Пример #1
0
static void
check_call (ipa_reference_local_vars_info_t local, tree call_expr) 
{
  int flags = call_expr_flags (call_expr);
  tree operand_list = TREE_OPERAND (call_expr, 1);
  tree operand;
  tree callee_t = get_callee_fndecl (call_expr);
  enum availability avail = AVAIL_NOT_AVAILABLE;

  for (operand = operand_list;
       operand != NULL_TREE;
       operand = TREE_CHAIN (operand))
    {
      tree argument = TREE_VALUE (operand);
      check_rhs_var (local, argument);
    }

  if (callee_t)
    {
      struct cgraph_node* callee = cgraph_node(callee_t);
      avail = cgraph_function_body_availability (callee);
    }

  if (avail == AVAIL_NOT_AVAILABLE || avail == AVAIL_OVERWRITABLE)
    if (local) 
      {
        if (flags & ECF_PURE) 
          local->calls_read_all = true;
        else 
          {
            local->calls_read_all = true;
            local->calls_write_all = true;
          }
      }
}
Пример #2
0
static tree
pass_through_call (tree call)
{
  tree callee = get_callee_fndecl (call);
  tree arglist = TREE_OPERAND (call, 1);

  if (callee
      && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL)
    switch (DECL_FUNCTION_CODE (callee))
      {
      case BUILT_IN_MEMCPY:
      case BUILT_IN_MEMMOVE:
      case BUILT_IN_MEMSET:
      case BUILT_IN_STRCPY:
      case BUILT_IN_STRNCPY:
      case BUILT_IN_STRCAT:
      case BUILT_IN_STRNCAT:
      case BUILT_IN_MEMCPY_CHK:
      case BUILT_IN_MEMMOVE_CHK:
      case BUILT_IN_MEMSET_CHK:
      case BUILT_IN_STRCPY_CHK:
      case BUILT_IN_STRNCPY_CHK:
      case BUILT_IN_STRCAT_CHK:
      case BUILT_IN_STRNCAT_CHK:
	if (arglist)
	  return TREE_VALUE (arglist);
	break;
      default:
	break;
      }

  return NULL_TREE;
}
static void
check_call (ipa_reference_local_vars_info_t local, tree call_expr) 
{
  int flags = call_expr_flags (call_expr);
  tree operand;
  tree callee_t = get_callee_fndecl (call_expr);
  enum availability avail = AVAIL_NOT_AVAILABLE;
  call_expr_arg_iterator iter;

  FOR_EACH_CALL_EXPR_ARG (operand, iter, call_expr)
    check_rhs_var (local, operand);

  if (callee_t)
    {
      struct cgraph_node* callee = cgraph_node(callee_t);
      avail = cgraph_function_body_availability (callee);
    }

  if (avail == AVAIL_NOT_AVAILABLE || avail == AVAIL_OVERWRITABLE)
    if (local) 
      {
	if (flags & ECF_PURE) 
	  local->calls_read_all = true;
	else 
	  {
	    local->calls_read_all = true;
	    local->calls_write_all = true;
	  }
      }
}
Пример #4
0
static unsigned
stmt_cost (tree stmt)
{
  tree rhs;
  unsigned cost = 1;

  /* Always try to create possibilities for unswitching.  */
  if (TREE_CODE (stmt) == COND_EXPR)
    return LIM_EXPENSIVE;

  rhs = GENERIC_TREE_OPERAND (stmt, 1);

  /* Hoisting memory references out should almost surely be a win.  */
  if (stmt_references_memory_p (stmt))
    cost += 20;

  switch (TREE_CODE (rhs))
    {
    case CALL_EXPR:
      /* We should be hoisting calls if possible.  */

      /* Unless the call is a builtin_constant_p; this always folds to a
	 constant, so moving it is useless.  */
      rhs = get_callee_fndecl (rhs);
      if (DECL_BUILT_IN_CLASS (rhs) == BUILT_IN_NORMAL
	  && DECL_FUNCTION_CODE (rhs) == BUILT_IN_CONSTANT_P)
	return 0;

      cost += 20;
      break;

    case MULT_EXPR:
    case TRUNC_DIV_EXPR:
    case CEIL_DIV_EXPR:
    case FLOOR_DIV_EXPR:
    case ROUND_DIV_EXPR:
    case EXACT_DIV_EXPR:
    case CEIL_MOD_EXPR:
    case FLOOR_MOD_EXPR:
    case ROUND_MOD_EXPR:
    case TRUNC_MOD_EXPR:
    case RDIV_EXPR:
      /* Division and multiplication are usually expensive.  */
      cost += 20;
      break;

    case LSHIFT_EXPR:
    case RSHIFT_EXPR:
      cost += 20;
      break;

    default:
      break;
    }

  return cost;
}
Пример #5
0
static unsigned HOST_WIDE_INT
alloc_object_size (tree call, int object_size_type)
{
  tree callee, arglist, a, bytes = NULL_TREE;
  unsigned int arg_mask = 0;

  gcc_assert (TREE_CODE (call) == CALL_EXPR);

  callee = get_callee_fndecl (call);
  arglist = TREE_OPERAND (call, 1);
  if (callee
      && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL)
    switch (DECL_FUNCTION_CODE (callee))
      {
      case BUILT_IN_MALLOC:
      case BUILT_IN_ALLOCA:
	arg_mask = 1;
	break;
      /*
      case BUILT_IN_REALLOC:
	arg_mask = 2;
	break;
	*/
      case BUILT_IN_CALLOC:
	arg_mask = 3;
	break;
      default:
	break;
      }

  for (a = arglist; arg_mask && a; arg_mask >>= 1, a = TREE_CHAIN (a))
    if (arg_mask & 1)
      {
	tree arg = TREE_VALUE (a);

	if (TREE_CODE (arg) != INTEGER_CST)
	  break;

	if (! bytes)
	  bytes = fold_convert (sizetype, arg);
	else
	  bytes = size_binop (MULT_EXPR, bytes,
			      fold_convert (sizetype, arg));
      }

  if (! arg_mask && bytes && host_integerp (bytes, 1))
    return tree_low_cst (bytes, 1);

  return unknown[object_size_type];
}
Пример #6
0
static void
check_call (funct_state local, tree call_expr) 
{
  int flags = call_expr_flags(call_expr);
  tree operand_list = TREE_OPERAND (call_expr, 1);
  tree operand;
  tree callee_t = get_callee_fndecl (call_expr);
  struct cgraph_node* callee;
  enum availability avail = AVAIL_NOT_AVAILABLE;

  for (operand = operand_list;
       operand != NULL_TREE;
       operand = TREE_CHAIN (operand))
    {
      tree argument = TREE_VALUE (operand);
      check_rhs_var (local, argument);
    }
  
