/* Optimize by combining instructions for GNU compiler.
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+ 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
This file is part of GCC.
static int total_attempts, total_merges, total_extras, total_successes;
+/* Sometimes combine tries to replace the right hand side of an insn
+ with the value of a REG_EQUAL note. This is the insn that has been
+ so modified, or null if none. */
+
+static rtx replaced_rhs_insn;
+
+/* When REPLACED_RHS_INSN is nonnull, this is a copy of the new right
+ hand side. */
+
+static rtx replaced_rhs_value;
\f
/* Vector mapping INSN_UIDs to cuids.
The cuids are like uids but increase monotonically always.
#define INSN_CUID(INSN) \
(INSN_UID (INSN) > max_uid_cuid ? insn_cuid (INSN) : uid_cuid[INSN_UID (INSN)])
-/* In case BITS_PER_WORD == HOST_BITS_PER_WIDE_INT, shifting by
- BITS_PER_WORD would invoke undefined behavior. Work around it. */
-
-#define UWIDE_SHIFT_LEFT_BY_BITS_PER_WORD(val) \
- (((unsigned HOST_WIDE_INT) (val) << (BITS_PER_WORD - 1)) << 1)
-
/* Maximum register number, which is the size of the tables below. */
static unsigned int combine_max_regno;
(1) We do not want to reinitialize at each label.
(2) It is useful, but not critical, to know the actual value assigned
- to a register. Often just its form is helpful.
+ to a register. Often just its form is helpful.
Therefore, we maintain the following fields:
unsigned HOST_WIDE_INT last_set_nonzero_bits;
char last_set_sign_bit_copies;
- ENUM_BITFIELD(machine_mode) last_set_mode : 8;
+ ENUM_BITFIELD(machine_mode) last_set_mode : 8;
/* Set nonzero if references to register n in expressions should not be
used. last_set_invalid is set nonzero when this register is being
unsigned char sign_bit_copies;
unsigned HOST_WIDE_INT nonzero_bits;
+
+ /* Record the value of the label_tick when the last truncation
+ happened. The field truncated_to_mode is only valid if
+ truncation_label == label_tick. */
+
+ int truncation_label;
+
+ /* Record the last truncation seen for this register. If truncation
+ is not a nop to this mode we might be able to save an explicit
+ truncation if we know that value already contains a truncated
+ value. */
+
+ ENUM_BITFIELD(machine_mode) truncated_to_mode : 8;
};
static struct reg_stat *reg_stat;
\f
/* Record one modification to rtl structure
- to be undone by storing old_contents into *where.
- is_int is 1 if the contents are an int. */
+ to be undone by storing old_contents into *where. */
struct undo
{
struct undo *next;
- int is_int;
- union {rtx r; int i;} old_contents;
- union {rtx *r; int *i;} where;
+ enum { UNDO_RTX, UNDO_INT, UNDO_MODE } kind;
+ union { rtx r; int i; enum machine_mode m; } old_contents;
+ union { rtx *r; int *i; } where;
};
/* Record a bunch of changes to be undone, up to MAX_UNDO of them.
static enum rtx_code simplify_comparison (enum rtx_code, rtx *, rtx *);
static void update_table_tick (rtx);
static void record_value_for_reg (rtx, rtx, rtx);
-static void check_promoted_subreg (rtx, rtx);
+static void check_conversions (rtx, rtx);
static void record_dead_and_set_regs_1 (rtx, rtx, void *);
static void record_dead_and_set_regs (rtx);
static int get_last_value_validate (rtx *, rtx, int, int);
static void record_promoted_value (rtx, rtx);
static int unmentioned_reg_p_1 (rtx *, void *);
static bool unmentioned_reg_p (rtx, rtx);
+static void record_truncated_value (rtx);
+static bool reg_truncated_to_mode (enum machine_mode, rtx);
+static rtx gen_lowpart_or_truncate (enum machine_mode, rtx);
\f
/* It is not safe to use ordinary gen_lowpart in combine.
#undef RTL_HOOKS_REG_NUM_SIGN_BIT_COPIES
#define RTL_HOOKS_REG_NUM_SIGN_BIT_COPIES reg_num_sign_bit_copies_for_combine
+#undef RTL_HOOKS_REG_TRUNCATED_TO_MODE
+#define RTL_HOOKS_REG_TRUNCATED_TO_MODE reg_truncated_to_mode
+
static const struct rtl_hooks combine_rtl_hooks = RTL_HOOKS_INITIALIZER;
\f
if (undobuf.frees)
buf = undobuf.frees, undobuf.frees = buf->next;
else
- buf = xmalloc (sizeof (struct undo));
+ buf = XNEW (struct undo);
- buf->is_int = 0;
+ buf->kind = UNDO_RTX;
buf->where.r = into;
buf->old_contents.r = oldval;
*into = newval;
if (undobuf.frees)
buf = undobuf.frees, undobuf.frees = buf->next;
else
- buf = xmalloc (sizeof (struct undo));
+ buf = XNEW (struct undo);
- buf->is_int = 1;
+ buf->kind = UNDO_INT;
buf->where.i = into;
buf->old_contents.i = oldval;
*into = newval;
}
#define SUBST_INT(INTO, NEWVAL) do_SUBST_INT(&(INTO), (NEWVAL))
+
+/* Similar to SUBST, but just substitute the mode. This is used when
+ changing the mode of a pseudo-register, so that any other
+ references to the entry in the regno_reg_rtx array will change as
+ well. */
+
+static void
+do_SUBST_MODE (rtx *into, enum machine_mode newval)
+{
+ struct undo *buf;
+ enum machine_mode oldval = GET_MODE (*into);
+
+ if (oldval == newval)
+ return;
+
+ if (undobuf.frees)
+ buf = undobuf.frees, undobuf.frees = buf->next;
+ else
+ buf = XNEW (struct undo);
+
+ buf->kind = UNDO_MODE;
+ buf->where.r = into;
+ buf->old_contents.m = oldval;
+ PUT_MODE (*into, newval);
+
+ buf->next = undobuf.undos, undobuf.undos = buf;
+}
+
+#define SUBST_MODE(INTO, NEWVAL) do_SUBST_MODE(&(INTO), (NEWVAL))
\f
/* Subroutine of try_combine. Determine whether the combine replacement
patterns NEWPAT and NEWI2PAT are cheaper according to insn_rtx_cost
Return nonzero if the combiner has turned an indirect jump
instruction into a direct jump. */
-int
+static int
combine_instructions (rtx f, unsigned int nregs)
{
rtx insn, next;
rtl_hooks = combine_rtl_hooks;
- reg_stat = xcalloc (nregs, sizeof (struct reg_stat));
+ reg_stat = XCNEWVEC (struct reg_stat, nregs);
init_recog_no_volatile ();
if (INSN_UID (insn) > i)
i = INSN_UID (insn);
- uid_cuid = xmalloc ((i + 1) * sizeof (int));
+ uid_cuid = XNEWVEC (int, i + 1);
max_uid_cuid = i;
nonzero_bits_mode = mode_for_size (HOST_BITS_PER_WIDE_INT, MODE_INT, 0);
sbitmap_zero (refresh_blocks);
/* Allocate array of current insn_rtx_costs. */
- uid_insn_cost = xcalloc (max_uid_cuid + 1, sizeof (int));
+ uid_insn_cost = XCNEWVEC (int, max_uid_cuid + 1);
last_insn_cost = max_uid_cuid;
for (insn = f, i = 0; insn; insn = NEXT_INSN (insn))
FOR_EACH_BB (this_basic_block)
{
for (insn = BB_HEAD (this_basic_block);
- insn != NEXT_INSN (BB_END (this_basic_block));
