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|
/* Classes for purging state at function_points.
Copyright (C) 2019-2024 Free Software Foundation, Inc.
Contributed by David Malcolm <dmalcolm@redhat.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/>. */
#include "config.h"
#define INCLUDE_MEMORY
#define INCLUDE_VECTOR
#include "system.h"
#include "coretypes.h"
#include "tree.h"
#include "timevar.h"
#include "tree-ssa-alias.h"
#include "function.h"
#include "basic-block.h"
#include "gimple.h"
#include "stringpool.h"
#include "tree-vrp.h"
#include "gimple-ssa.h"
#include "tree-ssanames.h"
#include "tree-phinodes.h"
#include "options.h"
#include "ssa-iterators.h"
#include "diagnostic-core.h"
#include "gimple-pretty-print.h"
#include "analyzer/analyzer.h"
#include "analyzer/call-string.h"
#include "analyzer/supergraph.h"
#include "analyzer/program-point.h"
#include "analyzer/analyzer-logging.h"
#include "analyzer/state-purge.h"
#include "analyzer/store.h"
#include "analyzer/region-model.h"
#include "gimple-walk.h"
#include "cgraph.h"
#if ENABLE_ANALYZER
/* Given NODE at an access, determine if this access is within
a decl that could be consider for purging, and if so, return the decl. */
static tree
get_candidate_for_purging (tree node)
{
tree iter = node;
while (1)
switch (TREE_CODE (iter))
{
default:
return NULL_TREE;
case ADDR_EXPR:
case MEM_REF:
case COMPONENT_REF:
iter = TREE_OPERAND (iter, 0);
continue;
case VAR_DECL:
if (is_global_var (iter))
return NULL_TREE;
else
return iter;
case PARM_DECL:
case RESULT_DECL:
return iter;
}
}
/* Class-based handler for walk_stmt_load_store_addr_ops at a particular
function_point, for populating the worklists within a state_purge_map. */
class gimple_op_visitor : public log_user
{
public:
gimple_op_visitor (state_purge_map *map,
const function_point &point,
const function &fun)
: log_user (map->get_logger ()),
m_map (map),
m_point (point),
m_fun (fun)
{}
bool on_load (gimple *stmt, tree base, tree op)
{
LOG_FUNC (get_logger ());
if (get_logger ())
{
pretty_printer pp;
pp_gimple_stmt_1 (&pp, stmt, 0, (dump_flags_t)0);
log ("on_load: %s; base: %qE, op: %qE",
pp_formatted_text (&pp), base, op);
}
if (tree node = get_candidate_for_purging (base))
add_needed (node);
return true;
}
bool on_store (gimple *stmt, tree base, tree op)
{
LOG_FUNC (get_logger ());
if (get_logger ())
{
pretty_printer pp;
pp_gimple_stmt_1 (&pp, stmt, 0, (dump_flags_t)0);
log ("on_store: %s; base: %qE, op: %qE",
pp_formatted_text (&pp), base, op);
}
return true;
}
bool on_addr (gimple *stmt, tree base, tree op)
{
LOG_FUNC (get_logger ());
if (get_logger ())
{
pretty_printer pp;
pp_gimple_stmt_1 (&pp, stmt, 0, (dump_flags_t)0);
log ("on_addr: %s; base: %qE, op: %qE",
pp_formatted_text (&pp), base, op);
}
if (TREE_CODE (op) != ADDR_EXPR)
return true;
if (tree node = get_candidate_for_purging (base))
{
add_needed (node);
add_pointed_to (node);
}
return true;
}
private:
void add_needed (tree decl)
{
gcc_assert (get_candidate_for_purging (decl) == decl);
state_purge_per_decl &data
= get_or_create_data_for_decl (decl);
data.add_needed_at (m_point);
/* Handle calls: if we're seeing a use at a call, then add a use at the
"after-supernode" point (in case of interprocedural call superedges). */
if (m_point.final_stmt_p ())
data.add_needed_at (m_point.get_next ());
}
void add_pointed_to (tree decl)
{
gcc_assert (get_candidate_for_purging (decl) == decl);
get_or_create_data_for_decl (decl).add_pointed_to_at (m_point);
}
state_purge_per_decl &
get_or_create_data_for_decl (tree decl)
{
return m_map->get_or_create_data_for_decl (m_fun, decl);
}
state_purge_map *m_map;
const function_point &m_point;
const function &m_fun;
};
static bool
my_load_cb (gimple *stmt, tree base, tree op, void *user_data)
{
gimple_op_visitor *x = (gimple_op_visitor *)user_data;
return x->on_load (stmt, base, op);
}
static bool
my_store_cb (gimple *stmt, tree base, tree op, void *user_data)
{
gimple_op_visitor *x = (gimple_op_visitor *)user_data;
return x->on_store (stmt, base, op);
}
static bool
my_addr_cb (gimple *stmt, tree base, tree op, void *user_data)
{
gimple_op_visitor *x = (gimple_op_visitor *)user_data;
return x->on_addr (stmt, base, op);
}
/* state_purge_map's ctor. Walk all SSA names in all functions, building
a state_purge_per_ssa_name instance for each.