  /* The const and pure flags are set by a variety of places in the
     compiler (including here).  If someone has already set the flags
     for the callee, (such as for some of the builtins) we will use
     them, otherwise we will compute our own information. 
  
     Const and pure functions have less clobber effects than other
     functions so we process these first.  Otherwise if it is a call
     outside the compilation unit or an indirect call we punt.  This
     leaves local calls which will be processed by following the call
     graph.  */  
  if (callee_t)
    {
      callee = cgraph_node(callee_t);
      avail = cgraph_function_body_availability (callee);

      /* When bad things happen to bad functions, they cannot be const
	 or pure.  */
      if (setjmp_call_p (callee_t))
	local->pure_const_state = IPA_NEITHER;

      if (DECL_BUILT_IN_CLASS (callee_t) == BUILT_IN_NORMAL)
	switch (DECL_FUNCTION_CODE (callee_t))
	  {
	  case BUILT_IN_LONGJMP:
	  case BUILT_IN_NONLOCAL_GOTO:
	    local->pure_const_state = IPA_NEITHER;
	    break;
	  default:
	    break;
	  }
    }

  /* The callee is either unknown (indirect call) or there is just no
     scannable code for it (external call) .  We look to see if there
     are any bits available for the callee (such as by declaration or
     because it is builtin) and process solely on the basis of those
     bits. */
  if (avail == AVAIL_NOT_AVAILABLE || avail == AVAIL_OVERWRITABLE)
    {
      if (flags & ECF_PURE) 
	{
	  if (local->pure_const_state == IPA_CONST)
	    local->pure_const_state = IPA_PURE;
	}
      else 
	local->pure_const_state = IPA_NEITHER;
    }
  else
    {
      /* We have the code and we will scan it for the effects. */
      if (flags & ECF_PURE) 
	{
	  if (local->pure_const_state == IPA_CONST)
	    local->pure_const_state = IPA_PURE;
	}
    }
}
Пример #7
0
void
do_jump (tree exp, rtx if_false_label, rtx if_true_label)
{
  enum tree_code code = TREE_CODE (exp);
  rtx temp;
  int i;
  tree type;
  enum machine_mode mode;
  rtx drop_through_label = 0;

  switch (code)
    {
    case ERROR_MARK:
      break;

    case INTEGER_CST:
      temp = integer_zerop (exp) ? if_false_label : if_true_label;
      if (temp)
        emit_jump (temp);
      break;

#if 0
      /* This is not true with #pragma weak  */
    case ADDR_EXPR:
      /* The address of something can never be zero.  */
      if (if_true_label)
        emit_jump (if_true_label);
      break;
#endif

    case NOP_EXPR:
      if (TREE_CODE (TREE_OPERAND (exp, 0)) == COMPONENT_REF
          || TREE_CODE (TREE_OPERAND (exp, 0)) == BIT_FIELD_REF
          || TREE_CODE (TREE_OPERAND (exp, 0)) == ARRAY_REF
          || TREE_CODE (TREE_OPERAND (exp, 0)) == ARRAY_RANGE_REF)
        goto normal;
    case CONVERT_EXPR:
      /* If we are narrowing the operand, we have to do the compare in the
         narrower mode.  */
      if ((TYPE_PRECISION (TREE_TYPE (exp))
           < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0)))))
        goto normal;
    case NON_LVALUE_EXPR:
    case ABS_EXPR:
    case NEGATE_EXPR:
    case LROTATE_EXPR:
    case RROTATE_EXPR:
      /* These cannot change zero->nonzero or vice versa.  */
      do_jump (TREE_OPERAND (exp, 0), if_false_label, if_true_label);
      break;

    case BIT_AND_EXPR:
      /* fold_single_bit_test() converts (X & (1 << C)) into (X >> C) & 1.
         See if the former is preferred for jump tests and restore it
         if so.  */
      if (integer_onep (TREE_OPERAND (exp, 1)))
        {
          tree exp0 = TREE_OPERAND (exp, 0);
          rtx set_label, clr_label;

          /* Strip narrowing integral type conversions.  */
          while ((TREE_CODE (exp0) == NOP_EXPR
                  || TREE_CODE (exp0) == CONVERT_EXPR
                  || TREE_CODE (exp0) == NON_LVALUE_EXPR)
                 && TREE_OPERAND (exp0, 0) != error_mark_node
                 && TYPE_PRECISION (TREE_TYPE (exp0))
                    <= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp0, 0))))
            exp0 = TREE_OPERAND (exp0, 0);