+ insn != NEXT_INSN (BB_END (this_basic_block));
insn = next ? next : NEXT_INSN (insn))
{
next = 0;
{
/* See if we know about function return values before this
insn based upon SUBREG flags. */
- check_promoted_subreg (insn, PATTERN (insn));
+ check_conversions (insn, PATTERN (insn));
/* Try this insn with each insn it links back to. */
be deleted or recognized by try_combine. */
rtx orig = SET_SRC (set);
SET_SRC (set) = note;
+ replaced_rhs_insn = temp;
+ replaced_rhs_value = copy_rtx (note);
next = try_combine (insn, temp, NULL_RTX,
&new_direct_jump_p);
+ replaced_rhs_insn = NULL;
if (next)
goto retry;
SET_SRC (set) = orig;
/* If this register is undefined at the start of the file, we can't
say what its contents were. */
&& ! REGNO_REG_SET_P
- (ENTRY_BLOCK_PTR->next_bb->il.rtl->global_live_at_start, REGNO (x))
+ (ENTRY_BLOCK_PTR->next_bb->il.rtl->global_live_at_start, REGNO (x))
&& GET_MODE_BITSIZE (GET_MODE (x)) <= HOST_BITS_PER_WIDE_INT)
{
if (set == 0 || GET_CODE (set) == CLOBBER)
for (i = XVECLEN (PATTERN (i3), 0) - 1; i >= 0; i--)
if (GET_CODE (XVECEXP (PATTERN (i3), 0, i)) == CLOBBER)
{
- /* Don't substitute for a register intended as a clobberable
+ /* Don't substitute for a register intended as a clobberable
operand. */
rtx reg = XEXP (XVECEXP (PATTERN (i3), 0, i), 0);
if (rtx_equal_p (reg, dest))
{
/* Make sure succ doesn't contain a volatile reference. */
if (succ != 0 && volatile_refs_p (PATTERN (succ)))
- return 0;
+ return 0;
for (p = NEXT_INSN (insn); p != i3; p = NEXT_INSN (p))
- if (INSN_P (p) && p != succ && volatile_refs_p (PATTERN (p)))
+ if (INSN_P (p) && p != succ && volatile_refs_p (PATTERN (p)))
return 0;
}
Consider:
- (set (reg:DI 101) (reg:DI 100))
+ (set (reg:DI 101) (reg:DI 100))
(set (subreg:SI (reg:DI 101) 0) <foo>)
This is NOT equivalent to:
- (parallel [(set (subreg:SI (reg:DI 100) 0) <foo>)
+ (parallel [(set (subreg:SI (reg:DI 100) 0) <foo>)
(set (reg:DI 101) (reg:DI 100))])
Not only does this modify 100 (in which case it might still be valid
new_mask >>= info->regno - regno;
else
new_mask <<= regno - info->regno;
- info->mask &= new_mask;
+ info->mask &= ~new_mask;
}
/* Return nonzero iff part of the return value is live during INSN, and
info.nregs = nregs;
info.mask = mask;
for (p = PREV_INSN (use); info.mask && p != insn; p = PREV_INSN (p))
- note_stores (PATTERN (insn), likely_spilled_retval_1, &info);
+ if (INSN_P (p))
+ note_stores (PATTERN (p), likely_spilled_retval_1, &info);
mask = info.mask;
/* Check if any of the (probably) live return value registers is
rtx i3dest_killed = 0;
/* SET_DEST and SET_SRC of I2 and I1. */
rtx i2dest, i2src, i1dest = 0, i1src = 0;
- /* PATTERN (I2), or a copy of it in certain cases. */
- rtx i2pat;
+ /* PATTERN (I1) and PATTERN (I2), or a copy of it in certain cases. */
+ rtx i1pat = 0, i2pat = 0;
/* Indicates if I2DEST or I1DEST is in I2SRC or I1_SRC. */
int i2dest_in_i2src = 0, i1dest_in_i1src = 0, i2dest_in_i1src = 0;
int i2dest_killed = 0, i1dest_killed = 0;
int offset = -1;
int width = 0;
- if (GET_CODE (dest) == STRICT_LOW_PART)
- {
- width = GET_MODE_BITSIZE (GET_MODE (XEXP (dest, 0)));
- offset = 0;
- }
- else if (GET_CODE (dest) == ZERO_EXTRACT)
+ if (GET_CODE (dest) == ZERO_EXTRACT)
{
if (GET_CODE (XEXP (dest, 1)) == CONST_INT
&& GET_CODE (XEXP (dest, 2)) == CONST_INT)
{
width = INTVAL (XEXP (dest, 1));
offset = INTVAL (XEXP (dest, 2));
-
+ dest = XEXP (dest, 0);
if (BITS_BIG_ENDIAN)
- offset = GET_MODE_BITSIZE (GET_MODE (XEXP (dest, 0)))
- - width - offset;
+ offset = GET_MODE_BITSIZE (GET_MODE (dest)) - width - offset;
}
}
- else if (subreg_lowpart_p (dest))
+ else
{
+ if (GET_CODE (dest) == STRICT_LOW_PART)
+ dest = XEXP (dest, 0);
width = GET_MODE_BITSIZE (GET_MODE (dest));
offset = 0;
}
- /* ??? Preserve the original logic to handle setting the high word
- of double-word pseudos, where inner is half the size of outer
- but not the lowpart. This could be generalized by handling
- SUBREG_BYTE, WORDS_BIG_ENDIAN and BYTES_BIG_ENDIAN ourselves.
- Unfortunately this logic is tricky to get right and probably
- not worth the effort. */
- else if (GET_MODE_BITSIZE (GET_MODE (SET_DEST (temp)))
- == 2 * GET_MODE_BITSIZE (GET_MODE (dest)))
+
+ if (offset >= 0)
{
- width = GET_MODE_BITSIZE (GET_MODE (dest));
- offset = width;
+ /* If this is the low part, we're done. */
+ if (subreg_lowpart_p (dest))
+ ;
+ /* Handle the case where inner is twice the size of outer. */
+ else if (GET_MODE_BITSIZE (GET_MODE (SET_DEST (temp)))
+ == 2 * GET_MODE_BITSIZE (GET_MODE (dest)))
+ offset += GET_MODE_BITSIZE (GET_MODE (dest));
+ /* Otherwise give up for now. */
+ else
+ offset = -1;
}
if (offset >= 0)
make up a dummy I1 that is
(set Y OP)
and change I2 to be
- (set (reg:CC X) (compare:CC Y (const_int 0)))
+ (set (reg:CC X) (compare:CC Y (const_int 0)))
(We can ignore any trailing CLOBBERs.)
rtx. If I2 is a PARALLEL, we just need the piece that assigns I2SRC to
I2DEST. */
- i2pat = (GET_CODE (PATTERN (i2)) == PARALLEL
- ? gen_rtx_SET (VOIDmode, i2dest, i2src)
- : PATTERN (i2));
-
if (added_sets_2)
- i2pat = copy_rtx (i2pat);
+ {
+ if (GET_CODE (PATTERN (i2)) == PARALLEL)
+ i2pat = gen_rtx_SET (VOIDmode, i2dest, copy_rtx (i2src));
+ else
+ i2pat = copy_rtx (PATTERN (i2));
+ }
+
+ if (added_sets_1)
+ {
+ if (GET_CODE (PATTERN (i1)) == PARALLEL)
+ i1pat = gen_rtx_SET (VOIDmode, i1dest, copy_rtx (i1src));
+ else
+ i1pat = copy_rtx (PATTERN (i1));
+ }
combine_merges++;
compare_mode))
{
unsigned int regno = REGNO (SET_DEST (newpat));
- rtx new_dest = gen_rtx_REG (compare_mode, regno);
+ rtx new_dest;
- if (regno >= FIRST_PSEUDO_REGISTER)
- SUBST (regno_reg_rtx[regno], new_dest);
+ if (regno < FIRST_PSEUDO_REGISTER)
+ new_dest = gen_rtx_REG (compare_mode, regno);
+ else
+ {
+ SUBST_MODE (regno_reg_rtx[regno], compare_mode);
+ new_dest = regno_reg_rtx[regno];
+ }
SUBST (SET_DEST (newpat), new_dest);
SUBST (XEXP (*cc_use, 0), new_dest);
}
if (added_sets_1)
- XVECEXP (newpat, 0, --total_sets)
- = (GET_CODE (PATTERN (i1)) == PARALLEL
- ? gen_rtx_SET (VOIDmode, i1dest, i1src) : PATTERN (i1));
+ XVECEXP (newpat, 0, --total_sets) = i1pat;
if (added_sets_2)
{
&& asm_noperands (newpat) < 0)
{
rtx m_split, *split;
- rtx ni2dest = i2dest;
/* See if the MD file can split NEWPAT. If it can't, see if letting it