Also, walk all loads and address-taken ops of local variables, building
a state_purge_per_decl as appropriate. */
state_purge_map::state_purge_map (const supergraph &sg,
region_model_manager *mgr,
logger *logger)
: log_user (logger), m_sg (sg)
{
LOG_FUNC (logger);
auto_timevar tv (TV_ANALYZER_STATE_PURGE);
cgraph_node *node;
FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node)
{
function *fun = node->get_fun ();
gcc_assert (fun);
if (logger)
log ("function: %s", function_name (fun));
tree name;
unsigned int i;;
FOR_EACH_SSA_NAME (i, name, fun)
{
/* For now, don't bother tracking the .MEM SSA names. */
if (tree var = SSA_NAME_VAR (name))
if (TREE_CODE (var) == VAR_DECL)
if (VAR_DECL_IS_VIRTUAL_OPERAND (var))
continue;
m_ssa_map.put (name, new state_purge_per_ssa_name (*this, name, *fun));
}
}
/* Find all uses of local vars.
We iterate through all function points, finding loads, stores, and
address-taken operations on locals, building a pair of worklists. */
for (auto snode : sg.m_nodes)
{
if (logger)
log ("SN: %i", snode->m_index);
/* We ignore m_returning_call and phi nodes. */
gimple *stmt;
unsigned i;
FOR_EACH_VEC_ELT (snode->m_stmts, i, stmt)
{
function *fun = snode->get_function ();
gcc_assert (fun);
function_point point (function_point::before_stmt (snode, i));
gimple_op_visitor v (this, point, *fun);
walk_stmt_load_store_addr_ops (stmt, &v,
my_load_cb, my_store_cb, my_addr_cb);
}
}
/* Now iterate through the m_decl_map, processing each pair of worklists. */
for (state_purge_map::decl_iterator iter = begin_decls ();
iter != end_decls ();
++iter)
{
state_purge_per_decl *per_decl_data = (*iter).second;
per_decl_data->process_worklists (*this, mgr);
}
}
/* state_purge_map's dtor. */
state_purge_map::~state_purge_map ()
{
for (auto iter : m_ssa_map)
delete iter.second;
for (auto iter : m_decl_map)
delete iter.second;
}
/* Get the state_purge_per_decl for local DECL within FUN, creating it
if necessary. */
state_purge_per_decl &
state_purge_map::get_or_create_data_for_decl (const function &fun, tree decl)
{
if (state_purge_per_decl **slot
= const_cast <decl_map_t&> (m_decl_map).get (decl))
return **slot;
state_purge_per_decl *result = new state_purge_per_decl (*this, decl, fun);
m_decl_map.put (decl, result);
return *result;
}
/* class state_purge_per_ssa_name : public state_purge_per_tree. */
/* state_purge_per_ssa_name's ctor.
Locate all uses of VAR within FUN.
Walk backwards from each use, marking program points, until
we reach the def stmt, populating m_points_needing_var.