          /* "exp0 ^ 1" inverts the sense of the single bit test.  */
          if (TREE_CODE (exp0) == BIT_XOR_EXPR
              && integer_onep (TREE_OPERAND (exp0, 1)))
            {
              exp0 = TREE_OPERAND (exp0, 0);
              clr_label = if_true_label;
              set_label = if_false_label;
            }
          else
            {
              clr_label = if_false_label;
              set_label = if_true_label;
            }

          if (TREE_CODE (exp0) == RSHIFT_EXPR)
            {
              tree arg = TREE_OPERAND (exp0, 0);
              tree shift = TREE_OPERAND (exp0, 1);
              tree argtype = TREE_TYPE (arg);
              if (TREE_CODE (shift) == INTEGER_CST
                  && compare_tree_int (shift, 0) >= 0
                  && compare_tree_int (shift, HOST_BITS_PER_WIDE_INT) < 0
                  && prefer_and_bit_test (TYPE_MODE (argtype),
                                          TREE_INT_CST_LOW (shift)))
                {
                  HOST_WIDE_INT mask = (HOST_WIDE_INT) 1
                                       << TREE_INT_CST_LOW (shift);
                  do_jump (build2 (BIT_AND_EXPR, argtype, arg,
                                   build_int_cst_type (argtype, mask)),
                           clr_label, set_label);
                  break;
                }
            }
        }

      /* If we are AND'ing with a small constant, do this comparison in the
         smallest type that fits.  If the machine doesn't have comparisons
         that small, it will be converted back to the wider comparison.
         This helps if we are testing the sign bit of a narrower object.
         combine can't do this for us because it can't know whether a
         ZERO_EXTRACT or a compare in a smaller mode exists, but we do.  */

      if (! SLOW_BYTE_ACCESS
          && TREE_CODE (TREE_OPERAND (exp, 1)) == INTEGER_CST
          && TYPE_PRECISION (TREE_TYPE (exp)) <= HOST_BITS_PER_WIDE_INT
          && (i = tree_floor_log2 (TREE_OPERAND (exp, 1))) >= 0
          && (mode = mode_for_size (i + 1, MODE_INT, 0)) != BLKmode
          && (type = lang_hooks.types.type_for_mode (mode, 1)) != 0
          && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (exp))
          && (cmp_optab->handlers[(int) TYPE_MODE (type)].insn_code
              != CODE_FOR_nothing))
        {
          do_jump (fold_convert (type, exp), if_false_label, if_true_label);
          break;
        }
      goto normal;

    case TRUTH_NOT_EXPR:
      do_jump (TREE_OPERAND (exp, 0), if_true_label, if_false_label);
      break;

    case COND_EXPR:
      {
        rtx label1 = gen_label_rtx ();
        if (!if_true_label || !if_false_label)
          {
            drop_through_label = gen_label_rtx ();
            if (!if_true_label)
              if_true_label = drop_through_label;
            if (!if_false_label)
              if_false_label = drop_through_label;
          }

        do_pending_stack_adjust ();
        do_jump (TREE_OPERAND (exp, 0), label1, NULL_RTX);
        do_jump (TREE_OPERAND (exp, 1), if_false_label, if_true_label);
        emit_label (label1);
        do_jump (TREE_OPERAND (exp, 2), if_false_label, if_true_label);
        break;
      }

    case TRUTH_ANDIF_EXPR:
    case TRUTH_ORIF_EXPR:
    case COMPOUND_EXPR:
      /* Lowered by gimplify.c.  */
      gcc_unreachable ();

    case COMPONENT_REF:
    case BIT_FIELD_REF:
    case ARRAY_REF:
    case ARRAY_RANGE_REF:
      {
        HOST_WIDE_INT bitsize, bitpos;
        int unsignedp;
        enum machine_mode mode;
        tree type;
        tree offset;
        int volatilep = 0;

        /* Get description of this reference.  We don't actually care
           about the underlying object here.  */
        get_inner_reference (exp, &bitsize, &bitpos, &offset, &mode,
                             &unsignedp, &volatilep, false);

        type = lang_hooks.types.type_for_size (bitsize, unsignedp);
        if (! SLOW_BYTE_ACCESS
            && type != 0 && bitsize >= 0
            && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (exp))
            && (cmp_optab->handlers[(int) TYPE_MODE (type)].insn_code
                != CODE_FOR_nothing))
          {
            do_jump (fold_convert (type, exp), if_false_label, if_true_label);
            break;
          }
        goto normal;
      }

    case EQ_EXPR:
      {
        tree inner_type = TREE_TYPE (TREE_OPERAND (exp, 0));

        gcc_assert (GET_MODE_CLASS (TYPE_MODE (inner_type))
                    != MODE_COMPLEX_FLOAT);
        gcc_assert (GET_MODE_CLASS (TYPE_MODE (inner_type))
                    != MODE_COMPLEX_INT);
        
        if (integer_zerop (TREE_OPERAND (exp, 1)))
          do_jump (TREE_OPERAND (exp, 0), if_true_label, if_false_label);
        else if (GET_MODE_CLASS (TYPE_MODE (inner_type)) == MODE_INT
                 && !can_compare_p (EQ, TYPE_MODE (inner_type), ccp_jump))
          do_jump_by_parts_equality (exp, if_false_label, if_true_label);
        else
          do_compare_and_jump (exp, EQ, EQ, if_false_label, if_true_label);
        break;
      }

    case MINUS_EXPR:
      /* Nonzero iff operands of minus differ.  */
      exp = build2 (NE_EXPR, TREE_TYPE (exp),
                    TREE_OPERAND (exp, 0),
                    TREE_OPERAND (exp, 1));
      /* FALLTHRU */
    case NE_EXPR:
      {
        tree inner_type = TREE_TYPE (TREE_OPERAND (exp, 0));

        gcc_assert (GET_MODE_CLASS (TYPE_MODE (inner_type))
                    != MODE_COMPLEX_FLOAT);
        gcc_assert (GET_MODE_CLASS (TYPE_MODE (inner_type))
                    != MODE_COMPLEX_INT);
        
        if (integer_zerop (TREE_OPERAND (exp, 1)))
          do_jump (TREE_OPERAND (exp, 0), if_false_label, if_true_label);
        else if (GET_MODE_CLASS (TYPE_MODE (inner_type)) == MODE_INT
           && !can_compare_p (NE, TYPE_MODE (inner_type), ccp_jump))
          do_jump_by_parts_equality (exp, if_true_label, if_false_label);
        else
          do_compare_and_jump (exp, NE, NE, if_false_label, if_true_label);
        break;
      }

