static unsigned int combine_max_regno;
-/* Record last point of death of (hard or pseudo) register n. */
+struct reg_stat {
+ /* Record last point of death of (hard or pseudo) register n. */
+ rtx last_death;
-static rtx *reg_last_death;
+ /* Record last point of modification of (hard or pseudo) register n. */
+ rtx last_set;
-/* Record last point of modification of (hard or pseudo) register n. */
+ /* The next group of fields allows the recording of the last value assigned
+ to (hard or pseudo) register n. We use this information to see if an
+ operation being processed is redundant given a prior operation performed
+ on the register. For example, an `and' with a constant is redundant if
+ all the zero bits are already known to be turned off.
-static rtx *reg_last_set;
+ We use an approach similar to that used by cse, but change it in the
+ following ways:
+
+ (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.
+
+ Therefore, we maintain the following fields:
+
+ last_set_value the last value assigned
+ last_set_label records the value of label_tick when the
+ register was assigned
+ last_set_table_tick records the value of label_tick when a
+ value using the register is assigned
+ last_set_invalid set to nonzero when it is not valid
+ to use the value of this register in some
+ register's value
+
+ To understand the usage of these tables, it is important to understand
+ the distinction between the value in last_set_value being valid and
+ the register being validly contained in some other expression in the
+ table.
+
+ (The next two parameters are out of date).
+
+ reg_stat[i].last_set_value is valid if it is nonzero, and either
+ reg_n_sets[i] is 1 or reg_stat[i].last_set_label == label_tick.
+
+ Register I may validly appear in any expression returned for the value
+ of another register if reg_n_sets[i] is 1. It may also appear in the
+ value for register J if reg_stat[j].last_set_invalid is zero, or
+ reg_stat[i].last_set_label < reg_stat[j].last_set_label.
+
+ If an expression is found in the table containing a register which may
+ not validly appear in an expression, the register is replaced by
+ something that won't match, (clobber (const_int 0)). */
+
+ /* Record last value assigned to (hard or pseudo) register n. */
+
+ rtx last_set_value;
+
+ /* Record the value of label_tick when an expression involving register n
+ is placed in last_set_value. */
+
+ int last_set_table_tick;
+
+ /* Record the value of label_tick when the value for register n is placed in
+ last_set_value. */
+
+ int last_set_label;
+
+ /* These fields are maintained in parallel with last_set_value and are
+ used to store the mode in which the register was last set, te bits
+ that were known to be zero when it was last set, and the number of
+ sign bits copies it was known to have when it was last set. */
+
+ unsigned HOST_WIDE_INT last_set_nonzero_bits;
+ char last_set_sign_bit_copies;
+ 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
+ assigned to and last_set_table_tick == label_tick. */
+
+ char last_set_invalid;
+
+ /* Some registers that are set more than once and used in more than one
+ basic block are nevertheless always set in similar ways. For example,
+ a QImode register may be loaded from memory in two places on a machine
+ where byte loads zero extend.
+
+ We record in the following fields if a register has some leading bits
+ that are always equal to the sign bit, and what we know about the
+ nonzero bits of a register, specifically which bits are known to be
+ zero.
+
+ If an entry is zero, it means that we don't know anything special. */
+
+ unsigned char sign_bit_copies;
+
+ unsigned HOST_WIDE_INT nonzero_bits;
+};
+
+static struct reg_stat *reg_stat;
/* Record the cuid of the last insn that invalidated memory
(anything that writes memory, and subroutine calls, but not pushes). */
those blocks as starting points. */
static sbitmap refresh_blocks;
\f
-/* The next group of arrays allows the recording of the last value assigned
- to (hard or pseudo) register n. We use this information to see if an
- operation being processed is redundant given a prior operation performed
- on the register. For example, an `and' with a constant is redundant if
- all the zero bits are already known to be turned off.
-
- We use an approach similar to that used by cse, but change it in the
- following ways:
-
- (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.
-
- Therefore, we maintain the following arrays:
-
- reg_last_set_value the last value assigned
- reg_last_set_label records the value of label_tick when the
- register was assigned
- reg_last_set_table_tick records the value of label_tick when a
- value using the register is assigned
- reg_last_set_invalid set to nonzero when it is not valid
- to use the value of this register in some
- register's value
-
- To understand the usage of these tables, it is important to understand
- the distinction between the value in reg_last_set_value being valid
- and the register being validly contained in some other expression in the
- table.
