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/* Interprocedural analyses.
Copyright (C) 2005-2021 Free Software Foundation, Inc.
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"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "rtl.h"
#include "tree.h"
#include "gimple.h"
#include "alloc-pool.h"
#include "tree-pass.h"
#include "ssa.h"
#include "tree-streamer.h"
#include "cgraph.h"
#include "diagnostic.h"
#include "fold-const.h"
#include "gimple-fold.h"
#include "tree-eh.h"
#include "calls.h"
#include "stor-layout.h"
#include "print-tree.h"
#include "gimplify.h"
#include "gimple-iterator.h"
#include "gimplify-me.h"
#include "gimple-walk.h"
#include "symbol-summary.h"
#include "ipa-prop.h"
#include "tree-cfg.h"
#include "tree-dfa.h"
#include "tree-inline.h"
#include "ipa-fnsummary.h"
#include "gimple-pretty-print.h"
#include "ipa-utils.h"
#include "dbgcnt.h"
#include "domwalk.h"
#include "builtins.h"
#include "tree-cfgcleanup.h"
#include "options.h"
#include "symtab-clones.h"
#include "attr-fnspec.h"
#include "gimple-range.h"
/* Function summary where the parameter infos are actually stored. */
ipa_node_params_t *ipa_node_params_sum = NULL;
function_summary <ipcp_transformation *> *ipcp_transformation_sum = NULL;
/* Edge summary for IPA-CP edge information. */
ipa_edge_args_sum_t *ipa_edge_args_sum;
/* Traits for a hash table for reusing already existing ipa_bits. */
struct ipa_bit_ggc_hash_traits : public ggc_cache_remove <ipa_bits *>
{
typedef ipa_bits *value_type;
typedef ipa_bits *compare_type;
static hashval_t
hash (const ipa_bits *p)
{
hashval_t t = (hashval_t) p->value.to_shwi ();
return iterative_hash_host_wide_int (p->mask.to_shwi (), t);
}
static bool
equal (const ipa_bits *a, const ipa_bits *b)
{
return a->value == b->value && a->mask == b->mask;
}
static const bool empty_zero_p = true;
static void
mark_empty (ipa_bits *&p)
{
p = NULL;
}
static bool
is_empty (const ipa_bits *p)
{
return p == NULL;
}
static bool
is_deleted (const ipa_bits *p)
{
return p == reinterpret_cast<const ipa_bits *> (1);
}
static void
mark_deleted (ipa_bits *&p)
{
p = reinterpret_cast<ipa_bits *> (1);
}
};
/* Hash table for avoid repeated allocations of equal ipa_bits. */
static GTY ((cache)) hash_table<ipa_bit_ggc_hash_traits> *ipa_bits_hash_table;
/* Traits for a hash table for reusing value_ranges used for IPA. Note that
the equiv bitmap is not hashed and is expected to be NULL. */
struct ipa_vr_ggc_hash_traits : public ggc_cache_remove <value_range *>
{
typedef value_range *value_type;
typedef value_range *compare_type;
static hashval_t
hash (const value_range *p)
{
inchash::hash hstate (p->kind ());
inchash::add_expr (p->min (), hstate);
inchash::add_expr (p->max (), hstate);
return hstate.end ();
}
static bool
equal (const value_range *a, const value_range *b)
{
return (a->equal_p (*b)
&& types_compatible_p (a->type (), b->type ()));
}
static const bool empty_zero_p = true;
static void
mark_empty (value_range *&p)
{
p = NULL;
}
static bool
is_empty (const value_range *p)
{
return p == NULL;
}
static bool
is_deleted (const value_range *p)
{
return p == reinterpret_cast<const value_range *> (1);
}
static void
mark_deleted (value_range *&p)
{
p = reinterpret_cast<value_range *> (1);
}
