 0);
*x = replace_rtx (l, l, new_l);
}
return 0;
}
/* If this is a JUMP_INSN, then we also need to fix the JUMP_LABEL
field. This is not handled by for_each_rtx because it doesn't
handle unprinted ('0') fields. */
if (JUMP_P (l) && JUMP_LABEL (l) == old_label)
JUMP_LABEL (l) = new_label;
if ((GET_CODE (l) == LABEL_REF
|| GET_CODE (l) == INSN_LIST)
&& XEXP (l, 0) == old_label)
{
XEXP (l, 0) = new_label;
if (update_label_nuses)
{
++LABEL_NUSES (new_label);
--LABEL_NUSES (old_label);
}
return 0;
}
return 0;
}
/* When *BODY is equal to X or X is directly referenced by *BODY
return nonzero, thus FOR_EACH_RTX stops traversing and returns nonzero
too, otherwise FOR_EACH_RTX continues traversing *BODY. */
static int
rtx_referenced_p_1 (rtx *body, void *x)
{
rtx y = (rtx) x;
if (*body == NULL_RTX)
return y == NULL_RTX;
/* Return true if a label_ref *BODY refers to label Y. */
if (GET_CODE (*body) == LABEL_REF && LABEL_P (y))
return XEXP (*body, 0) == y;
/* If *BODY is a reference to pool constant traverse the constant. */
if (GET_CODE (*body) == SYMBOL_REF
&& CONSTANT_POOL_ADDRESS_P (*body))
return rtx_referenced_p (y, get_pool_constant (*body));
/* By default, compare the RTL expressions. */
return rtx_equal_p (*body, y);
}
/* Return true if X is referenced in BODY. */
int
rtx_referenced_p (rtx x, rtx body)
{
return for_each_rtx (&body, rtx_referenced_p_1, x);
}
/* If INSN is a tablejump return true and store the label (before jump table) to
*LABELP and the jump table to *TABLEP. LABELP and TABLEP may be NULL. */
bool
tablejump_p (const_rtx insn, rtx *labelp, rtx *tablep)
{
rtx label, table;
if (JUMP_P (insn)
&& (label = JUMP_LABEL (insn)) != NULL_RTX
&& (table = next_active_insn (label)) != NULL_RTX
&& JUMP_P (table)
&& (GET_CODE (PATTERN (table)) == ADDR_VEC
|| GET_CODE (PATTERN (table)) == ADDR_DIFF_VEC))
{
if (labelp)
*labelp = label;
if (tablep)
*tablep = table;
return true;
}
return false;
}
/* A subroutine of computed_jump_p, return 1 if X contains a REG or MEM or
constant that is not in the constant pool and not in the condition
of an IF_THEN_ELSE. */
static int
computed_jump_p_1 (const_rtx x)
{
const enum rtx_code code = GET_CODE (x);
int i, j;
const char *fmt;
switch (code)
{
case LABEL_REF:
case PC:
return 0;
case CONST:
case CONST_INT:
case CONST_DOUBLE:
case CONST_FIXED:
case CONST_VECTOR:
case SYMBOL_REF:
case REG:
return 1;
case MEM:
return ! (GET_CODE (XEXP (x, 0)) == SYMBOL_REF
&& CONSTANT_POOL_ADDRESS_P (XEXP (x, 0)));
case IF_THEN_ELSE:
return (computed_jump_p_1 (XEXP (x, 1))
|| computed_jump_p_1 (XEXP (x, 2)));
default:
break;
}
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e'
&& computed_jump_p_1 (XEXP (x, i)))
return 1;
else if (fmt[i] == 'E')
for (j = 0; j < XVECLEN (x, i); j++)
if (computed_jump_p_1 (XVECEXP (x, i, j)))
return 1;
}
return 0;
}
/* Return nonzero if INSN is an indirect jump (aka computed jump).
