ipa-pure-const.cc File Reference

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "target.h"
#include "tree.h"
#include "gimple.h"
#include "tree-pass.h"
#include "tree-streamer.h"
#include "cgraph.h"
#include "diagnostic.h"
#include "calls.h"
#include "cfganal.h"
#include "tree-eh.h"
#include "gimple-iterator.h"
#include "gimple-walk.h"
#include "tree-cfg.h"
#include "tree-ssa-loop-niter.h"
#include "langhooks.h"
#include "ipa-utils.h"
#include "gimple-pretty-print.h"
#include "cfgloop.h"
#include "tree-scalar-evolution.h"
#include "intl.h"
#include "opts.h"
#include "ssa.h"
#include "alloc-pool.h"
#include "symbol-summary.h"
#include "sreal.h"
#include "ipa-cp.h"
#include "ipa-prop.h"
#include "ipa-fnsummary.h"
#include "symtab-thunks.h"
#include "dbgcnt.h"
#include "gcc-urlifier.h"

Include dependency graph for ipa-pure-const.cc:

Data Structures
class	funct_state_d
class	funct_state_summary_t

Macros
#define	DUMP_AND_RETURN(reason)

Typedefs
typedef class funct_state_d *	funct_state

Enumerations
enum	pure_const_state_e { IPA_CONST , IPA_PURE , IPA_NEITHER }
enum	malloc_state_e { STATE_MALLOC_TOP , STATE_MALLOC , STATE_MALLOC_BOTTOM }

Functions
static bool	gate_pure_const (void)
static bool	function_always_visible_to_compiler_p (tree decl)
static hash_set< tree > *	suggest_attribute (diagnostic_option_id option, tree decl, bool known_finite, hash_set< tree > *warned_about, const char *attrib_name)
static void	warn_function_pure (tree decl, bool known_finite)
static void	warn_function_const (tree decl, bool known_finite)
static void	warn_function_malloc (tree decl)
static void	warn_function_noreturn (tree decl)
void	warn_function_cold (tree decl)
void	warn_function_returns_nonnull (tree decl)
static void	check_decl (funct_state local, tree t, bool checking_write, bool ipa)
static void	check_op (funct_state local, tree t, bool checking_write)
static void	state_from_flags (enum pure_const_state_e *state, bool *looping, int flags, bool cannot_lead_to_return)
static void	better_state (enum pure_const_state_e *state, bool *looping, enum pure_const_state_e state2, bool looping2)
static void	worse_state (enum pure_const_state_e *state, bool *looping, enum pure_const_state_e state2, bool looping2, struct symtab_node *from, struct symtab_node *to)
bool	builtin_safe_for_const_function_p (bool *looping, tree callee)
static void	check_call (funct_state local, gcall *call, bool ipa)
static bool	check_load (gimple *, tree op, tree, void *data)
static bool	check_store (gimple *, tree op, tree, void *data)
static bool	check_ipa_load (gimple *, tree op, tree, void *data)
static bool	check_ipa_store (gimple *, tree op, tree, void *data)
static void	check_stmt (gimple_stmt_iterator *gsip, funct_state local, bool ipa)
static bool	check_retval_uses (tree retval, gimple *stmt)
static bool	malloc_candidate_p_1 (function *fun, tree retval, gimple *ret_stmt, bool ipa, bitmap visited)
static bool	malloc_candidate_p (function *fun, bool ipa)
bool	finite_function_p ()
static funct_state	analyze_function (struct cgraph_node *fn, bool ipa)
static void	pure_const_generate_summary (void)
static void	pure_const_write_summary (void)
static void	pure_const_read_summary (void)
static bool	ignore_edge_for_nothrow (struct cgraph_edge *e)
static bool	self_recursive_p (struct cgraph_node *node)
static bool	cdtor_p (cgraph_node *n, void *)
static bool	ignore_edge_for_pure_const (struct cgraph_edge *e)
static bool	skip_function_for_local_pure_const (struct cgraph_node *node)
bool	ipa_make_function_const (struct cgraph_node *node, bool looping, bool local)
bool	ipa_make_function_pure (struct cgraph_node *node, bool looping, bool local)
static bool	propagate_pure_const (void)
static void	propagate_nothrow (void)
static DEBUG_FUNCTION void	dump_malloc_lattice (FILE *dump_file, const char *s)
static void	propagate_malloc (void)
ipa_opt_pass_d *	make_pass_ipa_pure_const (gcc::context *ctxt)
gimple_opt_pass *	make_pass_local_pure_const (gcc::context *ctxt)
gimple_opt_pass *	make_pass_warn_function_noreturn (gcc::context *ctxt)
gimple_opt_pass *	make_pass_nothrow (gcc::context *ctxt)

