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reload1.c (move2add_note_store): Treat all registers about which no information is known as potential bases...

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* reload1.c (move2add_note_store): Treat all registers about which
no information is known as potential bases, and treat all
registers directly or indirectly derived from it as members of the
same set of values.
(reload_cse_move2add): Adjust accordingly.  Take mode and
offset of base register into account.

From-SVN: r39135
This commit is contained in:
Alexandre Oliva 2001-01-19 16:32:27 +00:00 committed by Alexandre Oliva
parent 5bea1ccf19
commit 61f5625b76
2 changed files with 154 additions and 90 deletions
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9
gcc/ChangeLog
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@ -1,3 +1,12 @@
Fri Jan 19 14:31:35 2001 Alexandre Oliva <aoliva@redhat.com>, J"orn Rennecke <amylaar@redhat.com>
* reload1.c (move2add_note_store): Treat all registers about which
no information is known as potential bases, and treat all
registers directly or indirectly derived from it as members of the
same set of values.
(reload_cse_move2add): Adjust accordingly. Take mode and
offset of base register into account.
Fri Jan 19 09:18:42 2001 J"orn Rennecke <amylaar@redhat.com>
* alias.c (find_base_value): Recognize TRUNCATE.

235
gcc/reload1.c
View File

@ -455,7 +455,7 @@ static void move2add_note_store PARAMS ((rtx, rtx, void *));
#ifdef AUTO_INC_DEC
static void add_auto_inc_notes PARAMS ((rtx, rtx));
#endif
static rtx gen_mode_int PARAMS ((enum machine_mode,
static HOST_WIDE_INT sext_for_mode PARAMS ((enum machine_mode,
HOST_WIDE_INT));
static void failed_reload PARAMS ((rtx, int));
static int set_reload_reg PARAMS ((int, int));
@ -8950,25 +8950,23 @@ reload_combine_note_use (xp, insn)
}
}
/* See if we can reduce the cost of a constant by replacing a move with
an add. */
/* See if we can reduce the cost of a constant by replacing a move
with an add. We track situations in which a register is set to a
constant or to a register plus a constant. */
/* We cannot do our optimization across labels. Invalidating all the
information about register contents we have would be costly, so we
use last_label_luid (local variable of reload_cse_move2add) to note
where the label is and then later disable any optimization that would
cross it.
use move2add_last_label_luid to note where the label is and then
later disable any optimization that would cross it.
reg_offset[n] / reg_base_reg[n] / reg_mode[n] are only valid if
reg_set_luid[n] is larger than last_label_luid[n] . */
reg_set_luid[n] is greater than last_label_luid[n] . */
static int reg_set_luid[FIRST_PSEUDO_REGISTER];
/* reg_offset[n] has to be CONST_INT for it and reg_base_reg[n] /
reg_mode[n] to be valid.
If reg_offset[n] is a CONST_INT and reg_base_reg[n] is negative, register n
has been set to reg_offset[n] in mode reg_mode[n] .
If reg_offset[n] is a CONST_INT and reg_base_reg[n] is non-negative,
register n has been set to the sum of reg_offset[n] and register
reg_base_reg[n], calculated in mode reg_mode[n] . */
static rtx reg_offset[FIRST_PSEUDO_REGISTER];
/* If reg_base_reg[n] is negative, register n has been set to
reg_offset[n] in mode reg_mode[n] .
