/* Process the death of hard register REGNO. This updates
hard_regs_live and START_DYING. */
static void
make_hard_regno_dead (int regno)
{
lra_assert (regno < FIRST_PSEUDO_REGISTER);
if (! TEST_HARD_REG_BIT (hard_regs_live, regno))
return;
sparseset_set_bit (start_dying, regno);
CLEAR_HARD_REG_BIT (hard_regs_live, regno);
}
static void
recompute_gain_for_pattern_seq (pattern_seq pseq)
{
matching_seq mseq;
rtx x;
int i;
int hascall;
HARD_REG_SET linkregs;
/* Initialize data. */
SET_HARD_REG_SET (linkregs);
pseq->link_reg = NULL_RTX;
pseq->abstracted_length = 0;
pseq->gain = -(seq_call_cost - seq_jump_cost + seq_return_cost);
/* Determine ABSTRACTED_LENGTH and COST for matching sequences of PSEQ.
ABSTRACTED_LENGTH may be less than MATCHING_LENGTH if sequences in the
same block overlap. */
for (mseq = pseq->matching_seqs; mseq; mseq = mseq->next_matching_seq)
{
/* Determine ABSTRACTED_LENGTH. */
if (mseq->next_matching_seq)
mseq->abstracted_length = (int)(mseq->next_matching_seq->idx -
mseq->idx);
else
mseq->abstracted_length = mseq->matching_length;
if (mseq->abstracted_length > mseq->matching_length)
mseq->abstracted_length = mseq->matching_length;
/* Compute the cost of sequence. */
RECOMPUTE_COST (mseq);
/* If COST is big enough registers live in this matching sequence
should not be used as a link register. Also set ABSTRACTED_LENGTH
of PSEQ. */
if (mseq->cost > seq_call_cost)
{
clear_regs_live_in_seq (&linkregs, mseq->insn,
mseq->abstracted_length);
if (mseq->abstracted_length > pseq->abstracted_length)
pseq->abstracted_length = mseq->abstracted_length;
}
}
/* Modify ABSTRACTED_LENGTH of PSEQ if pattern sequence overlaps with one
of the matching sequences. */
for (mseq = pseq->matching_seqs; mseq; mseq = mseq->next_matching_seq)
{
x = pseq->insn;
for (i = 0; (i < pseq->abstracted_length) && (x != mseq->insn); i++)
x = prev_insn_in_block (x);
pseq->abstracted_length = i;
}
/* Compute the cost of pattern sequence. */
RECOMPUTE_COST (pseq);
/* No gain if COST is too small. */
if (pseq->cost <= seq_call_cost)
{
pseq->gain = -1;
return;
}
/* Ensure that no matching sequence is longer than the pattern sequence. */
for (mseq = pseq->matching_seqs; mseq; mseq = mseq->next_matching_seq)
{
if (mseq->abstracted_length > pseq->abstracted_length)
{
mseq->abstracted_length = pseq->abstracted_length;
RECOMPUTE_COST (mseq);
}
/* Once the length is stabilizing the gain can be calculated. */
if (mseq->cost > seq_call_cost)
pseq->gain += mseq->cost - seq_call_cost;
}
/* No need to do further work if there is no gain. */
if (pseq->gain <= 0)
return;
/* Should not use registers live in the pattern sequence as link register.
*/
clear_regs_live_in_seq (&linkregs, pseq->insn, pseq->abstracted_length);
/* Determine whether pattern sequence contains a call_insn. */
hascall = 0;
x = pseq->insn;
for (i = 0; i < pseq->abstracted_length; i++)
{
if (CALL_P (x))
{
hascall = 1;
break;
}
x = prev_insn_in_block (x);
}
/* Should not use a register as a link register if - it is a fixed
register, or - the sequence contains a call insn and the register is a
call used register, or - the register needs to be saved if used in a
function but was not used before (since saving it can invalidate already
computed frame pointer offsets), or - the register cannot be used as a
base register. */
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
if (fixed_regs[i]
#ifdef REGNO_OK_FOR_INDIRECT_JUMP_P
|| (!REGNO_OK_FOR_INDIRECT_JUMP_P (i, Pmode))
#else
|| (!ok_for_base_p_1 (i, Pmode, MEM, SCRATCH))
|| (!reg_class_subset_p (REGNO_REG_CLASS (i),
base_reg_class (VOIDmode, MEM, SCRATCH)))
#endif
|| (hascall && call_used_regs[i])
|| (!call_used_regs[i] && !df_regs_ever_live_p (i)))
CLEAR_HARD_REG_BIT (linkregs, i);
/* Find an appropriate register to be used as the link register. */
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
if (TEST_HARD_REG_BIT (linkregs, i))
{
pseq->link_reg = gen_rtx_REG (Pmode, i);
break;
}
/* Abstraction is not possible if no link register is available, so set
gain to 0. */
if (!pseq->link_reg)
pseq->gain = 0;
}