    case LT_EXPR:
      mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)));
      if (GET_MODE_CLASS (mode) == MODE_INT
          && ! can_compare_p (LT, mode, ccp_jump))
        do_jump_by_parts_greater (exp, 1, if_false_label, if_true_label);
      else
        do_compare_and_jump (exp, LT, LTU, if_false_label, if_true_label);
      break;

    case LE_EXPR:
      mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)));
      if (GET_MODE_CLASS (mode) == MODE_INT
          && ! can_compare_p (LE, mode, ccp_jump))
        do_jump_by_parts_greater (exp, 0, if_true_label, if_false_label);
      else
        do_compare_and_jump (exp, LE, LEU, if_false_label, if_true_label);
      break;

    case GT_EXPR:
      mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)));
      if (GET_MODE_CLASS (mode) == MODE_INT
          && ! can_compare_p (GT, mode, ccp_jump))
        do_jump_by_parts_greater (exp, 0, if_false_label, if_true_label);
      else
        do_compare_and_jump (exp, GT, GTU, if_false_label, if_true_label);
      break;

    case GE_EXPR:
      mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)));
      if (GET_MODE_CLASS (mode) == MODE_INT
          && ! can_compare_p (GE, mode, ccp_jump))
        do_jump_by_parts_greater (exp, 1, if_true_label, if_false_label);
      else
        do_compare_and_jump (exp, GE, GEU, if_false_label, if_true_label);
      break;

    case UNORDERED_EXPR:
    case ORDERED_EXPR:
      {
        enum rtx_code cmp, rcmp;
        int do_rev;

        if (code == UNORDERED_EXPR)
          cmp = UNORDERED, rcmp = ORDERED;
        else
          cmp = ORDERED, rcmp = UNORDERED;
        mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)));

        do_rev = 0;
        if (! can_compare_p (cmp, mode, ccp_jump)
            && (can_compare_p (rcmp, mode, ccp_jump)
          /* If the target doesn't provide either UNORDERED or ORDERED
             comparisons, canonicalize on UNORDERED for the library.  */
          || rcmp == UNORDERED))
          do_rev = 1;

        if (! do_rev)
          do_compare_and_jump (exp, cmp, cmp, if_false_label, if_true_label);
        else
          do_compare_and_jump (exp, rcmp, rcmp, if_true_label, if_false_label);
      }
      break;

    {
      enum rtx_code rcode1;
      enum tree_code tcode1, tcode2;

      case UNLT_EXPR:
        rcode1 = UNLT;
        tcode1 = UNORDERED_EXPR;
        tcode2 = LT_EXPR;
        goto unordered_bcc;
      case UNLE_EXPR:
        rcode1 = UNLE;
        tcode1 = UNORDERED_EXPR;
        tcode2 = LE_EXPR;
        goto unordered_bcc;
      case UNGT_EXPR:
        rcode1 = UNGT;
        tcode1 = UNORDERED_EXPR;
        tcode2 = GT_EXPR;
        goto unordered_bcc;
      case UNGE_EXPR:
        rcode1 = UNGE;
        tcode1 = UNORDERED_EXPR;
        tcode2 = GE_EXPR;
        goto unordered_bcc;
      case UNEQ_EXPR:
        rcode1 = UNEQ;
        tcode1 = UNORDERED_EXPR;
        tcode2 = EQ_EXPR;
        goto unordered_bcc;
      case LTGT_EXPR:
        /* It is ok for LTGT_EXPR to trap when the result is unordered,
           so expand to (a < b) || (a > b).  */
        rcode1 = LTGT;
        tcode1 = LT_EXPR;
        tcode2 = GT_EXPR;
        goto unordered_bcc;

      unordered_bcc:
        mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)));
        if (can_compare_p (rcode1, mode, ccp_jump))
          do_compare_and_jump (exp, rcode1, rcode1, if_false_label,
                               if_true_label);
        else
          {
            tree op0 = save_expr (TREE_OPERAND (exp, 0));
            tree op1 = save_expr (TREE_OPERAND (exp, 1));
            tree cmp0, cmp1;

            /* If the target doesn't support combined unordered
               compares, decompose into two comparisons.  */
            if (if_true_label == 0)
              drop_through_label = if_true_label = gen_label_rtx ();
              
            cmp0 = fold_build2 (tcode1, TREE_TYPE (exp), op0, op1);
            cmp1 = fold_build2 (tcode2, TREE_TYPE (exp), op0, op1);
            do_jump (cmp0, 0, if_true_label);
            do_jump (cmp1, if_false_label, if_true_label);
          }
      }
      break;

    case TRUTH_AND_EXPR:
      /* High branch cost, expand as the bitwise AND of the conditions.
         Do the same if the RHS has side effects, because we're effectively
         turning a TRUTH_AND_EXPR into a TRUTH_ANDIF_EXPR.  */
      if (BRANCH_COST >= 4 || TREE_SIDE_EFFECTS (TREE_OPERAND (exp, 1)))
        goto normal;

      if (if_false_label == NULL_RTX)
        {
          drop_through_label = gen_label_rtx ();
          do_jump (TREE_OPERAND (exp, 0), drop_through_label, NULL_RTX);
          do_jump (TREE_OPERAND (exp, 1), NULL_RTX, if_true_label);
        }
      else
        {
          do_jump (TREE_OPERAND (exp, 0), if_false_label, NULL_RTX);
          do_jump (TREE_OPERAND (exp, 1), if_false_label, if_true_label);
        }
      break;

    case TRUTH_OR_EXPR:
      /* High branch cost, expand as the bitwise OR of the conditions.
         Do the same if the RHS has side effects, because we're effectively
         turning a TRUTH_OR_EXPR into a TRUTH_ORIF_EXPR.  */
      if (BRANCH_COST >= 4 || TREE_SIDE_EFFECTS (TREE_OPERAND (exp, 1)))
        goto normal;

      if (if_true_label == NULL_RTX)
        {
          drop_through_label = gen_label_rtx ();
          do_jump (TREE_OPERAND (exp, 0), NULL_RTX, drop_through_label);
          do_jump (TREE_OPERAND (exp, 1), if_false_label, NULL_RTX);
        }
      else
        {
          do_jump (TREE_OPERAND (exp, 0), NULL_RTX, if_true_label);
          do_jump (TREE_OPERAND (exp, 1), if_false_label, if_true_label);
        }
      break;