use I2DEST as a scratch register will help. In the latter case,
possible to try that as a scratch reg. This would require adding
more code to make it work though. */
- if (m_split == 0 && ! reg_overlap_mentioned_p (ni2dest, newpat))
+ if (m_split == 0 && ! reg_overlap_mentioned_p (i2dest, newpat))
{
- enum machine_mode new_mode = GET_MODE (SET_DEST (newpat));
- /* If I2DEST is a hard register or the only use of a pseudo,
- we can change its mode. */
- if (new_mode != GET_MODE (i2dest)
- && new_mode != VOIDmode
- && can_change_dest_mode (i2dest, added_sets_2, new_mode))
- ni2dest = gen_rtx_REG (GET_MODE (SET_DEST (newpat)),
- REGNO (i2dest));
+ enum machine_mode new_mode = GET_MODE (SET_DEST (newpat));
+ /* First try to split using the original register as a
+ scratch register. */
m_split = split_insns (gen_rtx_PARALLEL
(VOIDmode,
gen_rtvec (2, newpat,
gen_rtx_CLOBBER (VOIDmode,
- ni2dest))),
+ i2dest))),
i3);
- /* If the split with the mode-changed register didn't work, try
- the original register. */
- if (! m_split && ni2dest != i2dest)
+
+ /* If that didn't work, try changing the mode of I2DEST if
+ we can. */
+ if (m_split == 0
+ && new_mode != GET_MODE (i2dest)
+ && new_mode != VOIDmode
+ && can_change_dest_mode (i2dest, added_sets_2, new_mode))
{
- ni2dest = i2dest;
+ enum machine_mode old_mode = GET_MODE (i2dest);
+ rtx ni2dest;
+
+ if (REGNO (i2dest) < FIRST_PSEUDO_REGISTER)
+ ni2dest = gen_rtx_REG (new_mode, REGNO (i2dest));
+ else
+ {
+ SUBST_MODE (regno_reg_rtx[REGNO (i2dest)], new_mode);
+ ni2dest = regno_reg_rtx[REGNO (i2dest)];
+ }
+
m_split = split_insns (gen_rtx_PARALLEL
(VOIDmode,
gen_rtvec (2, newpat,
gen_rtx_CLOBBER (VOIDmode,
- i2dest))),
+ ni2dest))),
i3);
+
+ if (m_split == 0
+ && REGNO (i2dest) >= FIRST_PSEUDO_REGISTER)
+ {
+ struct undo *buf;
+
+ PUT_MODE (regno_reg_rtx[REGNO (i2dest)], old_mode);
+ buf = undobuf.undos;
+ undobuf.undos = buf->next;
+ buf->next = undobuf.frees;
+ undobuf.frees = buf;
+ }
}
}
i3set = single_set (NEXT_INSN (m_split));
i2set = single_set (m_split);
- /* In case we changed the mode of I2DEST, replace it in the
- pseudo-register table here. We can't do it above in case this
- code doesn't get executed and we do a split the other way. */
-
- if (REGNO (i2dest) >= FIRST_PSEUDO_REGISTER)
- SUBST (regno_reg_rtx[REGNO (i2dest)], ni2dest);
-
i2_code_number = recog_for_combine (&newi2pat, i2, &new_i2_notes);
/* If I2 or I3 has multiple SETs, we won't know how to track
validated that we can do this. */
if (GET_MODE (i2dest) != split_mode && split_mode != VOIDmode)
{
- newdest = gen_rtx_REG (split_mode, REGNO (i2dest));
-
- if (REGNO (i2dest) >= FIRST_PSEUDO_REGISTER)
- SUBST (regno_reg_rtx[REGNO (i2dest)], newdest);
+ if (REGNO (i2dest) < FIRST_PSEUDO_REGISTER)
+ newdest = gen_rtx_REG (split_mode, REGNO (i2dest));
+ else
+ {
+ SUBST_MODE (regno_reg_rtx[REGNO (i2dest)], split_mode);
+ newdest = regno_reg_rtx[REGNO (i2dest)];
+ }
}
/* If *SPLIT is a (mult FOO (const_int pow2)), convert it to
&& GET_CODE (SET_DEST (XVECEXP (newpat, 0, 1))) != STRICT_LOW_PART
&& ! use_crosses_set_p (SET_SRC (XVECEXP (newpat, 0, 1)),
INSN_CUID (i2))
- /* Don't pass sets with (USE (MEM ...)) dests to the following. */
- && GET_CODE (SET_DEST (XVECEXP (newpat, 0, 1))) != USE
- && GET_CODE (SET_DEST (XVECEXP (newpat, 0, 0))) != USE
&& ! reg_referenced_p (SET_DEST (XVECEXP (newpat, 0, 1)),
XVECEXP (newpat, 0, 0))
&& ! reg_referenced_p (SET_DEST (XVECEXP (newpat, 0, 0)),
XVECEXP (newpat, 0, 1))
&& ! (contains_muldiv (SET_SRC (XVECEXP (newpat, 0, 0)))
- && contains_muldiv (SET_SRC (XVECEXP (newpat, 0, 1)))))
+ && contains_muldiv (SET_SRC (XVECEXP (newpat, 0, 1))))
+#ifdef HAVE_cc0
+ /* We cannot split the parallel into two sets if both sets
+ reference cc0. */
+ && ! (reg_referenced_p (cc0_rtx, XVECEXP (newpat, 0, 0))
+ && reg_referenced_p (cc0_rtx, XVECEXP (newpat, 0, 1)))
+#endif
+ )
{
/* Normally, it doesn't matter which of the two is done first,
but it does if one references cc0. In that case, it has to
rtx ni2dest;
/* I3 now uses what used to be its destination and which is now
- I2's destination. This requires us to do a few adjustments. */
+ I2's destination. This requires us to do a few adjustments. */
PATTERN (i3) = newpat;
adjust_for_new_dest (i3);
/* We need a LOG_LINK from I3 to I2. But we used to have one,
- so we still will.
+ so we still will.
However, some later insn might be using I2's dest and have
a LOG_LINK pointing at I3. We must remove this link.
if (i3_subst_into_i2)
{
for (i = 0; i < XVECLEN (PATTERN (i2), 0); i++)
- if (GET_CODE (XVECEXP (PATTERN (i2), 0, i)) != USE
+ if ((GET_CODE (XVECEXP (PATTERN (i2), 0, i)) == SET
+ || GET_CODE (XVECEXP (PATTERN (i2), 0, i)) == CLOBBER)
&& REG_P (SET_DEST (XVECEXP (PATTERN (i2), 0, i)))
&& SET_DEST (XVECEXP (PATTERN (i2), 0, i)) != i2dest
&& ! find_reg_note (i2, REG_UNUSED,
for (undo = undobuf.undos; undo; undo = next)
{
next = undo->next;
- if (undo->is_int)
- *undo->where.i = undo->old_contents.i;
- else
- *undo->where.r = undo->old_contents.r;
+ switch (undo->kind)
+ {
+ case UNDO_RTX:
+ *undo->where.r = undo->old_contents.r;
+ break;
+ case UNDO_INT:
+ *undo->where.i = undo->old_contents.i;
+ break;
+ case UNDO_MODE:
+ PUT_MODE (*undo->where.r, undo->old_contents.m);
+ break;
+ default:
+ gcc_unreachable ();
+ }
undo->next = undobuf.frees;
undobuf.frees = undo;
}
undobuf.undos = 0;
}
-
\f
/* Find the innermost point within the rtx at LOC, possibly LOC itself,
where we have an arithmetic expression and return that point. LOC will
rtx negmask = gen_int_mode (~(mask << pos), mode);
SUBST (SET_SRC (x),
simplify_gen_binary (IOR, mode,
- simplify_gen_binary (AND, mode,
+ simplify_gen_binary (AND, mode,
dest, negmask),
or_mask));
}
&& ! (GET_CODE (XEXP (x, 1)) == SUBREG
&& OBJECT_P (SUBREG_REG (XEXP (x, 1)))))))
|| (UNARY_P (x)
- && (!OBJECT_P (XEXP (x, 0))
+ && (!OBJECT_P (XEXP (x, 0))
&& ! (GET_CODE (XEXP (x, 0)) == SUBREG
&& OBJECT_P (SUBREG_REG (XEXP (x, 0)))))))
{
else if (true_rtx == const0_rtx && false_rtx == const_true_rtx
&& ((reversed = reversed_comparison_code_parts
(cond_code, cond, cop1, NULL))
- != UNKNOWN))
+ != UNKNOWN))
x = simplify_gen_relational (reversed, mode, VOIDmode,
cond, cop1);
&& true_rtx == const0_rtx
&& ((reversed = reversed_comparison_code_parts
(cond_code, cond, cop1, NULL))
- != UNKNOWN))