-
- Entry I in reg_last_set_value is valid if it is nonzero, and either
- reg_n_sets[i] is 1 or reg_last_set_label[i] == label_tick.
-
- Register I may validly appear in any expression returned for the value
- of another register if reg_n_sets[i] is 1. It may also appear in the
- value for register J if reg_last_set_label[i] < reg_last_set_label[j] or
- reg_last_set_invalid[j] is zero.
-
- If an expression is found in the table containing a register which may
- not validly appear in an expression, the register is replaced by
- something that won't match, (clobber (const_int 0)).
-
- reg_last_set_invalid[i] is set nonzero when register I is being assigned
- to and reg_last_set_table_tick[i] == label_tick. */
-
-/* Record last value assigned to (hard or pseudo) register n. */
-
-static rtx *reg_last_set_value;
-
-/* Record the value of label_tick when the value for register n is placed in
- reg_last_set_value[n]. */
-
-static int *reg_last_set_label;
-
-/* Record the value of label_tick when an expression involving register n
- is placed in reg_last_set_value. */
-
-static int *reg_last_set_table_tick;
-
-/* Set nonzero if references to register n in expressions should not be
- used. */
-
-static char *reg_last_set_invalid;
-
/* Incremented for each label. */
static int label_tick;
-/* Some registers that are set more than once and used in more than one
- basic block are nevertheless always set in similar ways. For example,
- a QImode register may be loaded from memory in two places on a machine
- where byte loads zero extend.
-
- We record in the following array what we know about the nonzero
- bits of a register, specifically which bits are known to be zero.
-
- If an entry is zero, it means that we don't know anything special. */
-
-static unsigned HOST_WIDE_INT *reg_nonzero_bits;
-
-/* Mode used to compute significance in reg_nonzero_bits. It is the largest
- integer mode that can fit in HOST_BITS_PER_WIDE_INT. */
+/* Mode used to compute significance in reg_stat[].nonzero_bits. It is the
+ largest integer mode that can fit in HOST_BITS_PER_WIDE_INT. */
static enum machine_mode nonzero_bits_mode;
-/* Nonzero if we know that a register has some leading bits that are always
- equal to the sign bit. */
-
-static unsigned char *reg_sign_bit_copies;
-
-/* Nonzero when reg_nonzero_bits and reg_sign_bit_copies can be safely used.
- It is zero while computing them and after combine has completed. This
- former test prevents propagating values based on previously set values,
- which can be incorrect if a variable is modified in a loop. */
+/* Nonzero when reg_stat[].nonzero_bits and reg_stat[].sign_bit_copies can
+ be safely used. It is zero while computing them and after combine has
+ completed. This former test prevents propagating values based on
+ previously set values, which can be incorrect if a variable is modified
+ in a loop. */
static int nonzero_sign_valid;
-/* These arrays are maintained in parallel with reg_last_set_value
- and are used to store the mode in which the register was last set,
- the bits that were known to be zero when it was last set, and the
- number of sign bits copies it was known to have when it was last set. */
-
-static enum machine_mode *reg_last_set_mode;
-static unsigned HOST_WIDE_INT *reg_last_set_nonzero_bits;
-static char *reg_last_set_sign_bit_copies;
\f
/* Record one modification to rtl structure
to be undone by storing old_contents into *where.
