#include "obstack.h"
#include "insn-attr.h"
#include "resource.h"
+#include "params.h"
#ifdef DELAY_SLOTS
rtx trial, pat;
struct resources needed, set;
int i;
+ unsigned insns_to_search;
/* If INSN has any REG_UNUSED notes, it can't match anything since we
are allowed to not actually assign to such a register. */
return 0;
/* Scan backwards looking for a match. */
- for (trial = PREV_INSN (target); trial; trial = PREV_INSN (trial))
+ for (trial = PREV_INSN (target),
+ insns_to_search = MAX_DELAY_SLOT_INSN_SEARCH;
+ trial && insns_to_search > 0;
+ trial = PREV_INSN (trial), --insns_to_search)
{
if (GET_CODE (trial) == CODE_LABEL)
return 0;
/* Scan backwards until we reach a label or an insn that uses something
INSN sets or sets something insn uses or sets. */
- for (trial = PREV_INSN (target);
- trial && GET_CODE (trial) != CODE_LABEL;
- trial = PREV_INSN (trial))
+ for (trial = PREV_INSN (target),
+ insns_to_search = MAX_DELAY_SLOT_INSN_SEARCH;
+ trial && GET_CODE (trial) != CODE_LABEL && insns_to_search > 0;
+ trial = PREV_INSN (trial), --insns_to_search)
{
if (GET_CODE (trial) != INSN && GET_CODE (trial) != CALL_INSN
&& GET_CODE (trial) != JUMP_INSN)
&& ! simplejump_p (insn)
&& JUMP_LABEL (insn) != 0)))
{
+ /* Invariant: If insn is a JUMP_INSN, the insn's jump
+ label. Otherwise, zero. */
rtx target = 0;
int maybe_never = 0;
- struct resources needed_at_jump;
+ rtx pat, trial_delay;
CLEAR_RESOURCE (&needed);
CLEAR_RESOURCE (&set);
target = JUMP_LABEL (insn);
}
- for (trial = next_nonnote_insn (insn); trial; trial = next_trial)
- {
- rtx pat, trial_delay;
-
- next_trial = next_nonnote_insn (trial);
-
- if (GET_CODE (trial) == CODE_LABEL
- || GET_CODE (trial) == BARRIER)
- break;
+ if (target == 0)
+ for (trial = next_nonnote_insn (insn); trial; trial = next_trial)
+ {
+ next_trial = next_nonnote_insn (trial);
- /* We must have an INSN, JUMP_INSN, or CALL_INSN. */
- pat = PATTERN (trial);
+ if (GET_CODE (trial) == CODE_LABEL
+ || GET_CODE (trial) == BARRIER)
+ break;
- /* Stand-alone USE and CLOBBER are just for flow. */
- if (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER)
- continue;
+ /* We must have an INSN, JUMP_INSN, or CALL_INSN. */
+ pat = PATTERN (trial);
- /* If this already has filled delay slots, get the insn needing
- the delay slots. */
- if (GET_CODE (pat) == SEQUENCE)
- trial_delay = XVECEXP (pat, 0, 0);
- else
- trial_delay = trial;
-
- /* If this is a jump insn to our target, indicate that we have
- seen another jump to it. If we aren't handling a conditional
- jump, stop our search. Otherwise, compute the needs at its
- target and add them to NEEDED. */
- if (GET_CODE (trial_delay) == JUMP_INSN)
- {
- if (target == 0)
- break;
- else if (JUMP_LABEL (trial_delay) != target)
- {
- rtx ninsn =
- next_active_insn (JUMP_LABEL (trial_delay));
-
- mark_target_live_regs (get_insns (), ninsn,
- &needed_at_jump);
- needed.memory |= needed_at_jump.memory;
- needed.unch_memory |= needed_at_jump.unch_memory;
- IOR_HARD_REG_SET (needed.regs, needed_at_jump.regs);
- }
- }
+ /* Stand-alone USE and CLOBBER are just for flow. */
+ if (GET_CODE (pat) == USE || GET_CODE (pat) == CLOBBER)
+ continue;