+ != UNKNOWN))
x = simplify_gen_unary (NEG, mode,
simplify_gen_relational (reversed,
mode, VOIDmode,
return gen_lowpart (mode, SUBREG_REG (x));
if (GET_MODE_CLASS (GET_MODE (SUBREG_REG (x))) == MODE_CC)
- break;
+ break;
{
rtx temp;
temp = simplify_subreg (mode, SUBREG_REG (x), op0_mode,
if (GET_CODE (temp) == ASHIFTRT
&& GET_CODE (XEXP (temp, 1)) == CONST_INT
&& INTVAL (XEXP (temp, 1)) == GET_MODE_BITSIZE (mode) - 1)
- return simplify_shift_const (temp, LSHIFTRT, mode, XEXP (temp, 0),
+ return simplify_shift_const (NULL_RTX, LSHIFTRT, mode, XEXP (temp, 0),
INTVAL (XEXP (temp, 1)));
/* If X has only a single bit that might be nonzero, say, bit I, convert
tmp = simplify_relational_operation (old_code, compare_mode, VOIDmode,
op0, op1);
if (!tmp)
- new_code = old_code;
+ new_code = old_code;
else if (!CONSTANT_P (tmp))
- {
- new_code = GET_CODE (tmp);
- op0 = XEXP (tmp, 0);
- op1 = XEXP (tmp, 1);
- }
+ {
+ new_code = GET_CODE (tmp);
+ op0 = XEXP (tmp, 0);
+ op1 = XEXP (tmp, 1);
+ }
else
{
rtx pat = PATTERN (other_insn);
if (can_change_dest_mode (dest, 0, compare_mode))
{
unsigned int regno = REGNO (dest);
- rtx new_dest = gen_rtx_REG (compare_mode, regno);
+ rtx new_dest;
- if (regno >= FIRST_PSEUDO_REGISTER)
- SUBST (regno_reg_rtx[regno], new_dest);
+ if (regno < FIRST_PSEUDO_REGISTER)
+ new_dest = gen_rtx_REG (compare_mode, regno);
+ else
+ {
+ SUBST_MODE (regno_reg_rtx[regno], compare_mode);
+ new_dest = regno_reg_rtx[regno];
+ }
SUBST (SET_DEST (x), new_dest);
SUBST (XEXP (*cc_use, 0), new_dest);
{
SUBST(SET_SRC (x), op0);
src = SET_SRC (x);
- }
+ }
else
{
/* Otherwise, update the COMPARE if needed. */
+ (UNITS_PER_WORD - 1)) / UNITS_PER_WORD))
#ifndef WORD_REGISTER_OPERATIONS
&& (GET_MODE_SIZE (GET_MODE (src))
- < GET_MODE_SIZE (GET_MODE (SUBREG_REG (src))))
+ < GET_MODE_SIZE (GET_MODE (SUBREG_REG (src))))
#endif
#ifdef CANNOT_CHANGE_MODE_CLASS
&& ! (REG_P (dest) && REGNO (dest) < FIRST_PSEUDO_REGISTER
len = INTVAL (XEXP (x, 1));
pos = INTVAL (XEXP (x, 2));
- /* If this goes outside the object being extracted, replace the object
- with a (use (mem ...)) construct that only combine understands
- and is used only for this purpose. */
+ /* This should stay within the object being extracted, fail otherwise. */
if (len + pos > GET_MODE_BITSIZE (GET_MODE (XEXP (x, 0))))
- SUBST (XEXP (x, 0), gen_rtx_USE (GET_MODE (x), XEXP (x, 0)));
+ return x;
if (BITS_BIG_ENDIAN)
pos = GET_MODE_BITSIZE (GET_MODE (XEXP (x, 0))) - len - pos;
if (GET_CODE (x) == ZERO_EXTEND)
{
/* (zero_extend:DI (truncate:SI foo:DI)) is just foo:DI if we
- know that the last value didn't have any inappropriate bits
- set. */
+ know that the last value didn't have any inappropriate bits
+ set. */
if (GET_CODE (XEXP (x, 0)) == TRUNCATE
&& GET_MODE (XEXP (XEXP (x, 0), 0)) == GET_MODE (x)
&& GET_MODE_BITSIZE (GET_MODE (x)) <= HOST_BITS_PER_WIDE_INT
return SUBREG_REG (XEXP (x, 0));
/* (zero_extend:DI (truncate:SI foo:DI)) is just foo:DI when foo
- is a comparison and STORE_FLAG_VALUE permits. This is like
- the first case, but it works even when GET_MODE (x) is larger
- than HOST_WIDE_INT. */
+ is a comparison and STORE_FLAG_VALUE permits. This is like
+ the first case, but it works even when GET_MODE (x) is larger
+ than HOST_WIDE_INT. */
if (GET_CODE (XEXP (x, 0)) == TRUNCATE
&& GET_MODE (XEXP (XEXP (x, 0), 0)) == GET_MODE (x)
&& COMPARISON_P (XEXP (XEXP (x, 0), 0))
modewidth = GET_MODE_BITSIZE (GET_MODE (x));
if (modewidth + len >= pos)
- tem = simplify_shift_const (NULL_RTX, unsignedp ? LSHIFTRT : ASHIFTRT,
- GET_MODE (x),
- simplify_shift_const (NULL_RTX, ASHIFT,
- GET_MODE (x),
- XEXP (x, 0),
- modewidth - pos - len),
- modewidth - len);
-
+ {
+ enum machine_mode mode = GET_MODE (x);
+ tem = gen_lowpart (mode, XEXP (x, 0));
+ if (!tem || GET_CODE (tem) == CLOBBER)
+ return x;
+ tem = simplify_shift_const (NULL_RTX, ASHIFT, mode,
+ tem, modewidth - pos - len);
+ tem = simplify_shift_const (NULL_RTX, unsignedp ? LSHIFTRT : ASHIFTRT,
+ mode, tem, modewidth - len);
+ }
else if (unsignedp && len < HOST_BITS_PER_WIDE_INT)
tem = simplify_and_const_int (NULL_RTX, GET_MODE (x),
simplify_shift_const (NULL_RTX, LSHIFTRT,
len = INTVAL (XEXP (SET_DEST (x), 1));
pos = XEXP (SET_DEST (x), 2);
- /* If the position is constant and spans the width of INNER,
- surround INNER with a USE to indicate this. */
+ /* A constant position should stay within the width of INNER. */
if (GET_CODE (pos) == CONST_INT
&& INTVAL (pos) + len > GET_MODE_BITSIZE (GET_MODE (inner)))
- inner = gen_rtx_USE (GET_MODE (SET_DEST (x)), inner);
+ break;
if (BITS_BIG_ENDIAN)
{
it is an RTX that represents a variable starting position; otherwise,
POS is the (constant) starting bit position (counted from the LSB).
- INNER may be a USE. This will occur when we started with a bitfield
- that went outside the boundary of the object in memory, which is
- allowed on most machines. To isolate this case, we produce a USE
- whose mode is wide enough and surround the MEM with it. The only
- code that understands the USE is this routine. If it is not removed,
- it will cause the resulting insn not to match.
-
UNSIGNEDP is nonzero for an unsigned reference and zero for a
signed reference.
ignore the POS lowest bits, etc. */
enum machine_mode is_mode = GET_MODE (inner);
enum machine_mode inner_mode;
- enum machine_mode wanted_inner_mode = byte_mode;
+ enum machine_mode wanted_inner_mode;
enum machine_mode wanted_inner_reg_mode = word_mode;
enum machine_mode pos_mode = word_mode;
enum machine_mode extraction_mode = word_mode;
enum machine_mode tmode = mode_for_size (len, MODE_INT, 1);
- int spans_byte = 0;
rtx new = 0;
rtx orig_pos_rtx = pos_rtx;
HOST_WIDE_INT orig_pos;
- /* Get some information about INNER and get the innermost object. */
- if (GET_CODE (inner) == USE)
- /* (use:SI (mem:QI foo)) stands for (mem:SI foo). */
- /* We don't need to adjust the position because we set up the USE
- to pretend that it was a full-word object. */
- spans_byte = 1, inner = XEXP (inner, 0);
- else if (GET_CODE (inner) == SUBREG && subreg_lowpart_p (inner))
+ if (GET_CODE (inner) == SUBREG && subreg_lowpart_p (inner))
{
/* If going from (subreg:SI (mem:QI ...)) to (mem:QI ...),
consider just the QI as the memory to extract from.
appropriate STRICT_LOW_PART operation available.