We have to track program points rather than
just stmts since there could be empty basic blocks on the way. */
state_purge_per_ssa_name::state_purge_per_ssa_name (const state_purge_map &map,
tree name,
const function &fun)
: state_purge_per_tree (fun), m_points_needing_name (), m_name (name)
{
LOG_FUNC (map.get_logger ());
if (map.get_logger ())
{
map.log ("SSA name: %qE within %qD", name, fun.decl);
/* Show def stmt. */
const gimple *def_stmt = SSA_NAME_DEF_STMT (name);
pretty_printer pp;
pp_gimple_stmt_1 (&pp, def_stmt, 0, (dump_flags_t)0);
map.log ("def stmt: %s", pp_formatted_text (&pp));
}
auto_vec<function_point> worklist;
/* Add all immediate uses of name to the worklist.
Compare with debug_immediate_uses. */
imm_use_iterator iter;
use_operand_p use_p;
FOR_EACH_IMM_USE_FAST (use_p, iter, name)
{
if (USE_STMT (use_p))
{
const gimple *use_stmt = USE_STMT (use_p);
if (map.get_logger ())
{
pretty_printer pp;
pp_gimple_stmt_1 (&pp, use_stmt, 0, (dump_flags_t)0);
map.log ("used by stmt: %s", pp_formatted_text (&pp));
}
if (is_gimple_debug (use_stmt))
{
/* We skipped debug stmts when building the supergraph,
so ignore them now. */
if (map.get_logger ())
map.log ("skipping debug stmt");
continue;
}
const supernode *snode
= map.get_sg ().get_supernode_for_stmt (use_stmt);
/* If it's a use within a phi node, then we care about
which in-edge we came from. */
if (use_stmt->code == GIMPLE_PHI)
{
for (gphi_iterator gpi
= const_cast<supernode *> (snode)->start_phis ();
!gsi_end_p (gpi); gsi_next (&gpi))
{
gphi *phi = gpi.phi ();
if (phi == use_stmt)
{
/* Find arguments (and thus in-edges) which use NAME. */
for (unsigned arg_idx = 0;
arg_idx < gimple_phi_num_args (phi);
++arg_idx)
{
if (name == gimple_phi_arg (phi, arg_idx)->def)
{
edge in_edge = gimple_phi_arg_edge (phi, arg_idx);
const superedge *in_sedge
= map.get_sg ().get_edge_for_cfg_edge (in_edge);
function_point point
= function_point::before_supernode
(snode, in_sedge);
add_to_worklist (point, &worklist,
map.get_logger ());
m_points_needing_name.add (point);
}
}
}
}
}
else
{
function_point point = before_use_stmt (map, use_stmt);
add_to_worklist (point, &worklist, map.get_logger ());
m_points_needing_name.add (point);
/* We also need to add uses for conditionals and switches,
where the stmt "happens" at the after_supernode, for filtering
the out-edges. */
if (use_stmt == snode->get_last_stmt ())
{
if (map.get_logger ())
map.log ("last stmt in BB");
function_point point
= function_point::after_supernode (snode);
add_to_worklist (point, &worklist, map.get_logger ());
m_points_needing_name.add (point);
}
else
if (map.get_logger ())
map.log ("not last stmt in BB");
}
}
}
/* Process worklist by walking backwards until we reach the def stmt. */
{
log_scope s (map.get_logger (), "processing worklist");
while (worklist.length () > 0)
{
function_point point = worklist.pop ();
process_point (point, &worklist, map);
}
}
if (map.get_logger ())
{
map.log ("%qE in %qD is needed to process:", name, fun.decl);
/* Log m_points_needing_name, sorting it to avoid churn when comparing
dumps. */
auto_vec<function_point> points;
for (point_set_t::iterator iter = m_points_needing_name.begin ();
iter != m_points_needing_name.end ();
++iter)
points.safe_push (*iter);
points.qsort (function_point::cmp_ptr);
unsigned i;
function_point *point;
FOR_EACH_VEC_ELT (points, i, point)
{
map.start_log_line ();
map.get_logger ()->log_partial (" point: ");
point->print (map.get_logger ()->get_printer (), format (false));
map.end_log_line ();
}
}
}
/* Return true if the SSA name is needed at POINT. */
bool
state_purge_per_ssa_name::needed_at_point_p (const function_point &point) const
{
return const_cast <point_set_t &> (m_points_needing_name).contains (point);
}
/* Get the function_point representing immediately before USE_STMT.