static void do_SUBST (rtx *, rtx);
static void do_SUBST_INT (int *, int);
-static void init_reg_last_arrays (void);
+static void init_reg_last (void);
static void setup_incoming_promotions (void);
static void set_nonzero_bits_and_sign_copies (rtx, rtx, void *);
static int cant_combine_insn_p (rtx);
static void undo_commit (void);
static rtx *find_split_point (rtx *, rtx);
static rtx subst (rtx, rtx, rtx, int, int);
-static rtx combine_simplify_rtx (rtx, enum machine_mode, int, int);
+static rtx combine_simplify_rtx (rtx, enum machine_mode, int);
static rtx simplify_if_then_else (rtx);
static rtx simplify_set (rtx);
-static rtx simplify_logical (rtx, int);
+static rtx simplify_logical (rtx);
static rtx expand_compound_operation (rtx);
static rtx expand_field_assignment (rtx);
static rtx make_extraction (enum machine_mode, rtx, HOST_WIDE_INT,
See comments in gen_lowpart_for_combine. */
gen_lowpart = gen_lowpart_for_combine;
- reg_nonzero_bits = xcalloc (nregs, sizeof (unsigned HOST_WIDE_INT));
- reg_sign_bit_copies = xcalloc (nregs, sizeof (unsigned char));
-
- reg_last_death = xmalloc (nregs * sizeof (rtx));
- reg_last_set = xmalloc (nregs * sizeof (rtx));
- reg_last_set_value = xmalloc (nregs * sizeof (rtx));
- reg_last_set_table_tick = xmalloc (nregs * sizeof (int));
- reg_last_set_label = xmalloc (nregs * sizeof (int));
- reg_last_set_invalid = xmalloc (nregs * sizeof (char));
- reg_last_set_mode = xmalloc (nregs * sizeof (enum machine_mode));
- reg_last_set_nonzero_bits = xmalloc (nregs * sizeof (HOST_WIDE_INT));
- reg_last_set_sign_bit_copies = xmalloc (nregs * sizeof (char));
-
- init_reg_last_arrays ();
+ reg_stat = xcalloc (nregs, sizeof (struct reg_stat));
init_recog_no_volatile ();
nonzero_bits_mode = mode_for_size (HOST_BITS_PER_WIDE_INT, MODE_INT, 0);
- /* Don't use reg_nonzero_bits when computing it. This can cause problems
- when, for example, we have j <<= 1 in a loop. */
+ /* Don't use reg_stat[].nonzero_bits when computing it. This can cause
+ problems when, for example, we have j <<= 1 in a loop. */
nonzero_sign_valid = 0;
label_tick = 1;
last_call_cuid = 0;
mem_last_set = 0;
- init_reg_last_arrays ();
+ init_reg_last ();
setup_incoming_promotions ();
FOR_EACH_BB (this_basic_block)
/* Clean up. */
sbitmap_free (refresh_blocks);
- free (reg_nonzero_bits);
- free (reg_sign_bit_copies);
- free (reg_last_death);
- free (reg_last_set);
- free (reg_last_set_value);
- free (reg_last_set_table_tick);
- free (reg_last_set_label);
- free (reg_last_set_invalid);
- free (reg_last_set_mode);
- free (reg_last_set_nonzero_bits);
- free (reg_last_set_sign_bit_copies);
+ free (reg_stat);
free (uid_cuid);
{
return new_direct_jump_p;
}
-/* Wipe the reg_last_xxx arrays in preparation for another pass. */
+/* Wipe the last_xxx fields of reg_stat in preparation for another pass. */
static void
-init_reg_last_arrays (void)
+init_reg_last (void)
{
- unsigned int nregs = combine_max_regno;
-
- memset (reg_last_death, 0, nregs * sizeof (rtx));
- memset (reg_last_set, 0, nregs * sizeof (rtx));
- memset (reg_last_set_value, 0, nregs * sizeof (rtx));
- memset (reg_last_set_table_tick, 0, nregs * sizeof (int));
- memset (reg_last_set_label, 0, nregs * sizeof (int));
- memset (reg_last_set_invalid, 0, nregs * sizeof (char));
- memset (reg_last_set_mode, 0, nregs * sizeof (enum machine_mode));
- memset (reg_last_set_nonzero_bits, 0, nregs * sizeof (HOST_WIDE_INT));
- memset (reg_last_set_sign_bit_copies, 0, nregs * sizeof (char));
+ unsigned int i;
+ for (i = 0; i < combine_max_regno; i++)
+ memset (reg_stat + i, 0, offsetof (struct reg_stat, sign_bit_copies));
}
\f
/* Set up any promoted values for incoming argument registers. */
{
if (set == 0 || GET_CODE (set) == CLOBBER)
{
- reg_nonzero_bits[REGNO (x)] = GET_MODE_MASK (GET_MODE (x));
- reg_sign_bit_copies[REGNO (x)] = 1;
+ reg_stat[REGNO (x)].nonzero_bits = GET_MODE_MASK (GET_MODE (x));
+ reg_stat[REGNO (x)].sign_bit_copies = 1;
return;
}
#ifdef SHORT_IMMEDIATES_SIGN_EXTEND
/* If X is narrower than a word and SRC 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
+ sign-extend it for use in reg_stat[].nonzero_bits because some
machines (maybe most) will actually do the sign-extension
and this is the conservative approach.
