Ejemplo n.º 1
0
	{
	  edge e = find_edge (new_bb, dom_son);
	  if (e && single_pred_p (e->dest))
	    continue;
	  set_immediate_dominator (CDI_DOMINATORS, dom_son, switch_bb);
	  bbs_to_fix_dom.safe_push (dom_son);
	}
      dom_bbs.release ();
    }

  /* csui = (1 << (word_mode) idx) */
  csui = make_ssa_name (word_type_node);
  tmp = fold_build2 (LSHIFT_EXPR, word_type_node, word_mode_one,
		     fold_convert (word_type_node, idx));
  tmp = force_gimple_operand_gsi (&gsi, tmp,
				  /*simple=*/false, NULL_TREE,
				  /*before=*/true, GSI_SAME_STMT);
  shift_stmt = gimple_build_assign (csui, tmp);
  gsi_insert_before (&gsi, shift_stmt, GSI_SAME_STMT);
  update_stmt (shift_stmt);

  /* for each unique set of cases:
        if (const & csui) goto target  */
  for (k = 0; k < count; k++)
    {
      tmp = wide_int_to_tree (word_type_node, test[k].mask);
      tmp = fold_build2 (BIT_AND_EXPR, word_type_node, csui, tmp);
      tmp = force_gimple_operand_gsi (&gsi, tmp,
				      /*simple=*/true, NULL_TREE,
				      /*before=*/true, GSI_SAME_STMT);
      tmp = fold_build2 (NE_EXPR, boolean_type_node, tmp, word_mode_zero);
static bool
ifcombine_iforif (basic_block inner_cond_bb, basic_block outer_cond_bb)
{
  gimple inner_cond, outer_cond;
  tree name1, name2, bits1, bits2;

  inner_cond = last_stmt (inner_cond_bb);
  if (!inner_cond
      || gimple_code (inner_cond) != GIMPLE_COND)
    return false;

  outer_cond = last_stmt (outer_cond_bb);
  if (!outer_cond
      || gimple_code (outer_cond) != GIMPLE_COND)
    return false;

  /* See if we have two bit tests of the same name in both tests.
     In that case remove the outer test and change the inner one to
     test for name & (bits1 | bits2) != 0.  */
  if (recognize_bits_test (inner_cond, &name1, &bits1)
      && recognize_bits_test (outer_cond, &name2, &bits2))
    {
      gimple_stmt_iterator gsi;
      tree t;

      /* Find the common name which is bit-tested.  */
      if (name1 == name2)
	;
      else if (bits1 == bits2)
	{
	  t = name2;
	  name2 = bits2;
	  bits2 = t;
	  t = name1;
	  name1 = bits1;
	  bits1 = t;
	}
      else if (name1 == bits2)
	{
	  t = name2;
	  name2 = bits2;
	  bits2 = t;
	}
      else if (bits1 == name2)
	{
	  t = name1;
	  name1 = bits1;
	  bits1 = t;
	}
      else
	return false;

      /* As we strip non-widening conversions in finding a common
         name that is tested make sure to end up with an integral
	 type for building the bit operations.  */
      if (TYPE_PRECISION (TREE_TYPE (bits1))
	  >= TYPE_PRECISION (TREE_TYPE (bits2)))
	{
	  bits1 = fold_convert (unsigned_type_for (TREE_TYPE (bits1)), bits1);
	  name1 = fold_convert (TREE_TYPE (bits1), name1);
	  bits2 = fold_convert (unsigned_type_for (TREE_TYPE (bits2)), bits2);
	  bits2 = fold_convert (TREE_TYPE (bits1), bits2);
	}
      else
	{
	  bits2 = fold_convert (unsigned_type_for (TREE_TYPE (bits2)), bits2);
	  name1 = fold_convert (TREE_TYPE (bits2), name1);
	  bits1 = fold_convert (unsigned_type_for (TREE_TYPE (bits1)), bits1);
	  bits1 = fold_convert (TREE_TYPE (bits2), bits1);
	}