Subroutine of ctor. */
function_point
state_purge_per_ssa_name::before_use_stmt (const state_purge_map &map,
const gimple *use_stmt)
{
gcc_assert (use_stmt->code != GIMPLE_PHI);
const supernode *supernode
= map.get_sg ().get_supernode_for_stmt (use_stmt);
unsigned int stmt_idx = supernode->get_stmt_index (use_stmt);
return function_point::before_stmt (supernode, stmt_idx);
}
/* Add POINT to *WORKLIST if the point has not already been seen.
Subroutine of ctor. */
void
state_purge_per_ssa_name::add_to_worklist (const function_point &point,
auto_vec<function_point> *worklist,
logger *logger)
{
LOG_FUNC (logger);
if (logger)
{
logger->start_log_line ();
logger->log_partial ("point: '");
point.print (logger->get_printer (), format (false));
logger->log_partial ("' for worklist for %qE", m_name);
logger->end_log_line ();
}
gcc_assert (point.get_function () == &get_function ());
if (point.get_from_edge ())
gcc_assert (point.get_from_edge ()->get_kind () == SUPEREDGE_CFG_EDGE);
if (m_points_needing_name.contains (point))
{
if (logger)
logger->log ("already seen for %qE", m_name);
}
else
{
if (logger)
logger->log ("not seen; adding to worklist for %qE", m_name);
m_points_needing_name.add (point);
worklist->safe_push (point);
}
}
/* Return true iff NAME is used by any of the phi nodes in SNODE
when processing the in-edge with PHI_ARG_IDX. */
static bool
name_used_by_phis_p (tree name, const supernode *snode,
size_t phi_arg_idx)
{
gcc_assert (TREE_CODE (name) == SSA_NAME);
for (gphi_iterator gpi
= const_cast<supernode *> (snode)->start_phis ();
!gsi_end_p (gpi); gsi_next (&gpi))
{
gphi *phi = gpi.phi ();
if (gimple_phi_arg_def (phi, phi_arg_idx) == name)
return true;
}
return false;
}
/* Process POINT, popped from WORKLIST.
Iterate over predecessors of POINT, adding to WORKLIST. */
void
state_purge_per_ssa_name::process_point (const function_point &point,
auto_vec<function_point> *worklist,
const state_purge_map &map)
{
logger *logger = map.get_logger ();
LOG_FUNC (logger);
if (logger)
{
logger->start_log_line ();
logger->log_partial ("considering point: '");
point.print (logger->get_printer (), format (false));
logger->log_partial ("' for %qE", m_name);
logger->end_log_line ();
}
gimple *def_stmt = SSA_NAME_DEF_STMT (m_name);
const supernode *snode = point.get_supernode ();
switch (point.get_kind ())
{
default:
gcc_unreachable ();
case PK_ORIGIN:
break;
case PK_BEFORE_SUPERNODE:
{
for (gphi_iterator gpi
= const_cast<supernode *> (snode)->start_phis ();
!gsi_end_p (gpi); gsi_next (&gpi))
{
gcc_assert (point.get_from_edge ());
const cfg_superedge *cfg_sedge
= point.get_from_edge ()->dyn_cast_cfg_superedge ();
gcc_assert (cfg_sedge);
gphi *phi = gpi.phi ();
/* Are we at the def-stmt for m_name? */
if (phi == def_stmt)
{
if (name_used_by_phis_p (m_name, snode,
cfg_sedge->get_phi_arg_idx ()))
{
if (logger)
logger->log ("name in def stmt used within phis;"
" continuing");
}
else
{
if (logger)
logger->log ("name in def stmt not used within phis;"
" terminating");
return;
}
}
}
/* Add given pred to worklist. */
if (point.get_from_edge ())
{
gcc_assert (point.get_from_edge ()->m_src);
add_to_worklist
(function_point::after_supernode (point.get_from_edge ()->m_src),
worklist, logger);
}
else
{
/* Add any intraprocedually edge for a call. */
if (snode->m_returning_call)
{
gcall *returning_call = snode->m_returning_call;
cgraph_edge *cedge
= supergraph_call_edge (snode->m_fun,
returning_call);
if(cedge)
{
superedge *sedge
= map.get_sg ().get_intraprocedural_edge_for_call (cedge);
gcc_assert (sedge);
add_to_worklist
(function_point::after_supernode (sedge->m_src),
worklist, logger);
}
else
{
supernode *callernode
= map.get_sg ().get_supernode_for_stmt (returning_call);
gcc_assert (callernode);
add_to_worklist
(function_point::after_supernode (callernode),
worklist, logger);
}
}
}
}
break;
case PK_BEFORE_STMT:
{
if (def_stmt == point.get_stmt ())