};
/* Hash table for avoid repeated allocations of equal value_ranges. */
static GTY ((cache)) hash_table<ipa_vr_ggc_hash_traits> *ipa_vr_hash_table;
/* Holders of ipa cgraph hooks: */
static struct cgraph_node_hook_list *function_insertion_hook_holder;
/* Description of a reference to an IPA constant. */
struct ipa_cst_ref_desc
{
/* Edge that corresponds to the statement which took the reference. */
struct cgraph_edge *cs;
/* Linked list of duplicates created when call graph edges are cloned. */
struct ipa_cst_ref_desc *next_duplicate;
/* Number of references in IPA structures, IPA_UNDESCRIBED_USE if the value
if out of control. */
int refcount;
};
/* Allocation pool for reference descriptions. */
static object_allocator<ipa_cst_ref_desc> ipa_refdesc_pool
("IPA-PROP ref descriptions");
/* Return true if DECL_FUNCTION_SPECIFIC_OPTIMIZATION of the decl associated
with NODE should prevent us from analyzing it for the purposes of IPA-CP. */
static bool
ipa_func_spec_opts_forbid_analysis_p (struct cgraph_node *node)
{
tree fs_opts = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (node->decl);
if (!fs_opts)
return false;
return !opt_for_fn (node->decl, optimize) || !opt_for_fn (node->decl, flag_ipa_cp);
}
/* Return index of the formal whose tree is PTREE in function which corresponds
to INFO. */
static int
ipa_get_param_decl_index_1 (vec<ipa_param_descriptor, va_gc> *descriptors,
tree ptree)
{
int i, count;
count = vec_safe_length (descriptors);
for (i = 0; i < count; i++)
if ((*descriptors)[i].decl_or_type == ptree)
return i;
return -1;
}
/* Return index of the formal whose tree is PTREE in function which corresponds
to INFO. */
int
ipa_get_param_decl_index (class ipa_node_params *info, tree ptree)
{
return ipa_get_param_decl_index_1 (info->descriptors, ptree);
}
/* Populate the param_decl field in parameter DESCRIPTORS that correspond to
NODE. */
static void
ipa_populate_param_decls (struct cgraph_node *node,
vec<ipa_param_descriptor, va_gc> &descriptors)
{
tree fndecl;
tree fnargs;
tree parm;
int param_num;
fndecl = node->decl;
gcc_assert (gimple_has_body_p (fndecl));
fnargs = DECL_ARGUMENTS (fndecl);
param_num = 0;
for (parm = fnargs; parm; parm = DECL_CHAIN (parm))
{
descriptors[param_num].decl_or_type = parm;
unsigned int cost = estimate_move_cost (TREE_TYPE (parm), true);
descriptors[param_num].move_cost = cost;
/* Watch overflow, move_cost is a bitfield. */
gcc_checking_assert (cost == descriptors[param_num].move_cost);
param_num++;
}
}
/* Return how many formal parameters FNDECL has. */
int
count_formal_params (tree fndecl)
{
tree parm;
int count = 0;
gcc_assert (gimple_has_body_p (fndecl));
for (parm = DECL_ARGUMENTS (fndecl); parm; parm = DECL_CHAIN (parm))
count++;
return count;
}
/* Return the declaration of Ith formal parameter of the function corresponding
to INFO. Note there is no setter function as this array is built just once
using ipa_initialize_node_params. */
void
ipa_dump_param (FILE *file, class ipa_node_params *info, int i)
{
fprintf (file, "param #%i", i);
if ((*info->descriptors)[i].decl_or_type)
{
fprintf (file, " ");
print_generic_expr (file, (*info->descriptors)[i].decl_or_type);
}
}
/* If necessary, allocate vector of parameter descriptors in info of NODE.