If reg_base_reg[n] is non-negative, register n has been set to the
sum of reg_offset[n] and the value of register reg_base_reg[n]
before reg_set_luid[n], calculated in mode reg_mode[n] . */
static HOST_WIDE_INT reg_offset[FIRST_PSEUDO_REGISTER];
static int reg_base_reg[FIRST_PSEUDO_REGISTER];
static enum machine_mode reg_mode[FIRST_PSEUDO_REGISTER];
@ -8977,10 +8975,14 @@ static enum machine_mode reg_mode[FIRST_PSEUDO_REGISTER];
reload_cse_move2add and move2add_note_store. */
static int move2add_luid;
/* move2add_last_label_luid is set whenever a label is found. Labels
invalidate all previously collected reg_offset data. */
static int move2add_last_label_luid;
/* Generate a CONST_INT and force it in the range of MODE. */
static rtx
gen_mode_int (mode, value)
static HOST_WIDE_INT
sext_for_mode (mode, value)
enum machine_mode mode;
HOST_WIDE_INT value;
{
@ -8993,28 +8995,42 @@ gen_mode_int (mode, value)
&& (cval & ((HOST_WIDE_INT) 1 << (width - 1))) != 0)
cval |= (HOST_WIDE_INT) -1 << width;
return GEN_INT (cval);
return cval;
}
/* ??? We don't know how zero / sign extension is handled, hence we
can't go from a narrower to a wider mode. */
#define MODES_OK_FOR_MOVE2ADD(OUTMODE, INMODE) \
(GET_MODE_SIZE (OUTMODE) == GET_MODE_SIZE (INMODE) \
|| (GET_MODE_SIZE (OUTMODE) <= GET_MODE_SIZE (INMODE) \
&& TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (OUTMODE), \
GET_MODE_BITSIZE (INMODE))))
static void
reload_cse_move2add (first)
rtx first;
{
int i;
rtx insn;
int last_label_luid;
for (i = FIRST_PSEUDO_REGISTER - 1; i >= 0; i--)
reg_set_luid[i] = 0;
last_label_luid = 0;
move2add_luid = 1;
move2add_last_label_luid = 0;
move2add_luid = 2;
for (insn = first; insn; insn = NEXT_INSN (insn), move2add_luid++)
{
rtx pat, note;
if (GET_CODE (insn) == CODE_LABEL)
last_label_luid = move2add_luid;
{
move2add_last_label_luid = move2add_luid;
/* We're going to increment move2add_luid twice after a
label, so that we can use move2add_last_label_luid + 1 as
the luid for constants. */
move2add_luid++;
continue;
}
if (! INSN_P (insn))
continue;
pat = PATTERN (insn);
@ -9029,16 +9045,8 @@ reload_cse_move2add (first)
/* Check if we have valid information on the contents of this
register in the mode of REG. */
/* ??? We don't know how zero / sign extension is handled, hence
we can't go from a narrower to a wider mode. */
if (reg_set_luid[regno] > last_label_luid
&& ((GET_MODE_SIZE (GET_MODE (reg))
== GET_MODE_SIZE (reg_mode[regno]))
|| ((GET_MODE_SIZE (GET_MODE (reg))
<= GET_MODE_SIZE (reg_mode[regno]))
&& TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (GET_MODE (reg)),
GET_MODE_BITSIZE (reg_mode[regno]))))
&& GET_CODE (reg_offset[regno]) == CONST_INT)
if (reg_set_luid[regno] > move2add_last_label_luid
&& MODES_OK_FOR_MOVE2ADD (GET_MODE (reg), reg_mode[regno]))
{
/* Try to transform (set (REGX) (CONST_INT A))
...
@ -9051,9 +9059,9 @@ reload_cse_move2add (first)
if (GET_CODE (src) == CONST_INT && reg_base_reg[regno] < 0)
{
int success = 0;
rtx new_src
= gen_mode_int (GET_MODE (reg),
INTVAL (src) - INTVAL (reg_offset[regno]));
rtx new_src = GEN_INT (sext_for_mode (GET_MODE (reg),
INTVAL (src)
- reg_offset[regno]));
/* (set (reg) (plus (reg) (const_int 0))) is not canonical;
use (set (reg) (reg)) instead.
We don't delete this insn, nor do we convert it into a
@ -9068,7 +9076,7 @@ reload_cse_move2add (first)
gen_add2_insn (reg, new_src), 0);
reg_set_luid[regno] = move2add_luid;
reg_mode[regno] = GET_MODE (reg);
reg_offset[regno] = src;
reg_offset[regno] = INTVAL (src);
continue;
}
@ -9083,25 +9091,29 @@ reload_cse_move2add (first)
...