{
if (logger)
logger->log ("def stmt; terminating");
return;
}
if (point.get_stmt_idx () > 0)
add_to_worklist (function_point::before_stmt
(snode, point.get_stmt_idx () - 1),
worklist, logger);
else
{
/* Add before_supernode to worklist. This captures the in-edge,
so we have to do it once per in-edge. */
unsigned i;
superedge *pred;
FOR_EACH_VEC_ELT (snode->m_preds, i, pred)
add_to_worklist (function_point::before_supernode (snode,
pred),
worklist, logger);
}
}
break;
case PK_AFTER_SUPERNODE:
{
if (snode->m_stmts.length ())
add_to_worklist
(function_point::before_stmt (snode,
snode->m_stmts.length () - 1),
worklist, logger);
else
{
/* Add before_supernode to worklist. This captures the in-edge,
so we have to do it once per in-edge. */
unsigned i;
superedge *pred;
FOR_EACH_VEC_ELT (snode->m_preds, i, pred)
add_to_worklist (function_point::before_supernode (snode,
pred),
worklist, logger);
/* If it's the initial BB, add it, to ensure that we
have "before supernode" for the initial ENTRY block, and don't
erroneously purge SSA names for initial values of parameters. */
if (snode->entry_p ())
{
add_to_worklist
(function_point::before_supernode (snode, NULL),
worklist, logger);
}
}
}
break;
}
}
/* class state_purge_per_decl : public state_purge_per_tree. */
/* state_purge_per_decl's ctor. */
state_purge_per_decl::state_purge_per_decl (const state_purge_map &map,
tree decl,
const function &fun)
: state_purge_per_tree (fun),
m_decl (decl)
{
/* The RESULT_DECL is always needed at the end of its function. */
if (TREE_CODE (decl) == RESULT_DECL)
{
supernode *exit_snode = map.get_sg ().get_node_for_function_exit (fun);
add_needed_at (function_point::after_supernode (exit_snode));
}
}
/* Mark the value of the decl (or a subvalue within it) as being needed
at POINT. */
void
state_purge_per_decl::add_needed_at (const function_point &point)
{
m_points_needing_decl.add (point);
}
/* Mark that a pointer to the decl (or a region within it) is taken
at POINT. */
void
state_purge_per_decl::add_pointed_to_at (const function_point &point)
{
m_points_taking_address.add (point);
}
/* Process the worklists for this decl:
(a) walk backwards from points where we know the value of the decl
is needed, marking points until we get to a stmt that fully overwrites
the decl.
(b) walk forwards from points where the address of the decl is taken,
marking points as potentially needing the value of the decl. */
void
state_purge_per_decl::process_worklists (const state_purge_map &map,
region_model_manager *mgr)
{
logger *logger = map.get_logger ();
LOG_SCOPE (logger);
if (logger)
logger->log ("decl: %qE within %qD", m_decl, get_fndecl ());
/* Worklist for walking backwards from uses. */
{
auto_vec<function_point> worklist;
point_set_t seen;
/* Add all uses of the decl to the worklist. */
for (auto iter : m_points_needing_decl)
worklist.safe_push (iter);
region_model model (mgr);
model.push_frame (get_function (), NULL, NULL);
/* Process worklist by walking backwards until we reach a stmt
that fully overwrites the decl. */
{
log_scope s (logger, "processing worklist");
while (worklist.length () > 0)
{
function_point point = worklist.pop ();
process_point_backwards (point, &worklist, &seen, map, model);
}
}
}
/* Worklist for walking forwards from address-taken points. */
{
auto_vec<function_point> worklist;
point_set_t seen;
/* Add all uses of the decl to the worklist. */
for (auto iter : m_points_taking_address)
{
worklist.safe_push (iter);
/* Add to m_points_needing_decl (now that we traversed
it above for the backward worklist). */
m_points_needing_decl.add (iter);
}
/* Process worklist by walking forwards. */
{
log_scope s (logger, "processing worklist");
while (worklist.length () > 0)
{
function_point point = worklist.pop ();
process_point_forwards (point, &worklist, &seen, map);
}
}
}
}
/* Add POINT to *WORKLIST if the point is not already in *seen.