      /* Special case:
          __builtin_expect (<test>, 0)        and
          __builtin_expect (<test>, 1)

         We need to do this here, so that <test> is not converted to a SCC
         operation on machines that use condition code registers and COMPARE
         like the PowerPC, and then the jump is done based on whether the SCC
         operation produced a 1 or 0.  */
    case CALL_EXPR:
      /* Check for a built-in function.  */
      {
        tree fndecl = get_callee_fndecl (exp);
        tree arglist = TREE_OPERAND (exp, 1);

        if (fndecl
            && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
            && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_EXPECT
            && arglist != NULL_TREE
            && TREE_CHAIN (arglist) != NULL_TREE)
          {
            rtx seq = expand_builtin_expect_jump (exp, if_false_label,
                                                  if_true_label);

            if (seq != NULL_RTX)
              {
                emit_insn (seq);
                return;
              }
          }
      }
 
      /* Fall through and generate the normal code.  */
    default:
    normal:
      temp = expand_normal (exp);
      do_pending_stack_adjust ();
      /* The RTL optimizers prefer comparisons against pseudos.  */
      if (GET_CODE (temp) == SUBREG)
        {
          /* Compare promoted variables in their promoted mode.  */
          if (SUBREG_PROMOTED_VAR_P (temp)
              && REG_P (XEXP (temp, 0)))
            temp = XEXP (temp, 0);
          else
            temp = copy_to_reg (temp);
        }
      do_compare_rtx_and_jump (temp, CONST0_RTX (GET_MODE (temp)),
                               NE, TYPE_UNSIGNED (TREE_TYPE (exp)),
                               GET_MODE (temp), NULL_RTX,
                               if_false_label, if_true_label);
    }

  if (drop_through_label)
    {
      do_pending_stack_adjust ();
      emit_label (drop_through_label);
    }
}
Пример #8
0
void
do_jump (tree exp, rtx if_false_label, rtx if_true_label)
{
  enum tree_code code = TREE_CODE (exp);
  /* Some cases need to create a label to jump to
     in order to properly fall through.
     These cases set DROP_THROUGH_LABEL nonzero.  */
  rtx drop_through_label = 0;
  rtx temp;
  int i;
  tree type;
  enum machine_mode mode;

  emit_queue ();

  switch (code)
    {
    case ERROR_MARK:
      break;

    case INTEGER_CST:
      temp = integer_zerop (exp) ? if_false_label : if_true_label;
      if (temp)
        emit_jump (temp);
      break;

#if 0
      /* This is not true with #pragma weak  */
    case ADDR_EXPR:
      /* The address of something can never be zero.  */
      if (if_true_label)
        emit_jump (if_true_label);
      break;
#endif

    case UNSAVE_EXPR:
      do_jump (TREE_OPERAND (exp, 0), if_false_label, if_true_label);
      TREE_OPERAND (exp, 0)
	= (*lang_hooks.unsave_expr_now) (TREE_OPERAND (exp, 0));
      break;

    case NOP_EXPR:
      if (TREE_CODE (TREE_OPERAND (exp, 0)) == COMPONENT_REF
          || TREE_CODE (TREE_OPERAND (exp, 0)) == BIT_FIELD_REF
          || TREE_CODE (TREE_OPERAND (exp, 0)) == ARRAY_REF
          || TREE_CODE (TREE_OPERAND (exp, 0)) == ARRAY_RANGE_REF)
        goto normal;
    case CONVERT_EXPR:
      /* If we are narrowing the operand, we have to do the compare in the
         narrower mode.  */
      if ((TYPE_PRECISION (TREE_TYPE (exp))
           < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0)))))
        goto normal;
    case NON_LVALUE_EXPR:
    case REFERENCE_EXPR:
    case ABS_EXPR:
    case NEGATE_EXPR:
    case LROTATE_EXPR:
    case RROTATE_EXPR:
      /* These cannot change zero->nonzero or vice versa.  */
      do_jump (TREE_OPERAND (exp, 0), if_false_label, if_true_label);
      break;

    case WITH_RECORD_EXPR:
      /* Put the object on the placeholder list, recurse through our first
         operand, and pop the list.  */
      placeholder_list = tree_cons (TREE_OPERAND (exp, 1), NULL_TREE,
                                    placeholder_list);
      do_jump (TREE_OPERAND (exp, 0), if_false_label, if_true_label);
      placeholder_list = TREE_CHAIN (placeholder_list);
      break;

#if 0
      /* This is never less insns than evaluating the PLUS_EXPR followed by
         a test and can be longer if the test is eliminated.  */
    case PLUS_EXPR:
      /* Reduce to minus.  */
      exp = build (MINUS_EXPR, TREE_TYPE (exp),
                   TREE_OPERAND (exp, 0),
                   fold (build1 (NEGATE_EXPR, TREE_TYPE (TREE_OPERAND (exp, 1)),
                                 TREE_OPERAND (exp, 1))));
      /* Process as MINUS.  */
#endif

    case MINUS_EXPR:
      /* Nonzero iff operands of minus differ.  */
      do_compare_and_jump (build (NE_EXPR, TREE_TYPE (exp),
                                  TREE_OPERAND (exp, 0),
                                  TREE_OPERAND (exp, 1)),
                           NE, NE, if_false_label, if_true_label);
      break;

    case BIT_AND_EXPR:
      /* fold_single_bit_test() converts (X & (1 << C)) into (X >> C) & 1.
	 See if the former is preferred for jump tests and restore it
	 if so.  */
      if (integer_onep (TREE_OPERAND (exp, 1)))
	{
	  tree exp0 = TREE_OPERAND (exp, 0);
	  rtx set_label, clr_label;