      /* Do it.  */
      gsi = gsi_for_stmt (inner_cond);
      t = fold_build2 (BIT_IOR_EXPR, TREE_TYPE (name1), bits1, bits2);
      t = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
				    true, GSI_SAME_STMT);
      t = fold_build2 (BIT_AND_EXPR, TREE_TYPE (name1), name1, t);
      t = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
				    true, GSI_SAME_STMT);
      t = fold_build2 (NE_EXPR, boolean_type_node, t,
		       build_int_cst (TREE_TYPE (t), 0));
      t = canonicalize_cond_expr_cond (t);
      if (!t)
	return false;
      gimple_cond_set_condition_from_tree (inner_cond, t);
      update_stmt (inner_cond);

      /* Leave CFG optimization to cfg_cleanup.  */
      gimple_cond_set_condition_from_tree (outer_cond, boolean_false_node);
      update_stmt (outer_cond);

      if (dump_file)
	{
	  fprintf (dump_file, "optimizing bits or bits test to ");
	  print_generic_expr (dump_file, name1, 0);
	  fprintf (dump_file, " & T != 0\nwith temporary T = ");
	  print_generic_expr (dump_file, bits1, 0);
	  fprintf (dump_file, " | ");
	  print_generic_expr (dump_file, bits2, 0);
	  fprintf (dump_file, "\n");
	}

      return true;
    }

  /* See if we have two comparisons that we can merge into one.
     This happens for C++ operator overloading where for example
     GE_EXPR is implemented as GT_EXPR || EQ_EXPR.  */
  else if (TREE_CODE_CLASS (gimple_cond_code (inner_cond)) == tcc_comparison
	   && TREE_CODE_CLASS (gimple_cond_code (outer_cond)) == tcc_comparison
	   && operand_equal_p (gimple_cond_lhs (inner_cond),
			       gimple_cond_lhs (outer_cond), 0)
	   && operand_equal_p (gimple_cond_rhs (inner_cond),
			       gimple_cond_rhs (outer_cond), 0))
    {
      enum tree_code code1 = gimple_cond_code (inner_cond);
      enum tree_code code2 = gimple_cond_code (outer_cond);
      tree t;

      if (!(t = combine_comparisons (UNKNOWN_LOCATION,
	      			     TRUTH_ORIF_EXPR, code1, code2,
				     boolean_type_node,
				     gimple_cond_lhs (outer_cond),
				     gimple_cond_rhs (outer_cond))))
	return false;
      t = canonicalize_cond_expr_cond (t);
      if (!t)
	return false;
      gimple_cond_set_condition_from_tree (inner_cond, t);
      update_stmt (inner_cond);

      /* Leave CFG optimization to cfg_cleanup.  */
      gimple_cond_set_condition_from_tree (outer_cond, boolean_false_node);
      update_stmt (outer_cond);

      if (dump_file)
	{
	  fprintf (dump_file, "optimizing two comparisons to ");
	  print_generic_expr (dump_file, t, 0);
	  fprintf (dump_file, "\n");
	}

      return true;
    }

  return false;
}
static bool
ifcombine_ifandif (basic_block inner_cond_bb, basic_block outer_cond_bb)
{
  gimple_stmt_iterator gsi;
  gimple inner_cond, outer_cond;
  tree name1, name2, bit1, bit2;

  inner_cond = last_stmt (inner_cond_bb);
  if (!inner_cond
      || gimple_code (inner_cond) != GIMPLE_COND)
    return false;

  outer_cond = last_stmt (outer_cond_bb);
  if (!outer_cond
      || gimple_code (outer_cond) != GIMPLE_COND)
    return false;

  /* See if we test a single bit of the same name in both tests.  In
     that case remove the outer test, merging both else edges,
     and change the inner one to test for
     name & (bit1 | bit2) == (bit1 | bit2).  */
  if (recognize_single_bit_test (inner_cond, &name1, &bit1)
      && recognize_single_bit_test (outer_cond, &name2, &bit2)
      && name1 == name2)
    {
      tree t, t2;

