Esempio n. 1
0
static void
insert_value_copy_on_edge (edge e, int dest, tree src, source_location locus)
{
  rtx seq, x;
  enum machine_mode dest_mode, src_mode;
  int unsignedp;
  tree var;

  if (dump_file && (dump_flags & TDF_DETAILS))
    {
      fprintf (dump_file,
	       "Inserting a value copy on edge BB%d->BB%d : PART.%d = ",
	       e->src->index,
	       e->dest->index, dest);
      print_generic_expr (dump_file, src, TDF_SLIM);
      fprintf (dump_file, "\n");
    }

  gcc_assert (SA.partition_to_pseudo[dest]);

  set_location_for_edge (e);
  /* If a locus is provided, override the default.  */
  if (locus)
    set_curr_insn_source_location (locus);

  start_sequence ();

  var = SSA_NAME_VAR (partition_to_var (SA.map, dest));
  src_mode = TYPE_MODE (TREE_TYPE (src));
  dest_mode = GET_MODE (SA.partition_to_pseudo[dest]);
  gcc_assert (src_mode == TYPE_MODE (TREE_TYPE (var)));
  gcc_assert (!REG_P (SA.partition_to_pseudo[dest])
	      || dest_mode == promote_decl_mode (var, &unsignedp));

  if (src_mode != dest_mode)
    {
      x = expand_expr (src, NULL, src_mode, EXPAND_NORMAL);
      x = convert_modes (dest_mode, src_mode, x, unsignedp);
    }
  else if (src_mode == BLKmode)
    {
      x = SA.partition_to_pseudo[dest];
      store_expr (src, x, 0, false);
    }
  else
    x = expand_expr (src, SA.partition_to_pseudo[dest],
		     dest_mode, EXPAND_NORMAL);

  if (x != SA.partition_to_pseudo[dest])
    emit_move_insn (SA.partition_to_pseudo[dest], x);
  seq = get_insns ();
  end_sequence ();

  insert_insn_on_edge (seq, e);
}
Esempio n. 2
0
void
ubsan_expand_si_overflow_mul_check (gimple stmt)
{
  rtx res, op0, op1;
  tree lhs, fn, arg0, arg1;
  rtx_code_label *done_label, *do_error;
  rtx target = NULL_RTX;

  lhs = gimple_call_lhs (stmt);
  arg0 = gimple_call_arg (stmt, 0);
  arg1 = gimple_call_arg (stmt, 1);
  done_label = gen_label_rtx ();
  do_error = gen_label_rtx ();

  do_pending_stack_adjust ();
  op0 = expand_normal (arg0);
  op1 = expand_normal (arg1);

  machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
  if (lhs)
    target = expand_expr (lhs, NULL_RTX, VOIDmode, EXPAND_WRITE);

  enum insn_code icode = optab_handler (mulv4_optab, mode);
  if (icode != CODE_FOR_nothing)
    {
      struct expand_operand ops[4];
      rtx_insn *last = get_last_insn ();

      res = gen_reg_rtx (mode);
      create_output_operand (&ops[0], res, mode);
      create_input_operand (&ops[1], op0, mode);
      create_input_operand (&ops[2], op1, mode);
      create_fixed_operand (&ops[3], do_error);
      if (maybe_expand_insn (icode, 4, ops))
	{
	  last = get_last_insn ();
	  if (profile_status_for_fn (cfun) != PROFILE_ABSENT
	      && JUMP_P (last)
	      && any_condjump_p (last)
	      && !find_reg_note (last, REG_BR_PROB, 0))
	    add_int_reg_note (last, REG_BR_PROB, PROB_VERY_UNLIKELY);
	  emit_jump (done_label);
        }
      else
	{
	  delete_insns_since (last);
	  icode = CODE_FOR_nothing;
	}
    }