Add newly seen points to *SEEN and to m_points_needing_name. */
void
state_purge_per_decl::add_to_worklist (const function_point &point,
auto_vec<function_point> *worklist,
point_set_t *seen,
logger *logger)
{
LOG_FUNC (logger);
if (logger)
{
logger->start_log_line ();
logger->log_partial ("point: '");
point.print (logger->get_printer (), format (false));
logger->log_partial ("' for worklist for %qE", m_decl);
logger->end_log_line ();
}
gcc_assert (point.get_function () == &get_function ());
if (point.get_from_edge ())
gcc_assert (point.get_from_edge ()->get_kind () == SUPEREDGE_CFG_EDGE);
if (seen->contains (point))
{
if (logger)
logger->log ("already seen for %qE", m_decl);
}
else
{
if (logger)
logger->log ("not seen; adding to worklist for %qE", m_decl);
m_points_needing_decl.add (point);
seen->add (point);
worklist->safe_push (point);
}
}
/* Determine if REG_A and REG_B express writing to exactly the same
set of bits.
For example, when "s.field" is the only field of "s", and there's no
padding, this should return true. */
static bool
same_binding_p (const region *reg_a, const region *reg_b,
store_manager *store_mgr)
{
if (reg_a->get_base_region () != reg_b->get_base_region ())
return false;
if (reg_a->empty_p ())
return false;
const binding_key *bind_key_a = binding_key::make (store_mgr, reg_a);
if (reg_b->empty_p ())
return false;
const binding_key *bind_key_b = binding_key::make (store_mgr, reg_b);
return bind_key_a == bind_key_b;
}
/* Return true if STMT fully overwrites DECL. */
static bool
fully_overwrites_p (const gimple *stmt, tree decl,
const region_model &model)
{
if (tree lhs = gimple_get_lhs (stmt))
{
/* Determine if LHS fully overwrites DECL.
We can't just check for equality; consider the case of
"s.field = EXPR;" where the stmt writes to the only field
of "s", and there's no padding. */
const region *lhs_reg = model.get_lvalue (lhs, NULL);
const region *decl_reg = model.get_lvalue (decl, NULL);
if (same_binding_p (lhs_reg, decl_reg,
model.get_manager ()->get_store_manager ()))
return true;
}
return false;
}
/* Process POINT, popped from *WORKLIST.
Iterate over predecessors of POINT, adding to *WORKLIST and *SEEN,
until we get to a stmt that fully overwrites the decl. */
void
state_purge_per_decl::
process_point_backwards (const function_point &point,
auto_vec<function_point> *worklist,
point_set_t *seen,
const state_purge_map &map,
const region_model &model)
{
logger *logger = map.get_logger ();
LOG_FUNC (logger);
if (logger)
{
logger->start_log_line ();
logger->log_partial ("considering point: '");
point.print (logger->get_printer (), format (false));
logger->log_partial ("' for %qE", m_decl);
logger->end_log_line ();
}
const supernode *snode = point.get_supernode ();
switch (point.get_kind ())
{
default:
gcc_unreachable ();
case PK_ORIGIN:
break;
case PK_BEFORE_SUPERNODE:
{
/* Add given pred to worklist. */
if (point.get_from_edge ())
{
gcc_assert (point.get_from_edge ()->m_src);
add_to_worklist
(function_point::after_supernode (point.get_from_edge ()->m_src),
worklist, seen, logger);
}
else
{
/* Add any intraprocedually edge for a call. */
if (snode->m_returning_call)
{
gcall *returning_call = snode->m_returning_call;
cgraph_edge *cedge
= supergraph_call_edge (snode->m_fun,
returning_call);
if(cedge)
{
superedge *sedge
= map.get_sg ().get_intraprocedural_edge_for_call (cedge);
gcc_assert (sedge);
add_to_worklist
(function_point::after_supernode (sedge->m_src),
worklist, seen, logger);
