Data Structures
struct	object_size_info

Functions
static tree	compute_object_offset (const_tree, const_tree)
static unsigned HOST_WIDE_INT	addr_object_size (struct object_size_info *, const_tree, int)
static unsigned HOST_WIDE_INT	alloc_object_size (const_gimple, int)
static tree	pass_through_call (const_gimple)
static void	collect_object_sizes_for (struct object_size_info *, tree)
static void	expr_object_size (struct object_size_info *, tree, tree)
static bool	merge_object_sizes (struct object_size_info *, tree, tree, unsigned HOST_WIDE_INT)
static bool	plus_stmt_object_size (struct object_size_info *, tree, gimple)
static bool	cond_expr_object_size (struct object_size_info *, tree, gimple)
static unsigned int	compute_object_sizes (void)
static void	init_offset_limit (void)
static void	check_for_plus_in_loops (struct object_size_info *, tree)
static void	check_for_plus_in_loops_1 (struct object_size_info *, tree, unsigned int)
static tree	compute_object_offset ()
static unsigned HOST_WIDE_INT	alloc_object_size ()
static tree	pass_through_call ()
unsigned HOST_WIDE_INT	compute_builtin_object_size ()
static void	expr_object_size ()
static void	call_object_size ()
static void	unknown_object_size ()
static bool	plus_stmt_object_size ()
static bool	cond_expr_object_size ()
static void	collect_object_sizes_for ()
static void	check_for_plus_in_loops ()
void	init_object_sizes ()
void	fini_object_sizes ()
gimple_opt_pass *	make_pass_object_sizes ()

Variables
static const unsigned HOST_WIDE_INT	unknown [4] = { -1, -1, 0, 0 }
static unsigned HOST_WIDE_INT *	object_sizes [4]
static bitmap	computed [4]
static unsigned HOST_WIDE_INT	offset_limit

Function Documentation

static unsigned HOST_WIDE_INT addr_object_size	(	struct object_size_info *	osi,
		const_tree	ptr,
		int	object_size_type
	)

static

Compute __builtin_object_size for PTR, which is a ADDR_EXPR.
   OBJECT_SIZE_TYPE is the second argument from __builtin_object_size.
   If unknown, return unknown[object_size_type].

References bitmap_bit_p(), collect_object_sizes_for(), compute_builtin_object_size(), compute_object_offset(), double_int::fits_uhwi(), double_int::from_uhwi(), handled_component_p(), host_integerp(), HOST_WIDE_INT, double_int::is_negative(), mem_ref_offset(), object_sizes, offset_limit, object_size_info::pass, double_int::to_uhwi(), tree_int_cst_lt(), tree_low_cst(), and unknown.

Referenced by compute_builtin_object_size(), expr_object_size(), and plus_stmt_object_size().

static unsigned HOST_WIDE_INT alloc_object_size	(	const_gimple	,
		int
	)

static

Referenced by call_object_size().

static unsigned HOST_WIDE_INT alloc_object_size ( )

static

Compute __builtin_object_size for CALL, which is a GIMPLE_CALL.
   Handles various allocation calls.  OBJECT_SIZE_TYPE is the second
   argument from __builtin_object_size.  If unknown, return
   unknown[object_size_type].

References BUILT_IN_NORMAL, gimple_call_arg(), gimple_call_fndecl(), gimple_call_num_args(), host_integerp(), is_gimple_call(), lookup_attribute(), tree_low_cst(), and unknown.

static void call_object_size ( )

static

Compute object_sizes for PTR, defined to the result of a call.

References alloc_object_size(), HOST_WIDE_INT, is_gimple_call(), object_size_info::object_size_type, object_sizes, object_size_info::pass, and unknown.

Referenced by collect_object_sizes_for().

static void check_for_plus_in_loops	(	struct object_size_info *	,
		tree
	)

static

Referenced by compute_builtin_object_size().

static void check_for_plus_in_loops ( )

static

Check if some pointer we are computing object size of is being increased
   within a loop.  If yes, assume all the SSA variables participating in
   that loop have minimum object sizes 0.

References check_for_plus_in_loops_1(), object_size_info::depths, gimple_assign_rhs1(), gimple_assign_rhs2(), gimple_assign_rhs_code(), integer_zerop(), is_gimple_assign(), and object_size_info::tos.

static void check_for_plus_in_loops_1	(	struct object_size_info *	osi,
		tree	var,
		unsigned int	depth
	)

static

Helper function for check_for_plus_in_loops.  Called recursively
   to detect loops.