For MEM, we can avoid an extract if the field starts on an appropriate
- boundary and we can change the mode of the memory reference. However,
- we cannot directly access the MEM if we have a USE and the underlying
- MEM is not TMODE. This combination means that MEM was being used in a
- context where bits outside its mode were being referenced; that is only
- valid in bit-field insns. */
+ boundary and we can change the mode of the memory reference. */
if (tmode != BLKmode
- && ! (spans_byte && inner_mode != tmode)
&& ((pos_rtx == 0 && (pos % BITS_PER_WORD) == 0
&& !MEM_P (inner)
+ && (inner_mode == tmode
+ || !REG_P (inner)
+ || TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (tmode),
+ GET_MODE_BITSIZE (inner_mode))
+ || reg_truncated_to_mode (tmode, inner))
&& (! in_dest
|| (REG_P (inner)
&& have_insn_for (STRICT_LOW_PART, tmode))))
don't do anything with zero-extending field extracts starting at
the low-order bit since they are simple AND operations. */
if (pos_rtx == 0 && pos == 0 && ! in_dest
- && ! in_compare && ! spans_byte && unsignedp)
+ && ! in_compare && unsignedp)
return 0;
- /* Unless we are allowed to span bytes or INNER is not MEM, reject this if
- we would be spanning bytes or if the position is not a constant and the
- length is not 1. In all other cases, we would only be going outside
- our object in cases when an original shift would have been
- undefined. */
- if (! spans_byte && MEM_P (inner)
+ /* Unless INNER is not MEM, reject this if we would be spanning bytes or
+ if the position is not a constant and the length is not 1. In all
+ other cases, we would only be going outside our object in cases when
+ an original shift would have been undefined. */
+ if (MEM_P (inner)
&& ((pos_rtx == 0 && pos + len > GET_MODE_BITSIZE (is_mode))
|| (pos_rtx != 0 && len != 1)))
return 0;
&& GET_MODE_SIZE (pos_mode) < GET_MODE_SIZE (GET_MODE (pos_rtx)))
pos_mode = GET_MODE (pos_rtx);
- /* If this is not from memory, the desired mode is wanted_inner_reg_mode;
- if we have to change the mode of memory and cannot, the desired mode is
- EXTRACTION_MODE. */
+ /* If this is not from memory, the desired mode is the preferred mode
+ for an extraction pattern's first input operand, or word_mode if there
+ is none. */
if (!MEM_P (inner))
wanted_inner_mode = wanted_inner_reg_mode;
- else if (inner_mode != wanted_inner_mode
- && (mode_dependent_address_p (XEXP (inner, 0))
- || MEM_VOLATILE_P (inner)))
- wanted_inner_mode = extraction_mode;
+ else
+ {
+ /* Be careful not to go beyond the extracted object and maintain the
+ natural alignment of the memory. */
+ wanted_inner_mode = smallest_mode_for_size (len, MODE_INT);
+ while (pos % GET_MODE_BITSIZE (wanted_inner_mode) + len
+ > GET_MODE_BITSIZE (wanted_inner_mode))
+ {
+ wanted_inner_mode = GET_MODE_WIDER_MODE (wanted_inner_mode);
+ gcc_assert (wanted_inner_mode != VOIDmode);
+ }
+
+ /* If we have to change the mode of memory and cannot, the desired mode
+ is EXTRACTION_MODE. */
+ if (inner_mode != wanted_inner_mode
+ && (mode_dependent_address_p (XEXP (inner, 0))
+ || MEM_VOLATILE_P (inner)
+ || pos_rtx))
+ wanted_inner_mode = extraction_mode;
+ }
orig_pos = pos;
Note that it can only be less than 0 if !MEM_P (inner). */
}
- /* If INNER has a wider mode, make it smaller. If this is a constant
- extract, try to adjust the byte to point to the byte containing
+ /* If INNER has a wider mode, and this is a constant extraction, try to
+ make it smaller and adjust the byte to point to the byte containing
the value. */
if (wanted_inner_mode != VOIDmode
+ && inner_mode != wanted_inner_mode
+ && ! pos_rtx
&& GET_MODE_SIZE (wanted_inner_mode) < GET_MODE_SIZE (is_mode)
- && ((MEM_P (inner)
- && (inner_mode == wanted_inner_mode
- || (! mode_dependent_address_p (XEXP (inner, 0))
- && ! MEM_VOLATILE_P (inner))))))
+ && MEM_P (inner)
+ && ! mode_dependent_address_p (XEXP (inner, 0))
+ && ! MEM_VOLATILE_P (inner))
{
int offset = 0;
/* If bytes are big endian and we had a paradoxical SUBREG, we must
adjust OFFSET to compensate. */
if (BYTES_BIG_ENDIAN
- && ! spans_byte
&& GET_MODE_SIZE (inner_mode) < GET_MODE_SIZE (is_mode))
offset -= GET_MODE_SIZE (is_mode) - GET_MODE_SIZE (inner_mode);
- /* If this is a constant position, we can move to the desired byte.
- Be careful not to go beyond the original object and maintain the
- natural alignment of the memory. */
- if (pos_rtx == 0)
- {
- enum machine_mode bfmode = smallest_mode_for_size (len, MODE_INT);
- offset += (pos / GET_MODE_BITSIZE (bfmode)) * GET_MODE_SIZE (bfmode);
- pos %= GET_MODE_BITSIZE (bfmode);
- }
+ /* We can now move to the desired byte. */
+ offset += (pos / GET_MODE_BITSIZE (wanted_inner_mode))
+ * GET_MODE_SIZE (wanted_inner_mode);
+ pos %= GET_MODE_BITSIZE (wanted_inner_mode);
if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN
- && ! spans_byte
&& is_mode != wanted_inner_mode)
offset = (GET_MODE_SIZE (is_mode)
- GET_MODE_SIZE (wanted_inner_mode) - offset);
- if (offset != 0 || inner_mode != wanted_inner_mode)
- inner = adjust_address_nv (inner, wanted_inner_mode, offset);
+ inner = adjust_address_nv (inner, wanted_inner_mode, offset);
}
/* If INNER is not memory, we can always get it into the proper mode. If we
|| orig_pos + len > GET_MODE_BITSIZE (wanted_inner_mode)))
return 0;
+ if (orig_pos < 0)
+ return 0;
+
inner = force_to_mode (inner, wanted_inner_mode,
pos_rtx
|| len + orig_pos >= HOST_BITS_PER_WIDE_INT
{
rtx newer = force_to_mode (tem, mode, ~(HOST_WIDE_INT) 0,
0);
-
+
/* If we have something other than a SUBREG, we might have
done an expansion, so rerun ourselves. */
if (GET_CODE (newer) != SUBREG)
newer = make_compound_operation (newer, in_code);
-
+
return newer;
}
fmt = GET_RTX_FORMAT (code);
copied = false;
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
- if (fmt[i] == 'e')
- {
- rtx op = canon_reg_for_combine (XEXP (x, i), reg);
+ if (fmt[i] == 'e')
+ {
+ rtx op = canon_reg_for_combine (XEXP (x, i), reg);
if (op != XEXP (x, i))
{
if (!copied)
x = copy_rtx (x);
}
XEXP (x, i) = op;
- }
- }
- else if (fmt[i] == 'E')
- {
- int j;
- for (j = 0; j < XVECLEN (x, i); j++)
+ }
+ }
+ else if (fmt[i] == 'E')
+ {
+ int j;
+ for (j = 0; j < XVECLEN (x, i); j++)
{
- rtx op = canon_reg_for_combine (XVECEXP (x, i, j), reg);
- if (op != XVECEXP (x, i, j))
+ rtx op = canon_reg_for_combine (XVECEXP (x, i, j), reg);
+ if (op != XVECEXP (x, i, j))
{
if (!copied)
{
x = copy_rtx (x);
}
XVECEXP (x, i, j) = op;
- }
+ }
}
}
return x;
}
+/* Return X converted to MODE. If the value is already truncated to
+ MODE we can just return a subreg even though in the general case we
+ would need an explicit truncation. */
+
+static rtx
+gen_lowpart_or_truncate (enum machine_mode mode, rtx x)
+{
+ if (GET_MODE_SIZE (GET_MODE (x)) <= GET_MODE_SIZE (mode)
+ || TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (mode),
+ GET_MODE_BITSIZE (GET_MODE (x)))
+ || (REG_P (x) && reg_truncated_to_mode (mode, x)))
+ return gen_lowpart (mode, x);
+ else
+ return simplify_gen_unary (TRUNCATE, mode, x, GET_MODE (x));
+}
+
/* See if X can be simplified knowing that we will only refer to it in
MODE and will only refer to those bits that are nonzero in MASK.