(set (REGX) (plus (REGX) (CONST_INT B-A))) */
else if (GET_CODE (src) == REG
&& reg_base_reg[regno] == (int) REGNO (src)
&& reg_set_luid[regno] > reg_set_luid[REGNO (src)])
&& reg_set_luid[regno] == reg_set_luid[REGNO (src)]
&& reg_base_reg[regno] == reg_base_reg[REGNO (src)]
&& MODES_OK_FOR_MOVE2ADD (GET_MODE (reg),
reg_mode[REGNO (src)]))
{
rtx next = next_nonnote_insn (insn);
rtx set = NULL_RTX;
if (next)
set = single_set (next);
if (next
&& set
if (set
&& SET_DEST (set) == reg
&& GET_CODE (SET_SRC (set)) == PLUS
&& XEXP (SET_SRC (set), 0) == reg
&& GET_CODE (XEXP (SET_SRC (set), 1)) == CONST_INT)
{
rtx src3 = XEXP (SET_SRC (set), 1);
rtx new_src
= gen_mode_int (GET_MODE (reg),
INTVAL (src3)
- INTVAL (reg_offset[regno]));
HOST_WIDE_INT added_offset = INTVAL (src3);
HOST_WIDE_INT base_offset = reg_offset[REGNO (src)];
HOST_WIDE_INT regno_offset = reg_offset[regno];
rtx new_src = GEN_INT (sext_for_mode (GET_MODE (reg),
added_offset
+ base_offset
- regno_offset));
int success = 0;
if (new_src == const0_rtx)
@ -9124,9 +9136,10 @@ reload_cse_move2add (first)
NOTE_SOURCE_FILE (insn) = 0;
}
insn = next;
reg_set_luid[regno] = move2add_luid;
reg_mode[regno] = GET_MODE (reg);
reg_offset[regno] = src3;
reg_offset[regno] = sext_for_mode (GET_MODE (reg),
added_offset
+ base_offset);
continue;
}
}
@ -9138,14 +9151,10 @@ reload_cse_move2add (first)
if (REG_NOTE_KIND (note) == REG_INC
&& GET_CODE (XEXP (note, 0)) == REG)
{
/* Indicate that this register has been recently written to,
but the exact contents are not available. */
/* Reset the information about this register. */
int regno = REGNO (XEXP (note, 0));
if (regno < FIRST_PSEUDO_REGISTER)
{
reg_set_luid[regno] = move2add_luid;
reg_offset[regno] = note;
}
reg_set_luid[regno] = 0;
}
}
note_stores (PATTERN (insn), move2add_note_store, NULL);
@ -9156,10 +9165,8 @@ reload_cse_move2add (first)
for (i = FIRST_PSEUDO_REGISTER - 1; i >= 0; i--)
{
if (call_used_regs[i])
{
reg_set_luid[i] = move2add_luid;
reg_offset[i] = insn; /* Invalidate contents. */
}
/* Reset the information about this register. */
reg_set_luid[i] = 0;
}
}
}
@ -9191,11 +9198,7 @@ move2add_note_store (dst, set, data)
dst = XEXP (dst, 0);
if (GET_CODE (dst) == PRE_INC || GET_CODE (dst) == POST_DEC
|| GET_CODE (dst) == PRE_DEC || GET_CODE (dst) == POST_DEC)
{
regno = REGNO (XEXP (dst, 0));
reg_set_luid[regno] = move2add_luid;
reg_offset[regno] = dst;
}
reg_set_luid[REGNO (XEXP (dst, 0))] = 0;
return;
}
if (GET_CODE (dst) != REG)
@ -9209,54 +9212,106 @@ move2add_note_store (dst, set, data)
&& GET_CODE (SET_DEST (set)) != STRICT_LOW_PART)
{
rtx src = SET_SRC (set);
rtx base_reg;
HOST_WIDE_INT offset;
int base_regno;
/* This may be different from mode, if SET_DEST (set) is a
SUBREG. */
enum machine_mode dst_mode = GET_MODE (dst);
reg_mode[regno] = mode;
switch (GET_CODE (src))
{
case PLUS:
{
rtx src0 = XEXP (src, 0);