Variables
static const char *	pure_const_names [3] = {"const", "pure", "neither"}
static const char *	malloc_state_names [] = {"malloc_top", "malloc", "malloc_bottom"}
static funct_state_summary_t *	funct_state_summaries = NULL

Macro Definition Documentation

DUMP_AND_RETURN

#define DUMP_AND_RETURN

(

reason

)

Value:

{  \
  if (dump_file && (dump_flags & TDF_DETAILS))  \
    fprintf (dump_file, "\n%s is not a malloc candidate, reason: %s\n", \
             (node->dump_name ()), (reason));  \
  return false;  \
}

malloc_candidate_p() checks if FUN can possibly be annotated with malloc
attribute. Currently this function does a very conservative analysis.
FUN is considered to be a candidate if
1) It returns a value of pointer type.
2) SSA_NAME_DEF_STMT (return_value) is either a function call or
   a phi, and element of phi is either NULL or
   SSA_NAME_DEF_STMT(element) is function call.
3) The return-value has immediate uses only within comparisons (gcond or gassign)
   and return_stmt (and likewise a phi arg has immediate use only within comparison
   or the phi stmt).   

Referenced by malloc_candidate_p(), and malloc_candidate_p_1().

Typedef Documentation

funct_state

typedef class funct_state_d* funct_state

Enumeration Type Documentation

malloc_state_e

enum malloc_state_e

Enumerator
STATE_MALLOC_TOP
STATE_MALLOC
STATE_MALLOC_BOTTOM

pure_const_state_e

enum pure_const_state_e

Callgraph based analysis of static variables.
   Copyright (C) 2004-2025 Free Software Foundation, Inc.
   Contributed by Kenneth Zadeck <zadeck@naturalbridge.com>

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/>.   

This file marks functions as being either const (TREE_READONLY) or
pure (DECL_PURE_P).  It can also set a variant of these that
are allowed to loop indefinitely (DECL_LOOPING_CONST_PURE_P).

This must be run after inlining decisions have been made since
otherwise, the local sets will not contain information that is
consistent with post inlined state.  The global sets are not prone
to this problem since they are by definition transitive.   

The code in this module is called by the ipa pass manager. It
should be one of the later passes since it's information is used by
the rest of the compilation.  

Lattice values for const and pure functions.  Everything starts out
being const, then may drop to pure and then neither depending on
what is found.   

Enumerator
IPA_CONST
IPA_PURE
IPA_NEITHER

Function Documentation

analyze_function()

funct_state analyze_function ( struct cgraph_node * fn, bool ipa )

static

This is the main routine for finding the reference patterns for
global variables within a function FN.   

References symtab_node::alias, better_state(), cgraph_node::cannot_return_p(), cfun, check_stmt(), symtab_node::decl, DECL_IS_MALLOC, DECL_STRUCT_FUNCTION, dump_file, dump_flags, symtab_node::dump_name(), end(), finite_function_p(), flags_from_decl_or_type(), FOR_EACH_BB_FN, gcc_assert, thunk_info::get(), walk_stmt_info::gsi, gsi_end_p(), gsi_next(), gsi_start_bb(), gsi_stmt(), infer_nonnull_range_by_dereference(), IPA_CONST, IPA_NEITHER, IPA_PURE, malloc_candidate_p(), null_pointer_node, pop_cfun(), push_cfun(), state_from_flags(), STATE_MALLOC, STATE_MALLOC_BOTTOM, STATE_MALLOC_TOP, stmt_can_throw_external(), TDF_DETAILS, cgraph_node::thunk, and TREE_NOTHROW.

Referenced by funct_state_summary_t::insert(), modref_summaries::insert(), modref_summaries_lto::insert(), and pure_const_generate_summary().

better_state()

void better_state ( enum pure_const_state_e * state, bool * looping, enum pure_const_state_e state2, bool looping2 )

inlinestatic

Merge STATE and STATE2 and LOOPING and LOOPING2 and store
into STATE and LOOPING better of the two variants.
Be sure to merge looping correctly.  IPA_NEITHER functions
have looping 0 even if they don't have to return.   