      /* Do it.  */
      gsi = gsi_for_stmt (inner_cond);
      t = fold_build2 (LSHIFT_EXPR, TREE_TYPE (name1),
		       build_int_cst (TREE_TYPE (name1), 1), bit1);
      t2 = fold_build2 (LSHIFT_EXPR, TREE_TYPE (name1),
		        build_int_cst (TREE_TYPE (name1), 1), bit2);
      t = fold_build2 (BIT_IOR_EXPR, TREE_TYPE (name1), t, t2);
      t = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
				    true, GSI_SAME_STMT);
      t2 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (name1), name1, t);
      t2 = force_gimple_operand_gsi (&gsi, t2, true, NULL_TREE,
				     true, GSI_SAME_STMT);
      t = fold_build2 (EQ_EXPR, boolean_type_node, t2, t);
      t = canonicalize_cond_expr_cond (t);
      if (!t)
	return false;
      gimple_cond_set_condition_from_tree (inner_cond, t);
      update_stmt (inner_cond);

      /* Leave CFG optimization to cfg_cleanup.  */
      gimple_cond_set_condition_from_tree (outer_cond, boolean_true_node);
      update_stmt (outer_cond);

      if (dump_file)
	{
	  fprintf (dump_file, "optimizing double bit test to ");
	  print_generic_expr (dump_file, name1, 0);
	  fprintf (dump_file, " & T == T\nwith temporary T = (1 << ");
	  print_generic_expr (dump_file, bit1, 0);
	  fprintf (dump_file, ") | (1 << ");
	  print_generic_expr (dump_file, bit2, 0);
	  fprintf (dump_file, ")\n");
	}

      return true;
    }

  /* See if we have two comparisons that we can merge into one.  */
  else if (TREE_CODE_CLASS (gimple_cond_code (inner_cond)) == tcc_comparison
	   && TREE_CODE_CLASS (gimple_cond_code (outer_cond)) == tcc_comparison
	   && operand_equal_p (gimple_cond_lhs (inner_cond),
			       gimple_cond_lhs (outer_cond), 0)
	   && operand_equal_p (gimple_cond_rhs (inner_cond),
			       gimple_cond_rhs (outer_cond), 0))
    {
      enum tree_code code1 = gimple_cond_code (inner_cond);
      enum tree_code code2 = gimple_cond_code (outer_cond);
      tree t;

      if (!(t = combine_comparisons (UNKNOWN_LOCATION,
	      			     TRUTH_ANDIF_EXPR, code1, code2,
				     boolean_type_node,
				     gimple_cond_lhs (outer_cond),
				     gimple_cond_rhs (outer_cond))))
	return false;
      t = canonicalize_cond_expr_cond (t);
      if (!t)
	return false;
      gimple_cond_set_condition_from_tree (inner_cond, t);
      update_stmt (inner_cond);

      /* Leave CFG optimization to cfg_cleanup.  */
      gimple_cond_set_condition_from_tree (outer_cond, boolean_true_node);
      update_stmt (outer_cond);

      if (dump_file)
	{
	  fprintf (dump_file, "optimizing two comparisons to ");
	  print_generic_expr (dump_file, t, 0);
	  fprintf (dump_file, "\n");
	}

      return true;
    }

  return false;
}
Ejemplo n.º 4
0
tree
create_mem_ref (gimple_stmt_iterator *gsi, tree type, aff_tree *addr,
		tree alias_ptr_type, tree iv_cand, tree base_hint, bool speed)
{
  tree mem_ref, tmp;
  struct mem_address parts;

  addr_to_parts (type, addr, iv_cand, base_hint, &parts, speed);
  gimplify_mem_ref_parts (gsi, &parts);
  mem_ref = create_mem_ref_raw (type, alias_ptr_type, &parts, true);
  if (mem_ref)
    return mem_ref;

  /* The expression is too complicated.  Try making it simpler.  */

  if (parts.step && !integer_onep (parts.step))
    {
      /* Move the multiplication to index.  */
      gcc_assert (parts.index);
      parts.index = force_gimple_operand_gsi (gsi,
				fold_build2 (MULT_EXPR, sizetype,
					     parts.index, parts.step),
				true, NULL_TREE, true, GSI_SAME_STMT);
      parts.step = NULL_TREE;

      mem_ref = create_mem_ref_raw (type, alias_ptr_type, &parts, true);
      if (mem_ref)
	return mem_ref;
    }

  if (parts.symbol)
    {
      tmp = parts.symbol;
      gcc_assert (is_gimple_val (tmp));