}
else
{
supernode *callernode
= map.get_sg ().get_supernode_for_stmt (returning_call);
gcc_assert (callernode);
add_to_worklist
(function_point::after_supernode (callernode),
worklist, seen, logger);
}
}
}
}
break;
case PK_BEFORE_STMT:
{
/* This is somewhat equivalent to how the SSA case handles
def-stmts. */
if (fully_overwrites_p (point.get_stmt (), m_decl, model)
/* ...but we mustn't be at a point that also consumes the
current value of the decl when it's generating the new
value, for cases such as
struct st s;
s = foo ();
s = bar (s);
where we want to make sure that we don't stop at the:
s = bar (s);
since otherwise we would erroneously purge the state of "s"
after:
s = foo ();
*/
&& !m_points_needing_decl.contains (point))
{
if (logger)
logger->log ("stmt fully overwrites %qE; terminating", m_decl);
return;
}
if (point.get_stmt_idx () > 0)
add_to_worklist (function_point::before_stmt
(snode, point.get_stmt_idx () - 1),
worklist, seen, logger);
else
{
/* Add before_supernode to worklist. This captures the in-edge,
so we have to do it once per in-edge. */
unsigned i;
superedge *pred;
FOR_EACH_VEC_ELT (snode->m_preds, i, pred)
add_to_worklist (function_point::before_supernode (snode,
pred),
worklist, seen, logger);
}
}
break;
case PK_AFTER_SUPERNODE:
{
if (snode->m_stmts.length ())
add_to_worklist
(function_point::before_stmt (snode,
snode->m_stmts.length () - 1),
worklist, seen, logger);
else
{
/* Add before_supernode to worklist. This captures the in-edge,
so we have to do it once per in-edge. */
unsigned i;
superedge *pred;
FOR_EACH_VEC_ELT (snode->m_preds, i, pred)
add_to_worklist (function_point::before_supernode (snode,
pred),
worklist, seen, logger);
}
}
break;
}
}
/* Process POINT, popped from *WORKLIST.
Iterate over successors of POINT, adding to *WORKLIST and *SEEN. */
void
state_purge_per_decl::
process_point_forwards (const function_point &point,
auto_vec<function_point> *worklist,
point_set_t *seen,
const state_purge_map &map)
{
logger *logger = map.get_logger ();
LOG_FUNC (logger);
if (logger)
{
logger->start_log_line ();
logger->log_partial ("considering point: '");
point.print (logger->get_printer (), format (false));
logger->log_partial ("' for %qE", m_decl);
logger->end_log_line ();
}
const supernode *snode = point.get_supernode ();
switch (point.get_kind ())
{
default:
case PK_ORIGIN:
gcc_unreachable ();
case PK_BEFORE_SUPERNODE:
{
function_point next = point.get_next ();
add_to_worklist (next, worklist, seen, logger);
}
break;
case PK_BEFORE_STMT:
{
/* Perhaps we should stop at a clobber of the decl,
but that ought to purge state for us explicitly. */
function_point next = point.get_next ();
add_to_worklist (next, worklist, seen, logger);
}
break;
case PK_AFTER_SUPERNODE:
{
/* Look at interprocedural out-edges. */
unsigned i;
superedge *succ;
FOR_EACH_VEC_ELT (snode->m_succs, i, succ)
{
enum edge_kind kind = succ->get_kind ();
if (kind == SUPEREDGE_CFG_EDGE
|| kind == SUPEREDGE_INTRAPROCEDURAL_CALL)
add_to_worklist (function_point::before_supernode (succ->m_dest,
succ),
worklist, seen, logger);
}
}
break;
}
}
/* Return true if the decl is needed at POINT. */
bool
state_purge_per_decl::needed_at_point_p (const function_point &point) const
{
return const_cast <point_set_t &> (m_points_needing_decl).contains (point);
}
/* class state_purge_annotator : public dot_annotator. */
/* Implementation of dot_annotator::add_node_annotations vfunc for
state_purge_annotator.