References IPA_NEITHER, and MIN.

Referenced by analyze_function(), and propagate_pure_const().

builtin_safe_for_const_function_p()

bool builtin_safe_for_const_function_p	(	bool *	looping,
		tree	callee )

Recognize special cases of builtins that are by themselves not const
but function using them is.   

References BUILT_IN_NORMAL, CASE_BUILT_IN_ALLOCA, DECL_BUILT_IN_CLASS, and DECL_FUNCTION_CODE().

Referenced by check_call(), and propagate_pure_const().

cdtor_p()

bool cdtor_p ( cgraph_node * n, void *  )

static

Return true if N is cdtor that is not const or pure.  In this case we may
need to remove unreachable function if it is marked const/pure.   

References symtab_node::decl, DECL_LOOPING_CONST_OR_PURE_P, DECL_PURE_P, DECL_STATIC_CONSTRUCTOR, DECL_STATIC_DESTRUCTOR, and TREE_READONLY.

Referenced by ipa_make_function_const(), and ipa_make_function_pure().

check_call()

void check_call ( funct_state local, gcall * call, bool ipa )

static

Check the parameters of a function call to CALL_EXPR to see if
there are any references in the parameters that are not allowed for
pure or const functions.  Also check to see if this is either an
indirect call, a call outside the compilation unit, or has special
attributes that may also effect the purity.  The CALL_EXPR node for
the entire call expression.   

References BUILT_IN_NORMAL, builtin_safe_for_const_function_p(), cfun, current_function_decl, DECL_ASSEMBLER_NAME, DECL_BUILT_IN_CLASS, DECL_FUNCTION_CODE(), dump_file, dump_flags, ECF_NORETURN, ECF_NOTHROW, gimple_call_builtin_p(), gimple_call_flags(), gimple_call_fndecl(), gimple_call_internal_p(), gimple_num_ops(), gimple_op(), i, IDENTIFIER_POINTER, IPA_CONST, IPA_NEITHER, lookup_stmt_eh_lp(), nonfreeing_call_p(), NULL, recursive_call_p(), setjmp_call_p(), state_from_flags(), stmt_can_throw_external(), stmt_could_throw_p(), TDF_DETAILS, tree_could_throw_p(), and worse_state().

Referenced by check_stmt().

check_decl()

void check_decl ( funct_state local, tree t, bool checking_write, bool ipa )

inlinestatic

Check to see if the use (or definition when CHECKING_WRITE is true)
variable T is legal in a function that is either pure or const.   

References DECL_EXTERNAL, DECL_PRESERVE_P, dump_file, IPA_CONST, IPA_NEITHER, IPA_PURE, TREE_PUBLIC, TREE_READONLY, TREE_STATIC, and TREE_THIS_VOLATILE.

Referenced by check_ipa_load(), check_ipa_store(), check_load(), and check_store().

check_ipa_load()

bool check_ipa_load ( gimple * , tree op, tree , void * data )

static

Wrapper around check_decl for loads in ipa mode.   

References check_decl(), check_op(), and DECL_P.

Referenced by check_stmt().

check_ipa_store()

bool check_ipa_store ( gimple * , tree op, tree , void * data )

static

Wrapper around check_decl for stores in ipa mode.   

References check_decl(), check_op(), and DECL_P.

Referenced by check_stmt().

check_load()

bool check_load ( gimple * , tree op, tree , void * data )

static

Wrapper around check_decl for loads in local more.   

References check_decl(), check_op(), and DECL_P.

Referenced by check_stmt().

check_op()

void check_op ( funct_state local, tree t, bool checking_write )

inlinestatic

Check to see if the use (or definition when CHECKING_WRITE is true)
variable T is legal in a function that is either pure or const.   

References dump_file, get_base_address(), IPA_CONST, IPA_NEITHER, IPA_PURE, refs_local_or_readonly_memory_p(), and TREE_THIS_VOLATILE.

Referenced by check_ipa_load(), check_ipa_store(), check_load(), and check_store().

check_retval_uses()

bool check_retval_uses ( tree retval, gimple * stmt )

static

Check that RETVAL is used only in STMT and in comparisons against 0.
RETVAL is return value of the function and STMT is return stmt.   