      /* Add the symbol to base, eventually forcing it to register.  */
      if (parts.base)
	{
	  gcc_assert (useless_type_conversion_p
				(sizetype, TREE_TYPE (parts.base)));

	  if (parts.index)
	    {
	      parts.base = force_gimple_operand_gsi_1 (gsi,
			fold_build_pointer_plus (tmp, parts.base),
			is_gimple_mem_ref_addr, NULL_TREE, true, GSI_SAME_STMT);
	    }
	  else
	    {
	      parts.index = parts.base;
	      parts.base = tmp;
	    }
	}
      else
	parts.base = tmp;
      parts.symbol = NULL_TREE;

      mem_ref = create_mem_ref_raw (type, alias_ptr_type, &parts, true);
      if (mem_ref)
	return mem_ref;
    }

  if (parts.index)
    {
      /* Add index to base.  */
      if (parts.base)
	{
	  parts.base = force_gimple_operand_gsi_1 (gsi,
			fold_build_pointer_plus (parts.base, parts.index),
			is_gimple_mem_ref_addr, NULL_TREE, true, GSI_SAME_STMT);
	}
      else
	parts.base = parts.index;
      parts.index = NULL_TREE;

      mem_ref = create_mem_ref_raw (type, alias_ptr_type, &parts, true);
      if (mem_ref)
	return mem_ref;
    }

  if (parts.offset && !integer_zerop (parts.offset))
    {
      /* Try adding offset to base.  */
      if (parts.base)
	{
	  parts.base = force_gimple_operand_gsi_1 (gsi,
			fold_build_pointer_plus (parts.base, parts.offset),
			is_gimple_mem_ref_addr, NULL_TREE, true, GSI_SAME_STMT);
	}
      else
	parts.base = parts.offset;

      parts.offset = NULL_TREE;

      mem_ref = create_mem_ref_raw (type, alias_ptr_type, &parts, true);
      if (mem_ref)
	return mem_ref;
    }

  /* Verify that the address is in the simplest possible shape
     (only a register).  If we cannot create such a memory reference,
     something is really wrong.  */
  gcc_assert (parts.symbol == NULL_TREE);
  gcc_assert (parts.index == NULL_TREE);
  gcc_assert (!parts.step || integer_onep (parts.step));
  gcc_assert (!parts.offset || integer_zerop (parts.offset));
  gcc_unreachable ();
}
Ejemplo n.º 5
0
Archivo: ubsan.c Proyecto: didemoto/gcc
static void
instrument_bool_enum_load (gimple_stmt_iterator *gsi)
{
  gimple stmt = gsi_stmt (*gsi);
  tree rhs = gimple_assign_rhs1 (stmt);
  tree type = TREE_TYPE (rhs);
  tree minv = NULL_TREE, maxv = NULL_TREE;

  if (TREE_CODE (type) == BOOLEAN_TYPE && (flag_sanitize & SANITIZE_BOOL))
    {
      minv = boolean_false_node;
      maxv = boolean_true_node;
    }
  else if (TREE_CODE (type) == ENUMERAL_TYPE
	   && (flag_sanitize & SANITIZE_ENUM)
	   && TREE_TYPE (type) != NULL_TREE
	   && TREE_CODE (TREE_TYPE (type)) == INTEGER_TYPE
	   && (TYPE_PRECISION (TREE_TYPE (type))
	       < GET_MODE_PRECISION (TYPE_MODE (type))))
    {
      minv = TYPE_MIN_VALUE (TREE_TYPE (type));
      maxv = TYPE_MAX_VALUE (TREE_TYPE (type));
    }
  else
    return;

  int modebitsize = GET_MODE_BITSIZE (TYPE_MODE (type));
  HOST_WIDE_INT bitsize, bitpos;
  tree offset;
  enum machine_mode mode;
  int volatilep = 0, unsignedp = 0;
  tree base = get_inner_reference (rhs, &bitsize, &bitpos, &offset, &mode,
				   &unsignedp, &volatilep, false);
  tree utype = build_nonstandard_integer_type (modebitsize, 1);

  if ((TREE_CODE (base) == VAR_DECL && DECL_HARD_REGISTER (base))
      || (bitpos % modebitsize) != 0
      || bitsize != modebitsize
      || GET_MODE_BITSIZE (TYPE_MODE (utype)) != modebitsize
      || TREE_CODE (gimple_assign_lhs (stmt)) != SSA_NAME)
    return;

