blob: 662e2d66842711ecb5a4e07322f7f49938eb2d7a [file] [log] [blame]
/* Interprocedural semantic function equality pass
Copyright (C) 2014-2021 Free Software Foundation, Inc.
Contributed by Jan Hubicka <hubicka@ucw.cz> and Martin Liska <mliska@suse.cz>
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
/* Gimple identical code folding (class func_checker) is an infrastructure
capable of comparing two given functions. The class compares every
gimple statement and uses many dictionaries to map source and target
SSA_NAMEs, declarations and other components.
To use the infrastructure, create an instance of func_checker and call
a comparison function based on type of gimple statement. */
/* Prints string STRING to a FILE with a given number of SPACE_COUNT. */
#define FPUTS_SPACES(file, space_count, string) \
fprintf (file, "%*s" string, space_count, " ");
/* fprintf function wrapper that transforms given FORMAT to follow given
number for SPACE_COUNT and call fprintf for a FILE. */
#define FPRINTF_SPACES(file, space_count, format, ...) \
fprintf (file, "%*s" format, space_count, " ", ##__VA_ARGS__);
/* Logs a MESSAGE to dump_file if exists and returns false. FUNC is name
of function and LINE is location in the source file. */
static inline bool
return_false_with_message_1 (const char *message, const char *filename,
const char *func, unsigned int line)
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, " false returned: '%s' in %s at %s:%u\n", message, func,
filename, line);
return false;
}
/* Logs a MESSAGE to dump_file if exists and returns false. */
#define return_false_with_msg(message) \
return_false_with_message_1 (message, __FILE__, __func__, __LINE__)
/* Return false and log that false value is returned. */
#define return_false() return_false_with_msg ("")
/* Logs return value if RESULT is false. FUNC is name of function and LINE
is location in the source file. */
static inline bool
return_with_result (bool result, const char *filename,
const char *func, unsigned int line)
{
if (!result && dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, " false returned: '' in %s at %s:%u\n", func,
filename, line);
return result;
}
/* Logs return value if RESULT is false. */
#define return_with_debug(result) return_with_result \
(result, __FILE__, __func__, __LINE__)
/* Verbose logging function logging statements S1 and S2 of a CODE.
FUNC is name of function and LINE is location in the source file. */
static inline bool
return_different_stmts_1 (gimple *s1, gimple *s2, const char *code,
const char *func, unsigned int line)
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, " different statement for code: %s (%s:%u):\n",
code, func, line);
print_gimple_stmt (dump_file, s1, 3, TDF_DETAILS);
print_gimple_stmt (dump_file, s2, 3, TDF_DETAILS);
}
return false;
}
/* Verbose logging function logging statements S1 and S2 of a CODE. */
#define return_different_stmts(s1, s2, code) \
return_different_stmts_1 (s1, s2, code, __func__, __LINE__)
namespace ipa_icf_gimple {
/* Basic block struct for semantic equality pass. */
class sem_bb
{
public:
sem_bb (basic_block bb_, unsigned nondbg_stmt_count_, unsigned edge_count_):
bb (bb_), nondbg_stmt_count (nondbg_stmt_count_), edge_count (edge_count_) {}
/* Basic block the structure belongs to. */
basic_block bb;
/* Number of non-debug statements in the basic block. */
unsigned nondbg_stmt_count;
/* Number of edges connected to the block. */
unsigned edge_count;
};
/* A class aggregating all connections and semantic equivalents
for a given pair of semantic function candidates. */
class func_checker : ao_compare
{
public:
/* Default constructor. */
func_checker ():
m_source_func_decl (NULL_TREE), m_target_func_decl (NULL_TREE),
m_ignored_source_nodes (NULL), m_ignored_target_nodes (NULL),
m_ignore_labels (false), m_tbaa (true)
{
m_source_ssa_names.create (0);
m_target_ssa_names.create (0);
}
/* Initialize internal structures for a given SOURCE_FUNC_DECL and
TARGET_FUNC_DECL. Strict polymorphic comparison is processed if
an option COMPARE_POLYMORPHIC is true. For special cases, one can
set IGNORE_LABELS to skip label comparison.
