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[PATCH] Group reg_* variables in combine into an array of structs
- From: Paolo Bonzini <bonzini at gnu dot org>
- To: gcc-patches at gcc dot gnu dot org
- Cc: Roger Sayle <roger at eyesopen dot com>
- Date: Thu, 29 Apr 2004 10:13:36 +0200
- Subject: [PATCH] Group reg_* variables in combine into an array of structs
I've had quite too many things to do latelly and I've really made too
many mistakes, so I'll stop working on GCC for a while; but, I still
have this pending patch, which may bring a little more locality of
reference.
In Nov 1999, David Miller did something similar to CSE's per-quantity
and register equivalence tables, and asked whether other similar
cleanups would be desirable. He was told yes, but he never went on (or
at least, never did this to combine).
Bootstrapped/regtested i686-pc-linux-gnu, ok for mainline?
Paolo
2004-04-27 Paolo Bonzini <bonzini@gnu.org>
Replace several arrays with a struct of arrays.
* combine.c (struct reg_stat): New.
(init_reg_last_arrays): Renamed to...
(init_reg_last): ...this. Callers adjusted.
(reg_stat): New.
(combine_instructions): Allocate it and use it.
(reg_last_death, reg_last_set, reg_last_set_value,
reg_last_set_label, reg_last_set_table_tick,
reg_last_set_invalid, reg_nonzero_bits, reg_sign_bit_copies,
reg_last_set_mode, reg_last_set_nonzero_bits,
reg_last_set_sign_bit_copies): Replace throughout
with items of reg_stat.
diff -up gcc-save/gcc/combine.c gcc/gcc/combine.c
--- gcc-save/gcc/combine.c 2004-04-23 12:34:04.000000000 +0200
+++ gcc/gcc/combine.c 2004-04-27 19:16:50.000000000 +0200
@@ -143,13 +143,103 @@ static int max_uid_cuid;
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;
+
+ /* Record last point of modification of (hard or pseudo) register n. */
+ rtx last_set;
+
+ /* 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.
+
+ 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.
-static rtx *reg_last_death;
+ Therefore, we maintain the following fields:
-/* Record last point of modification of (hard or pseudo) register n. */
+ 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 paragraphs 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;
-static rtx *reg_last_set;
+ /* 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). */
@@ -197,110 +287,23 @@ static basic_block this_basic_block;
those blocks as starting points. */
static sbitmap refresh_blocks;
-/* 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;
/* Record one modification to rtl structure
to be undone by storing old_contents into *where.
@@ -336,7 +339,7 @@ static int n_occurrences;
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);
@@ -523,20 +526,7 @@ combine_instructions (rtx f, unsigned in
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 ();
@@ -551,8 +541,8 @@ combine_instructions (rtx f, unsigned in
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;
@@ -605,7 +595,7 @@ combine_instructions (rtx f, unsigned in
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)
@@ -768,17 +758,7 @@ combine_instructions (rtx f, unsigned in
/* 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);
{
@@ -805,22 +785,14 @@ combine_instructions (rtx f, unsigned in
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));
}
/* Set up any promoted values for incoming argument registers. */
@@ -878,8 +849,8 @@ set_nonzero_bits_and_sign_copies (rtx x,
{
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;
}
@@ -901,7 +872,7 @@ set_nonzero_bits_and_sign_copies (rtx x,
#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.
@@ -920,18 +891,18 @@ set_nonzero_bits_and_sign_copies (rtx x,
#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;
}
}
}
@@ -1101,7 +1072,7 @@ can_combine_p (rtx insn, rtx i3, rtx pre
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
@@ -2331,18 +2302,18 @@ try_combine (rtx i3, rtx i2, rtx i1, int
&& 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)))
@@ -2783,9 +2754,10 @@ try_combine (rtx i3, rtx i2, rtx i1, int
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);
@@ -8170,17 +8142,17 @@ nonzero_bits1 (rtx x, enum machine_mode
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);
@@ -8189,8 +8161,8 @@ nonzero_bits1 (rtx x, enum machine_mode
#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
@@ -8208,9 +8180,9 @@ nonzero_bits1 (rtx x, enum machine_mode
#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. */
@@ -8666,23 +8638,23 @@ num_sign_bit_copies1 (rtx x, enum machin
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:
@@ -10983,7 +11320,7 @@ reversed_comparison (rtx exp, enum machi
}
/* 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
@@ -11002,7 +11339,7 @@ update_table_tick (rtx x)
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;
}
@@ -11050,8 +11387,9 @@ update_table_tick (rtx x)
/* 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)
@@ -11095,13 +11433,13 @@ record_value_for_reg (rtx reg, rtx insn,
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. */
@@ -11117,40 +11455,40 @@ record_value_for_reg (rtx reg, rtx insn,
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));
}
}
@@ -11195,11 +11533,11 @@ record_dead_and_set_regs_1 (rtx dest, rt
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)
@@ -11219,7 +11557,7 @@ 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);
@@ -11230,11 +11568,11 @@ record_dead_and_set_regs (rtx insn)
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);
@@ -11282,10 +11620,10 @@ record_promoted_value (rtx insn, rtx sub
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)
@@ -11355,14 +11693,14 @@ get_last_value_validate (rtx *loc, rtx i
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);
@@ -11454,7 +11792,7 @@ get_last_value (rtx x)
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
@@ -11467,7 +11805,7 @@ get_last_value (rtx x)
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
@@ -11476,20 +11814,20 @@ get_last_value (rtx x)
/* 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;
@@ -11518,8 +11856,8 @@ use_crosses_set_p (rtx x, int from_cuid)
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;
}
@@ -11779,7 +12117,7 @@ move_deaths (rtx x, rtx maybe_kill_insn,
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. */
@@ -11806,7 +12144,7 @@ move_deaths (rtx x, rtx maybe_kill_insn,
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
@@ -12413,14 +12751,14 @@ distribute_notes (rtx notes, rtx from_in
|| 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