Tablejumps and casesi insns are not considered indirect jumps;
we can recognize them by a (use (label_ref)). */
int
computed_jump_p (const_rtx insn)
{
int i;
if (JUMP_P (insn))
{
rtx pat = PATTERN (insn);
/* If we have a JUMP_LABEL set, we're not a computed jump. */
if (JUMP_LABEL (insn) != NULL)
return 0;
if (GET_CODE (pat) == PARALLEL)
{
int len = XVECLEN (pat, 0);
int has_use_labelref = 0;
for (i = len - 1; i >= 0; i--)
if (GET_CODE (XVECEXP (pat, 0, i)) == USE
&& (GET_CODE (XEXP (XVECEXP (pat, 0, i), 0))
== LABEL_REF))
has_use_labelref = 1;
if (! has_use_labelref)
for (i = len - 1; i >= 0; i--)
if (GET_CODE (XVECEXP (pat, 0, i)) == SET
&& SET_DEST (XVECEXP (pat, 0, i)) == pc_rtx
&& computed_jump_p_1 (SET_SRC (XVECEXP (pat, 0, i))))
return 1;
}
else if (GET_CODE (pat) == SET
&& SET_DEST (pat) == pc_rtx
&& computed_jump_p_1 (SET_SRC (pat)))
return 1;
}
return 0;
}
/* Optimized loop of for_each_rtx, trying to avoid useless recursive
calls. Processes the subexpressions of EXP and passes them to F. */
static int
for_each_rtx_1 (rtx exp, int n, rtx_function f, void *data)
{
int result, i, j;
const char *format = GET_RTX_FORMAT (GET_CODE (exp));
rtx *x;
for (; format[n] != '\0'; n++)
{
switch (format[n])
{
case 'e':
/* Call F on X. */
x = &XEXP (exp, n);
result = (*f) (x, data);
if (result == -1)
/* Do not traverse sub-expressions. */
continue;
else if (result != 0)
/* Stop the traversal. */
return result;
if (*x == NULL_RTX)
/* There are no sub-expressions. */
continue;
i = non_rtx_starting_operands[GET_CODE (*x)];
if (i >= 0)
{
result = for_each_rtx_1 (*x, i, f, data);
if (result != 0)
return result;
}
break;
case 'V':
case 'E':
if (XVEC (exp, n) == 0)
continue;
for (j = 0; j < XVECLEN (exp, n); ++j)
{
/* Call F on X. */
x = &XVECEXP (exp, n, j);
result = (*f) (x, data);
if (result == -1)
/* Do not traverse sub-expressions. */
continue;
else if (result != 0)
/* Stop the traversal. */
return result;
if (*x == NULL_RTX)
/* There are no sub-expressions. */
continue;
i = non_rtx_starting_operands[GET_CODE (*x)];
if (i >= 0)
{
result = for_each_rtx_1 (*x, i, f, data);
if (result != 0)
return result;
}
}
break;
default:
/* Nothing to do. */
break;
}
}
return 0;
}
/* Traverse X via depth-first search, calling F for each
sub-expression (including X itself). F is also passed the DATA.
If F returns -1, do not traverse sub-expressions, but continue
traversing the rest of the tree. If F ever returns any other
nonzero value, stop the traversal, and return the value returned
by F. Otherwise, return 0. This function does not traverse inside
tree structure that contains RTX_EXPRs, or into sub-expressions
whose format code is `0' since it is not known whether or not those
codes are actually RTL.
This routine is very general, and could (should?) be used to
implement many of the other routines in this file. */
int
for_each_rtx (rtx *x, rtx_function f, void *data)
{
int result;
int i;
/* Call F on X. */
result = (*f) (x, data);
if (result == -1)
/* Do not traverse sub-expressions. */
return 0;
else if (result != 0)
/* Stop the traversal. */
return result;
if (*x == NULL_RTX)
/* There are no sub-expressions. */
return 0;
i = non_rtx_starting_operands[GET_CODE (*x)];
if (i < 0)
return 0;
return for_each_rtx_1 (*x, i, f, data);
}
/* Searches X for any reference to REGNO, returning the rtx of the
reference found if any. Otherwise, returns NULL_RTX. */
rtx
regno_use_in (unsigned int regno, rtx x)
{
const char *fmt;
int i, j;
rtx tem;
if (REG_P (x) && REGNO (x) == regno)
return x;
fmt = GET_RTX_FORMAT (GET_CODE (x));
for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
{
if (fmt[i] == 'e')
{
if ((tem = regno_use_in (regno, XEXP (x, i))))
return tem;
}
else if (fmt[i] == 'E')
for (j = XVECLEN (x, i) - 1; j >= 0; j--)
if ((tem = regno_use_in (regno , XVECEXP (x, i, j))))
return tem;
}
return NULL_RTX;
}
/* Return a value indicating whether OP, an operand of a commutative
operation, is preferred as the first or second operand. The higher
the value, the stronger the preference for being the first operand.