Similarly, IGNORE_SOURCE_DECLS and IGNORE_TARGET_DECLS are sets
of declarations that can be skipped. */
func_checker (tree source_func_decl, tree target_func_decl,
bool ignore_labels = false,
bool tbaa = true,
hash_set<symtab_node *> *ignored_source_nodes = NULL,
hash_set<symtab_node *> *ignored_target_nodes = NULL);
/* Memory release routine. */
virtual ~func_checker ();
/* Function visits all gimple labels and creates corresponding
mapping between basic blocks and labels. */
void parse_labels (sem_bb *bb);
/* Basic block equivalence comparison function that returns true if
basic blocks BB1 and BB2 correspond. */
bool compare_bb (sem_bb *bb1, sem_bb *bb2);
/* Verifies that trees T1 and T2 are equivalent from perspective of ICF. */
bool compare_ssa_name (const_tree t1, const_tree t2);
/* Verification function for edges E1 and E2. */
bool compare_edge (edge e1, edge e2);
/* Verifies for given GIMPLEs S1 and S2 that
call statements are semantically equivalent. */
bool compare_gimple_call (gcall *s1, gcall *s2);
/* Verifies for given GIMPLEs S1 and S2 that
assignment statements are semantically equivalent. */
bool compare_gimple_assign (gimple *s1, gimple *s2);
/* Verifies for given GIMPLEs S1 and S2 that
condition statements are semantically equivalent. */
bool compare_gimple_cond (gimple *s1, gimple *s2);
/* Verifies for given GIMPLE_LABEL stmts S1 and S2 that
label statements are semantically equivalent. */
bool compare_gimple_label (const glabel *s1, const glabel *s2);
/* Verifies for given GIMPLE_SWITCH stmts S1 and S2 that
switch statements are semantically equivalent. */
bool compare_gimple_switch (const gswitch *s1, const gswitch *s2);
/* Verifies for given GIMPLE_RETURN stmts S1 and S2 that
return statements are semantically equivalent. */
bool compare_gimple_return (const greturn *s1, const greturn *s2);
/* Verifies for given GIMPLEs S1 and S2 that
goto statements are semantically equivalent. */
bool compare_gimple_goto (gimple *s1, gimple *s2);
/* Verifies for given GIMPLE_RESX stmts S1 and S2 that
resx statements are semantically equivalent. */
bool compare_gimple_resx (const gresx *s1, const gresx *s2);
/* Verifies for given GIMPLE_ASM stmts S1 and S2 that ASM statements
are equivalent.
For the beginning, the pass only supports equality for
'__asm__ __volatile__ ("", "", "", "memory")'. */
bool compare_gimple_asm (const gasm *s1, const gasm *s2);
/* Verification function for declaration trees T1 and T2. */
bool compare_decl (const_tree t1, const_tree t2);
/* Compute hash map MAP that determines loads and stores of STMT. */
enum operand_access_type {OP_MEMORY, OP_NORMAL};
typedef hash_set<tree> operand_access_type_map;
/* Function responsible for comparison of various operands T1 and T2.
If these components, from functions FUNC1 and FUNC2, are equal, true
is returned. */
bool compare_operand (tree t1, tree t2, operand_access_type type);
/* Compares GIMPLE ASM inputs (or outputs) where we iterate tree chain
and compare both TREE_PURPOSEs and TREE_VALUEs. */
bool compare_asm_inputs_outputs (tree t1, tree t2,
operand_access_type_map *map);
/* Verifies that trees T1 and T2, representing function declarations
are equivalent from perspective of ICF. */
bool compare_function_decl (tree t1, tree t2);
/* Verifies that trees T1 and T2 do correspond. */
bool compare_variable_decl (const_tree t1, const_tree t2);
/* Compare loop information for basic blocks BB1 and BB2. */
bool compare_loops (basic_block bb1, basic_block bb2);
/* Return true if types are compatible for polymorphic call analysis.
COMPARE_PTR indicates if polymorphic type comparison should be
done for pointers, too. */
static bool compatible_polymorphic_types_p (tree t1, tree t2,
bool compare_ptr);
/* Return true if types are compatible from perspective of ICF.
FIRST_ARGUMENT indicates if the comparison is called for
first parameter of a function. */
static bool compatible_types_p (tree t1, tree t2);
/* Compute hash map determining access types of operands. */
static void classify_operands (const gimple *stmt,
operand_access_type_map *map);
/* Return access type of a given operand. */
static operand_access_type get_operand_access_type
(operand_access_type_map *map, tree);
private:
/* Vector mapping source SSA names to target ones. */
vec <int> m_source_ssa_names;
/* Vector mapping target SSA names to source ones. */
vec <int> m_target_ssa_names;
/* Source TREE function declaration. */
tree m_source_func_decl;
/* Target TREE function declaration. */
tree m_target_func_decl;
/* Source symbol nodes that should be skipped by
declaration comparison. */
hash_set<symtab_node *> *m_ignored_source_nodes;
/* Target symbol nodes that should be skipped by
declaration comparison. */
hash_set<symtab_node *> *m_ignored_target_nodes;
/* Source to target edge map. */
hash_map <edge, edge> m_edge_map;
/* Source to target declaration map. */
hash_map <const_tree, const_tree> m_decl_map;
/* Label to basic block index mapping. */
hash_map <const_tree, int> m_label_bb_map;
/* Flag if ignore labels in comparison. */
bool m_ignore_labels;
/* Flag if we should compare type based alias analysis info. */
bool m_tbaa;
public:
/* Return true if two operands are equal. The flags fields can be used
to specify OEP flags described above. */
virtual bool operand_equal_p (const_tree, const_tree, unsigned int flags);
/* Generate a hash value for an expression. This can be used iteratively
by passing a previous result as the HSTATE argument. */
virtual void hash_operand (const_tree, inchash::hash &, unsigned flags);
void hash_operand (const_tree, inchash::hash &, unsigned flags,
operand_access_type access);
};
} // ipa_icf_gimple namespace