  if (icode == CODE_FOR_nothing)
    {
      struct separate_ops ops;
      machine_mode hmode
	= mode_for_size (GET_MODE_PRECISION (mode) / 2, MODE_INT, 1);
      ops.op0 = arg0;
      ops.op1 = arg1;
      ops.op2 = NULL_TREE;
      ops.location = gimple_location (stmt);
      if (GET_MODE_2XWIDER_MODE (mode) != VOIDmode
	  && targetm.scalar_mode_supported_p (GET_MODE_2XWIDER_MODE (mode)))
	{
	  machine_mode wmode = GET_MODE_2XWIDER_MODE (mode);
	  ops.code = WIDEN_MULT_EXPR;
	  ops.type
	    = build_nonstandard_integer_type (GET_MODE_PRECISION (wmode), 0);

	  res = expand_expr_real_2 (&ops, NULL_RTX, wmode, EXPAND_NORMAL);
	  rtx hipart = expand_shift (RSHIFT_EXPR, wmode, res,
				     GET_MODE_PRECISION (mode), NULL_RTX, 0);
	  hipart = gen_lowpart (mode, hipart);
	  res = gen_lowpart (mode, res);
	  rtx signbit = expand_shift (RSHIFT_EXPR, mode, res,
				      GET_MODE_PRECISION (mode) - 1,
				      NULL_RTX, 0);
	  /* RES is low half of the double width result, HIPART
	     the high half.  There was overflow if
	     HIPART is different from RES < 0 ? -1 : 0.  */
	  emit_cmp_and_jump_insns (signbit, hipart, EQ, NULL_RTX, mode,
				   false, done_label, PROB_VERY_LIKELY);
	}
      else if (hmode != BLKmode
	       && 2 * GET_MODE_PRECISION (hmode) == GET_MODE_PRECISION (mode))
	{
	  rtx_code_label *large_op0 = gen_label_rtx ();
	  rtx_code_label *small_op0_large_op1 = gen_label_rtx ();
	  rtx_code_label *one_small_one_large = gen_label_rtx ();
	  rtx_code_label *both_ops_large = gen_label_rtx ();
	  rtx_code_label *after_hipart_neg = gen_label_rtx ();
	  rtx_code_label *after_lopart_neg = gen_label_rtx ();
	  rtx_code_label *do_overflow = gen_label_rtx ();
	  rtx_code_label *hipart_different = gen_label_rtx ();

	  unsigned int hprec = GET_MODE_PRECISION (hmode);
	  rtx hipart0 = expand_shift (RSHIFT_EXPR, mode, op0, hprec,
				      NULL_RTX, 0);
	  hipart0 = gen_lowpart (hmode, hipart0);
	  rtx lopart0 = gen_lowpart (hmode, op0);
	  rtx signbit0 = expand_shift (RSHIFT_EXPR, hmode, lopart0, hprec - 1,
				       NULL_RTX, 0);
	  rtx hipart1 = expand_shift (RSHIFT_EXPR, mode, op1, hprec,
				      NULL_RTX, 0);
	  hipart1 = gen_lowpart (hmode, hipart1);
	  rtx lopart1 = gen_lowpart (hmode, op1);
	  rtx signbit1 = expand_shift (RSHIFT_EXPR, hmode, lopart1, hprec - 1,
				       NULL_RTX, 0);

	  res = gen_reg_rtx (mode);

	  /* True if op0 resp. op1 are known to be in the range of
	     halfstype.  */
	  bool op0_small_p = false;
	  bool op1_small_p = false;
	  /* True if op0 resp. op1 are known to have all zeros or all ones
	     in the upper half of bits, but are not known to be
	     op{0,1}_small_p.  */
	  bool op0_medium_p = false;
	  bool op1_medium_p = false;
	  /* -1 if op{0,1} is known to be negative, 0 if it is known to be
	     nonnegative, 1 if unknown.  */
	  int op0_sign = 1;
	  int op1_sign = 1;