We use negative values to indicate a preference for the first operand
and positive values for the second operand. */
int
commutative_operand_precedence (rtx op)
{
enum rtx_code code = GET_CODE (op);
/* Constants always come the second operand. Prefer "nice" constants. */
if (code == CONST_INT)
return -8;
if (code == CONST_DOUBLE)
return -7;
if (code == CONST_FIXED)
return -7;
op = avoid_constant_pool_reference (op);
code = GET_CODE (op);
switch (GET_RTX_CLASS (code))
{
case RTX_CONST_OBJ:
if (code == CONST_INT)
return -6;
if (code == CONST_DOUBLE)
return -5;
if (code == CONST_FIXED)
return -5;
return -4;
case RTX_EXTRA:
/* SUBREGs of objects should come second. */
if (code == SUBREG && OBJECT_P (SUBREG_REG (op)))
return -3;
return 0;
case RTX_OBJ:
/* Complex expressions should be the first, so decrease priority
of objects. Prefer pointer objects over non pointer objects. */
if ((REG_P (op) && REG_POINTER (op))
|| (MEM_P (op) && MEM_POINTER (op)))
return -1;
return -2;
case RTX_COMM_ARITH:
/* Prefer operands that are themselves commutative to be first.
This helps to make things linear. In particular,
(and (and (reg) (reg)) (not (reg))) is canonical. */
return 4;
case RTX_BIN_ARITH:
/* If only one operand is a binary expression, it will be the first
operand. In particular, (plus (minus (reg) (reg)) (neg (reg)))
is canonical, although it will usually be further simplified. */
return 2;
case RTX_UNARY:
/* Then prefer NEG and NOT. */
if (code == NEG || code == NOT)
return 1;
default:
return 0;
}
}
/* Return 1 iff it is necessary to swap operands of commutative operation
in order to canonicalize expression. */
bool
swap_commutative_operands_p (rtx x, rtx y)
{
return (commutative_operand_precedence (x)
< commutative_operand_precedence (y));
}
/* Return 1 if X is an autoincrement side effect and the register is
not the stack pointer. */
int
auto_inc_p (const_rtx x)
{
switch (GET_CODE (x))
{
case PRE_INC:
case POST_INC:
case PRE_DEC:
case POST_DEC:
case PRE_MODIFY:
case POST_MODIFY:
/* There are no REG_INC notes for SP. */
if (XEXP (x, 0) != stack_pointer_rtx)
return 1;
default:
break;
}
return 0;
}
/* Return nonzero if IN contains a piece of rtl that has the address LOC. */
int
loc_mentioned_in_p (rtx *loc, const_rtx in)
{
enum rtx_code code;
const char *fmt;
int i, j;
if (!in)
return 0;
code = GET_CODE (in);
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e')
{
if (loc == &XEXP (in, i) || loc_mentioned_in_p (loc, XEXP (in, i)))
return 1;
}
else if (fmt[i] == 'E')
for (j = XVECLEN (in, i) - 1; j >= 0; j--)
if (loc == &XVECEXP (in, i, j)
|| loc_mentioned_in_p (loc, XVECEXP (in, i, j)))
return 1;
}
return 0;
}
/* Helper function for subreg_lsb. Given a subreg's OUTER_MODE, INNER_MODE,
and SUBREG_BYTE, return the bit offset where the subreg begins
(counting from the least significant bit of the operand). */
unsigned int
subreg_lsb_1 (enum machine_mode outer_mode,
enum machine_mode inner_mode,
unsigned int subreg_byte)
{
unsigned int bitpos;
unsigned int byte;
unsigned int word;
/* A paradoxical subreg begins at bit position 0. */
if (GET_MODE_BITSIZE (outer_mode) > GET_MODE_BITSIZE (inner_mode))
return 0;
if (WORDS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
/* If the subreg crosses a word boundary ensure that