References bitmap_bit_p(), bitmap_clear_bit(), bitmap_set_bit(), phi_arg_d::def, object_size_info::depths, gimple_assign_rhs1(), gimple_assign_rhs2(), gimple_assign_rhs_code(), gimple_assign_single_p(), gimple_assign_unary_nop_p(), gimple_phi_arg(), gimple_phi_num_args(), integer_zerop(), object_size_info::object_size_type, object_sizes, pass_through_call(), object_size_info::reexamine, object_size_info::stack, and object_size_info::tos.

Referenced by check_for_plus_in_loops().

static void collect_object_sizes_for	(	struct object_size_info *	,
		tree
	)

static

Referenced by addr_object_size(), compute_builtin_object_size(), and merge_object_sizes().

static void collect_object_sizes_for ( )

static

Compute object sizes for VAR.
   For ADDR_EXPR an object size is the number of remaining bytes
   to the end of the object (where what is considered an object depends on
   OSI->object_size_type).
   For allocation GIMPLE_CALL like malloc or calloc object size is the size
   of the allocation.
   For POINTER_PLUS_EXPR where second operand is a constant integer,
   object size is object size of the first operand minus the constant.
   If the constant is bigger than the number of remaining bytes until the
   end of the object, object size is 0, but if it is instead a pointer
   subtraction, object size is unknown[object_size_type].
   To differentiate addition from subtraction, ADDR_EXPR returns
   unknown[object_size_type] for all objects bigger than half of the address
   space, and constants less than half of the address space are considered
   addition, while bigger constants subtraction.
   For a memcpy like GIMPLE_CALL that always returns one of its arguments, the
   object size is object size of that argument.
   Otherwise, object size is the maximum of object sizes of variables
   that it might be set to.

References bitmap_bit_p(), bitmap_clear_bit(), bitmap_set_bit(), call_object_size(), cond_expr_object_size(), phi_arg_d::def, dump_file, dump_flags, expr_object_size(), gimple_assign_rhs1(), gimple_assign_rhs_code(), gimple_assign_single_p(), gimple_assign_unary_nop_p(), gimple_phi_arg(), gimple_phi_num_args(), merge_object_sizes(), object_size_info::object_size_type, object_sizes, object_size_info::pass, pass_through_call(), plus_stmt_object_size(), print_generic_expr(), object_size_info::reexamine, unknown, unknown_object_size(), and object_size_info::visited.

unsigned HOST_WIDE_INT compute_builtin_object_size ( )

Compute __builtin_object_size value for PTR.  OBJECT_SIZE_TYPE is the
   second argument from __builtin_object_size.

References addr_object_size(), bitmap_bit_p(), bitmap_copy(), bitmap_empty_p(), bitmap_set_bit(), object_size_info::changed, check_for_plus_in_loops(), collect_object_sizes_for(), object_size_info::depths, dump_file, dump_flags, free(), HOST_WIDE_INT_PRINT_UNSIGNED, init_offset_limit(), object_size_info::object_size_type, object_sizes, offset_limit, object_size_info::pass, print_generic_expr(), object_size_info::reexamine, object_size_info::stack, object_size_info::tos, unknown, and object_size_info::visited.

Referenced by addr_object_size(), and fold_builtin_object_size().

static tree compute_object_offset	(	const_tree	,
		const_tree
	)

static

Referenced by addr_object_size(), and compute_object_offset().

static tree compute_object_offset ( )

static

Compute offset of EXPR within VAR.  Return error_mark_node
   if unknown.

References compute_object_offset(), double_int_to_tree(), mem_ref_offset(), tree_int_cst_sgn(), and tree_low_cst().

static unsigned int compute_object_sizes ( )

static

Simple pass to optimize all __builtin_object_size () builtins.

References build_zero_cst(), BUILT_IN_NORMAL, dump_file, dump_flags, fini_object_sizes(), fold_call_stmt(), gimple_call_arg(), gimple_call_fndecl(), gimple_call_num_args(), gsi_end_p(), gsi_next(), gsi_start_bb(), gsi_stmt(), host_integerp(), HOST_WIDE_INT, init_object_sizes(), object_size_info::object_size_type, print_gimple_stmt(), tree_low_cst(), and update_call_from_tree().

static bool cond_expr_object_size	(	struct object_size_info *	,
		tree	,
		gimple
	)

static

Referenced by collect_object_sizes_for().

static bool cond_expr_object_size ( )

static

Compute object_sizes for VAR, defined at STMT, which is
   a COND_EXPR.  Return true if the object size might need reexamination
   later.