Return true if they were allocated, false if not. */
static bool
ipa_alloc_node_params (struct cgraph_node *node, int param_count)
{
ipa_node_params *info = ipa_node_params_sum->get_create (node);
if (!info->descriptors && param_count)
{
vec_safe_grow_cleared (info->descriptors, param_count, true);
return true;
}
else
return false;
}
/* Initialize the ipa_node_params structure associated with NODE by counting
the function parameters, creating the descriptors and populating their
param_decls. */
void
ipa_initialize_node_params (struct cgraph_node *node)
{
ipa_node_params *info = ipa_node_params_sum->get_create (node);
if (!info->descriptors
&& ipa_alloc_node_params (node, count_formal_params (node->decl)))
ipa_populate_param_decls (node, *info->descriptors);
}
/* Print the jump functions associated with call graph edge CS to file F. */
static void
ipa_print_node_jump_functions_for_edge (FILE *f, struct cgraph_edge *cs)
{
ipa_edge_args *args = ipa_edge_args_sum->get (cs);
int count = ipa_get_cs_argument_count (args);
for (int i = 0; i < count; i++)
{
struct ipa_jump_func *jump_func;
enum jump_func_type type;
jump_func = ipa_get_ith_jump_func (args, i);
type = jump_func->type;
fprintf (f, " param %d: ", i);
if (type == IPA_JF_UNKNOWN)
fprintf (f, "UNKNOWN\n");
else if (type == IPA_JF_CONST)
{
tree val = jump_func->value.constant.value;
fprintf (f, "CONST: ");
print_generic_expr (f, val);
if (TREE_CODE (val) == ADDR_EXPR
&& TREE_CODE (TREE_OPERAND (val, 0)) == CONST_DECL)
{
fprintf (f, " -> ");
print_generic_expr (f, DECL_INITIAL (TREE_OPERAND (val, 0)));
}
fprintf (f, "\n");
}
else if (type == IPA_JF_PASS_THROUGH)
{
fprintf (f, "PASS THROUGH: ");
fprintf (f, "%d, op %s",
jump_func->value.pass_through.formal_id,
get_tree_code_name(jump_func->value.pass_through.operation));
if (jump_func->value.pass_through.operation != NOP_EXPR)
{
fprintf (f, " ");
print_generic_expr (f, jump_func->value.pass_through.operand);
}
if (jump_func->value.pass_through.agg_preserved)
fprintf (f, ", agg_preserved");
fprintf (f, "\n");
}
else if (type == IPA_JF_ANCESTOR)
{
fprintf (f, "ANCESTOR: ");
fprintf (f, "%d, offset " HOST_WIDE_INT_PRINT_DEC,
jump_func->value.ancestor.formal_id,
jump_func->value.ancestor.offset);
if (jump_func->value.ancestor.agg_preserved)
fprintf (f, ", agg_preserved");
fprintf (f, "\n");
}
if (jump_func->agg.items)
{
struct ipa_agg_jf_item *item;
int j;
fprintf (f, " Aggregate passed by %s:\n",
jump_func->agg.by_ref ? "reference" : "value");
FOR_EACH_VEC_ELT (*jump_func->agg.items, j, item)
{
fprintf (f, " offset: " HOST_WIDE_INT_PRINT_DEC ", ",
item->offset);
fprintf (f, "type: ");
print_generic_expr (f, item->type);
fprintf (f, ", ");
if (item->jftype == IPA_JF_PASS_THROUGH)
fprintf (f, "PASS THROUGH: %d,",
item->value.pass_through.formal_id);
else if (item->jftype == IPA_JF_LOAD_AGG)
{
fprintf (f, "LOAD AGG: %d",
item->value.pass_through.formal_id);
fprintf (f, " [offset: " HOST_WIDE_INT_PRINT_DEC ", by %s],",
item->value.load_agg.offset,
item->value.load_agg.by_ref ? "reference"
: "value");
}
if (item->jftype == IPA_JF_PASS_THROUGH
|| item->jftype == IPA_JF_LOAD_AGG)
{
fprintf (f, " op %s",
get_tree_code_name (item->value.pass_through.operation));
if (item->value.pass_through.operation != NOP_EXPR)
{
fprintf (f, " ");
print_generic_expr (f, item->value.pass_through.operand);
}
}
else if (item->jftype == IPA_JF_CONST)
{
fprintf (f, "CONST: ");
print_generic_expr (f, item->value.constant);
}
else if (item->jftype == IPA_JF_UNKNOWN)
fprintf (f, "UNKNOWN: " HOST_WIDE_INT_PRINT_DEC " bits",
tree_to_uhwi (TYPE_SIZE (item->type)));
fprintf (f, "\n");
}
}
class ipa_polymorphic_call_context *ctx
= ipa_get_ith_polymorhic_call_context (args, i);
if (ctx && !ctx->useless_p ())
{
fprintf (f, " Context: ");
ctx->dump (dump_file);
}
if (jump_func->bits)
{
fprintf (f, " value: ");
print_hex (jump_func->bits->value, f);
fprintf (f, ", mask: ");
print_hex (jump_func->bits->mask, f);
fprintf (f, "\n");
}
else
fprintf (f, " Unknown bits\n");
if (jump_func->m_vr)
{
fprintf (f, " VR ");
fprintf (f, "%s[",
(jump_func->m_vr->kind () == VR_ANTI_RANGE) ? "~" : "");
print_decs (wi::to_wide (jump_func->m_vr->min ()), f);
fprintf (f, ", ");
