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(move_deaths): New parameter maybe_kill_insn.

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Don't move note if reg killed by maybe_kill_insn.
(try_combine): Pass new arg to move_deaths.

From-SVN: r12311
This commit is contained in:
Richard Kenner 1996-06-19 17:50:05 -04:00
parent fbe912dd09
commit 6eb12cef1d
1 changed files with 28 additions and 11 deletions
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39
gcc/combine.c
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@ -440,7 +440,7 @@ static rtx get_last_value PROTO((rtx));
static int use_crosses_set_p PROTO((rtx, int));
static void reg_dead_at_p_1 PROTO((rtx, rtx));
static int reg_dead_at_p PROTO((rtx, rtx));
static void move_deaths PROTO((rtx, int, rtx, rtx *));
static void move_deaths PROTO((rtx, rtx, int, rtx, rtx *));
static int reg_bitfield_target_p PROTO((rtx, rtx));
static void distribute_notes PROTO((rtx, rtx, rtx, rtx, rtx, rtx));
static void distribute_links PROTO((rtx));
@ -2204,11 +2204,18 @@ try_combine (i3, i2, i1)
}
/* Get death notes for everything that is now used in either I3 or
I2 and used to die in a previous insn. */
I2 and used to die in a previous insn. If we built two new
patterns, move from I1 to I2 then I2 to I3 so that we get the
proper movement on registers that I2 modifies. */
move_deaths (newpat, i1 ? INSN_CUID (i1) : INSN_CUID (i2), i3, &midnotes);
if (newi2pat)
move_deaths (newi2pat, INSN_CUID (i1), i2, &midnotes);
{
move_deaths (newi2pat, NULL_RTX, INSN_CUID (i1), i2, &midnotes);
move_deaths (newpat, newi2pat, INSN_CUID (i1), i3, &midnotes);
}
else
move_deaths (newpat, NULL_RTX, i1 ? INSN_CUID (i1) : INSN_CUID (i2),
i3, &midnotes);
/* Distribute all the LOG_LINKS and REG_NOTES from I1, I2, and I3. */
if (i3notes)
@ -10489,12 +10496,15 @@ remove_death (regno, insn)
TO_INSN (exclusive), put a REG_DEAD note for that register in the
list headed by PNOTES.
That said, don't move registers killed by maybe_kill_insn.
This is done when X is being merged by combination into TO_INSN. These
notes will then be distributed as needed. */
static void
move_deaths (x, from_cuid, to_insn, pnotes)
move_deaths (x, maybe_kill_insn, from_cuid, to_insn, pnotes)
rtx x;
rtx maybe_kill_insn;
int from_cuid;
rtx to_insn;
rtx *pnotes;
@ -10509,6 +10519,11 @@ move_deaths (x, from_cuid, to_insn, pnotes)
register rtx where_dead = reg_last_death[regno];
register rtx before_dead, after_dead;
/* Don't move the register if it gets killed in between from and to */
if (maybe_kill_insn && reg_set_p (x, maybe_kill_insn)
&& !reg_referenced_p (x, maybe_kill_insn))
return;
/* WHERE_DEAD could be a USE insn made by combine, so first we
make sure that we have insns with valid INSN_CUID values. */
before_dead = where_dead;
@ -10566,7 +10581,7 @@ move_deaths (x, from_cuid, to_insn, pnotes)
for (i = regno + 1; i < ourend; i++)
move_deaths (gen_rtx (REG, reg_raw_mode[i], i),
from_cuid, to_insn, &oldnotes);
maybe_kill_insn, from_cuid, to_insn, &oldnotes);
}
if (note != 0 && GET_MODE (XEXP (note, 0)) == GET_MODE (x))
@ -10587,7 +10602,7 @@ move_deaths (x, from_cuid, to_insn, pnotes)
{
rtx dest = SET_DEST (x);
move_deaths (SET_SRC (x), from_cuid, to_insn, pnotes);
move_deaths (SET_SRC (x), maybe_kill_insn, from_cuid, to_insn, pnotes);
/* In the case of a ZERO_EXTRACT, a STRICT_LOW_PART, or a SUBREG
that accesses one word of a multi-word item, some
@ -10602,7 +10617,7 @@ move_deaths (x, from_cuid, to_insn, pnotes)
== ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))
+ UNITS_PER_WORD - 1) / UNITS_PER_WORD))))
{
move_deaths (dest, from_cuid, to_insn, pnotes);
move_deaths (dest, maybe_kill_insn, from_cuid, to_insn, pnotes);
return;
}
@ -10616,7 +10631,8 @@ move_deaths (x, from_cuid, to_insn, pnotes)
being replaced so the old value is not used in this insn. */
if (GET_CODE (dest) == MEM)
move_deaths (XEXP (dest, 0), from_cuid, to_insn, pnotes);
move_deaths (XEXP (dest, 0), maybe_kill_insn, from_cuid,
to_insn, pnotes);
return;
}
@ -10632,10 +10648,11 @@ move_deaths (x, from_cuid, to_insn, pnotes)
{
register int j;
for (j = XVECLEN (x, i) - 1; j >= 0; j--)
move_deaths (XVECEXP (x, i, j), from_cuid, to_insn, pnotes);
move_deaths (XVECEXP (x, i, j), maybe_kill_insn, from_cuid,
to_insn, pnotes);
}
else if (fmt[i] == 'e')
move_deaths (XEXP (x, i), from_cuid, to_insn, pnotes);
move_deaths (XEXP (x, i), maybe_kill_insn, from_cuid, to_insn, pnotes);
}
}