it also begins and ends on a word boundary. */
gcc_assert (!((subreg_byte % UNITS_PER_WORD
+ GET_MODE_SIZE (outer_mode)) > UNITS_PER_WORD
&& (subreg_byte % UNITS_PER_WORD
|| GET_MODE_SIZE (outer_mode) % UNITS_PER_WORD)));
if (WORDS_BIG_ENDIAN)
word = (GET_MODE_SIZE (inner_mode)
- (subreg_byte + GET_MODE_SIZE (outer_mode))) / UNITS_PER_WORD;
else
word = subreg_byte / UNITS_PER_WORD;
bitpos = word * BITS_PER_WORD;
if (BYTES_BIG_ENDIAN)
byte = (GET_MODE_SIZE (inner_mode)
- (subreg_byte + GET_MODE_SIZE (outer_mode))) % UNITS_PER_WORD;
else
byte = subreg_byte % UNITS_PER_WORD;
bitpos += byte * BITS_PER_UNIT;
return bitpos;
}
/* Given a subreg X, return the bit offset where the subreg begins
(counting from the least significant bit of the reg). */
unsigned int
subreg_lsb (const_rtx x)
{
return subreg_lsb_1 (GET_MODE (x), GET_MODE (SUBREG_REG (x)),
SUBREG_BYTE (x));
}
/* Fill in information about a subreg of a hard register.
xregno - A regno of an inner hard subreg_reg (or what will become one).
xmode - The mode of xregno.
offset - The byte offset.
ymode - The mode of a top level SUBREG (or what may become one).
info - Pointer to structure to fill in. */
static void
subreg_get_info (unsigned int xregno, enum machine_mode xmode,
unsigned int offset, enum machine_mode ymode,
struct subreg_info *info)
{
int nregs_xmode, nregs_ymode;
int mode_multiple, nregs_multiple;
int offset_adj, y_offset, y_offset_adj;
int regsize_xmode, regsize_ymode;
bool rknown;
gcc_assert (xregno < FIRST_PSEUDO_REGISTER);
rknown = false;
/* If there are holes in a non-scalar mode in registers, we expect
that it is made up of its units concatenated together. */
if (HARD_REGNO_NREGS_HAS_PADDING (xregno, xmode))
{
enum machine_mode xmode_unit;
nregs_xmode = HARD_REGNO_NREGS_WITH_PADDING (xregno, xmode);
if (GET_MODE_INNER (xmode) == VOIDmode)
xmode_unit = xmode;
else
xmode_unit = GET_MODE_INNER (xmode);
gcc_assert (HARD_REGNO_NREGS_HAS_PADDING (xregno, xmode_unit));
gcc_assert (nregs_xmode
== (GET_MODE_NUNITS (xmode)
* HARD_REGNO_NREGS_WITH_PADDING (xregno, xmode_unit)));
gcc_assert (hard_regno_nregs[xregno][xmode]
== (hard_regno_nregs[xregno][xmode_unit]
* GET_MODE_NUNITS (xmode)));
/* You can only ask for a SUBREG of a value with holes in the middle
if you don't cross the holes. (Such a SUBREG should be done by
picking a different register class, or doing it in memory if
necessary.) An example of a value with holes is XCmode on 32-bit
x86 with -m128bit-long-double; it's represented in 6 32-bit registers,
3 for each part, but in memory it's two 128-bit parts.
Padding is assumed to be at the end (not necessarily the 'high part')
of each unit. */
if ((offset / GET_MODE_SIZE (xmode_unit) + 1
< GET_MODE_NUNITS (xmode))
&& (offset / GET_MODE_SIZE (xmode_unit)
!= ((offset + GET_MODE_SIZE (ymode) - 1)
/ GET_MODE_SIZE (xmode_unit))))
{
info->representable_p = false;
rknown = true;
}
}
else
nregs_xmode = hard_regno_nregs[xregno][xmode];
nregs_ymode = hard_regno_nregs[xregno][ymode];
/* Paradoxical subregs are otherwise valid. */
if (!rknown
&& offset == 0
&& GET_MODE_SIZE (ymode) > GET_MODE_SIZE (xmode))
{
info->representable_p = true;
/* If this is a big endian paradoxical subreg, which uses more
actual hard registers than the original register, we must
return a negative offset so that we find the prope