If other bits are being computed or if masking operations are done
nonzero = nonzero_bits (x, mode);
/* If none of the bits in X are needed, return a zero. */
- if (! just_select && (nonzero & mask) == 0)
+ if (!just_select && (nonzero & mask) == 0 && !side_effects_p (x))
x = const0_rtx;
/* If X is a CONST_INT, return a new one. Do this here since the
if (GET_CODE (x) == CONST_INT)
{
if (SCALAR_INT_MODE_P (mode))
- return gen_int_mode (INTVAL (x) & mask, mode);
+ return gen_int_mode (INTVAL (x) & mask, mode);
else
{
x = GEN_INT (INTVAL (x) & mask);
generating something that won't match. */
return x;
- case USE:
- /* X is a (use (mem ..)) that was made from a bit-field extraction that
- spanned the boundary of the MEM. If we are now masking so it is
- within that boundary, we don't need the USE any more. */
- if (! BITS_BIG_ENDIAN
- && (mask & ~GET_MODE_MASK (GET_MODE (XEXP (x, 0)))) == 0)
- return force_to_mode (XEXP (x, 0), mode, mask, next_select);
- break;
-
case SIGN_EXTEND:
case ZERO_EXTEND:
case ZERO_EXTRACT:
/* For most binary operations, just propagate into the operation and
change the mode if we have an operation of that mode. */
- op0 = gen_lowpart (op_mode,
- force_to_mode (XEXP (x, 0), mode, mask,
- next_select));
- op1 = gen_lowpart (op_mode,
- force_to_mode (XEXP (x, 1), mode, mask,
+ op0 = gen_lowpart_or_truncate (op_mode,
+ force_to_mode (XEXP (x, 0), mode, mask,
+ next_select));
+ op1 = gen_lowpart_or_truncate (op_mode,
+ force_to_mode (XEXP (x, 1), mode, mask,
next_select));
if (op_mode != GET_MODE (x) || op0 != XEXP (x, 0) || op1 != XEXP (x, 1))
else
mask = fuller_mask;
- op0 = gen_lowpart (op_mode,
- force_to_mode (XEXP (x, 0), op_mode,
- mask, next_select));
+ op0 = gen_lowpart_or_truncate (op_mode,
+ force_to_mode (XEXP (x, 0), op_mode,
+ mask, next_select));
if (op_mode != GET_MODE (x) || op0 != XEXP (x, 0))
x = simplify_gen_binary (code, op_mode, op0, XEXP (x, 1));
if ((mask & ~nonzero) == 0)
{
- x = simplify_shift_const (x, LSHIFTRT, GET_MODE (x),
+ x = simplify_shift_const (NULL_RTX, LSHIFTRT, GET_MODE (x),
XEXP (x, 0), INTVAL (XEXP (x, 1)));
if (GET_CODE (x) != ASHIFTRT)
return force_to_mode (x, mode, mask, next_select);
mask = fuller_mask;
unop:
- op0 = gen_lowpart (op_mode,
- force_to_mode (XEXP (x, 0), mode, mask,
- next_select));
+ op0 = gen_lowpart_or_truncate (op_mode,
+ force_to_mode (XEXP (x, 0), mode, mask,
+ next_select));
if (op_mode != GET_MODE (x) || op0 != XEXP (x, 0))
x = simplify_gen_unary (code, op_mode, op0, op_mode);
break;
written in a narrower mode. We play it safe and do not do so. */
SUBST (XEXP (x, 1),
- gen_lowpart (GET_MODE (x), force_to_mode (XEXP (x, 1), mode,
- mask, next_select)));
+ gen_lowpart_or_truncate (GET_MODE (x),
+ force_to_mode (XEXP (x, 1), mode,
+ mask, next_select)));
SUBST (XEXP (x, 2),
- gen_lowpart (GET_MODE (x), force_to_mode (XEXP (x, 2), mode,
- mask, next_select)));
+ gen_lowpart_or_truncate (GET_MODE (x),
+ force_to_mode (XEXP (x, 2), mode,
+ mask, next_select)));
break;
default:
}
/* Ensure we return a value of the proper mode. */
- return gen_lowpart (mode, x);
+ return gen_lowpart_or_truncate (mode, x);
}
\f
/* Return nonzero if X is an expression that has one of two values depending on
*ptrue = simplify_gen_relational (code, mode, VOIDmode,
true0, true1);
*pfalse = simplify_gen_relational (code, mode, VOIDmode,
- false0, false1);
+ false0, false1);
}
else
{
if (XEXP (x, 0) != r)
{
/* We must simplify the zero_extend here, before we lose
- track of the original inner_mode. */
+ track of the original inner_mode. */
new = simplify_unary_operation (ZERO_EXTEND, GET_MODE (x),
r, inner_mode);
if (new)
expanding a bit field assignment. When we apply the distributive
law to this, we get (ior (and (A (not B))) (and (B (not B)))),
which then simplifies to (and (A (not B))).
-
+
Note that no checks happen on the validity of applying the inverse
distributive law. This is pointless since we can do it in the
few places where this routine is called.
return NULL_RTX;
/* Otherwise, return an AND. */
- constop = trunc_int_for_mode (constop, mode);
- return simplify_gen_binary (AND, mode, varop, GEN_INT (constop));
+ return simplify_gen_binary (AND, mode, varop, gen_int_mode (constop, mode));
}
return tem;
if (!x)
- x = simplify_gen_binary (AND, GET_MODE (varop), varop, GEN_INT (constop));
+ x = simplify_gen_binary (AND, GET_MODE (varop), varop,
+ gen_int_mode (constop, mode));
if (GET_MODE (x) != mode)
x = gen_lowpart (mode, x);
return x;
if (reg_stat[REGNO (x)].last_set_value != 0
&& (reg_stat[REGNO (x)].last_set_mode == mode
- || (GET_MODE_CLASS (reg_stat[REGNO (x)].last_set_mode) == MODE_INT
+ || (GET_MODE_CLASS (reg_stat[REGNO (x)].last_set_mode) == MODE_INT
&& GET_MODE_CLASS (mode) == MODE_INT))
&& (reg_stat[REGNO (x)].last_set_label == label_tick
|| (REGNO (x) >= FIRST_PSEUDO_REGISTER
&& REG_N_SETS (REGNO (x)) == 1
&& ! REGNO_REG_SET_P
- (ENTRY_BLOCK_PTR->next_bb->il.rtl->global_live_at_start,
+ (ENTRY_BLOCK_PTR->next_bb->il.rtl->global_live_at_start,
REGNO (x))))
&& INSN_CUID (reg_stat[REGNO (x)].last_set) < subst_low_cuid)
{
{
#ifdef SHORT_IMMEDIATES_SIGN_EXTEND
/* If X is narrower than MODE and TEM is a non-negative
- constant that would appear negative in the mode of X,
- sign-extend it for use in reg_nonzero_bits because some
- machines (maybe most) will actually do the sign-extension
- and this is the conservative approach.
+ constant that would appear negative in the mode of X,
+ sign-extend it for use in reg_nonzero_bits because some
+ machines (maybe most) will actually do the sign-extension
+ and this is the conservative approach.
- ??? For 2.5, try to tighten up the MD files in this regard
- instead of this kludge. */
+ ??? For 2.5, try to tighten up the MD files in this regard
+ instead of this kludge. */
if (GET_MODE_BITSIZE (GET_MODE (x)) < GET_MODE_BITSIZE (mode)
&& GET_CODE (tem) == CONST_INT
unsigned HOST_WIDE_INT mask = reg_stat[REGNO (x)].nonzero_bits;
if (GET_MODE_BITSIZE (GET_MODE (x)) < GET_MODE_BITSIZE (mode))
- /* We don't know anything about the upper bits. */
- mask |= GET_MODE_MASK (mode) ^ GET_MODE_MASK (GET_MODE (x));
+ /* We don't know anything about the upper bits. */
+ mask |= GET_MODE_MASK (mode) ^ GET_MODE_MASK (GET_MODE (x));
*nonzero &= mask;
}
if (reg_stat[REGNO (x)].last_set_value != 0
&& reg_stat[REGNO (x)].last_set_mode == mode
&& (reg_stat[REGNO (x)].last_set_label == label_tick
- || (REGNO (x) >= FIRST_PSEUDO_REGISTER
+ || (REGNO (x) >= FIRST_PSEUDO_REGISTER
&& REG_N_SETS (REGNO (x)) == 1
&& ! REGNO_REG_SET_P
- (ENTRY_BLOCK_PTR->next_bb->il.rtl->global_live_at_start,
+ (ENTRY_BLOCK_PTR->next_bb->il.rtl->global_live_at_start,
REGNO (x))))
&& INSN_CUID (reg_stat[REGNO (x)].last_set) < subst_low_cuid)
{
if (nonzero_sign_valid && reg_stat[REGNO (x)].sign_bit_copies != 0
&& GET_MODE_BITSIZE (GET_MODE (x)) == GET_MODE_BITSIZE (mode))
*result = reg_stat[REGNO (x)].sign_bit_copies;
-
+
return NULL;
}
\f
== 0))
code = LSHIFTRT;
- if (code == LSHIFTRT
- && GET_MODE_BITSIZE (shift_mode) <= HOST_BITS_PER_WIDE_INT
- && !(nonzero_bits (varop, shift_mode) >> count))
- varop = const0_rtx;
- if (code == ASHIFT
- && GET_MODE_BITSIZE (shift_mode) <= HOST_BITS_PER_WIDE_INT
- && !((nonzero_bits (varop, shift_mode) << count)
- & GET_MODE_MASK (shift_mode)))
+ if (((code == LSHIFTRT
+ && GET_MODE_BITSIZE (shift_mode) <= HOST_BITS_PER_WIDE_INT
+ && !(nonzero_bits (varop, shift_mode) >> count))
+ || (code == ASHIFT
+ && GET_MODE_BITSIZE (shift_mode) <= HOST_BITS_PER_WIDE_INT
+ && !((nonzero_bits (varop, shift_mode) << count)
+ & GET_MODE_MASK (shift_mode))))
+ && !side_effects_p (varop))