References dyn_cast(), FOR_EACH_IMM_USE_STMT, gimple_assign_rhs2(), gimple_assign_rhs_code(), gimple_cond_rhs(), integer_zerop(), is_gimple_debug(), tcc_comparison, and TREE_CODE_CLASS.

Referenced by malloc_candidate_p_1().

check_stmt()

void check_stmt ( gimple_stmt_iterator * gsip, funct_state local, bool ipa )

static

Look into pointer pointed to by GSIP and figure out what interesting side
effects it has.   

References as_a(), cfun, check_call(), check_ipa_load(), check_ipa_store(), check_load(), check_store(), DECL_NONLOCAL, dump_file, gimple_asm_clobbers_memory_p(), gimple_asm_volatile_p(), gimple_clobber_p(), gimple_has_volatile_ops(), gimple_label_label(), gsi_stmt(), IPA_NEITHER, is_gimple_debug(), print_gimple_stmt(), stmt_can_throw_external(), stmt_could_throw_p(), and walk_stmt_load_store_ops().

Referenced by analyze_function().

check_store()

bool check_store ( gimple * , tree op, tree , void * data )

static

Wrapper around check_decl for stores in local more.   

References check_decl(), check_op(), and DECL_P.

Referenced by check_stmt().

dump_malloc_lattice()

DEBUG_FUNCTION void dump_malloc_lattice ( FILE * dump_file, const char * s )

static

Debugging function to dump state of malloc lattice.   

References dump_file, symtab_node::dump_name(), FOR_EACH_FUNCTION, funct_state_summaries, and malloc_state_names.

Referenced by propagate_malloc().

finite_function_p()

bool finite_function_p

(

)

Return true if function is known to be finite.   

References cfun, dump_file, dump_flags, finite_loop_p(), flow_loops_dump(), loop_optimizer_finalize(), loop_optimizer_init(), LOOPS_HAVE_PREHEADERS, LOOPS_HAVE_RECORDED_EXITS, LOOPS_HAVE_SIMPLE_LATCHES, mark_dfs_back_edges(), mark_irreducible_loops(), NULL, loop::num, scev_finalize(), scev_initialize(), and TDF_DETAILS.

Referenced by analyze_function().

function_always_visible_to_compiler_p()

bool function_always_visible_to_compiler_p ( tree decl )

static

Try to guess if function body will always be visible to compiler
when compiling the call and whether compiler will be able
to propagate the information by itself.   

References DECL_COMDAT, DECL_DECLARED_INLINE_P, and TREE_PUBLIC.

Referenced by suggest_attribute().

gate_pure_const()

bool gate_pure_const ( void )

static

ignore_edge_for_nothrow()

bool ignore_edge_for_nothrow ( struct cgraph_edge * e )

static

We only propagate across edges that can throw externally and their callee
is not interposable.   

References AVAIL_INTERPOSABLE, symtab_node::binds_to_current_def_p(), cgraph_edge::callee, cgraph_edge::caller, cgraph_edge::can_throw_external, symtab_node::decl, cgraph_node::function_or_virtual_thunk_symbol(), opt_for_fn, and TREE_NOTHROW.

Referenced by propagate_nothrow().

ignore_edge_for_pure_const()

bool ignore_edge_for_pure_const ( struct cgraph_edge * e )

static

Skip edges from and to nodes without ipa_pure_const enabled.
Ignore not available symbols.   

References AVAIL_INTERPOSABLE, cgraph_edge::callee, cgraph_edge::caller, symtab_node::decl, cgraph_node::function_or_virtual_thunk_symbol(), and opt_for_fn.

Referenced by propagate_pure_const().

ipa_make_function_const()

bool ipa_make_function_const	(	struct cgraph_node *	node,
		bool	looping,
		bool	local )

Make function const and output warning.  If LOCAL is true,
return true if anything changed.  Otherwise return true if
we may have introduced removale ctors.   

References cgraph_node::call_for_symbol_and_aliases(), cdtor_p(), dbg_cnt(), symtab_node::decl, DECL_LOOPING_CONST_OR_PURE_P, dump_file, symtab_node::dump_name(), NULL, cgraph_node::set_const_flag(), skip_function_for_local_pure_const(), TREE_READONLY, and warn_function_const().

Referenced by propagate_pure_const().

ipa_make_function_pure()

bool ipa_make_function_pure	(	struct cgraph_node *	node,
		bool	looping,
		bool	local )

Make function const and output warning.  If LOCAL is true,
return true if anything changed.  Otherwise return true if
we may have introduced removale ctors.   