print_decs (wi::to_wide (jump_func->m_vr->max ()), f);
fprintf (f, "]\n");
}
else
fprintf (f, " Unknown VR\n");
}
}
/* Print the jump functions of all arguments on all call graph edges going from
NODE to file F. */
void
ipa_print_node_jump_functions (FILE *f, struct cgraph_node *node)
{
struct cgraph_edge *cs;
fprintf (f, " Jump functions of caller %s:\n", node->dump_name ());
for (cs = node->callees; cs; cs = cs->next_callee)
{
fprintf (f, " callsite %s -> %s : \n",
node->dump_name (),
cs->callee->dump_name ());
if (!ipa_edge_args_info_available_for_edge_p (cs))
fprintf (f, " no arg info\n");
else
ipa_print_node_jump_functions_for_edge (f, cs);
}
for (cs = node->indirect_calls; cs; cs = cs->next_callee)
{
class cgraph_indirect_call_info *ii;
ii = cs->indirect_info;
if (ii->agg_contents)
fprintf (f, " indirect %s callsite, calling param %i, "
"offset " HOST_WIDE_INT_PRINT_DEC ", %s",
ii->member_ptr ? "member ptr" : "aggregate",
ii->param_index, ii->offset,
ii->by_ref ? "by reference" : "by_value");
else
fprintf (f, " indirect %s callsite, calling param %i, "
"offset " HOST_WIDE_INT_PRINT_DEC,
ii->polymorphic ? "polymorphic" : "simple", ii->param_index,
ii->offset);
if (cs->call_stmt)
{
fprintf (f, ", for stmt ");
print_gimple_stmt (f, cs->call_stmt, 0, TDF_SLIM);
}
else
fprintf (f, "\n");
if (ii->polymorphic)
ii->context.dump (f);
if (!ipa_edge_args_info_available_for_edge_p (cs))
fprintf (f, " no arg info\n");
else
ipa_print_node_jump_functions_for_edge (f, cs);
}
}
/* Print ipa_jump_func data structures of all nodes in the call graph to F. */
void
ipa_print_all_jump_functions (FILE *f)
{
struct cgraph_node *node;
fprintf (f, "\nJump functions:\n");
FOR_EACH_FUNCTION (node)
{
ipa_print_node_jump_functions (f, node);
}
}
/* Set jfunc to be a know-really nothing jump function. */
static void
ipa_set_jf_unknown (struct ipa_jump_func *jfunc)
{
jfunc->type = IPA_JF_UNKNOWN;
}
/* Set JFUNC to be a copy of another jmp (to be used by jump function
combination code). The two functions will share their rdesc. */
static void
ipa_set_jf_cst_copy (struct ipa_jump_func *dst,
struct ipa_jump_func *src)
{
gcc_checking_assert (src->type == IPA_JF_CONST);
dst->type = IPA_JF_CONST;
dst->value.constant = src->value.constant;
}
/* Set JFUNC to be a constant jmp function. */
static void
ipa_set_jf_constant (struct ipa_jump_func *jfunc, tree constant,
struct cgraph_edge *cs)
{
jfunc->type = IPA_JF_CONST;
jfunc->value.constant.value = unshare_expr_without_location (constant);
if (TREE_CODE (constant) == ADDR_EXPR
&& (TREE_CODE (TREE_OPERAND (constant, 0)) == FUNCTION_DECL
|| (TREE_CODE (TREE_OPERAND (constant, 0)) == VAR_DECL
&& TREE_STATIC (TREE_OPERAND (constant, 0)))))
{
struct ipa_cst_ref_desc *rdesc;
rdesc = ipa_refdesc_pool.allocate ();
rdesc->cs = cs;
rdesc->next_duplicate = NULL;
rdesc->refcount = 1;
jfunc->value.constant.rdesc = rdesc;
}
else
jfunc->value.constant.rdesc = NULL;
}
/* Set JFUNC to be a simple pass-through jump function. */
static void
ipa_set_jf_simple_pass_through (struct ipa_jump_func *jfunc, int formal_id,
bool agg_preserved)
{
jfunc->type = IPA_JF_PASS_THROUGH;
jfunc->value.pass_through.operand = NULL_TREE;
jfunc->value.pass_through.formal_id = formal_id;
jfunc->value.pass_through.operation = NOP_EXPR;
jfunc->value.pass_through.agg_preserved = agg_preserved;
}
/* Set JFUNC to be an unary pass through jump function. */
static void
ipa_set_jf_unary_pass_through (struct ipa_jump_func *jfunc, int formal_id,
enum tree_code operation)
{
jfunc->type = IPA_JF_PASS_THROUGH;
jfunc->value.pass_through.operand = NULL_TREE;
jfunc->value.pass_through.formal_id = formal_id;
jfunc->value.pass_through.operation = operation;
jfunc->value.pass_through.agg_preserved = false;
}
/* Set JFUNC to be an arithmetic pass through jump function. */
static void
ipa_set_jf_arith_pass_through (struct ipa_jump_func *jfunc, int formal_id,
tree operand, enum tree_code operation)
{
jfunc->type = IPA_JF_PASS_THROUGH;
jfunc->value.pass_through.operand = unshare_expr_without_location (operand);
jfunc->value.pass_through.formal_id = formal_id;
jfunc->value.pass_through.operation = operation;
jfunc->value.pass_through.agg_preserved = false;
}
/* Set JFUNC to be an ancestor jump function. */