	  if (TREE_CODE (arg0) == SSA_NAME)
	    {
	      wide_int arg0_min, arg0_max;
	      if (get_range_info (arg0, &arg0_min, &arg0_max) == VR_RANGE)
		{
		  unsigned int mprec0 = wi::min_precision (arg0_min, SIGNED);
		  unsigned int mprec1 = wi::min_precision (arg0_max, SIGNED);
		  if (mprec0 <= hprec && mprec1 <= hprec)
		    op0_small_p = true;
		  else if (mprec0 <= hprec + 1 && mprec1 <= hprec + 1)
		    op0_medium_p = true;
		  if (!wi::neg_p (arg0_min, TYPE_SIGN (TREE_TYPE (arg0))))
		    op0_sign = 0;
		  else if (wi::neg_p (arg0_max, TYPE_SIGN (TREE_TYPE (arg0))))
		    op0_sign = -1;
		}
	    }
	  if (TREE_CODE (arg1) == SSA_NAME)
	    {
	      wide_int arg1_min, arg1_max;
	      if (get_range_info (arg1, &arg1_min, &arg1_max) == VR_RANGE)
		{
		  unsigned int mprec0 = wi::min_precision (arg1_min, SIGNED);
		  unsigned int mprec1 = wi::min_precision (arg1_max, SIGNED);
		  if (mprec0 <= hprec && mprec1 <= hprec)
		    op1_small_p = true;
		  else if (mprec0 <= hprec + 1 && mprec1 <= hprec + 1)
		    op1_medium_p = true;
		  if (!wi::neg_p (arg1_min, TYPE_SIGN (TREE_TYPE (arg1))))
		    op1_sign = 0;
		  else if (wi::neg_p (arg1_max, TYPE_SIGN (TREE_TYPE (arg1))))
		    op1_sign = -1;
		}
	    }

	  int smaller_sign = 1;
	  int larger_sign = 1;
	  if (op0_small_p)
	    {
	      smaller_sign = op0_sign;
	      larger_sign = op1_sign;
	    }
	  else if (op1_small_p)
	    {
	      smaller_sign = op1_sign;
	      larger_sign = op0_sign;
	    }
	  else if (op0_sign == op1_sign)
	    {
	      smaller_sign = op0_sign;
	      larger_sign = op0_sign;
	    }

	  if (!op0_small_p)
	    emit_cmp_and_jump_insns (signbit0, hipart0, NE, NULL_RTX, hmode,
				     false, large_op0, PROB_UNLIKELY);

	  if (!op1_small_p)
	    emit_cmp_and_jump_insns (signbit1, hipart1, NE, NULL_RTX, hmode,
				     false, small_op0_large_op1,
				     PROB_UNLIKELY);

	  /* If both op0 and op1 are sign extended from hmode to mode,
	     the multiplication will never overflow.  We can do just one
	     hmode x hmode => mode widening multiplication.  */
	  if (GET_CODE (lopart0) == SUBREG)
	    {
	      SUBREG_PROMOTED_VAR_P (lopart0) = 1;
	      SUBREG_PROMOTED_SET (lopart0, 0);
	    }
	  if (GET_CODE (lopart1) == SUBREG)
	    {
	      SUBREG_PROMOTED_VAR_P (lopart1) = 1;
	      SUBREG_PROMOTED_SET (lopart1, 0);
	    }
	  tree halfstype = build_nonstandard_integer_type (hprec, 0);
	  ops.op0 = make_tree (halfstype, lopart0);
	  ops.op1 = make_tree (halfstype, lopart1);
	  ops.code = WIDEN_MULT_EXPR;
	  ops.type = TREE_TYPE (arg0);
	  rtx thisres
	    = expand_expr_real_2 (&ops, NULL_RTX, mode, EXPAND_NORMAL);
	  emit_move_insn (res, thisres);
	  emit_jump (done_label);

	  emit_label (small_op0_large_op1);

	  /* If op0 is sign extended from hmode to mode, but op1 is not,
	     just swap the arguments and handle it as op1 sign extended,
	     op0 not.  */
	  rtx larger = gen_reg_rtx (mode);
	  rtx hipart = gen_reg_rtx (hmode);
	  rtx lopart = gen_reg_rtx (hmode);
	  emit_move_insn (larger, op1);
	  emit_move_insn (hipart, hipart1);
	  emit_move_insn (lopart, lopart0);
	  emit_jump (one_small_one_large);

	  emit_label (large_op0);

	  if (!op1_small_p)
	    emit_cmp_and_jump_insns (signbit1, hipart1, NE, NULL_RTX, hmode,
				     false, both_ops_large, PROB_UNLIKELY);