#endif
/* Don't call nonzero_bits if it cannot change anything. */
- if (reg_nonzero_bits[REGNO (x)] != ~(unsigned HOST_WIDE_INT) 0)
- reg_nonzero_bits[REGNO (x)]
+ if (reg_stat[REGNO (x)].nonzero_bits != ~(unsigned HOST_WIDE_INT) 0)
+ reg_stat[REGNO (x)].nonzero_bits
|= nonzero_bits (src, nonzero_bits_mode);
num = num_sign_bit_copies (SET_SRC (set), GET_MODE (x));
- if (reg_sign_bit_copies[REGNO (x)] == 0
- || reg_sign_bit_copies[REGNO (x)] > num)
- reg_sign_bit_copies[REGNO (x)] = num;
+ if (reg_stat[REGNO (x)].sign_bit_copies == 0
+ || reg_stat[REGNO (x)].sign_bit_copies > num)
+ reg_stat[REGNO (x)].sign_bit_copies = num;
}
else
{
- reg_nonzero_bits[REGNO (x)] = GET_MODE_MASK (GET_MODE (x));
- reg_sign_bit_copies[REGNO (x)] = 1;
+ reg_stat[REGNO (x)].nonzero_bits = GET_MODE_MASK (GET_MODE (x));
+ reg_stat[REGNO (x)].sign_bit_copies = 1;
}
}
}
does not use any registers whose values alter in between. However,
If the insns are adjacent, a use can't cross a set even though we
think it might (this can happen for a sequence of insns each setting
- the same destination; reg_last_set of that register might point to
+ the same destination; last_set of that register might point to
a NOTE). If INSN has a REG_EQUIV note, the register is always
equivalent to the memory so the substitution is valid even if there
are intervening stores. Also, don't move a volatile asm or
&& GET_CODE (SET_DEST (XVECEXP (newpat, 0, 1))) != STRICT_LOW_PART
&& ! (temp = SET_DEST (XVECEXP (newpat, 0, 1)),
(GET_CODE (temp) == REG
- && reg_nonzero_bits[REGNO (temp)] != 0
+ && reg_stat[REGNO (temp)].nonzero_bits != 0
&& GET_MODE_BITSIZE (GET_MODE (temp)) < BITS_PER_WORD
&& GET_MODE_BITSIZE (GET_MODE (temp)) < HOST_BITS_PER_INT
- && (reg_nonzero_bits[REGNO (temp)]
+ && (reg_stat[REGNO (temp)].nonzero_bits
!= GET_MODE_MASK (word_mode))))
&& ! (GET_CODE (SET_DEST (XVECEXP (newpat, 0, 1))) == SUBREG
&& (temp = SUBREG_REG (SET_DEST (XVECEXP (newpat, 0, 1))),
(GET_CODE (temp) == REG
- && reg_nonzero_bits[REGNO (temp)] != 0
+ && reg_stat[REGNO (temp)].nonzero_bits != 0
&& GET_MODE_BITSIZE (GET_MODE (temp)) < BITS_PER_WORD
&& GET_MODE_BITSIZE (GET_MODE (temp)) < HOST_BITS_PER_INT
- && (reg_nonzero_bits[REGNO (temp)]
+ && (reg_stat[REGNO (temp)].nonzero_bits
!= GET_MODE_MASK (word_mode)))))
&& ! reg_overlap_mentioned_p (SET_DEST (XVECEXP (newpat, 0, 1)),
SET_SRC (XVECEXP (newpat, 0, 1)))
REG_N_SETS (regno)--;
}
- /* Update reg_nonzero_bits et al for any changes that may have been made
- to this insn. The order of set_nonzero_bits_and_sign_copies() is
- important. Because newi2pat can affect nonzero_bits of newpat */
+ /* Update reg_stat[].nonzero_bits et al for any changes that may have
+ been made to this insn. The order of
+ set_nonzero_bits_and_sign_copies() is important. Because newi2pat
+ can affect nonzero_bits of newpat */
if (newi2pat)
note_stores (newi2pat, set_nonzero_bits_and_sign_copies, NULL);
note_stores (newpat, set_nonzero_bits_and_sign_copies, NULL);
/* If X is sufficiently simple, don't bother trying to do anything
with it. */
if (code != CONST_INT && code != REG && code != CLOBBER)
- x = combine_simplify_rtx (x, op0_mode, i == 3, in_dest);
+ x = combine_simplify_rtx (x, op0_mode, in_dest);
if (GET_CODE (x) == code)
break;
outer level; call `subst' to simplify recursively. Return the new
expression.