static void
ipa_set_ancestor_jf (struct ipa_jump_func *jfunc, HOST_WIDE_INT offset,
int formal_id, bool agg_preserved)
{
jfunc->type = IPA_JF_ANCESTOR;
jfunc->value.ancestor.formal_id = formal_id;
jfunc->value.ancestor.offset = offset;
jfunc->value.ancestor.agg_preserved = agg_preserved;
}
/* Get IPA BB information about the given BB. FBI is the context of analyzis
of this function body. */
static struct ipa_bb_info *
ipa_get_bb_info (struct ipa_func_body_info *fbi, basic_block bb)
{
gcc_checking_assert (fbi);
return &fbi->bb_infos[bb->index];
}
/* Structure to be passed in between detect_type_change and
check_stmt_for_type_change. */
struct prop_type_change_info
{
/* Offset into the object where there is the virtual method pointer we are
looking for. */
HOST_WIDE_INT offset;
/* The declaration or SSA_NAME pointer of the base that we are checking for
type change. */
tree object;
/* Set to true if dynamic type change has been detected. */
bool type_maybe_changed;
};
/* Return true if STMT can modify a virtual method table pointer.
This function makes special assumptions about both constructors and
destructors which are all the functions that are allowed to alter the VMT
pointers. It assumes that destructors begin with assignment into all VMT
pointers and that constructors essentially look in the following way:
1) The very first thing they do is that they call constructors of ancestor
sub-objects that have them.
2) Then VMT pointers of this and all its ancestors is set to new values
corresponding to the type corresponding to the constructor.
3) Only afterwards, other stuff such as constructor of member sub-objects
and the code written by the user is run. Only this may include calling
virtual functions, directly or indirectly.
There is no way to call a constructor of an ancestor sub-object in any
other way.
This means that we do not have to care whether constructors get the correct
type information because they will always change it (in fact, if we define
the type to be given by the VMT pointer, it is undefined).
The most important fact to derive from the above is that if, for some
statement in the section 3, we try to detect whether the dynamic type has
changed, we can safely ignore all calls as we examine the function body
backwards until we reach statements in section 2 because these calls cannot
be ancestor constructors or destructors (if the input is not bogus) and so
do not change the dynamic type (this holds true only for automatically
allocated objects but at the moment we devirtualize only these). We then
must detect that statements in section 2 change the dynamic type and can try
to derive the new type. That is enough and we can stop, we will never see
the calls into constructors of sub-objects in this code. Therefore we can
safely ignore all call statements that we traverse.
*/
static bool
stmt_may_be_vtbl_ptr_store (gimple *stmt)
{
if (is_gimple_call (stmt))
return false;
if (gimple_clobber_p (stmt))
return false;
else if (is_gimple_assign (stmt))
{
tree lhs = gimple_assign_lhs (stmt);
if (!AGGREGATE_TYPE_P (TREE_TYPE (lhs)))
{
if (flag_strict_aliasing
&& !POINTER_TYPE_P (TREE_TYPE (lhs)))
return false;
if (TREE_CODE (lhs) == COMPONENT_REF
&& !DECL_VIRTUAL_P (TREE_OPERAND (lhs, 1)))
return false;
/* In the future we might want to use get_ref_base_and_extent to find
if there is a field corresponding to the offset and if so, proceed
almost like if it was a component ref. */
}
}
return true;
}
/* Callback of walk_aliased_vdefs and a helper function for detect_type_change
to check whether a particular statement may modify the virtual table
pointerIt stores its result into DATA, which points to a
prop_type_change_info structure. */
static bool
check_stmt_for_type_change (ao_ref *ao ATTRIBUTE_UNUSED, tree vdef, void *data)
{
gimple *stmt = SSA_NAME_DEF_STMT (vdef);
struct prop_type_change_info *tci = (struct prop_type_change_info *) data;
if (stmt_may_be_vtbl_ptr_store (stmt))
{
tci->type_maybe_changed = true;
return true;
}
else
return false;
}
/* See if ARG is PARAM_DECl describing instance passed by pointer
or reference in FUNCTION. Return false if the dynamic type may change
in between beggining of the function until CALL is invoked.
