/* Return any length adjustment needed by INSN which already has its length
computed as LENGTH. Return zero if no adjustment is necessary.
- For the PA: function calls, millicode calls, and short conditional branches
- with unfilled delay slots need an adjustment by +1 (to account for
- the NOP which will be inserted into the instruction stream).
+ For the PA: function calls, millicode calls, and backwards short
+ conditional branches with unfilled delay slots need an adjustment by +1
+ (to account for the NOP which will be inserted into the instruction stream).
Also compute the length of an inline block move here as it is too
- complicated to express as a length attribute in pa.md.
-
- (For 2.5) Indirect calls do not need length adjustment as their
- delay slot is filled internally in the output template.
-
- (For 2.5) No adjustment is necessary for jump tables or casesi insns. */
+ complicated to express as a length attribute in pa.md. */
int
pa_adjust_insn_length (insn, length)
rtx insn;
{
rtx pat = PATTERN (insn);
- /* Call insn with an unfilled delay slot. */
+ /* Call insns which are *not* indirect and have unfilled delay slots. */
if (GET_CODE (insn) == CALL_INSN)
- return 1;
+ {
+
+ if (GET_CODE (XVECEXP (pat, 0, 0)) == CALL
+ && GET_CODE (XEXP (XEXP (XVECEXP (pat, 0, 0), 0), 0)) == SYMBOL_REF)
+ return 1;
+ else if (GET_CODE (XVECEXP (pat, 0, 0)) == SET
+ && GET_CODE (XEXP (XEXP (XEXP (XVECEXP (pat, 0, 0), 1), 0), 0))
+ == SYMBOL_REF)
+ return 1;
+ else
+ return 0;
+ }
/* Millicode insn with an unfilled delay slot. */
else if (GET_CODE (insn) == INSN
&& GET_CODE (pat) != SEQUENCE
&& GET_MODE (XEXP (XVECEXP (pat, 0, 0), 1)) == BLKmode)
return compute_movstrsi_length (insn) - 1;
/* Conditional branch with an unfilled delay slot. */
- else if (GET_CODE (insn) == JUMP_INSN && ! simplejump_p (insn)
- && length != 2 && length != 4)
- return 1;
+ else if (GET_CODE (insn) == JUMP_INSN && ! simplejump_p (insn))
+ {
+ /* Adjust a short backwards conditional with an unfilled delay slot. */
+ if (GET_CODE (pat) == SET
+ && length == 1
+ && ! forward_branch_p (insn))
+ return 1;
+ /* Adjust dbra insn with short backwards conditional branch with
+ unfilled delay slot -- only for case where counter is in a register. */
+ else if (GET_CODE (pat) == PARALLEL
+ && GET_CODE (XVECEXP (pat, 0, 1)) == SET
+ && GET_CODE (XEXP (XVECEXP (pat, 0, 1), 0)) == REG
+ && length == 1
+ && ! forward_branch_p (insn))
+ return 1;
+ else
+ return 0;
+ }
else
return 0;
}
static char buf[100];
int useskip = 0;
+ /* If this is a long branch with its delay slot unfilled, set `nullify'
+ as it can nullify the delay slot and save a nop. */
+ if (length == 2 && dbr_sequence_length () == 0)
+ nullify = 1;
+
+ /* If this is a short forward conditional branch which did not get
+ its delay slot filled, the delay slot can still be nullified. */
+ if (! nullify && length == 1 && dbr_sequence_length () == 0)
+ nullify = forward_branch_p (insn);
+
/* A forward branch over a single nullified insn can be done with a
comclr instruction. This avoids a single cycle penalty due to
mis-predicted branch if we fall through (branch not taken). */
-
if (length == 1
- && JUMP_LABEL (insn) == next_nonnote_insn (NEXT_INSN (insn))
+ && next_real_insn (insn) != 0
+ && get_attr_length (next_real_insn (insn)) == 1
+ && JUMP_LABEL (insn) == next_nonnote_insn (next_real_insn (insn))
&& nullify)
useskip = 1;
switch (length)
{
-
- /* Short conditional branch. May nullify either direction. */
+ /* All short conditional branches except backwards with an unfilled
+ delay slot. */
case 1:
if (useskip)
strcpy (buf, "com%I2clr,");
else if (nullify)
strcat (buf, ",n %2,%1,%0");
else
- strcat (buf, " %2,%1,%0%#");
+ strcat (buf, " %2,%1,%0");
break;
- /* Long conditional branch, possible forward nullification. Also
- note all conditional branches have a length of 4 when not
- optimizing! */
+ /* All long conditionals. Note an short backward branch with an
+ unfilled delay slot is treated just like a long backward branch
+ with an unfilled delay slot. */
case 2:
- case 4:
- strcpy (buf, "com%I2clr,");
- if (negated)
- strcat (buf, "%S3");
- else
- strcat (buf, "%B3");
- /* Nullify the delay slot if the delay slot was explicitly
- nullified by the delay branch scheduler or if no insn
- could be placed in the delay slot. */
- if (nullify)
- strcat (buf, " %2,%1,0\n\tbl,n %0,0");
- else
- strcat (buf, " %2,%1,0\n\tbl%* %0,0");
- break;
-
- /* Long backward conditional branch with nullification. */
- case 3:
- strcpy (buf, "com%I2b,");
- if (negated)