varop = const0_rtx;
switch (GET_CODE (varop))
}
break;
- case USE:
- /* Similar to the case above, except that we can only do this if
- the resulting mode is the same as that of the underlying
- MEM and adjust the address depending on the *bits* endianness
- because of the way that bit-field extract insns are defined. */
- if ((code == ASHIFTRT || code == LSHIFTRT)
- && (tmode = mode_for_size (GET_MODE_BITSIZE (mode) - count,
- MODE_INT, 1)) != BLKmode
- && tmode == GET_MODE (XEXP (varop, 0)))
- {
- if (BITS_BIG_ENDIAN)
- new = XEXP (varop, 0);
- else
- {
- new = copy_rtx (XEXP (varop, 0));
- SUBST (XEXP (new, 0),
- plus_constant (XEXP (new, 0),
- count / BITS_PER_UNIT));
- }
-
- varop = gen_rtx_fmt_e (code == ASHIFTRT ? SIGN_EXTEND
- : ZERO_EXTEND, mode, new);
- count = 0;
- continue;
- }
- break;
-
case SUBREG:
/* If VAROP is a SUBREG, strip it as long as the inner operand has
the same number of words as what we've seen so far. Then store
&& INTVAL (XEXP (varop, 1)) >= 0
&& INTVAL (XEXP (varop, 1)) < GET_MODE_BITSIZE (GET_MODE (varop))
&& GET_MODE_BITSIZE (result_mode) <= HOST_BITS_PER_WIDE_INT
- && GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT)
+ && GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
+ && !VECTOR_MODE_P (result_mode))
{
enum rtx_code first_code = GET_CODE (varop);
unsigned int first_count = INTVAL (XEXP (varop, 1));
&& 0 > trunc_int_for_mode (INTVAL (XEXP (varop, 1)),
shift_mode))
&& (new = simplify_const_binary_operation (code, result_mode,
- XEXP (varop, 1),
- GEN_INT (count))) != 0
+ XEXP (varop, 1),
+ GEN_INT (count))) != 0
&& GET_CODE (new) == CONST_INT
&& merge_outer_ops (&outer_op, &outer_const, GET_CODE (varop),
INTVAL (new), result_mode, &complement_p))
for some (ashiftrt (xor)). */
if (GET_CODE (XEXP (varop, 1)) == CONST_INT
&& !(code == ASHIFTRT && GET_CODE (varop) == XOR
- && 0 > trunc_int_for_mode (INTVAL (XEXP (varop, 1)),
+ && 0 > trunc_int_for_mode (INTVAL (XEXP (varop, 1)),
shift_mode)))
{
rtx lhs = simplify_shift_const (NULL_RTX, code, shift_mode,
varop = apply_distributive_law (varop);
count = 0;
- continue;
+ continue;
}
break;
if (code == ASHIFT
&& GET_CODE (XEXP (varop, 1)) == CONST_INT
&& (new = simplify_const_binary_operation (ASHIFT, result_mode,
- XEXP (varop, 1),
- GEN_INT (count))) != 0
+ XEXP (varop, 1),
+ GEN_INT (count))) != 0
&& GET_CODE (new) == CONST_INT
&& merge_outer_ops (&outer_op, &outer_const, PLUS,
INTVAL (new), result_mode, &complement_p))
&& GET_CODE (XEXP (varop, 1)) == CONST_INT
&& mode_signbit_p (result_mode, XEXP (varop, 1))
&& (new = simplify_const_binary_operation (code, result_mode,
- XEXP (varop, 1),
- GEN_INT (count))) != 0
+ XEXP (varop, 1),
+ GEN_INT (count))) != 0
&& GET_CODE (new) == CONST_INT
&& merge_outer_ops (&outer_op, &outer_const, XOR,
INTVAL (new), result_mode, &complement_p))
GET_MODE_MASK (result_mode) >> orig_count);
/* Do the remainder of the processing in RESULT_MODE. */
- x = gen_lowpart (result_mode, x);
+ x = gen_lowpart_or_truncate (result_mode, x);
/* If COMPLEMENT_P is set, we have to complement X before doing the outer
operation. */
if (outer_op == AND)
x = simplify_and_const_int (NULL_RTX, result_mode, x, outer_const);
else if (outer_op == SET)
- /* This means that we have determined that the result is
- equivalent to a constant. This should be rare. */
- x = GEN_INT (outer_const);
+ {
+ /* This means that we have determined that the result is
+ equivalent to a constant. This should be rare. */
+ if (!side_effects_p (x))
+ x = GEN_INT (outer_const);
+ }
else if (GET_RTX_CLASS (outer_op) == RTX_UNARY)
x = simplify_gen_unary (outer_op, result_mode, x, result_mode);
else
&& ! unsigned_comparison_p
&& (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT)
&& ((unsigned HOST_WIDE_INT) const_op
- < (((unsigned HOST_WIDE_INT) 1
+ < (((unsigned HOST_WIDE_INT) 1
<< (GET_MODE_BITSIZE (mode) - 1))))
&& cmp_optab->handlers[(int) mode].insn_code != CODE_FOR_nothing)
{
HOST_WIDE_INT c1 = -INTVAL (XEXP (SUBREG_REG (op0), 1));
if ((c1 > 0
- && (unsigned HOST_WIDE_INT) c1
+ && (unsigned HOST_WIDE_INT) c1
< (unsigned HOST_WIDE_INT) 1 << (mode_width - 1)
&& (equality_comparison_p || unsigned_comparison_p)
/* (A - C1) zero-extends if it is positive and sign-extends
{
op0 = SUBREG_REG (op0);
continue;
- }
+ }
}
/* If the inner mode is narrower and we are extracting the low part,
case UNEQ: case LTGT:
case LT: case LTU: case UNLT: case LE: case LEU: case UNLE:
case GT: case GTU: case UNGT: case GE: case GEU: case UNGE:
- case UNORDERED: case ORDERED:
+ case UNORDERED: case ORDERED:
/* We can't do anything if OP0 is a condition code value, rather
than an actual data value. */
if (const_op != 0
{
op0 = simplify_and_const_int
(NULL_RTX, mode, gen_rtx_LSHIFTRT (mode,
- XEXP (op0, 1),
- XEXP (XEXP (op0, 0), 1)),
+ XEXP (op0, 1),
+ XEXP (XEXP (op0, 0), 1)),
(HOST_WIDE_INT) 1);
continue;
}
/* If this AND operation is really a ZERO_EXTEND from a narrower
mode, the constant fits within that mode, and this is either an
equality or unsigned comparison, try to do this comparison in
- the narrower mode. */
+ the narrower mode.
+
+ Note that in:
+
+ (ne:DI (and:DI (reg:DI 4) (const_int 0xffffffff)) (const_int 0))
+ -> (ne:DI (reg:SI 4) (const_int 0))
+
+ unless TRULY_NOOP_TRUNCATION allows it or the register is
+ known to hold a value of the required mode the
+ transformation is invalid. */
if ((equality_comparison_p || unsigned_comparison_p)
&& GET_CODE (XEXP (op0, 1)) == CONST_INT
&& (i = exact_log2 ((INTVAL (XEXP (op0, 1))
& GET_MODE_MASK (mode))
+ 1)) >= 0
&& const_op >> i == 0
- && (tmode = mode_for_size (i, MODE_INT, 1)) != BLKmode)
+ && (tmode = mode_for_size (i, MODE_INT, 1)) != BLKmode
+ && (TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (tmode),
+ GET_MODE_BITSIZE (GET_MODE (op0)))
+ || (REG_P (XEXP (op0, 0))
+ && reg_truncated_to_mode (tmode, XEXP (op0, 0)))))
{
op0 = gen_lowpart (tmode, XEXP (op0, 0));
continue;
{
/* For paradoxical subregs, allow case 1 as above. Case 3 isn't
implemented. */
- if (REG_P (SUBREG_REG (op0)))
+ if (REG_P (SUBREG_REG (op0)))
{
op0 = SUBREG_REG (op0);
op1 = gen_lowpart (GET_MODE (op0), op1);
reg_stat[i].last_set_nonzero_bits = 0;
reg_stat[i].last_set_sign_bit_copies = 0;
reg_stat[i].last_death = 0;
+ reg_stat[i].truncated_to_mode = 0;
}
/* Mark registers that are being referenced in this value. */
for (i = regno; i < endregno; i++)
{
reg_stat[i].last_set_label = label_tick;
- if (value && reg_stat[i].last_set_table_tick == label_tick)
+ if (!insn || (value && reg_stat[i].last_set_table_tick == label_tick))
reg_stat[i].last_set_invalid = 1;
else
reg_stat[i].last_set_invalid = 0;
if (GET_CODE (dest) == SUBREG)
dest = SUBREG_REG (dest);
+ if (!record_dead_insn)
+ {
+ if (REG_P (dest))
+ record_value_for_reg (dest, NULL_RTX, NULL_RTX);
+ return;
+ }
+
if (REG_P (dest))
{
/* If we are setting the whole register, we know its value. Otherwise
reg_stat[i].last_set_nonzero_bits = 0;
reg_stat[i].last_set_sign_bit_copies = 0;
reg_stat[i].last_death = 0;
+ reg_stat[i].truncated_to_mode = 0;
}
last_call_cuid = mem_last_set = INSN_CUID (insn);
- /* Don't bother recording what this insn does. It might set the
- return value register, but we can't combine into a call
- pattern anyway, so there's no point trying (and it may cause
- a crash, if e.g. we wind up asking for last_set_value of a
- SUBREG of the return value register). */
- return;
+ /* We can't combine into a call pattern. Remember, though, that
+ the return value register is set at this CUID. We could
+ still replace a register with the return value from the
+ wrong subroutine call! */