	  /* Strip narrowing integral type conversions.  */
	  while ((TREE_CODE (exp0) == NOP_EXPR
		  || TREE_CODE (exp0) == CONVERT_EXPR
		  || TREE_CODE (exp0) == NON_LVALUE_EXPR)
		 && TREE_OPERAND (exp0, 0) != error_mark_node
		 && TYPE_PRECISION (TREE_TYPE (exp0))
		    <= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp0, 0))))
	    exp0 = TREE_OPERAND (exp0, 0);

	  /* "exp0 ^ 1" inverts the sense of the single bit test.  */
	  if (TREE_CODE (exp0) == BIT_XOR_EXPR
	      && integer_onep (TREE_OPERAND (exp0, 1)))
	    {
	      exp0 = TREE_OPERAND (exp0, 0);
	      clr_label = if_true_label;
	      set_label = if_false_label;
	    }
	  else
	    {
	      clr_label = if_false_label;
	      set_label = if_true_label;
	    }

	  if (TREE_CODE (exp0) == RSHIFT_EXPR)
	    {
	      tree arg = TREE_OPERAND (exp0, 0);
	      tree shift = TREE_OPERAND (exp0, 1);
	      tree argtype = TREE_TYPE (arg);
	      if (TREE_CODE (shift) == INTEGER_CST
		  && compare_tree_int (shift, 0) >= 0
		  && compare_tree_int (shift, HOST_BITS_PER_WIDE_INT) < 0
		  && prefer_and_bit_test (TYPE_MODE (argtype),
					  TREE_INT_CST_LOW (shift)))
		{
		  HOST_WIDE_INT mask = (HOST_WIDE_INT) 1
				       << TREE_INT_CST_LOW (shift);
		  tree t = build_int_2 (mask, 0);
		  TREE_TYPE (t) = argtype;
		  do_jump (build (BIT_AND_EXPR, argtype, arg, t),
			   clr_label, set_label);
		  break;
		}
	    }
	}

      /* If we are AND'ing with a small constant, do this comparison in the
         smallest type that fits.  If the machine doesn't have comparisons
         that small, it will be converted back to the wider comparison.
         This helps if we are testing the sign bit of a narrower object.
         combine can't do this for us because it can't know whether a
         ZERO_EXTRACT or a compare in a smaller mode exists, but we do.  */

      if (! SLOW_BYTE_ACCESS
          && TREE_CODE (TREE_OPERAND (exp, 1)) == INTEGER_CST
          && TYPE_PRECISION (TREE_TYPE (exp)) <= HOST_BITS_PER_WIDE_INT
          && (i = tree_floor_log2 (TREE_OPERAND (exp, 1))) >= 0
          && (mode = mode_for_size (i + 1, MODE_INT, 0)) != BLKmode
          && (type = (*lang_hooks.types.type_for_mode) (mode, 1)) != 0
          && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (exp))
          && (cmp_optab->handlers[(int) TYPE_MODE (type)].insn_code
              != CODE_FOR_nothing))
        {
          do_jump (convert (type, exp), if_false_label, if_true_label);
          break;
        }
      goto normal;

    case TRUTH_NOT_EXPR:
      do_jump (TREE_OPERAND (exp, 0), if_true_label, if_false_label);
      break;

    case TRUTH_ANDIF_EXPR:
      if (if_false_label == 0)
        if_false_label = drop_through_label = gen_label_rtx ();
      do_jump (TREE_OPERAND (exp, 0), if_false_label, NULL_RTX);
      start_cleanup_deferral ();
      do_jump (TREE_OPERAND (exp, 1), if_false_label, if_true_label);
      end_cleanup_deferral ();
      break;

    case TRUTH_ORIF_EXPR:
      if (if_true_label == 0)
        if_true_label = drop_through_label = gen_label_rtx ();
      do_jump (TREE_OPERAND (exp, 0), NULL_RTX, if_true_label);
      start_cleanup_deferral ();
      do_jump (TREE_OPERAND (exp, 1), if_false_label, if_true_label);
      end_cleanup_deferral ();
      break;

    case COMPOUND_EXPR:
      push_temp_slots ();
      expand_expr (TREE_OPERAND (exp, 0), const0_rtx, VOIDmode, 0);
      preserve_temp_slots (NULL_RTX);
      free_temp_slots ();
      pop_temp_slots ();
      emit_queue ();
      do_pending_stack_adjust ();
      do_jump (TREE_OPERAND (exp, 1), if_false_label, if_true_label);
      break;

    case COMPONENT_REF:
    case BIT_FIELD_REF:
    case ARRAY_REF:
    case ARRAY_RANGE_REF:
      {
        HOST_WIDE_INT bitsize, bitpos;
        int unsignedp;
        enum machine_mode mode;
        tree type;
        tree offset;
        int volatilep = 0;

        /* Get description of this reference.  We don't actually care
           about the underlying object here.  */
        get_inner_reference (exp, &bitsize, &bitpos, &offset, &mode,
                             &unsignedp, &volatilep);

        type = (*lang_hooks.types.type_for_size) (bitsize, unsignedp);
        if (! SLOW_BYTE_ACCESS
            && type != 0 && bitsize >= 0
            && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (exp))
            && (cmp_optab->handlers[(int) TYPE_MODE (type)].insn_code
          != CODE_FOR_nothing))
          {
            do_jump (convert (type, exp), if_false_label, if_true_label);
            break;
          }
        goto normal;
      }

    case COND_EXPR:
      /* Do (a ? 1 : 0) and (a ? 0 : 1) as special cases.  */
      if (integer_onep (TREE_OPERAND (exp, 1))
          && integer_zerop (TREE_OPERAND (exp, 2)))
        do_jump (TREE_OPERAND (exp, 0), if_false_label, if_true_label);

      else if (integer_zerop (TREE_OPERAND (exp, 1))
               && integer_onep (TREE_OPERAND (exp, 2)))
        do_jump (TREE_OPERAND (exp, 0), if_true_label, if_false_label);

      else
      {
        rtx label1 = gen_label_rtx ();
        drop_through_label = gen_label_rtx ();

        do_jump (TREE_OPERAND (exp, 0), label1, NULL_RTX);

        start_cleanup_deferral ();
        /* Now the THEN-expression.  */
        do_jump (TREE_OPERAND (exp, 1),
                 if_false_label ? if_false_label : drop_through_label,
                 if_true_label ? if_true_label : drop_through_label);
        /* In case the do_jump just above never jumps.  */
        do_pending_stack_adjust ();
        emit_label (label1);