References expr_object_size(), gimple_assign_rhs2(), gimple_assign_rhs3(), gimple_assign_rhs_code(), merge_object_sizes(), object_size_info::object_size_type, object_sizes, object_size_info::reexamine, and unknown.

static void expr_object_size	(	struct object_size_info *	,
		tree	,
		tree
	)

static

Referenced by collect_object_sizes_for(), and cond_expr_object_size().

static void expr_object_size ( )

static

Compute object_sizes for PTR, defined to VALUE, which is not an SSA_NAME.

References addr_object_size(), HOST_WIDE_INT, object_size_info::object_size_type, object_sizes, object_size_info::pass, and unknown.

void fini_object_sizes ( void )

Destroy data structures after the object size computation.

References free(), object_size_info::object_size_type, and object_sizes.

Referenced by compute_object_sizes().

void init_object_sizes ( void )

Initialize data structures for the object size computation.

References HOST_WIDE_INT, init_offset_limit(), object_size_info::object_size_type, and object_sizes.

Referenced by compute_object_sizes().

static void init_offset_limit ( )

static

Initialize OFFSET_LIMIT variable.

References host_integerp(), offset_limit, and tree_low_cst().

Referenced by compute_builtin_object_size(), and init_object_sizes().

gimple_opt_pass* make_pass_object_sizes ( )

static bool merge_object_sizes	(	struct object_size_info *	osi,
		tree	dest,
		tree	orig,
		unsigned HOST_WIDE_INT	offset
	)

static

Merge object sizes of ORIG + OFFSET into DEST.  Return true if
   the object size might need reexamination later.

References bitmap_bit_p(), object_size_info::changed, collect_object_sizes_for(), HOST_WIDE_INT, object_size_info::object_size_type, object_sizes, offset, offset_limit, object_size_info::pass, object_size_info::reexamine, and unknown.

Referenced by collect_object_sizes_for(), cond_expr_object_size(), and plus_stmt_object_size().

static tree pass_through_call ( const_gimple )

static

Referenced by check_for_plus_in_loops_1(), and collect_object_sizes_for().

static tree pass_through_call ( )

static

If object size is propagated from one of function's arguments directly
   to its return value, return that argument for GIMPLE_CALL statement CALL.
   Otherwise return NULL.

References BUILT_IN_NORMAL, gimple_call_arg(), gimple_call_fndecl(), and gimple_call_num_args().

static bool plus_stmt_object_size	(	struct object_size_info *	,
		tree	,
		gimple
	)

static

Referenced by collect_object_sizes_for().

static bool plus_stmt_object_size ( )

static

Compute object_sizes for VAR, defined to the result of an assignment
   with operator POINTER_PLUS_EXPR.  Return true if the object size might
   need reexamination  later.

References addr_object_size(), gimple_assign_rhs1(), gimple_assign_rhs2(), gimple_assign_rhs_code(), host_integerp(), HOST_WIDE_INT, merge_object_sizes(), object_size_info::object_size_type, object_sizes, offset_limit, tree_low_cst(), and unknown.

static void unknown_object_size ( )

static

Compute object_sizes for PTR, defined to an unknown value.

References HOST_WIDE_INT, object_size_info::object_size_type, object_sizes, object_size_info::pass, and unknown.

Referenced by collect_object_sizes_for().

Variable Documentation

bitmap computed[4]

static

Bitmaps what object sizes have been computed already.

unsigned HOST_WIDE_INT* object_sizes[4]

static

object_sizes[0] is upper bound for number of bytes till the end of
   the object.
   object_sizes[1] is upper bound for number of bytes till the end of
   the subobject (innermost array or field with address taken).
   object_sizes[2] is lower bound for number of bytes till the end of
   the object and object_sizes[3] lower bound for subobject.

Referenced by addr_object_size(), call_object_size(), check_for_plus_in_loops_1(), collect_object_sizes_for(), compute_builtin_object_size(), cond_expr_object_size(), expr_object_size(), fini_object_sizes(), init_object_sizes(), merge_object_sizes(), plus_stmt_object_size(), and unknown_object_size().

unsigned HOST_WIDE_INT offset_limit

static

Maximum value of offset we consider to be addition.

Referenced by addr_object_size(), compute_builtin_object_size(), init_offset_limit(), merge_object_sizes(), and plus_stmt_object_size().

const unsigned HOST_WIDE_INT unknown[4] = { -1, -1, 0, 0 }

static

Referenced by addr_object_size(), alloc_object_size(), call_object_size(), collect_object_sizes_for(), compute_builtin_object_size(), cond_expr_object_size(), expr_object_size(), go_define(), max_fn(), merge_object_sizes(), min_fn(), plus_stmt_object_size(), unknown_object_size(), and write_length_unit_log().

Data Structures

Functions

Variables

Function Documentation

Variable Documentation