if (GET_CODE (XEXP (src, 0)) == REG)
{
base_reg = XEXP (src, 0);
if (GET_CODE (src0) == REG)
{
if (REGNO (src0) != regno
|| reg_offset[regno] != const0_rtx)
reg_base_reg[regno] = REGNO (src0);
if (GET_CODE (XEXP (src, 1)) == CONST_INT)
offset = INTVAL (XEXP (src, 1));
else if (GET_CODE (XEXP (src, 1)) == REG
&& (reg_set_luid[REGNO (XEXP (src, 1))]
> move2add_last_label_luid)
&& (MODES_OK_FOR_MOVE2ADD
(dst_mode, reg_mode[REGNO (XEXP (src, 1))])))
{
if (reg_base_reg[REGNO (XEXP (src, 1))] < 0)
offset = reg_offset[REGNO (XEXP (src, 1))];
/* Maybe the first register is known to be a
constant. */
else if (reg_set_luid[REGNO (base_reg)]
> move2add_last_label_luid
&& (MODES_OK_FOR_MOVE2ADD
(dst_mode, reg_mode[REGNO (XEXP (src, 1))]))
&& reg_base_reg[REGNO (base_reg)] < 0)
{
offset = reg_offset[REGNO (base_reg)];
base_reg = XEXP (src, 1);
}
else
goto invalidate;
}
else
goto invalidate;
reg_set_luid[regno] = move2add_luid;
reg_offset[regno] = XEXP (src, 1);
break;
}
break;
}
reg_set_luid[regno] = move2add_luid;
reg_offset[regno] = set; /* Invalidate contents. */
break;
}
goto invalidate;
case REG:
reg_base_reg[regno] = REGNO (SET_SRC (set));
reg_offset[regno] = const0_rtx;
reg_set_luid[regno] = move2add_luid;
base_reg = src;
offset = 0;
break;
default:
case CONST_INT:
/* Start tracking the register as a constant. */
reg_base_reg[regno] = -1;
reg_offset[regno] = SET_SRC (set);
reg_set_luid[regno] = move2add_luid;
break;
reg_offset[regno] = INTVAL (SET_SRC (set));
/* We assign the same luid to all registers set to constants. */
reg_set_luid[regno] = move2add_last_label_luid + 1;
reg_mode[regno] = mode;
return;
default:
invalidate:
/* Invalidate the contents of the register. */
reg_set_luid[regno] = 0;
return;
}
base_regno = REGNO (base_reg);
/* If information about the base register is not valid, set it
up as a new base register, pretending its value is known
starting from the current insn. */
if (reg_set_luid[base_regno] <= move2add_last_label_luid)
{
reg_base_reg[base_regno] = base_regno;
reg_offset[base_regno] = 0;
reg_set_luid[base_regno] = move2add_luid;
reg_mode[base_regno] = mode;
}
else if (! MODES_OK_FOR_MOVE2ADD (dst_mode,
reg_mode[base_regno]))
goto invalidate;
reg_mode[regno] = mode;
/* Copy base information from our base register. */
reg_set_luid[regno] = reg_set_luid[base_regno];
reg_base_reg[regno] = reg_base_reg[base_regno];
/* Compute the sum of the offsets or constants. */
reg_offset[regno] = sext_for_mode (dst_mode,
offset
+ reg_offset[base_regno]);
}
else
{
unsigned int endregno = regno + HARD_REGNO_NREGS (regno, mode);
for (i = regno; i < endregno; i++)
{
/* Indicate that this register has been recently written to,
but the exact contents are not available. */
reg_set_luid[i] = move2add_luid;
reg_offset[i] = dst;
}
/* Reset the information about this register. */
reg_set_luid[i] = 0;
}
}