Generally functions are not allowed to change type of such instances,
but they call destructors. We assume that methods cannot destroy the THIS
pointer. Also as a special cases, constructor and destructors may change
type of the THIS pointer. */
static bool
param_type_may_change_p (tree function, tree arg, gimple *call)
{
/* Pure functions cannot do any changes on the dynamic type;
that require writting to memory. */
if (flags_from_decl_or_type (function) & (ECF_PURE | ECF_CONST))
return false;
/* We need to check if we are within inlined consturctor
or destructor (ideally we would have way to check that the
inline cdtor is actually working on ARG, but we don't have
easy tie on this, so punt on all non-pure cdtors.
We may also record the types of cdtors and once we know type
of the instance match them.
Also code unification optimizations may merge calls from
different blocks making return values unreliable. So
do nothing during late optimization. */
if (DECL_STRUCT_FUNCTION (function)->after_inlining)
return true;
if (TREE_CODE (arg) == SSA_NAME
&& SSA_NAME_IS_DEFAULT_DEF (arg)
&& TREE_CODE (SSA_NAME_VAR (arg)) == PARM_DECL)
{
/* Normal (non-THIS) argument. */
if ((SSA_NAME_VAR (arg) != DECL_ARGUMENTS (function)
|| TREE_CODE (TREE_TYPE (function)) != METHOD_TYPE)
/* THIS pointer of an method - here we want to watch constructors
and destructors as those definitely may change the dynamic
type. */
|| (TREE_CODE (TREE_TYPE (function)) == METHOD_TYPE
&& !DECL_CXX_CONSTRUCTOR_P (function)
&& !DECL_CXX_DESTRUCTOR_P (function)
&& (SSA_NAME_VAR (arg) == DECL_ARGUMENTS (function))))
{
/* Walk the inline stack and watch out for ctors/dtors. */
for (tree block = gimple_block (call); block && TREE_CODE (block) == BLOCK;
block = BLOCK_SUPERCONTEXT (block))
if (inlined_polymorphic_ctor_dtor_block_p (block, false))
return true;
return false;
}
}
return true;
}
/* Detect whether the dynamic type of ARG of COMP_TYPE has changed (before
callsite CALL) by looking for assignments to its virtual table pointer. If
it is, return true. ARG is the object itself (not a pointer
to it, unless dereferenced). BASE is the base of the memory access as
returned by get_ref_base_and_extent, as is the offset.
This is helper function for detect_type_change and detect_type_change_ssa
that does the heavy work which is usually unnecesary. */
static bool
detect_type_change_from_memory_writes (ipa_func_body_info *fbi, tree arg,
tree base, tree comp_type, gcall *call,
HOST_WIDE_INT offset)
{
struct prop_type_change_info tci;
ao_ref ao;
gcc_checking_assert (DECL_P (arg)
|| TREE_CODE (arg) == MEM_REF
|| handled_component_p (arg));
comp_type = TYPE_MAIN_VARIANT (comp_type);
/* Const calls cannot call virtual methods through VMT and so type changes do
not matter. */
if (!flag_devirtualize || !gimple_vuse (call)
/* Be sure expected_type is polymorphic. */
|| !comp_type
|| TREE_CODE (comp_type) != RECORD_TYPE
|| !TYPE_BINFO (TYPE_MAIN_VARIANT (comp_type))
|| !BINFO_VTABLE (TYPE_BINFO (TYPE_MAIN_VARIANT (comp_type))))
return true;
if (fbi->aa_walk_budget == 0)
return false;
ao_ref_init (&ao, arg);
ao.base = base;
ao.offset = offset;
ao.size = POINTER_SIZE;
ao.max_size = ao.size;
tci.offset = offset;
tci.object = get_base_address (arg);
tci.type_maybe_changed = false;
int walked
= walk_aliased_vdefs (&ao, gimple_vuse (call), check_stmt_for_type_change,
&tci, NULL, NULL, fbi->aa_walk_budget);
if (walked >= 0)
fbi->aa_walk_budget -= walked;
else
fbi->aa_walk_budget = 0;
if (walked >= 0 && !tci.type_maybe_changed)
return false;
return true;
}
/* Detect whether the dynamic type of ARG of COMP_TYPE may have changed.