References cgraph_node::call_for_symbol_and_aliases(), cdtor_p(), dbg_cnt(), symtab_node::decl, DECL_LOOPING_CONST_OR_PURE_P, DECL_PURE_P, dump_file, symtab_node::dump_name(), NULL, cgraph_node::set_pure_flag(), skip_function_for_local_pure_const(), TREE_READONLY, and warn_function_pure().

Referenced by propagate_pure_const().

make_pass_ipa_pure_const()

ipa_opt_pass_d * make_pass_ipa_pure_const

(

gcc::context *

ctxt

)

make_pass_local_pure_const()

gimple_opt_pass * make_pass_local_pure_const

(

gcc::context *

ctxt

)

make_pass_nothrow()

gimple_opt_pass * make_pass_nothrow

(

gcc::context *

ctxt

)

make_pass_warn_function_noreturn()

gimple_opt_pass * make_pass_warn_function_noreturn

(

gcc::context *

ctxt

)

malloc_candidate_p()

bool malloc_candidate_p ( function * fun, bool ipa )

static

References function::decl, DECL_NAME, DUMP_AND_RETURN, dump_file, dump_flags, dyn_cast(), EDGE_COUNT, EXIT_BLOCK_PTR_FOR_FN, FOR_EACH_EDGE, cgraph_node::get_create(), gimple_return_retval(), gsi_last_bb(), gsi_stmt(), IDENTIFIER_POINTER, malloc_candidate_p_1(), basic_block_def::preds, TDF_DETAILS, TREE_CODE, TREE_TYPE, and visited.

Referenced by analyze_function().

malloc_candidate_p_1()

bool malloc_candidate_p_1 ( function * fun, tree retval, gimple * ret_stmt, bool ipa, bitmap visited )

static

References bitmap_set_bit, check_retval_uses(), function::decl, DECL_IS_MALLOC, DUMP_AND_RETURN, dyn_cast(), cgraph_node::get_create(), cgraph_node::get_edge(), gimple_call_fndecl(), gimple_phi_arg_def(), gimple_phi_num_args(), i, integer_zerop(), ipa_call_summaries, is_a(), ipa_call_summary::is_return_callee_uncaptured, malloc_candidate_p_1(), SSA_NAME_DEF_STMT, SSA_NAME_VERSION, TREE_CODE, and visited.

Referenced by malloc_candidate_p(), and malloc_candidate_p_1().

propagate_malloc()

void propagate_malloc ( void )

static

Propagate malloc attribute across the callgraph.   

References symtab_node::alias, AVAIL_INTERPOSABLE, cgraph_node::callees, changed, symtab_node::decl, DECL_IS_MALLOC, symtab_node::definition, dump_file, dump_flags, dump_malloc_lattice(), symtab_node::dump_name(), FOR_EACH_DEFINED_FUNCTION, FOR_EACH_FUNCTION, free(), funct_state_summaries, cgraph_node::get_availability(), i, cgraph_node::indirect_calls, cgraph_node::inlined_to, ipa_call_summaries, ipa_free_postorder_info(), ipa_reverse_postorder(), ipa_call_summary::is_return_callee_uncaptured, cgraph_edge::next_callee, cgraph_node::set_malloc_flag(), STATE_MALLOC, STATE_MALLOC_BOTTOM, symtab, TDF_DETAILS, TREE_TYPE, VOID_TYPE_P, and warn_function_malloc().

propagate_nothrow()

void propagate_nothrow ( void )

static

Produce transitive closure over the callgraph and compute nothrow
attributes.   

References symtab_node::alias, symtab_node::aux, AVAIL_INTERPOSABLE, symtab_node::binds_to_current_def_p(), cgraph_edge::callee, cgraph_node::callees, cgraph_edge::caller, cgraph_edge::can_throw_external, symtab_node::decl, cgraph_node::dump_cgraph(), dump_file, symtab_node::dump_name(), cgraph_indirect_call_info::ecf_flags, ECF_NOTHROW, free(), funct_state_summaries, cgraph_node::get_availability(), i, ignore_edge_for_nothrow(), cgraph_node::indirect_calls, cgraph_edge::indirect_info, cgraph_node::inlined_to, ipa_free_postorder_info(), ipa_print_order(), ipa_reduced_postorder(), cgraph_edge::next_callee, ipa_dfs_info::next_cycle, opt_for_fn, cgraph_node::set_nothrow_flag(), symtab, TREE_NOTHROW, and y.

propagate_pure_const()

bool propagate_pure_const ( void )

static

Produce transitive closure over the callgraph and compute pure/const
attributes.   