+ note_stores (PATTERN (insn), record_dead_and_set_regs_1, NULL_RTX);
}
-
- note_stores (PATTERN (insn), record_dead_and_set_regs_1, insn);
+ else
+ note_stores (PATTERN (insn), record_dead_and_set_regs_1, insn);
}
/* If a SUBREG has the promoted bit set, it is in fact a property of the
}
}
-/* Scan X for promoted SUBREGs. For each one found,
- note what it implies to the registers used in it. */
+/* Check if X, a register, is known to contain a value already
+ truncated to MODE. In this case we can use a subreg to refer to
+ the truncated value even though in the generic case we would need
+ an explicit truncation. */
+
+static bool
+reg_truncated_to_mode (enum machine_mode mode, rtx x)
+{
+ enum machine_mode truncated = reg_stat[REGNO (x)].truncated_to_mode;
+
+ if (truncated == 0 || reg_stat[REGNO (x)].truncation_label != label_tick)
+ return false;
+ if (GET_MODE_SIZE (truncated) <= GET_MODE_SIZE (mode))
+ return true;
+ if (TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (mode),
+ GET_MODE_BITSIZE (truncated)))
+ return true;
+ return false;
+}
+
+/* X is a REG or a SUBREG. If X is some sort of a truncation record
+ it. For non-TRULY_NOOP_TRUNCATION targets we might be able to turn
+ a truncate into a subreg using this information. */
+
+static void
+record_truncated_value (rtx x)
+{
+ enum machine_mode truncated_mode;
+
+ if (GET_CODE (x) == SUBREG && REG_P (SUBREG_REG (x)))
+ {
+ enum machine_mode original_mode = GET_MODE (SUBREG_REG (x));
+ truncated_mode = GET_MODE (x);
+
+ if (GET_MODE_SIZE (original_mode) <= GET_MODE_SIZE (truncated_mode))
+ return;
+
+ if (TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (truncated_mode),
+ GET_MODE_BITSIZE (original_mode)))
+ return;
+
+ x = SUBREG_REG (x);
+ }
+ /* ??? For hard-regs we now record everything. We might be able to
+ optimize this using last_set_mode. */
+ else if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
+ truncated_mode = GET_MODE (x);
+ else
+ return;
+
+ if (reg_stat[REGNO (x)].truncated_to_mode == 0
+ || reg_stat[REGNO (x)].truncation_label < label_tick
+ || (GET_MODE_SIZE (truncated_mode)
+ < GET_MODE_SIZE (reg_stat[REGNO (x)].truncated_to_mode)))
+ {
+ reg_stat[REGNO (x)].truncated_to_mode = truncated_mode;
+ reg_stat[REGNO (x)].truncation_label = label_tick;
+ }
+}
+
+/* Scan X for promoted SUBREGs and truncated REGs. For each one
+ found, note what it implies to the registers used in it. */
static void
-check_promoted_subreg (rtx insn, rtx x)
+check_conversions (rtx insn, rtx x)
{
- if (GET_CODE (x) == SUBREG && SUBREG_PROMOTED_VAR_P (x)
- && REG_P (SUBREG_REG (x)))
- record_promoted_value (insn, x);
+ if (GET_CODE (x) == SUBREG || REG_P (x))
+ {
+ if (GET_CODE (x) == SUBREG
+ && SUBREG_PROMOTED_VAR_P (x)
+ && REG_P (SUBREG_REG (x)))
+ record_promoted_value (insn, x);
+
+ record_truncated_value (x);
+ }
else
{
const char *format = GET_RTX_FORMAT (GET_CODE (x));
switch (format[i])
{
case 'e':
- check_promoted_subreg (insn, XEXP (x, i));
+ check_conversions (insn, XEXP (x, i));
break;
case 'V':
case 'E':
if (XVEC (x, i) != 0)
for (j = 0; j < XVECLEN (x, i); j++)
- check_promoted_subreg (insn, XVECEXP (x, i, j));
+ check_conversions (insn, XVECEXP (x, i, j));
break;
}
}
{
rtx place = 0, place2 = 0;
- /* If this NOTE references a pseudo register, ensure it references
- the latest copy of that register. */
- if (XEXP (note, 0) && REG_P (XEXP (note, 0))
- && REGNO (XEXP (note, 0)) >= FIRST_PSEUDO_REGISTER)
- XEXP (note, 0) = regno_reg_rtx[REGNO (XEXP (note, 0))];
-
next_note = XEXP (note, 1);
switch (REG_NOTE_KIND (note))
{
if (place && JUMP_P (place))
{
rtx label = JUMP_LABEL (place);
-
+
if (!label)
JUMP_LABEL (place) = XEXP (note, 0);
else
if (place2 && JUMP_P (place2))
{
rtx label = JUMP_LABEL (place2);
-
+
if (!label)
JUMP_LABEL (place2) = XEXP (note, 0);
else
break;
case REG_DEAD:
- /* If the register is used as an input in I3, it dies there.
+ /* If we replaced the right hand side of FROM_INSN with a
+ REG_EQUAL note, the original use of the dying register
+ will not have been combined into I3 and I2. In such cases,
+ FROM_INSN is guaranteed to be the first of the combined
+ instructions, so we simply need to search back before
+ FROM_INSN for the previous use or set of this register,
+ then alter the notes there appropriately.
+
+ If the register is used as an input in I3, it dies there.
Similarly for I2, if it is nonzero and adjacent to I3.
If the register is not used as an input in either I3 or I2
use of A and put the death note there. */
if (from_insn
- && CALL_P (from_insn)
- && find_reg_fusage (from_insn, USE, XEXP (note, 0)))
- place = from_insn;
- else if (reg_referenced_p (XEXP (note, 0), PATTERN (i3)))
- place = i3;
- else if (i2 != 0 && next_nonnote_insn (i2) == i3
- && reg_referenced_p (XEXP (note, 0), PATTERN (i2)))
- place = i2;
-
- if (place == 0
- && (rtx_equal_p (XEXP (note, 0), elim_i2)
- || rtx_equal_p (XEXP (note, 0), elim_i1)))
- break;
+ && from_insn == replaced_rhs_insn
+ && !reg_overlap_mentioned_p (XEXP (note, 0), replaced_rhs_value))
+ tem = from_insn;
+ else
+ {
+ if (from_insn
+ && CALL_P (from_insn)
+ && find_reg_fusage (from_insn, USE, XEXP (note, 0)))
+ place = from_insn;
+ else if (reg_referenced_p (XEXP (note, 0), PATTERN (i3)))
+ place = i3;
+ else if (i2 != 0 && next_nonnote_insn (i2) == i3
+ && reg_referenced_p (XEXP (note, 0), PATTERN (i2)))
+ place = i2;
+ else if (rtx_equal_p (XEXP (note, 0), elim_i2)
+ || rtx_equal_p (XEXP (note, 0), elim_i1))
+ break;
+ tem = i3;
+ }
if (place == 0)
{
basic_block bb = this_basic_block;
- /* You might think you could search back from FROM_INSN
- rather than from I3, but combine tries to split invalid
- combined instructions. This can result in the old I2
- or I1 moving later in the insn sequence. */
- for (tem = PREV_INSN (i3); place == 0; tem = PREV_INSN (tem))
+ for (tem = PREV_INSN (tem); place == 0; tem = PREV_INSN (tem))
{
if (! INSN_P (tem))
{
continue;
}
- /* If the register is being set at TEM, see if that is all
- TEM is doing. If so, delete TEM. Otherwise, make this
- into a REG_UNUSED note instead. Don't delete sets to
- global register vars. */
- if ((REGNO (XEXP (note, 0)) >= FIRST_PSEUDO_REGISTER
- || !global_regs[REGNO (XEXP (note, 0))])
+ /* If TEM is a (reaching) definition of the use to which the
+ note was attached, see if that is all TEM is doing. If so,
+ delete TEM. Otherwise, make this into a REG_UNUSED note
+ instead. Don't delete sets to global register vars. */
+ if ((!from_insn
+ || INSN_CUID (tem) < INSN_CUID (from_insn))
+ && (REGNO (XEXP (note, 0)) >= FIRST_PSEUDO_REGISTER
+ || !global_regs[REGNO (XEXP (note, 0))])
&& reg_set_p (XEXP (note, 0), PATTERN (tem)))
{
rtx set = single_set (tem);
|| (CALL_P (tem)
&& find_reg_fusage (tem, USE, XEXP (note, 0))))
{
- /* This may not be the correct place for the death
- note if FROM_INSN is before TEM, and the reg is
- set between FROM_INSN and TEM. The reg might
- die two or more times. An existing death note
- means we are looking at the wrong live range. */
- if (from_insn
- && INSN_CUID (from_insn) < INSN_CUID (tem)
- && find_regno_note (tem, REG_DEAD,
- REGNO (XEXP (note, 0))))
- {
- tem = from_insn;
- if (tem == BB_HEAD (bb))
- break;
- continue;
- }
-
place = tem;
/* If we are doing a 3->2 combination, and we have a
}
/* Try combining insns through substitution. */
-static void
+static unsigned int
rest_of_handle_combine (void)
{
int rebuild_jump_labels_after_combine
delete_dead_jumptables ();
cleanup_cfg (CLEANUP_EXPENSIVE | CLEANUP_UPDATE_LIFE);
}
+ return 0;
}
struct tree_opt_pass pass_combine =
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