- strcat (buf, "%S3");
+ /* Handle weird backwards branch with a filled delay slot
+ with is nullified. */
+ if (dbr_sequence_length () != 0
+ && ! forward_branch_p (insn)
+ && nullify)
+ {
+ strcpy (buf, "com%I2b,");
+ if (negated)
+ strcat (buf, "%S3");
+ else
+ strcat (buf, "%B3");
+ strcat (buf, ",n %2,%1,.+12\n\tbl %0,0");
+ }
else
- strcat (buf, "%B3");
- strcat (buf, " %2,%1,.+16\n\tnop\n\t bl %0,0");
+ {
+ strcpy (buf, "com%I2clr,");
+ if (negated)
+ strcat (buf, "%S3");
+ else
+ strcat (buf, "%B3");
+ if (nullify)
+ strcat (buf, " %2,%1,0\n\tbl,n %0,0");
+ else
+ strcat (buf, " %2,%1,0\n\tbl %0,0");
+ }
break;
default:
abort();
- }
+ }
return buf;
}
static char buf[100];
int useskip = 0;
+ /* If this is a long branch with its delay slot unfilled, set `nullify'
+ as it can nullify the delay slot and save a nop. */
+ if (length == 2 && dbr_sequence_length () == 0)
+ nullify = 1;
+
+ /* If this is a short forward conditional branch which did not get
+ its delay slot filled, the delay slot can still be nullified. */
+ if (! nullify && length == 1 && dbr_sequence_length () == 0)
+ nullify = forward_branch_p (insn);
+
/* A forward branch over a single nullified insn can be done with a
extrs instruction. This avoids a single cycle penalty due to
mis-predicted branch if we fall through (branch not taken). */
if (length == 1
- && JUMP_LABEL (insn) == next_nonnote_insn (NEXT_INSN (insn))
+ && next_real_insn (insn) != 0
+ && get_attr_length (next_real_insn (insn)) == 1
+ && JUMP_LABEL (insn) == next_nonnote_insn (next_real_insn (insn))
&& nullify)
useskip = 1;
switch (length)
{
- /* Short conditional branch. May nullify either direction. */
+ /* All short conditional branches except backwards with an unfilled
+ delay slot. */
case 1:
if (useskip)
strcpy (buf, "extrs,");
else if (nullify && ! negated)
strcat (buf, ",n %0,%1,%2");
else if (! nullify && negated)
- strcat (buf, "%0,%1,%3%#");
+ strcat (buf, "%0,%1,%3");
else if (! nullify && ! negated)
- strcat (buf, " %0,%1,%2%#");
+ strcat (buf, " %0,%1,%2");
break;
- /* Long conditional branch, possible forward nullification. Also
- note all conditional branches have a length of 4 when not
- optimizing! */
+ /* All long conditionals. Note an short backward branch with an
+ unfilled delay slot is treated just like a long backward branch
+ with an unfilled delay slot. */
case 2:
- case 4:
- strcpy (buf, "extrs,");
- if ((which == 0 && negated)
- || (which == 1 && ! negated))
- strcat (buf, "<");
- else
- strcat (buf, ">=");
- /* Nullify the delay slot if the delay slot was explicitly
- nullified by the delay branch scheduler or if no insn
- could be placed in the delay slot. */
- if (nullify && negated)
- strcat (buf, " %0,%1,1,0\n\tbl,n %3,0");
- else if (nullify && ! negated)
- strcat (buf, " %0,%1,1,0\n\tbl,n %2,0");
- else if (negated)
- strcat (buf, " %0,%1,1,0\n\tbl%* %3,0");
- else
- strcat (buf, " %0,%1,1,0\n\tbl%* %2,0");
- break;
-
- /* Long backward conditional branch with nullification. */
- case 3:
- strcpy (buf, "bb,");
- if ((which == 0 && negated)
- || (which == 1 && ! negated))
- strcat (buf, "<");
- else
- strcat (buf, ">=");
- if (negated)
- strcat (buf, " %0,%1,.+16\n\tnop\n\t bl %3,0");
+ /* Handle weird backwards branch with a filled delay slot
+ with is nullified. */
+ if (dbr_sequence_length () != 0
+ && ! forward_branch_p (insn)
+ && nullify)
+ {
+ strcpy (buf, "bb,");
+ if ((which == 0 && negated)
+ || (which == 1 && ! negated))
+ strcat (buf, "<");
+ else
+ strcat (buf, ">=");
+ if (negated)
+ strcat (buf, " %0,%1,.+12\n\tbl %3,0");
+ else
+ strcat (buf, " %0,%1,.+12\n\tbl %2,0");
+ }
else
- strcat (buf, " %0,%1,.+16\n\tnop\n\t bl %2,0");
+ {
+ strcpy (buf, "extrs,");
+ if ((which == 0 && negated)
+ || (which == 1 && ! negated))
+ strcat (buf, "<");
+ else
+ strcat (buf, ">=");
+ if (nullify && negated)
+ strcat (buf, " %0,%1,1,0\n\tbl,n %3,0");
+ else if (nullify && ! negated)
+ strcat (buf, " %0,%1,1,0\n\tbl,n %2,0");
+ else if (negated)
+ strcat (buf, " %0,%1,1,0\n\tbl %3,0");
+ else
+ strcat (buf, " %0,%1,1,0\n\tbl %2,0");
+ }
break;
default:
abort();
- }
+ }
return buf;
}
{
return (GET_CODE (op) == CONST_INT && shadd_constant_p (INTVAL (op)));
}
+
+/* Return 1 if INSN branches forward. Should be using insn_addresses
+ to avoid walking through all the insns... */
+int
+forward_branch_p (insn)
+ rtx insn;
+{
+ rtx label = JUMP_LABEL (insn);
+
+ while (insn)
+ {
+ if (insn == label)
+ break;
+ else
+ insn = NEXT_INSN (insn);
+ }
+
+ return (insn == label);
+}
+
projects / gcc.git / commitdiff