- OP0_MODE is the original mode of XEXP (x, 0); LAST is nonzero if this
- will be the iteration even if an expression with a code different from
- X is returned; IN_DEST is nonzero if we are inside a SET_DEST. */
+ OP0_MODE is the original mode of XEXP (x, 0). IN_DEST is nonzero
+ if we are inside a SET_DEST. */
static rtx
-combine_simplify_rtx (rtx x, enum machine_mode op0_mode, int last,
- int in_dest)
+combine_simplify_rtx (rtx x, enum machine_mode op0_mode, int in_dest)
{
enum rtx_code code = GET_CODE (x);
enum machine_mode mode = GET_MODE (x);
{
/* Try to simplify the expression further. */
rtx tor = gen_binary (IOR, mode, XEXP (x, 0), XEXP (x, 1));
- temp = combine_simplify_rtx (tor, mode, last, in_dest);
+ temp = combine_simplify_rtx (tor, mode, in_dest);
/* If we could, great. If not, do not go ahead with the IOR
replacement, since PLUS appears in many special purpose
case AND:
case IOR:
case XOR:
- return simplify_logical (x, last);
+ return simplify_logical (x);
case ABS:
/* (abs (neg <foo>)) -> (abs <foo>) */
rtx op0, op1, tmp;
int other_changed = 0;
enum machine_mode compare_mode = GET_MODE (dest);
- enum machine_mode tmp_mode;
if (GET_CODE (src) == COMPARE)
op0 = XEXP (src, 0), op1 = XEXP (src, 1);
else
op0 = src, op1 = const0_rtx;
- /* Check whether the comparison is known at compile time. */
- if (GET_MODE (op0) != VOIDmode)
- tmp_mode = GET_MODE (op0);
- else if (GET_MODE (op1) != VOIDmode)
- tmp_mode = GET_MODE (op1);
+ tmp = simplify_relational_operation (old_code, compare_mode, VOIDmode,
+ op0, op1);
+ if (!tmp)
+ new_code = old_code;
+ else if (!CONSTANT_P (tmp))
+ {
+ new_code = GET_CODE (tmp);
+ op0 = XEXP (tmp, 0);
+ op1 = XEXP (tmp, 1);
+ }
else
- tmp_mode = compare_mode;
- tmp = simplify_const_relational_operation (old_code, tmp_mode,
- op0, op1);
- if (tmp != NULL_RTX)
{
rtx pat = PATTERN (other_insn);
undobuf.other_insn = other_insn;
}
/* Simplify our comparison, if possible. */
- new_code = simplify_comparison (old_code, &op0, &op1);
+ new_code = simplify_comparison (new_code, &op0, &op1);
#ifdef SELECT_CC_MODE
/* If this machine has CC modes other than CCmode, check to see if we
need to use a different CC mode here. */
- compare_mode = SELECT_CC_MODE (new_code, op0, op1);
+ if (GET_MODE_CLASS (GET_MODE (op0)) == MODE_CC)
+ compare_mode = GET_MODE (op0);
+ else
+ compare_mode = SELECT_CC_MODE (new_code, op0, op1);
#ifndef HAVE_cc0
/* If the mode changed, we have to change SET_DEST, the mode in the
}
\f
/* Simplify, X, and AND, IOR, or XOR operation, and return the simplified
- result. LAST is nonzero if this is the last retry. */
+ result. */
static rtx
-simplify_logical (rtx x, int last)
+simplify_logical (rtx x)
{
enum machine_mode mode = GET_MODE (x);
rtx op0 = XEXP (x, 0);
/* If we have (ior (and (X C1) C2)) and the next restart would be
the last, simplify this by making C1 as small as possible
- and then exit. */
- if (last
- && GET_CODE (x) == IOR && GET_CODE (op0) == AND
+ and then exit. Only do this if C1 actually changes: for now
+ this only saves memory but, should this transformation be
+ moved to simplify-rtx.c, we'd risk unbounded recursion there. */
+ if (GET_CODE (x) == IOR && GET_CODE (op0) == AND
&& GET_CODE (XEXP (op0, 1)) == CONST_INT
- && GET_CODE (op1) == CONST_INT)
+ && GET_CODE (op1) == CONST_INT
+ && (INTVAL (XEXP (op0, 1)) & INTVAL (op1)) != 0)
return gen_binary (IOR, mode,
gen_binary (AND, mode, XEXP (op0, 0),
GEN_INT (INTVAL (XEXP (op0, 1))
{
/* Get the bit number of the first 1 bit from the right, -1 if none. */
int pos = exact_log2 (m & -m);
- int len;
+ int len = 0;
- if (pos < 0)
- return -1;
-
- /* Now shift off the low-order zero bits and see if we have a power of
