#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));
}
}
\f
-/* 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];
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;
{
&& (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);
/* 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))
...
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
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;
}
...
(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)
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;
}
}
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);
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;
}
}
}
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)
&& 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 (src0) == REG)
- {
- if (REGNO (src0) != regno
- || reg_offset[regno] != const0_rtx)
- reg_base_reg[regno] = REGNO (src0);
+ if (GET_CODE (XEXP (src, 0)) == REG)
+ {
+ base_reg = XEXP (src, 0);
+
+ 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;
}
}
projects / gcc.git / commitdiff