If it is, return true. ARG is the object itself (not a pointer
to it, unless dereferenced). BASE is the base of the memory access as
returned by get_ref_base_and_extent, as is the offset. */
static bool
detect_type_change (ipa_func_body_info *fbi, tree arg, tree base,
tree comp_type, gcall *call,
HOST_WIDE_INT offset)
{
if (!flag_devirtualize)
return false;
if (TREE_CODE (base) == MEM_REF
&& !param_type_may_change_p (current_function_decl,
TREE_OPERAND (base, 0),
call))
return false;
return detect_type_change_from_memory_writes (fbi, arg, base, comp_type,
call, offset);
}
/* Like detect_type_change but ARG is supposed to be a non-dereferenced pointer
SSA name (its dereference will become the base and the offset is assumed to
be zero). */
static bool
detect_type_change_ssa (ipa_func_body_info *fbi, tree arg, tree comp_type,
gcall *call)
{
gcc_checking_assert (TREE_CODE (arg) == SSA_NAME);
if (!flag_devirtualize
|| !POINTER_TYPE_P (TREE_TYPE (arg)))
return false;
if (!param_type_may_change_p (current_function_decl, arg, call))
return false;
arg = build2 (MEM_REF, ptr_type_node, arg,
build_int_cst (ptr_type_node, 0));
return detect_type_change_from_memory_writes (fbi, arg, arg, comp_type,
call, 0);
}
/* Callback of walk_aliased_vdefs. Flags that it has been invoked to the
boolean variable pointed to by DATA. */
static bool
mark_modified (ao_ref *ao ATTRIBUTE_UNUSED, tree vdef ATTRIBUTE_UNUSED,
void *data)
{
bool *b = (bool *) data;
*b = true;
return true;
}
/* Find the nearest valid aa status for parameter specified by INDEX that
dominates BB. */
static struct ipa_param_aa_status *
find_dominating_aa_status (struct ipa_func_body_info *fbi, basic_block bb,
int index)
{
while (true)
{
bb = get_immediate_dominator (CDI_DOMINATORS, bb);
if (!bb)
return NULL;
struct ipa_bb_info *bi = ipa_get_bb_info (fbi, bb);
if (!bi->param_aa_statuses.is_empty ()
&& bi->param_aa_statuses[index].valid)
return &bi->param_aa_statuses[index];
}
}
/* Get AA status structure for the given BB and parameter with INDEX. Allocate
structures and/or intialize the result with a dominating description as
necessary. */
static struct ipa_param_aa_status *
parm_bb_aa_status_for_bb (struct ipa_func_body_info *fbi, basic_block bb,
int index)
{
gcc_checking_assert (fbi);
struct ipa_bb_info *bi = ipa_get_bb_info (fbi, bb);
if (bi->param_aa_statuses.is_empty ())
bi->param_aa_statuses.safe_grow_cleared (fbi->param_count, true);
struct ipa_param_aa_status *paa = &bi->param_aa_statuses[index];
if (!paa->valid)
{
gcc_checking_assert (!paa->parm_modified
&& !paa->ref_modified
&& !paa->pt_modified);
struct ipa_param_aa_status *dom_paa;
dom_paa = find_dominating_aa_status (fbi, bb, index);
if (dom_paa)
*paa = *dom_paa;
else
paa->valid = true;
}
return paa;
}
/* Return true if a load from a formal parameter PARM_LOAD is known to retrieve
a value known not to be modified in this function before reaching the
statement STMT. FBI holds information about the function we have so far
gathered but do not survive the summary building stage. */
static bool
parm_preserved_before_stmt_p (struct ipa_func_body_info *fbi, int index,
gimple *stmt, tree parm_load)
{
struct ipa_param_aa_status *paa;
bool modified = false;
ao_ref refd;
tree base = get_base_address (parm_load);
gcc_assert (TREE_CODE (base) == PARM_DECL);
if (TREE_READONLY (base))
return true;
gcc_checking_assert (fbi);
paa = parm_bb_aa_status_for_bb (fbi, gimple_bb (stmt), index);