- two minus 1. */
- len = exact_log2 ((m >> pos) + 1);
+ if (pos >= 0)
+ /* Now shift off the low-order zero bits and see if we have a
+ power of two minus 1. */
+ len = exact_log2 ((m >> pos) + 1);
if (len <= 0)
- return -1;
+ pos = -1;
*plen = len;
return pos;
value. Otherwise, use the previously-computed global nonzero bits
for this register. */
- if (reg_last_set_value[REGNO (x)] != 0
- && (reg_last_set_mode[REGNO (x)] == mode
- || (GET_MODE_CLASS (reg_last_set_mode[REGNO (x)]) == MODE_INT
+ 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 (mode) == MODE_INT))
- && (reg_last_set_label[REGNO (x)] == label_tick
+ && (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->global_live_at_start,
REGNO (x))))
- && INSN_CUID (reg_last_set[REGNO (x)]) < subst_low_cuid)
- return reg_last_set_nonzero_bits[REGNO (x)] & nonzero;
+ && INSN_CUID (reg_stat[REGNO (x)].last_set) < subst_low_cuid)
+ return reg_stat[REGNO (x)].last_set_nonzero_bits & nonzero;
tem = get_last_value (x);
#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
+ sign-extend it for use in reg_stat[].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
#endif
return nonzero_bits_with_known (tem, mode) & nonzero;
}
- else if (nonzero_sign_valid && reg_nonzero_bits[REGNO (x)])
+ else if (nonzero_sign_valid && reg_stat[REGNO (x)].nonzero_bits)
{
- unsigned HOST_WIDE_INT mask = reg_nonzero_bits[REGNO (x)];
+ unsigned HOST_WIDE_INT mask = reg_stat[REGNO (x)].nonzero_bits;
if (GET_MODE_BITSIZE (GET_MODE (x)) < mode_width)
/* We don't know anything about the upper bits. */
return GET_MODE_BITSIZE (Pmode) - GET_MODE_BITSIZE (ptr_mode) + 1;
#endif
- if (reg_last_set_value[REGNO (x)] != 0
- && reg_last_set_mode[REGNO (x)] == mode
- && (reg_last_set_label[REGNO (x)] == label_tick
+ 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
&& REG_N_SETS (REGNO (x)) == 1
&& ! REGNO_REG_SET_P (ENTRY_BLOCK_PTR->next_bb->global_live_at_start,
REGNO (x))))
- && INSN_CUID (reg_last_set[REGNO (x)]) < subst_low_cuid)
- return reg_last_set_sign_bit_copies[REGNO (x)];
+ && INSN_CUID (reg_stat[REGNO (x)].last_set) < subst_low_cuid)
+ return reg_stat[REGNO (x)].last_set_sign_bit_copies;
tem = get_last_value (x);
if (tem != 0)
return num_sign_bit_copies_with_known (tem, mode);
- if (nonzero_sign_valid && reg_sign_bit_copies[REGNO (x)] != 0
+ if (nonzero_sign_valid && reg_stat[REGNO (x)].sign_bit_copies != 0
&& GET_MODE_BITSIZE (GET_MODE (x)) == bitwidth)
- return reg_sign_bit_copies[REGNO (x)];
+ return reg_stat[REGNO (x)].sign_bit_copies;
break;
case MEM:
}
\f
/* Utility function for following routine. Called when X is part of a value
- being stored into reg_last_set_value. Sets reg_last_set_table_tick
+ being stored into last_set_value. Sets last_set_table_tick
for each register mentioned. Similar to mention_regs in cse.c */
static void
unsigned int r;
for (r = regno; r < endregno; r++)
- reg_last_set_table_tick[r] = label_tick;
+ reg_stat[r].last_set_table_tick = label_tick;
return;
}
/* Record that REG is set to VALUE in insn INSN. If VALUE is zero, we
are saying that the register is clobbered and we no longer know its
- value. If INSN is zero, don't update reg_last_set; this is only permitted
- with VALUE also zero and is used to invalidate the register. */
+ value. If INSN is zero, don't update reg_stat[].last_set; this is
+ only permitted with VALUE also zero and is used to invalidate the
+ register. */
static void
record_value_for_reg (rtx reg, rtx insn, rtx value)
for (i = regno; i < endregno; i++)
{
if (insn)
- reg_last_set[i] = insn;
+ reg_stat[i].last_set = insn;
- reg_last_set_value[i] = 0;
- reg_last_set_mode[i] = 0;