- /* See if we have a resource problem before we try to
- split. */
- if (target == 0
- && GET_CODE (pat) != SEQUENCE
- && ! insn_references_resource_p (trial, &set, 1)
- && ! insn_sets_resource_p (trial, &set, 1)
- && ! insn_sets_resource_p (trial, &needed, 1)
+ /* If this already has filled delay slots, get the insn needing
+ the delay slots. */
+ if (GET_CODE (pat) == SEQUENCE)
+ trial_delay = XVECEXP (pat, 0, 0);
+ else
+ trial_delay = trial;
+
+ /* Stop our search when seeing an unconditional jump. */
+ if (GET_CODE (trial_delay) == JUMP_INSN)
+ break;
+
+ /* See if we have a resource problem before we try to
+ split. */
+ if (GET_CODE (pat) != SEQUENCE
+ && ! insn_references_resource_p (trial, &set, 1)
+ && ! insn_sets_resource_p (trial, &set, 1)
+ && ! insn_sets_resource_p (trial, &needed, 1)
#ifdef HAVE_cc0
- && ! (reg_mentioned_p (cc0_rtx, pat) && ! sets_cc0_p (pat))
+ && ! (reg_mentioned_p (cc0_rtx, pat) && ! sets_cc0_p (pat))
#endif
- && ! (maybe_never && may_trap_p (pat))
- && (trial = try_split (pat, trial, 0))
- && eligible_for_delay (insn, slots_filled, trial, flags))
- {
- next_trial = next_nonnote_insn (trial);
- delay_list = add_to_delay_list (trial, delay_list);
+ && ! (maybe_never && may_trap_p (pat))
+ && (trial = try_split (pat, trial, 0))
+ && eligible_for_delay (insn, slots_filled, trial, flags))
+ {
+ next_trial = next_nonnote_insn (trial);
+ delay_list = add_to_delay_list (trial, delay_list);
#ifdef HAVE_cc0
- if (reg_mentioned_p (cc0_rtx, pat))
- link_cc0_insns (trial);
+ if (reg_mentioned_p (cc0_rtx, pat))
+ link_cc0_insns (trial);
#endif
- delete_insn (trial);
- if (slots_to_fill == ++slots_filled)
- break;
- continue;
- }
+ delete_insn (trial);
+ if (slots_to_fill == ++slots_filled)
+ break;
+ continue;
+ }
- mark_set_resources (trial, &set, 0, MARK_SRC_DEST_CALL);
- mark_referenced_resources (trial, &needed, 1);
+ mark_set_resources (trial, &set, 0, MARK_SRC_DEST_CALL);
+ mark_referenced_resources (trial, &needed, 1);
- /* Ensure we don't put insns between the setting of cc and the
- comparison by moving a setting of cc into an earlier delay
- slot since these insns could clobber the condition code. */
- set.cc = 1;
+ /* Ensure we don't put insns between the setting of cc and the
+ comparison by moving a setting of cc into an earlier delay
+ slot since these insns could clobber the condition code. */
+ set.cc = 1;
- /* If this is a call or jump, we might not get here. */
- if (GET_CODE (trial_delay) == CALL_INSN
- || GET_CODE (trial_delay) == JUMP_INSN)
- maybe_never = 1;
- }
+ /* If this is a call or jump, we might not get here. */
+ if (GET_CODE (trial_delay) == CALL_INSN
+ || GET_CODE (trial_delay) == JUMP_INSN)
+ maybe_never = 1;
+ }
/* If there are slots left to fill and our search was stopped by an
unconditional branch, try the insn at the branch target. We can
}
/* If this insn is expected to branch, first try to get insns from our
- target, then our fallthrough insns. If it is not, expected to branch,
+ target, then our fallthrough insns. If it is not expected to branch,
try the other order. */
if (prediction > 0)
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