  location_t loc = gimple_location (stmt);
  tree ptype = build_pointer_type (TREE_TYPE (rhs));
  tree atype = reference_alias_ptr_type (rhs);
  gimple g = gimple_build_assign (make_ssa_name (ptype, NULL),
				  build_fold_addr_expr (rhs));
  gimple_set_location (g, loc);
  gsi_insert_before (gsi, g, GSI_SAME_STMT);
  tree mem = build2 (MEM_REF, utype, gimple_assign_lhs (g),
		     build_int_cst (atype, 0));
  tree urhs = make_ssa_name (utype, NULL);
  g = gimple_build_assign (urhs, mem);
  gimple_set_location (g, loc);
  gsi_insert_before (gsi, g, GSI_SAME_STMT);
  minv = fold_convert (utype, minv);
  maxv = fold_convert (utype, maxv);
  if (!integer_zerop (minv))
    {
      g = gimple_build_assign_with_ops (MINUS_EXPR,
					make_ssa_name (utype, NULL),
					urhs, minv);
      gimple_set_location (g, loc);
      gsi_insert_before (gsi, g, GSI_SAME_STMT);
    }

  gimple_stmt_iterator gsi2 = *gsi;
  basic_block then_bb, fallthru_bb;
  *gsi = create_cond_insert_point (gsi, true, false, true,
				   &then_bb, &fallthru_bb);
  g = gimple_build_cond (GT_EXPR, gimple_assign_lhs (g),
			 int_const_binop (MINUS_EXPR, maxv, minv),
			 NULL_TREE, NULL_TREE);
  gimple_set_location (g, loc);
  gsi_insert_after (gsi, g, GSI_NEW_STMT);

  gimple_assign_set_rhs_with_ops (&gsi2, NOP_EXPR, urhs, NULL_TREE);
  update_stmt (stmt);

  tree data = ubsan_create_data ("__ubsan_invalid_value_data",
				 loc, NULL,
				 ubsan_type_descriptor (type, false),
				 NULL_TREE);
  data = build_fold_addr_expr_loc (loc, data);
  tree fn = builtin_decl_explicit (BUILT_IN_UBSAN_HANDLE_LOAD_INVALID_VALUE);

  gsi2 = gsi_after_labels (then_bb);
  tree val = force_gimple_operand_gsi (&gsi2, ubsan_encode_value (urhs),
				       true, NULL_TREE, true, GSI_SAME_STMT);
  g = gimple_build_call (fn, 2, data, val);
  gimple_set_location (g, loc);
  gsi_insert_before (&gsi2, g, GSI_SAME_STMT);
}
Ejemplo n.º 6
0
static bool
ifcombine_ifandif (basic_block inner_cond_bb, bool inner_inv,
		   basic_block outer_cond_bb, bool outer_inv, bool result_inv)
{
  gimple_stmt_iterator gsi;
  gimple inner_cond, outer_cond;
  tree name1, name2, bit1, bit2, bits1, bits2;

  inner_cond = last_stmt (inner_cond_bb);
  if (!inner_cond
      || gimple_code (inner_cond) != GIMPLE_COND)
    return false;

  outer_cond = last_stmt (outer_cond_bb);
  if (!outer_cond
      || gimple_code (outer_cond) != GIMPLE_COND)
    return false;

  /* See if we test a single bit of the same name in both tests.  In
     that case remove the outer test, merging both else edges,
     and change the inner one to test for
     name & (bit1 | bit2) == (bit1 | bit2).  */
  if (recognize_single_bit_test (inner_cond, &name1, &bit1, inner_inv)
      && recognize_single_bit_test (outer_cond, &name2, &bit2, outer_inv)
      && name1 == name2)
    {
      tree t, t2;