- reg_last_set_nonzero_bits[i] = 0;
- reg_last_set_sign_bit_copies[i] = 0;
- reg_last_death[i] = 0;
+ reg_stat[i].last_set_value = 0;
+ reg_stat[i].last_set_mode = 0;
+ reg_stat[i].last_set_nonzero_bits = 0;
+ reg_stat[i].last_set_sign_bit_copies = 0;
+ reg_stat[i].last_death = 0;
}
/* Mark registers that are being referenced in this value. */
for (i = regno; i < endregno; i++)
{
- reg_last_set_label[i] = label_tick;
- if (value && reg_last_set_table_tick[i] == label_tick)
- reg_last_set_invalid[i] = 1;
+ reg_stat[i].last_set_label = label_tick;
+ if (value && reg_stat[i].last_set_table_tick == label_tick)
+ reg_stat[i].last_set_invalid = 1;
else
- reg_last_set_invalid[i] = 0;
+ reg_stat[i].last_set_invalid = 0;
}
/* The value being assigned might refer to X (like in "x++;"). In that
case, we must replace it with (clobber (const_int 0)) to prevent
infinite loops. */
if (value && ! get_last_value_validate (&value, insn,
- reg_last_set_label[regno], 0))
+ reg_stat[regno].last_set_label, 0))
{
value = copy_rtx (value);
if (! get_last_value_validate (&value, insn,
- reg_last_set_label[regno], 1))
+ reg_stat[regno].last_set_label, 1))
value = 0;
}
/* For the main register being modified, update the value, the mode, the
nonzero bits, and the number of sign bit copies. */
- reg_last_set_value[regno] = value;
+ reg_stat[regno].last_set_value = value;
if (value)
{
enum machine_mode mode = GET_MODE (reg);
subst_low_cuid = INSN_CUID (insn);
- reg_last_set_mode[regno] = mode;
+ reg_stat[regno].last_set_mode = mode;
if (GET_MODE_CLASS (mode) == MODE_INT
&& GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT)
mode = nonzero_bits_mode;
- reg_last_set_nonzero_bits[regno] = nonzero_bits (value, mode);
- reg_last_set_sign_bit_copies[regno]
+ reg_stat[regno].last_set_nonzero_bits = nonzero_bits (value, mode);
+ reg_stat[regno].last_set_sign_bit_copies
= num_sign_bit_copies (value, GET_MODE (reg));
}
}
for the things done by INSN. This is the last thing done in processing
INSN in the combiner loop.
- We update reg_last_set, reg_last_set_value, reg_last_set_mode,
- reg_last_set_nonzero_bits, reg_last_set_sign_bit_copies, reg_last_death,
- and also the similar information mem_last_set (which insn most recently
- modified memory) and last_call_cuid (which insn was the most recent
- subroutine call). */
+ We update reg_stat[], in particular fields last_set, last_set_value,
+ last_set_mode, last_set_nonzero_bits, last_set_sign_bit_copies,
+ last_death, and also the similar information mem_last_set (which insn
+ most recently modified memory) and last_call_cuid (which insn was the
+ most recent subroutine call). */
static void
record_dead_and_set_regs (rtx insn)
: 1);
for (i = regno; i < endregno; i++)
- reg_last_death[i] = insn;
+ reg_stat[i].last_death = insn;
}
else if (REG_NOTE_KIND (link) == REG_INC)
record_value_for_reg (XEXP (link, 0), insn, NULL_RTX);
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i))
{
- reg_last_set_value[i] = 0;
- reg_last_set_mode[i] = 0;
- reg_last_set_nonzero_bits[i] = 0;
- reg_last_set_sign_bit_copies[i] = 0;
- reg_last_death[i] = 0;
+ reg_stat[i].last_set_value = 0;
+ reg_stat[i].last_set_mode = 0;
+ reg_stat[i].last_set_nonzero_bits = 0;
+ reg_stat[i].last_set_sign_bit_copies = 0;
+ reg_stat[i].last_death = 0;
}
last_call_cuid = mem_last_set = INSN_CUID (insn);
continue;
}
- if (reg_last_set[regno] == insn)
+ if (reg_stat[regno].last_set == insn)
{
if (SUBREG_PROMOTED_UNSIGNED_P (subreg) > 0)
- reg_last_set_nonzero_bits[regno] &= GET_MODE_MASK (mode);
+ reg_stat[regno].last_set_nonzero_bits &= GET_MODE_MASK (mode);
}
if (GET_CODE (SET_SRC (set)) == REG)
unsigned int j;
