/* While scanning basic block BB, we found a match of length MATCH_LEN,
starting at INSN. Perform the replacement, removing the old insns and
- replacing them with ATTEMPT. Returns the last insn emitted. */
+ replacing them with ATTEMPT. Returns the last insn emitted, or NULL
+ if the replacement is rejected. */
static rtx
peep2_attempt (basic_block bb, rtx insn, int match_len, rtx attempt)
{
int i;
rtx last, note, before_try, x;
+ rtx old_insn, new_insn;
bool was_call = false;
+ /* If we are splittind an RTX_FRAME_RELATED_P insn, do not allow it to
+ match more than one insn, or to be split into more than one insn. */
+ old_insn = peep2_insn_data[peep2_current].insn;
+ if (RTX_FRAME_RELATED_P (old_insn))
+ {
+ bool any_note = false;
+
+ if (match_len != 0)
+ return NULL;
+
+ /* Look for one "active" insn. I.e. ignore any "clobber" insns that
+ may be in the stream for the purpose of register allocation. */
+ if (active_insn_p (attempt))
+ new_insn = attempt;
+ else
+ new_insn = next_active_insn (attempt);
+ if (next_active_insn (new_insn))
+ return NULL;
+
+ /* We have a 1-1 replacement. Copy over any frame-related info. */
+ RTX_FRAME_RELATED_P (new_insn) = 1;
+
+ /* Allow the backend to fill in a note during the split. */
+ for (note = REG_NOTES (new_insn); note ; note = XEXP (note, 1))
+ switch (REG_NOTE_KIND (note))
+ {
+ case REG_FRAME_RELATED_EXPR:
+ case REG_CFA_DEF_CFA:
+ case REG_CFA_ADJUST_CFA:
+ case REG_CFA_OFFSET:
+ case REG_CFA_REGISTER:
+ case REG_CFA_EXPRESSION:
+ case REG_CFA_RESTORE:
+ case REG_CFA_SET_VDRAP:
+ any_note = true;
+ break;
+ default:
+ break;
+ }
+
+ /* If the backend didn't supply a note, copy one over. */
+ if (!any_note)
+ for (note = REG_NOTES (old_insn); note ; note = XEXP (note, 1))
+ switch (REG_NOTE_KIND (note))
+ {
+ case REG_FRAME_RELATED_EXPR:
+ case REG_CFA_DEF_CFA:
+ case REG_CFA_ADJUST_CFA:
+ case REG_CFA_OFFSET:
+ case REG_CFA_REGISTER:
+ case REG_CFA_EXPRESSION:
+ case REG_CFA_RESTORE:
+ case REG_CFA_SET_VDRAP:
+ add_reg_note (new_insn, REG_NOTE_KIND (note), XEXP (note, 0));
+ any_note = true;
+ break;
+ default:
+ break;
+ }
+
+ /* If there still isn't a note, make sure the unwind info sees the
+ same expression as before the split. */
+ if (!any_note)
+ {
+ rtx old_set, new_set;
+
+ /* The old insn had better have been simple, or annotated. */
+ old_set = single_set (old_insn);
+ gcc_assert (old_set != NULL);
+
+ new_set = single_set (new_insn);
+ if (!new_set || !rtx_equal_p (new_set, old_set))
+ add_reg_note (new_insn, REG_FRAME_RELATED_EXPR, old_set);
+ }
+ }
+
/* If we are splitting a CALL_INSN, look for the CALL_INSN
in SEQ and copy our CALL_INSN_FUNCTION_USAGE and other
cfg-related call notes. */
for (i = 0; i <= match_len; ++i)
{
int j;
- rtx old_insn, new_insn, note;
j = peep2_buf_position (peep2_current + i);
old_insn = peep2_insn_data[j].insn;
if (peep2_current_count == MAX_INSNS_PER_PEEP2)
return false;
- /* If an insn has RTX_FRAME_RELATED_P set, peephole substitution would lose
- the REG_FRAME_RELATED_EXPR that is attached. */
+ /* If an insn has RTX_FRAME_RELATED_P set, do not allow it to be matched with
+ any other pattern, lest it change the semantics of the frame info. */
if (RTX_FRAME_RELATED_P (insn))
{
/* Let the buffer drain first. */
if (peep2_current_count > 0)
return false;
- /* Step over the insn then return true without adding the insn
- to the buffer; this will cause us to process the next
- insn. */
- df_simulate_one_insn_forwards (bb, insn, live);
- return true;
+ /* Now the insn will be the only thing in the buffer. */
}
pos = peep2_buf_position (peep2_current + peep2_current_count);
attempt = peephole2_insns (PATTERN (head), head, &match_len);
if (attempt != NULL)
{
- rtx last;
- last = peep2_attempt (bb, head, match_len, attempt);
- peep2_update_life (bb, match_len, last, PREV_INSN (attempt));
- }
- else
- {
- /* If no match, advance the buffer by one insn. */
- peep2_current = peep2_buf_position (peep2_current + 1);
- peep2_current_count--;
+ rtx last = peep2_attempt (bb, head, match_len, attempt);
+ if (last)
+ {
+ peep2_update_life (bb, match_len, last, PREV_INSN (attempt));
+ continue;
+ }
}
+
+ /* No match: advance the buffer by one insn. */
+ peep2_current = peep2_buf_position (peep2_current + 1);
+ peep2_current_count--;
}
}
projects / gcc.git / commitdiff