      /* Do it.  */
      gsi = gsi_for_stmt (inner_cond);
      t = fold_build2 (LSHIFT_EXPR, TREE_TYPE (name1),
		       build_int_cst (TREE_TYPE (name1), 1), bit1);
      t2 = fold_build2 (LSHIFT_EXPR, TREE_TYPE (name1),
		        build_int_cst (TREE_TYPE (name1), 1), bit2);
      t = fold_build2 (BIT_IOR_EXPR, TREE_TYPE (name1), t, t2);
      t = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
				    true, GSI_SAME_STMT);
      t2 = fold_build2 (BIT_AND_EXPR, TREE_TYPE (name1), name1, t);
      t2 = force_gimple_operand_gsi (&gsi, t2, true, NULL_TREE,
				     true, GSI_SAME_STMT);
      t = fold_build2 (result_inv ? NE_EXPR : EQ_EXPR,
		       boolean_type_node, t2, t);
      t = canonicalize_cond_expr_cond (t);
      if (!t)
	return false;
      gimple_cond_set_condition_from_tree (inner_cond, t);
      update_stmt (inner_cond);

      /* Leave CFG optimization to cfg_cleanup.  */
      gimple_cond_set_condition_from_tree (outer_cond,
	outer_inv ? boolean_false_node : boolean_true_node);
      update_stmt (outer_cond);

      if (dump_file)
	{
	  fprintf (dump_file, "optimizing double bit test to ");
	  print_generic_expr (dump_file, name1, 0);
	  fprintf (dump_file, " & T == T\nwith temporary T = (1 << ");
	  print_generic_expr (dump_file, bit1, 0);
	  fprintf (dump_file, ") | (1 << ");
	  print_generic_expr (dump_file, bit2, 0);
	  fprintf (dump_file, ")\n");
	}

      return true;
    }

  /* See if we have two bit tests of the same name in both tests.
     In that case remove the outer test and change the inner one to
     test for name & (bits1 | bits2) != 0.  */
  else if (recognize_bits_test (inner_cond, &name1, &bits1, !inner_inv)
      && recognize_bits_test (outer_cond, &name2, &bits2, !outer_inv))
    {
      gimple_stmt_iterator gsi;
      tree t;

      /* Find the common name which is bit-tested.  */
      if (name1 == name2)
	;
      else if (bits1 == bits2)
	{
	  t = name2;
	  name2 = bits2;
	  bits2 = t;
	  t = name1;
	  name1 = bits1;
	  bits1 = t;
	}
      else if (name1 == bits2)
	{
	  t = name2;
	  name2 = bits2;
	  bits2 = t;
	}
      else if (bits1 == name2)
	{
	  t = name1;
	  name1 = bits1;
	  bits1 = t;
	}
      else
	return false;

      /* As we strip non-widening conversions in finding a common
         name that is tested make sure to end up with an integral
	 type for building the bit operations.  */
      if (TYPE_PRECISION (TREE_TYPE (bits1))
	  >= TYPE_PRECISION (TREE_TYPE (bits2)))
	{
	  bits1 = fold_convert (unsigned_type_for (TREE_TYPE (bits1)), bits1);
	  name1 = fold_convert (TREE_TYPE (bits1), name1);
	  bits2 = fold_convert (unsigned_type_for (TREE_TYPE (bits2)), bits2);
	  bits2 = fold_convert (TREE_TYPE (bits1), bits2);
	}
      else
	{
	  bits2 = fold_convert (unsigned_type_for (TREE_TYPE (bits2)), bits2);
	  name1 = fold_convert (TREE_TYPE (bits2), name1);
	  bits1 = fold_convert (unsigned_type_for (TREE_TYPE (bits1)), bits1);
	  bits1 = fold_convert (TREE_TYPE (bits2), bits1);
	}

      /* Do it.  */
      gsi = gsi_for_stmt (inner_cond);
      t = fold_build2 (BIT_IOR_EXPR, TREE_TYPE (name1), bits1, bits2);
      t = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
				    true, GSI_SAME_STMT);
      t = fold_build2 (BIT_AND_EXPR, TREE_TYPE (name1), name1, t);
      t = force_gimple_operand_gsi (&gsi, t, true, NULL_TREE,
				    true, GSI_SAME_STMT);
      t = fold_build2 (result_inv ? NE_EXPR : EQ_EXPR, boolean_type_node, t,
		       build_int_cst (TREE_TYPE (t), 0));
      t = canonicalize_cond_expr_cond (t);
      if (!t)
	return false;
      gimple_cond_set_condition_from_tree (inner_cond, t);
      update_stmt (inner_cond);