for (j = regno; j < endregno; j++)
- if (reg_last_set_invalid[j]
+ if (reg_stat[j].last_set_invalid
/* If this is a pseudo-register that was only set once and not
live at the beginning of the function, it is always valid. */
|| (! (regno >= FIRST_PSEUDO_REGISTER
&& REG_N_SETS (regno) == 1
&& (! REGNO_REG_SET_P
(ENTRY_BLOCK_PTR->next_bb->global_live_at_start, regno)))
- && reg_last_set_label[j] > tick))
+ && reg_stat[j].last_set_label > tick))
{
if (replace)
*loc = gen_rtx_CLOBBER (GET_MODE (x), const0_rtx);
return 0;
regno = REGNO (x);
- value = reg_last_set_value[regno];
+ value = reg_stat[regno].last_set_value;
/* If we don't have a value, or if it isn't for this basic block and
it's either a hard register, set more than once, or it's a live
block. */
if (value == 0
- || (reg_last_set_label[regno] != label_tick
+ || (reg_stat[regno].last_set_label != label_tick
&& (regno < FIRST_PSEUDO_REGISTER
|| REG_N_SETS (regno) != 1
|| (REGNO_REG_SET_P
/* If the value was set in a later insn than the ones we are processing,
we can't use it even if the register was only set once. */
- if (INSN_CUID (reg_last_set[regno]) >= subst_low_cuid)
+ if (INSN_CUID (reg_stat[regno].last_set) >= subst_low_cuid)
return 0;
/* If the value has all its registers valid, return it. */
- if (get_last_value_validate (&value, reg_last_set[regno],
- reg_last_set_label[regno], 0))
+ if (get_last_value_validate (&value, reg_stat[regno].last_set,
+ reg_stat[regno].last_set_label, 0))
return value;
/* Otherwise, make a copy and replace any invalid register with
(clobber (const_int 0)). If that fails for some reason, return 0. */
value = copy_rtx (value);
- if (get_last_value_validate (&value, reg_last_set[regno],
- reg_last_set_label[regno], 1))
+ if (get_last_value_validate (&value, reg_stat[regno].last_set,
+ reg_stat[regno].last_set_label, 1))
return value;
return 0;
return 1;
#endif
for (; regno < endreg; regno++)
- if (reg_last_set[regno]
- && INSN_CUID (reg_last_set[regno]) > from_cuid)
+ if (reg_stat[regno].last_set
+ && INSN_CUID (reg_stat[regno].last_set) > from_cuid)
return 1;
return 0;
}
if (code == REG)
{
unsigned int regno = REGNO (x);
- rtx where_dead = reg_last_death[regno];
+ rtx where_dead = reg_stat[regno].last_death;
rtx before_dead, after_dead;
/* Don't move the register if it gets killed in between from and to. */
rtx note = remove_death (regno, where_dead);
/* It is possible for the call above to return 0. This can occur
- when reg_last_death points to I2 or I1 that we combined with.
+ when last_death points to I2 or I1 that we combined with.
In that case make a new note.
We must also check for the case where X is a hard register
libcall sequence, don't add the notes. */
else if (XEXP (note, 0) == from_insn)
tem = place = 0;
+ /* Don't add the dangling REG_RETVAL note. */
+ else if (! tem)
+ place = 0;
}
break;
libcall sequence, don't add the notes. */
else if (XEXP (note, 0) == from_insn)
tem = place = 0;
+ /* Don't add the dangling REG_LIBCALL note. */
+ else if (! tem)
+ place = 0;
}
break;
|| reg_bitfield_target_p (XEXP (note, 0), PATTERN (place)))
{
/* Unless the register previously died in PLACE, clear
- reg_last_death. [I no longer understand why this is
+ last_death. [I no longer understand why this is
being done.] */
- if (reg_last_death[regno] != place)
- reg_last_death[regno] = 0;
+ if (reg_stat[regno].last_death != place)
+ reg_stat[regno].last_death = 0;
place = 0;
}
else
- reg_last_death[regno] = place;
+ reg_stat[regno].last_death = place;
/* If this is a death note for a hard reg that is occupying
multiple registers, ensure that we are still using all
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