References symtab_node::alias, symtab_node::aux, AVAIL_INTERPOSABLE, better_state(), builtin_safe_for_const_function_p(), cgraph_edge::callee, cgraph_node::callees, cgraph_edge::caller, ipa_ref::cannot_lead_to_return(), cgraph_edge::cannot_lead_to_return_p(), count, symtab_node::decl, cgraph_node::dump_cgraph(), dump_file, dump_flags, symtab_node::dump_name(), cgraph_indirect_call_info::ecf_flags, flags_from_decl_or_type(), free(), funct_state_summaries, gcc_unreachable, cgraph_node::get_availability(), i, ignore_edge_for_pure_const(), cgraph_node::indirect_calls, cgraph_edge::indirect_info, cgraph_node::inlined_to, IPA_CONST, ipa_free_postorder_info(), ipa_make_function_const(), ipa_make_function_pure(), IPA_NEITHER, ipa_print_order(), IPA_PURE, ipa_reduced_postorder(), IPA_REF_ADDR, IPA_REF_LOAD, IPA_REF_STORE, symtab_node::iterate_reference(), cgraph_edge::next_callee, ipa_dfs_info::next_cycle, cgraph_node::nonfreeing_fn, NULL, pure_const_names, cgraph_edge::recursive_p(), ipa_ref::referred, self_recursive_p(), state_from_flags(), symtab, TDF_DETAILS, TREE_READONLY, ipa_ref::use, worse_state(), and y.

pure_const_generate_summary()

void pure_const_generate_summary ( void )

static

Analyze each function in the cgraph to see if it is locally PURE or
CONST.   

References a, analyze_function(), current_pass, symtab_node::decl, FOR_EACH_DEFINED_FUNCTION, free(), funct_state_summaries, and opt_for_fn.

pure_const_read_summary()

void pure_const_read_summary ( void )

static

Deserialize the ipa info for lto.   

References bp_unpack_value(), count, current_pass, symtab_node::decl, dump_file, symtab_node::dump_name(), dyn_cast(), ECF_CONST, ECF_NOTHROW, ECF_PURE, flags_from_decl_or_type(), funct_state_summaries, i, lto_create_simple_input_block(), lto_destroy_simple_input_block(), lto_get_file_decl_data(), LTO_section_ipa_pure_const, lto_symtab_encoder_deref(), malloc_state_names, pure_const_names, streamer_read_bitpack(), streamer_read_uhwi(), and lto_file_decl_data::symtab_node_encoder.

pure_const_write_summary()

void pure_const_write_summary ( void )

static

Serialize the ipa info for lto.   

References bitpack_create(), bp_pack_value(), funct_state_d::can_free, funct_state_d::can_throw, count, lto_simple_output_block::decl_state, symtab_node::definition, funct_state_summaries, funct_state_d::looping, funct_state_d::looping_previously_known, lsei_cgraph_node(), lsei_end_p(), lsei_next_function_in_partition(), lsei_start_function_in_partition(), lto_create_simple_output_block(), lto_destroy_simple_output_block(), lto_get_out_decl_state(), LTO_section_ipa_pure_const, lto_symtab_encoder_encode(), lto_simple_output_block::main_stream, funct_state_d::malloc_state, NULL, funct_state_d::pure_const_state, funct_state_d::state_previously_known, streamer_write_bitpack(), streamer_write_uhwi_stream(), and lto_out_decl_state::symtab_node_encoder.

self_recursive_p()

bool self_recursive_p ( struct cgraph_node * node )

static

Return true if NODE is self recursive function.
Indirectly recursive functions appears as non-trivial strongly
connected components, so we need to care about self recursion
only.   

References cgraph_edge::callee, cgraph_node::callees, cgraph_node::function_symbol(), and cgraph_edge::next_callee.

Referenced by propagate_pure_const().

skip_function_for_local_pure_const()

bool skip_function_for_local_pure_const ( struct cgraph_node * node )

static

Return true if function should be skipped for local pure const analysis.   

References AVAIL_INTERPOSABLE, dump_file, function_called_by_processed_nodes_p(), cgraph_node::get_availability(), and symtab_node::has_aliases_p().

