static void
init_label_info (rtx f)
{
rtx insn;
for (insn = f; insn; insn = NEXT_INSN (insn))
{
if (LABEL_P (insn))
LABEL_NUSES (insn) = (LABEL_PRESERVE_P (insn) != 0);
/* REG_LABEL_TARGET notes (including the JUMP_LABEL field) are
sticky and not reset here; that way we won't lose association
with a label when e.g. the source for a target register
disappears out of reach for targets that may use jump-target
registers. Jump transformations are supposed to transform
any REG_LABEL_TARGET notes. The target label reference in a
branch may disappear from the branch (and from the
instruction before it) for other reasons, like register
allocation. */
if (INSN_P (insn))
{
rtx note, next;
for (note = REG_NOTES (insn); note; note = next)
{
next = XEXP (note, 1);
if (REG_NOTE_KIND (note) == REG_LABEL_OPERAND
&& ! reg_mentioned_p (XEXP (note, 0), PATTERN (insn)))
remove_note (insn, note);
}
}
}
}
static void
erase_matching_seqs (void)
{
seq_block sb;
matching_seq mseq;
rtx insn;
basic_block bb;
rtx retlabel, saveinsn, callinsn;
int i;
for (sb = seq_blocks; sb; sb = sb->next_seq_block)
{
for (mseq = sb->matching_seqs; mseq; mseq = mseq->next_matching_seq)
{
insn = mseq->insn;
bb = BLOCK_FOR_INSN (insn);
/* Get the label after the sequence. This will be the return
address. The label will be referenced using a symbol_ref so
protect it from deleting. */
retlabel = block_label_after (insn);
LABEL_PRESERVE_P (retlabel) = 1;
/* Delete the insns of the sequence. */
for (i = 0; i < sb->length; i++)
insn = prev_insn_in_block (insn);
delete_basic_block (split_block_and_df_analyze (bb, insn));
/* Emit an insn saving the return address to the link register
before the deleted sequence. */
saveinsn = emit_insn_after (gen_move_insn (pattern_seqs->link_reg,
gen_symbol_ref_rtx_for_label
(retlabel)),
BB_END (bb));
BLOCK_FOR_INSN (saveinsn) = bb;
/* Emit a jump to the appropriate part of the pattern sequence
after the save insn. Also update the basic block. */
callinsn = emit_jump_insn_after (gen_jump (sb->label), saveinsn);
JUMP_LABEL (callinsn) = sb->label;
LABEL_NUSES (sb->label)++;
BLOCK_FOR_INSN (callinsn) = bb;
BB_END (bb) = callinsn;
/* Maintain control flow and liveness information. */
SET_REGNO_REG_SET (df_get_live_out (bb),
REGNO (pattern_seqs->link_reg));
emit_barrier_after (BB_END (bb));
make_single_succ_edge (bb, BLOCK_FOR_INSN (sb->label), 0);
IOR_REG_SET (df_get_live_out (bb),
df_get_live_in (BLOCK_FOR_INSN (sb->label)));
make_edge (BLOCK_FOR_INSN (seq_blocks->label),
BLOCK_FOR_INSN (retlabel), EDGE_ABNORMAL);
}
}
}
static void
split_pattern_seq (void)
{
rtx insn;
basic_block bb;
rtx retlabel, retjmp, saveinsn;
int i;
seq_block sb;
insn = pattern_seqs->insn;
bb = BLOCK_FOR_INSN (insn);
/* Get the label after the sequence. This will be the return address. The
label will be referenced using a symbol_ref so protect it from
deleting. */
retlabel = block_label_after (insn);
LABEL_PRESERVE_P (retlabel) = 1;
/* Emit an indirect jump via the link register after the sequence acting
as the return insn. Also emit a barrier and update the basic block. */
if (!find_reg_note (BB_END (bb), REG_NORETURN, NULL))
retjmp = emit_jump_insn_after (gen_indirect_jump (pattern_seqs->link_reg),
BB_END (bb));
emit_barrier_after (BB_END (bb));
/* Replace all outgoing edges with a new one to the block of RETLABEL. */
while (EDGE_COUNT (bb->succs) != 0)
remove_edge (EDGE_SUCC (bb, 0));
make_edge (bb, BLOCK_FOR_INSN (retlabel), EDGE_ABNORMAL);
/* Split the sequence according to SEQ_BLOCKS and cache the label of the
resulting basic blocks. */
i = 0;
for (sb = seq_blocks; sb; sb = sb->next_seq_block)
{
for (; i < sb->length; i++)
insn = prev_insn_in_block (insn);
sb->label = block_label (split_block_and_df_analyze (bb, insn));
}
/* Emit an insn saving the return address to the link register before the
sequence. */
saveinsn = emit_insn_after (gen_move_insn (pattern_seqs->link_reg,
gen_symbol_ref_rtx_for_label
(retlabel)), BB_END (bb));
/* Update liveness info. */
SET_REGNO_REG_SET (df_get_live_out (bb),
REGNO (pattern_seqs->link_reg));
}
void
replace_call_placeholder (rtx insn, sibcall_use_t use)
{
if (use == sibcall_use_tail_recursion)
emit_insn_before (XEXP (PATTERN (insn), 2), insn);
else if (use == sibcall_use_sibcall)
emit_insn_before (XEXP (PATTERN (insn), 1), insn);
else if (use == sibcall_use_normal)
emit_insn_before (XEXP (PATTERN (insn), 0), insn);
else
abort ();
/* Turn off LABEL_PRESERVE_P for the tail recursion label if it
exists. We only had to set it long enough to keep the jump
pass above from deleting it as unused. */
if (XEXP (PATTERN (insn), 3))
LABEL_PRESERVE_P (XEXP (PATTERN (insn), 3)) = 0;
/* "Delete" the placeholder insn. */
remove_insn (insn);
}