      /* Leave CFG optimization to cfg_cleanup.  */
      gimple_cond_set_condition_from_tree (outer_cond,
	outer_inv ? boolean_false_node : boolean_true_node);
      update_stmt (outer_cond);

      if (dump_file)
	{
	  fprintf (dump_file, "optimizing bits or bits test to ");
	  print_generic_expr (dump_file, name1, 0);
	  fprintf (dump_file, " & T != 0\nwith temporary T = ");
	  print_generic_expr (dump_file, bits1, 0);
	  fprintf (dump_file, " | ");
	  print_generic_expr (dump_file, bits2, 0);
	  fprintf (dump_file, "\n");
	}

      return true;
    }

  /* See if we have two comparisons that we can merge into one.  */
  else if (TREE_CODE_CLASS (gimple_cond_code (inner_cond)) == tcc_comparison
	   && TREE_CODE_CLASS (gimple_cond_code (outer_cond)) == tcc_comparison)
    {
      tree t;
      enum tree_code inner_cond_code = gimple_cond_code (inner_cond);
      enum tree_code outer_cond_code = gimple_cond_code (outer_cond);

      /* Invert comparisons if necessary (and possible).  */
      if (inner_inv)
	inner_cond_code = invert_tree_comparison (inner_cond_code,
	  HONOR_NANS (TYPE_MODE (TREE_TYPE (gimple_cond_lhs (inner_cond)))));
      if (inner_cond_code == ERROR_MARK)
	return false;
      if (outer_inv)
	outer_cond_code = invert_tree_comparison (outer_cond_code,
	  HONOR_NANS (TYPE_MODE (TREE_TYPE (gimple_cond_lhs (outer_cond)))));
      if (outer_cond_code == ERROR_MARK)
	return false;
      /* Don't return false so fast, try maybe_fold_or_comparisons?  */

      if (!(t = maybe_fold_and_comparisons (inner_cond_code,
					    gimple_cond_lhs (inner_cond),
					    gimple_cond_rhs (inner_cond),
					    outer_cond_code,
					    gimple_cond_lhs (outer_cond),
					    gimple_cond_rhs (outer_cond))))
	{
	  tree t1, t2;
	  gimple_stmt_iterator gsi;
	  if (!LOGICAL_OP_NON_SHORT_CIRCUIT)
	    return false;
	  /* Only do this optimization if the inner bb contains only the conditional. */
	  if (!gsi_one_before_end_p (gsi_start_nondebug_after_labels_bb (inner_cond_bb)))
	    return false;
	  t1 = fold_build2_loc (gimple_location (inner_cond),
				inner_cond_code,
				boolean_type_node,
				gimple_cond_lhs (inner_cond),
				gimple_cond_rhs (inner_cond));
	  t2 = fold_build2_loc (gimple_location (outer_cond),
				outer_cond_code,
				boolean_type_node,
				gimple_cond_lhs (outer_cond),
				gimple_cond_rhs (outer_cond));
	  t = fold_build2_loc (gimple_location (inner_cond), 
			       TRUTH_AND_EXPR, boolean_type_node, t1, t2);
	  if (result_inv)
	    {
	      t = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (t), t);
	      result_inv = false;
	    }
	  gsi = gsi_for_stmt (inner_cond);
	  t = force_gimple_operand_gsi_1 (&gsi, t, is_gimple_condexpr, NULL, true,
					  GSI_SAME_STMT);
        }
      if (result_inv)
	t = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (t), t);
      t = canonicalize_cond_expr_cond (t);
      if (!t)
	return false;
      gimple_cond_set_condition_from_tree (inner_cond, t);
      update_stmt (inner_cond);

      /* Leave CFG optimization to cfg_cleanup.  */
      gimple_cond_set_condition_from_tree (outer_cond,
	outer_inv ? boolean_false_node : boolean_true_node);
      update_stmt (outer_cond);

      if (dump_file)
	{
	  fprintf (dump_file, "optimizing two comparisons to ");
	  print_generic_expr (dump_file, t, 0);
	  fprintf (dump_file, "\n");
	}

      return true;
    }

  return false;
}