Referenced by ipa_make_function_const(), and ipa_make_function_pure().

state_from_flags()

void state_from_flags ( enum pure_const_state_e * state, bool * looping, int flags, bool cannot_lead_to_return )

static

compute state based on ECF FLAGS and store to STATE and LOOPING.   

References dump_file, dump_flags, ECF_CONST, ECF_LOOPING_CONST_OR_PURE, ECF_PURE, IPA_CONST, IPA_NEITHER, IPA_PURE, and TDF_DETAILS.

Referenced by analyze_function(), check_call(), and propagate_pure_const().

suggest_attribute()

hash_set< tree > * suggest_attribute ( diagnostic_option_id option, tree decl, bool known_finite, hash_set< tree > * warned_about, const char * attrib_name )

static

Emit suggestion about attribute ATTRIB_NAME for DECL.  KNOWN_FINITE
is true if the function is known to be finite.  The diagnostic is
controlled by OPTION.  WARNED_ABOUT is a hash_set<tree> unique for
OPTION, this function may initialize it and it is always returned
by the function.   

References hash_set< KeyId, Lazy, Traits >::add(), hash_set< KeyId, Lazy, Traits >::contains(), DECL_SOURCE_LOCATION, function_always_visible_to_compiler_p(), G_, global_options, option(), option_enabled(), lang_hooks::option_lang_mask, TREE_THIS_VOLATILE, and warning_at().

Referenced by warn_function_cold(), warn_function_const(), warn_function_malloc(), warn_function_noreturn(), warn_function_pure(), and warn_function_returns_nonnull().

warn_function_cold()

void warn_function_cold

(

tree

decl

)

In ipa-pure-const.cc    

References suggest_attribute().

Referenced by compute_function_frequency().

warn_function_const()

void warn_function_const ( tree decl, bool known_finite )

static

Emit suggestion about __attribute_((const)) for DECL.  KNOWN_FINITE
is true if the function is known to be finite.   

References suggest_attribute(), TREE_TYPE, and VOID_TYPE_P.

Referenced by ipa_make_function_const().

warn_function_malloc()

void warn_function_malloc ( tree decl )

static

Emit suggestion about __attribute__((malloc)) for DECL.   

References suggest_attribute().

Referenced by propagate_malloc().

warn_function_noreturn()

void warn_function_noreturn ( tree decl )

static

Emit suggestion about __attribute__((noreturn)) for DECL.   

References lang_hooks::missing_noreturn_ok_p, suggest_attribute(), and targetm.

warn_function_pure()

void warn_function_pure ( tree decl, bool known_finite )

static

Emit suggestion about __attribute_((pure)) for DECL.  KNOWN_FINITE
is true if the function is known to be finite.   

References suggest_attribute(), TREE_TYPE, and VOID_TYPE_P.

Referenced by ipa_make_function_pure().

warn_function_returns_nonnull()

void warn_function_returns_nonnull

(

tree

decl

)

References suggest_attribute().

Referenced by execute_ranger_vrp().

worse_state()

void worse_state ( enum pure_const_state_e * state, bool * looping, enum pure_const_state_e state2, bool looping2, struct symtab_node * from, struct symtab_node * to )

inlinestatic

Merge STATE and STATE2 and LOOPING and LOOPING2 and store
into STATE and LOOPING worse of the two variants.
N is the actual node called.   

References symtab_node::binds_to_current_def_p(), symtab_node::decl, dump_file, dump_flags, symtab_node::dump_name(), IPA_CONST, IPA_PURE, MAX, TDF_DETAILS, and TREE_READONLY.

Referenced by check_call(), and propagate_pure_const().

Variable Documentation

funct_state_summaries

funct_state_summary_t* funct_state_summaries = NULL

static

Referenced by dump_malloc_lattice(), funct_state_summary_t::insert(), propagate_malloc(), propagate_nothrow(), propagate_pure_const(), pure_const_generate_summary(), pure_const_read_summary(), and pure_const_write_summary().

malloc_state_names

const char* malloc_state_names[] = {"malloc_top", "malloc", "malloc_bottom"}

static

Referenced by dump_malloc_lattice(), and pure_const_read_summary().

pure_const_names

const char* pure_const_names[3] = {"const", "pure", "neither"}

static

Referenced by propagate_pure_const(), and pure_const_read_summary().