	  /* If op1 is sign extended from hmode to mode, but op0 is not,
	     prepare larger, hipart and lopart pseudos and handle it together
	     with small_op0_large_op1.  */
	  emit_move_insn (larger, op0);
	  emit_move_insn (hipart, hipart0);
	  emit_move_insn (lopart, lopart1);

	  emit_label (one_small_one_large);

	  /* lopart is the low part of the operand that is sign extended
	     to mode, larger is the the other operand, hipart is the
	     high part of larger and lopart0 and lopart1 are the low parts
	     of both operands.
	     We perform lopart0 * lopart1 and lopart * hipart widening
	     multiplications.  */
	  tree halfutype = build_nonstandard_integer_type (hprec, 1);
	  ops.op0 = make_tree (halfutype, lopart0);
	  ops.op1 = make_tree (halfutype, lopart1);
	  rtx lo0xlo1
	    = expand_expr_real_2 (&ops, NULL_RTX, mode, EXPAND_NORMAL);

	  ops.op0 = make_tree (halfutype, lopart);
	  ops.op1 = make_tree (halfutype, hipart);
	  rtx loxhi = gen_reg_rtx (mode);
	  rtx tem = expand_expr_real_2 (&ops, NULL_RTX, mode, EXPAND_NORMAL);
	  emit_move_insn (loxhi, tem);

	  /* if (hipart < 0) loxhi -= lopart << (bitsize / 2);  */
	  if (larger_sign == 0)
	    emit_jump (after_hipart_neg);
	  else if (larger_sign != -1)
	    emit_cmp_and_jump_insns (hipart, const0_rtx, GE, NULL_RTX, hmode,
				     false, after_hipart_neg, PROB_EVEN);

	  tem = convert_modes (mode, hmode, lopart, 1);
	  tem = expand_shift (LSHIFT_EXPR, mode, tem, hprec, NULL_RTX, 1);
	  tem = expand_simple_binop (mode, MINUS, loxhi, tem, NULL_RTX,
				     1, OPTAB_DIRECT);
	  emit_move_insn (loxhi, tem);

	  emit_label (after_hipart_neg);

	  /* if (lopart < 0) loxhi -= larger;  */
	  if (smaller_sign == 0)
	    emit_jump (after_lopart_neg);
	  else if (smaller_sign != -1)
	    emit_cmp_and_jump_insns (lopart, const0_rtx, GE, NULL_RTX, hmode,
				     false, after_lopart_neg, PROB_EVEN);

	  tem = expand_simple_binop (mode, MINUS, loxhi, larger, NULL_RTX,
				     1, OPTAB_DIRECT);
	  emit_move_insn (loxhi, tem);

	  emit_label (after_lopart_neg);

	  /* loxhi += (uns) lo0xlo1 >> (bitsize / 2);  */
	  tem = expand_shift (RSHIFT_EXPR, mode, lo0xlo1, hprec, NULL_RTX, 1);
	  tem = expand_simple_binop (mode, PLUS, loxhi, tem, NULL_RTX,
				     1, OPTAB_DIRECT);
	  emit_move_insn (loxhi, tem);

	  /* if (loxhi >> (bitsize / 2)
		 == (hmode) loxhi >> (bitsize / 2 - 1))  */
	  rtx hipartloxhi = expand_shift (RSHIFT_EXPR, mode, loxhi, hprec,
					  NULL_RTX, 0);
	  hipartloxhi = gen_lowpart (hmode, hipartloxhi);
	  rtx lopartloxhi = gen_lowpart (hmode, loxhi);
	  rtx signbitloxhi = expand_shift (RSHIFT_EXPR, hmode, lopartloxhi,
					   hprec - 1, NULL_RTX, 0);

	  emit_cmp_and_jump_insns (signbitloxhi, hipartloxhi, NE, NULL_RTX,
				   hmode, false, do_overflow,
				   PROB_VERY_UNLIKELY);