        /* Now the ELSE-expression.  */
        do_jump (TREE_OPERAND (exp, 2),
           if_false_label ? if_false_label : drop_through_label,
           if_true_label ? if_true_label : drop_through_label);
        end_cleanup_deferral ();
      }
      break;

    case EQ_EXPR:
      {
        tree inner_type = TREE_TYPE (TREE_OPERAND (exp, 0));

        if (GET_MODE_CLASS (TYPE_MODE (inner_type)) == MODE_COMPLEX_FLOAT
            || GET_MODE_CLASS (TYPE_MODE (inner_type)) == MODE_COMPLEX_INT)
          {
            tree exp0 = save_expr (TREE_OPERAND (exp, 0));
            tree exp1 = save_expr (TREE_OPERAND (exp, 1));
            do_jump
              (fold
               (build (TRUTH_ANDIF_EXPR, TREE_TYPE (exp),
                 fold (build (EQ_EXPR, TREE_TYPE (exp),
                  fold (build1 (REALPART_EXPR,
                    TREE_TYPE (inner_type),
                    exp0)),
                  fold (build1 (REALPART_EXPR,
                    TREE_TYPE (inner_type),
                    exp1)))),
                 fold (build (EQ_EXPR, TREE_TYPE (exp),
                  fold (build1 (IMAGPART_EXPR,
                    TREE_TYPE (inner_type),
                    exp0)),
                  fold (build1 (IMAGPART_EXPR,
                    TREE_TYPE (inner_type),
                    exp1)))))),
               if_false_label, if_true_label);
          }

        else if (integer_zerop (TREE_OPERAND (exp, 1)))
          do_jump (TREE_OPERAND (exp, 0), if_true_label, if_false_label);

        else if (GET_MODE_CLASS (TYPE_MODE (inner_type)) == MODE_INT
                 && !can_compare_p (EQ, TYPE_MODE (inner_type), ccp_jump))
          do_jump_by_parts_equality (exp, if_false_label, if_true_label);
        else
          do_compare_and_jump (exp, EQ, EQ, if_false_label, if_true_label);
        break;
      }

    case NE_EXPR:
      {
        tree inner_type = TREE_TYPE (TREE_OPERAND (exp, 0));

        if (GET_MODE_CLASS (TYPE_MODE (inner_type)) == MODE_COMPLEX_FLOAT
            || GET_MODE_CLASS (TYPE_MODE (inner_type)) == MODE_COMPLEX_INT)
          {
            tree exp0 = save_expr (TREE_OPERAND (exp, 0));
            tree exp1 = save_expr (TREE_OPERAND (exp, 1));
            do_jump
              (fold
               (build (TRUTH_ORIF_EXPR, TREE_TYPE (exp),
                 fold (build (NE_EXPR, TREE_TYPE (exp),
                  fold (build1 (REALPART_EXPR,
                    TREE_TYPE (inner_type),
                    exp0)),
                  fold (build1 (REALPART_EXPR,
                    TREE_TYPE (inner_type),
                    exp1)))),
                 fold (build (NE_EXPR, TREE_TYPE (exp),
                    fold (build1 (IMAGPART_EXPR,
                      TREE_TYPE (inner_type),
                      exp0)),
                    fold (build1 (IMAGPART_EXPR,
                      TREE_TYPE (inner_type),
                      exp1)))))),
               if_false_label, if_true_label);
          }

        else if (integer_zerop (TREE_OPERAND (exp, 1)))
          do_jump (TREE_OPERAND (exp, 0), if_false_label, if_true_label);

        else if (GET_MODE_CLASS (TYPE_MODE (inner_type)) == MODE_INT
           && !can_compare_p (NE, TYPE_MODE (inner_type), ccp_jump))
          do_jump_by_parts_equality (exp, if_true_label, if_false_label);
        else
          do_compare_and_jump (exp, NE, NE, if_false_label, if_true_label);
        break;
      }

    case LT_EXPR:
      mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)));
      if (GET_MODE_CLASS (mode) == MODE_INT
          && ! can_compare_p (LT, mode, ccp_jump))
        do_jump_by_parts_greater (exp, 1, if_false_label, if_true_label);
      else
        do_compare_and_jump (exp, LT, LTU, if_false_label, if_true_label);
      break;

    case LE_EXPR:
      mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)));
      if (GET_MODE_CLASS (mode) == MODE_INT
          && ! can_compare_p (LE, mode, ccp_jump))
        do_jump_by_parts_greater (exp, 0, if_true_label, if_false_label);
      else
        do_compare_and_jump (exp, LE, LEU, if_false_label, if_true_label);
      break;

    case GT_EXPR:
      mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)));
      if (GET_MODE_CLASS (mode) == MODE_INT
          && ! can_compare_p (GT, mode, ccp_jump))
        do_jump_by_parts_greater (exp, 0, if_false_label, if_true_label);
      else
        do_compare_and_jump (exp, GT, GTU, if_false_label, if_true_label);
      break;

    case GE_EXPR:
      mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)));
      if (GET_MODE_CLASS (mode) == MODE_INT
          && ! can_compare_p (GE, mode, ccp_jump))
        do_jump_by_parts_greater (exp, 1, if_true_label, if_false_label);
      else
        do_compare_and_jump (exp, GE, GEU, if_false_label, if_true_label);
      break;