Add an additional record showing which names are purged on entry
to the supernode N. */
bool
state_purge_annotator::add_node_annotations (graphviz_out *gv,
const supernode &n,
bool within_table) const
{
if (m_map == NULL)
return false;
if (within_table)
return false;
pretty_printer *pp = gv->get_pp ();
pp_printf (pp, "annotation_for_node_%i", n.m_index);
pp_printf (pp, " [shape=none,margin=0,style=filled,fillcolor=%s,label=\"",
"lightblue");
pp_write_text_to_stream (pp);
/* Different in-edges mean different names need purging.
Determine which points to dump. */
auto_vec<function_point> points;
if (n.entry_p () || n.m_returning_call)
points.safe_push (function_point::before_supernode (&n, NULL));
else
for (auto inedge : n.m_preds)
points.safe_push (function_point::before_supernode (&n, inedge));
points.safe_push (function_point::after_supernode (&n));
for (auto & point : points)
{
point.print (pp, format (true));
pp_newline (pp);
print_needed (gv, point, false);
pp_newline (pp);
}
pp_string (pp, "\"];\n\n");
pp_flush (pp);
return false;
}
/* Print V to GV as a comma-separated list in braces, titling it with TITLE.
If WITHIN_TABLE is true, print it within a <TR>
Subroutine of state_purge_annotator::print_needed. */
static void
print_vec_of_names (graphviz_out *gv, const char *title,
const auto_vec<tree> &v, bool within_table)
{
pretty_printer *pp = gv->get_pp ();
tree name;
unsigned i;
if (within_table)
gv->begin_trtd ();
pp_printf (pp, "%s: {", title);
FOR_EACH_VEC_ELT (v, i, name)
{
if (i > 0)
pp_string (pp, ", ");
pp_printf (pp, "%qE", name);
}
pp_printf (pp, "}");
if (within_table)
{
pp_write_text_as_html_like_dot_to_stream (pp);
gv->end_tdtr ();
}
pp_newline (pp);
}
/* Implementation of dot_annotator::add_stmt_annotations for
state_purge_annotator.
Add text showing which names are purged at STMT. */
void
state_purge_annotator::add_stmt_annotations (graphviz_out *gv,
const gimple *stmt,
bool within_row) const
{
if (within_row)
return;
if (m_map == NULL)
return;
if (stmt->code == GIMPLE_PHI)
return;
pretty_printer *pp = gv->get_pp ();
pp_newline (pp);
const supernode *supernode = m_map->get_sg ().get_supernode_for_stmt (stmt);
unsigned int stmt_idx = supernode->get_stmt_index (stmt);
function_point before_stmt
(function_point::before_stmt (supernode, stmt_idx));
print_needed (gv, before_stmt, true);
}
/* Get the decls and SSA names needed and not-needed at POINT, and
print them to GV.
If WITHIN_TABLE is true, print them within <TR> elements. */
void
state_purge_annotator::print_needed (graphviz_out *gv,
const function_point &point,
bool within_table) const
{
auto_vec<tree> needed;
auto_vec<tree> not_needed;
for (state_purge_map::ssa_iterator iter = m_map->begin_ssas ();
iter != m_map->end_ssas ();
++iter)
{
tree name = (*iter).first;
state_purge_per_ssa_name *per_name_data = (*iter).second;
if (&per_name_data->get_function () == point.get_function ())
{
if (per_name_data->needed_at_point_p (point))
needed.safe_push (name);
else
not_needed.safe_push (name);
}
}
for (state_purge_map::decl_iterator iter = m_map->begin_decls ();
iter != m_map->end_decls ();
++iter)
{
tree decl = (*iter).first;
state_purge_per_decl *per_decl_data = (*iter).second;
if (&per_decl_data->get_function () == point.get_function ())
{
if (per_decl_data->needed_at_point_p (point))
needed.safe_push (decl);
else
not_needed.safe_push (decl);
}
}
print_vec_of_names (gv, "needed here", needed, within_table);
print_vec_of_names (gv, "not needed here", not_needed, within_table);
}
#endif /* #if ENABLE_ANALYZER */
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