	  /* res = (loxhi << (bitsize / 2)) | (hmode) lo0xlo1;  */
	  rtx loxhishifted = expand_shift (LSHIFT_EXPR, mode, loxhi, hprec,
					   NULL_RTX, 1);
	  tem = convert_modes (mode, hmode, gen_lowpart (hmode, lo0xlo1), 1);

	  tem = expand_simple_binop (mode, IOR, loxhishifted, tem, res,
				     1, OPTAB_DIRECT);
	  if (tem != res)
	    emit_move_insn (res, tem);
	  emit_jump (done_label);

	  emit_label (both_ops_large);

	  /* If both operands are large (not sign extended from hmode),
	     then perform the full multiplication which will be the result
	     of the operation.  The only cases which don't overflow are
	     some cases where both hipart0 and highpart1 are 0 or -1.  */
	  ops.code = MULT_EXPR;
	  ops.op0 = make_tree (TREE_TYPE (arg0), op0);
	  ops.op1 = make_tree (TREE_TYPE (arg0), op1);
	  tem = expand_expr_real_2 (&ops, NULL_RTX, mode, EXPAND_NORMAL);
	  emit_move_insn (res, tem);

	  if (!op0_medium_p)
	    {
	      tem = expand_simple_binop (hmode, PLUS, hipart0, const1_rtx,
					 NULL_RTX, 1, OPTAB_DIRECT);
	      emit_cmp_and_jump_insns (tem, const1_rtx, GTU, NULL_RTX, hmode,
				       true, do_error, PROB_VERY_UNLIKELY);
	    }

	  if (!op1_medium_p)
	    {
	      tem = expand_simple_binop (hmode, PLUS, hipart1, const1_rtx,
					 NULL_RTX, 1, OPTAB_DIRECT);
	      emit_cmp_and_jump_insns (tem, const1_rtx, GTU, NULL_RTX, hmode,
				       true, do_error, PROB_VERY_UNLIKELY);
	    }

	  /* At this point hipart{0,1} are both in [-1, 0].  If they are the
	     same, overflow happened if res is negative, if they are different,
	     overflow happened if res is positive.  */
	  if (op0_sign != 1 && op1_sign != 1 && op0_sign != op1_sign)
	    emit_jump (hipart_different);
	  else if (op0_sign == 1 || op1_sign == 1)
	    emit_cmp_and_jump_insns (hipart0, hipart1, NE, NULL_RTX, hmode,
				     true, hipart_different, PROB_EVEN);

	  emit_cmp_and_jump_insns (res, const0_rtx, LT, NULL_RTX, mode, false,
				   do_error, PROB_VERY_UNLIKELY);
	  emit_jump (done_label);

	  emit_label (hipart_different);

	  emit_cmp_and_jump_insns (res, const0_rtx, GE, NULL_RTX, mode, false,
				   do_error, PROB_VERY_UNLIKELY);
	  emit_jump (done_label);

	  emit_label (do_overflow);

	  /* Overflow, do full multiplication and fallthru into do_error.  */
	  ops.op0 = make_tree (TREE_TYPE (arg0), op0);
	  ops.op1 = make_tree (TREE_TYPE (arg0), op1);
	  tem = expand_expr_real_2 (&ops, NULL_RTX, mode, EXPAND_NORMAL);
	  emit_move_insn (res, tem);
	}
      else
	{
	  ops.code = MULT_EXPR;
	  ops.type = TREE_TYPE (arg0);
	  res = expand_expr_real_2 (&ops, NULL_RTX, mode, EXPAND_NORMAL);
	  emit_jump (done_label);
	}
    }

  emit_label (do_error);
  /* Expand the ubsan builtin call.  */
  push_temp_slots ();
  fn = ubsan_build_overflow_builtin (MULT_EXPR, gimple_location (stmt),
				     TREE_TYPE (arg0), arg0, arg1);
  expand_normal (fn);
  pop_temp_slots ();
  do_pending_stack_adjust ();

  /* We're done.  */
  emit_label (done_label);

  if (lhs)
    emit_move_insn (target, res);
}