    case UNORDERED_EXPR:
    case ORDERED_EXPR:
      {
        enum rtx_code cmp, rcmp;
        int do_rev;

        if (code == UNORDERED_EXPR)
          cmp = UNORDERED, rcmp = ORDERED;
        else
          cmp = ORDERED, rcmp = UNORDERED;
        mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)));

        do_rev = 0;
        if (! can_compare_p (cmp, mode, ccp_jump)
            && (can_compare_p (rcmp, mode, ccp_jump)
          /* If the target doesn't provide either UNORDERED or ORDERED
             comparisons, canonicalize on UNORDERED for the library.  */
          || rcmp == UNORDERED))
          do_rev = 1;

        if (! do_rev)
          do_compare_and_jump (exp, cmp, cmp, if_false_label, if_true_label);
        else
          do_compare_and_jump (exp, rcmp, rcmp, if_true_label, if_false_label);
      }
      break;

    {
      enum rtx_code rcode1;
      enum tree_code tcode2;

      case UNLT_EXPR:
        rcode1 = UNLT;
        tcode2 = LT_EXPR;
        goto unordered_bcc;
      case UNLE_EXPR:
        rcode1 = UNLE;
        tcode2 = LE_EXPR;
        goto unordered_bcc;
      case UNGT_EXPR:
        rcode1 = UNGT;
        tcode2 = GT_EXPR;
        goto unordered_bcc;
      case UNGE_EXPR:
        rcode1 = UNGE;
        tcode2 = GE_EXPR;
        goto unordered_bcc;
      case UNEQ_EXPR:
        rcode1 = UNEQ;
        tcode2 = EQ_EXPR;
        goto unordered_bcc;

      unordered_bcc:
        mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0)));
        if (can_compare_p (rcode1, mode, ccp_jump))
          do_compare_and_jump (exp, rcode1, rcode1, if_false_label,
                               if_true_label);
        else
          {
            tree op0 = save_expr (TREE_OPERAND (exp, 0));
            tree op1 = save_expr (TREE_OPERAND (exp, 1));
            tree cmp0, cmp1;

            /* If the target doesn't support combined unordered
               compares, decompose into UNORDERED + comparison.  */
            cmp0 = fold (build (UNORDERED_EXPR, TREE_TYPE (exp), op0, op1));
            cmp1 = fold (build (tcode2, TREE_TYPE (exp), op0, op1));
            exp = build (TRUTH_ORIF_EXPR, TREE_TYPE (exp), cmp0, cmp1);
            do_jump (exp, if_false_label, if_true_label);
          }
      }
      break;

      /* Special case:
          __builtin_expect (<test>, 0)	and
          __builtin_expect (<test>, 1)

         We need to do this here, so that <test> is not converted to a SCC
         operation on machines that use condition code registers and COMPARE
         like the PowerPC, and then the jump is done based on whether the SCC
         operation produced a 1 or 0.  */
    case CALL_EXPR:
      /* Check for a built-in function.  */
      {
	tree fndecl = get_callee_fndecl (exp);
	tree arglist = TREE_OPERAND (exp, 1);

	if (fndecl
	    && DECL_BUILT_IN (fndecl)
	    && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_EXPECT
	    && arglist != NULL_TREE
	    && TREE_CHAIN (arglist) != NULL_TREE)
	  {
	    rtx seq = expand_builtin_expect_jump (exp, if_false_label,
						  if_true_label);

	    if (seq != NULL_RTX)
	      {
		emit_insn (seq);
		return;
	      }
	  }
      }
      /* Fall through and generate the normal code.  */

    default:
    normal:
      temp = expand_expr (exp, NULL_RTX, VOIDmode, 0);
#if 0
      /* This is not needed any more and causes poor code since it causes
         comparisons and tests from non-SI objects to have different code
         sequences.  */
      /* Copy to register to avoid generating bad insns by cse
         from (set (mem ...) (arithop))  (set (cc0) (mem ...)).  */
      if (!cse_not_expected && GET_CODE (temp) == MEM)
        temp = copy_to_reg (temp);
#endif
      do_pending_stack_adjust ();
      /* Do any postincrements in the expression that was tested.  */
      emit_queue ();

      if (GET_CODE (temp) == CONST_INT
          || (GET_CODE (temp) == CONST_DOUBLE && GET_MODE (temp) == VOIDmode)
          || GET_CODE (temp) == LABEL_REF)
        {
          rtx target = temp == const0_rtx ? if_false_label : if_true_label;
          if (target)
            emit_jump (target);
        }
      else if (GET_MODE_CLASS (GET_MODE (temp)) == MODE_INT
               && ! can_compare_p (NE, GET_MODE (temp), ccp_jump))
        /* Note swapping the labels gives us not-equal.  */
        do_jump_by_parts_equality_rtx (temp, if_true_label, if_false_label);
      else if (GET_MODE (temp) != VOIDmode)
	{
	  /* The RTL optimizers prefer comparisons against pseudos.  */
	  if (GET_CODE (temp) == SUBREG)
	    {
	      /* Compare promoted variables in their promoted mode.  */
	      if (SUBREG_PROMOTED_VAR_P (temp)
		  && GET_CODE (XEXP (temp, 0)) == REG)
		temp = XEXP (temp, 0);
	      else
		temp = copy_to_reg (temp);
	    }
	  do_compare_rtx_and_jump (temp, CONST0_RTX (GET_MODE (temp)),
				   NE, TREE_UNSIGNED (TREE_TYPE (exp)),
				   GET_MODE (temp), NULL_RTX,
				   if_false_label, if_true_label);
	}
      else
        abort ();
    }

  if (drop_through_label)
    {
      /* If do_jump produces code that might be jumped around,
         do any stack adjusts from that code, before the place
         where control merges in.  */
      do_pending_stack_adjust ();
      emit_label (drop_through_label);
    }
}