gcc-8.3/gcc/lra_final_code_change()

参照元†

gcc-8.3/gcc/lra()

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説明†

パス: gcc-8.3/gcc/lra-spills.c

FIXME: これは何？
- 説明

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引数†

なし

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返り値†

なし

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参考†

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実装†

/* Final change of pseudos got hard registers into the corresponding
   hard registers and removing temporary clobbers.  */
void
lra_final_code_change (void)
{
  int i, hard_regno;
  basic_block bb;
  rtx_insn *insn, *curr;
  int max_regno = max_reg_num ();

  for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
    if (lra_reg_info[i].nrefs != 0
	&& (hard_regno = lra_get_regno_hard_regno (i)) >= 0)
      SET_REGNO (regno_reg_rtx[i], hard_regno);

- gcc-8.3/gcc/lra_get_regno_hard_regno()
- gcc-8.3/gcc/SET_REGNO()

  FOR_EACH_BB_FN (bb, cfun)
    FOR_BB_INSNS_SAFE (bb, insn, curr)
      if (INSN_P (insn))
	{

	  rtx pat = PATTERN (insn);

	  if (GET_CODE (pat) == CLOBBER && LRA_TEMP_CLOBBER_P (pat))
	    {
	      /* Remove clobbers temporarily created in LRA.  We don't
		 need them anymore and don't want to waste compiler
		 time processing them in a few subsequent passes.  */
	      lra_invalidate_insn_data (insn);
	      delete_insn (insn);
	      continue;
	    }

	  /* IRA can generate move insns involving pseudos.  It is
	     better remove them earlier to speed up compiler a bit.
	     It is also better to do it here as they might not pass
	     final RTL check in LRA, (e.g. insn moving a control
	     register into itself).  So remove an useless move insn
	     unless next insn is USE marking the return reg (we should
	     save this as some subsequent optimizations assume that
	     such original insns are saved).  */
	  if (NONJUMP_INSN_P (insn) && GET_CODE (pat) == SET
	      && REG_P (SET_SRC (pat)) && REG_P (SET_DEST (pat))
	      && REGNO (SET_SRC (pat)) == REGNO (SET_DEST (pat))
	      && (! return_regno_p (REGNO (SET_SRC (pat)))
		  || ! regno_in_use_p (insn, REGNO (SET_SRC (pat)))))
	    {
	      lra_invalidate_insn_data (insn);
	      delete_insn (insn);
	      continue;
	    }

	  lra_insn_recog_data_t id = lra_get_insn_recog_data (insn);
	  struct lra_insn_reg *reg;

	  for (reg = id->regs; reg != NULL; reg = reg->next)
	    if (reg->regno >= FIRST_PSEUDO_REGISTER
		&& lra_reg_info [reg->regno].nrefs == 0)
	      break;

- gcc-8.3/gcc/lra_insn_recog_data_t
- gcc-8.3/gcc/lra_insn_reg

	  if (reg != NULL)
	    {
	      /* Pseudos still can be in debug insns in some very rare
		 and complicated cases, e.g. the pseudo was removed by
		 inheritance and the debug insn is not EBBs where the
		 inheritance happened.  It is difficult and time
		 consuming to find what hard register corresponds the
		 pseudo -- so just remove the debug insn.  Another
		 solution could be assigning hard reg/memory but it
		 would be a misleading info.  It is better not to have
		 info than have it wrong.  */
	      lra_assert (DEBUG_INSN_P (insn));
	      lra_invalidate_insn_data (insn);
	      delete_insn (insn);
	      continue;
	    }

	  struct lra_static_insn_data *static_id = id->insn_static_data;
	  bool insn_change_p = false;

	  for (i = id->insn_static_data->n_operands - 1; i >= 0; i--)
	    if ((DEBUG_INSN_P (insn) || ! static_id->operand[i].is_operator)
		&& alter_subregs (id->operand_loc[i], ! DEBUG_INSN_P (insn)))
	      {
		lra_update_dup (id, i);
		insn_change_p = true;
	      }
	  if (insn_change_p)
	    lra_update_operator_dups (id);
	}

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