if (paa->parm_modified || fbi->aa_walk_budget == 0)
return false;
gcc_checking_assert (gimple_vuse (stmt) != NULL_TREE);
ao_ref_init (&refd, parm_load);
int walked = walk_aliased_vdefs (&refd, gimple_vuse (stmt), mark_modified,
&modified, NULL, NULL,
fbi->aa_walk_budget);
if (walked < 0)
{
modified = true;
fbi->aa_walk_budget = 0;
}
else
fbi->aa_walk_budget -= walked;
if (paa && modified)
paa->parm_modified = true;
return !modified;
}
/* If STMT is an assignment that loads a value from an parameter declaration,
return the index of the parameter in ipa_node_params which has not been
modified. Otherwise return -1. */
static int
load_from_unmodified_param (struct ipa_func_body_info *fbi,
vec<ipa_param_descriptor, va_gc> *descriptors,
gimple *stmt)
{
int index;
tree op1;
if (!gimple_assign_single_p (stmt))
return -1;
op1 = gimple_assign_rhs1 (stmt);
if (TREE_CODE (op1) != PARM_DECL)
return -1;
index = ipa_get_param_decl_index_1 (descriptors, op1);
if (index < 0
|| !parm_preserved_before_stmt_p (fbi, index, stmt, op1))
return -1;
return index;
}
/* Return true if memory reference REF (which must be a load through parameter
with INDEX) loads data that are known to be unmodified in this function
before reaching statement STMT. */
static bool
parm_ref_data_preserved_p (struct ipa_func_body_info *fbi,
int index, gimple *stmt, tree ref)
{
struct ipa_param_aa_status *paa;
bool modified = false;
ao_ref refd;
gcc_checking_assert (fbi);
paa = parm_bb_aa_status_for_bb (fbi, gimple_bb (stmt), index);
if (paa->ref_modified || fbi->aa_walk_budget == 0)
return false;
gcc_checking_assert (gimple_vuse (stmt));
ao_ref_init (&refd, ref);
int walked = walk_aliased_vdefs (&refd, gimple_vuse (stmt), mark_modified,
&modified, NULL, NULL,
fbi->aa_walk_budget);
if (walked < 0)
{
modified = true;
fbi->aa_walk_budget = 0;
}
else
fbi->aa_walk_budget -= walked;
if (modified)
paa->ref_modified = true;
return !modified;
}
/* Return true if the data pointed to by PARM (which is a parameter with INDEX)
is known to be unmodified in this function before reaching call statement
CALL into which it is passed. FBI describes the function body. */
static bool
parm_ref_data_pass_through_p (struct ipa_func_body_info *fbi, int index,
gimple *call, tree parm)
{
bool modified = false;
ao_ref refd;
/* It's unnecessary to calculate anything about memory contnets for a const
function because it is not goin to use it. But do not cache the result
either. Also, no such calculations for non-pointers. */
if (!gimple_vuse (call)
|| !POINTER_TYPE_P (TREE_TYPE (parm)))
return false;
struct ipa_param_aa_status *paa = parm_bb_aa_status_for_bb (fbi,
gimple_bb (call),
index);
if (paa->pt_modified || fbi->aa_walk_budget == 0)
return false;
ao_ref_init_from_ptr_and_size (&refd, parm, NULL_TREE);
int walked = walk_aliased_vdefs (&refd, gimple_vuse (call), mark_modified,
&modified, NULL, NULL,
fbi->aa_walk_budget);
if (walked < 0)
{
fbi->aa_walk_budget = 0;
modified = true;
}
else
fbi->aa_walk_budget -= walked;
if (modified)
paa->pt_modified = true;
return !modified;
}
/* Return true if we can prove that OP is a memory reference loading
data from an aggregate passed as a parameter.
The function works in two modes. If GUARANTEED_UNMODIFIED is NULL, it return
false if it cannot prove that the value has not been modified before the
load in STMT. If GUARANTEED_UNMODIFIED is not NULL, it will return true even
if it cannot prove the value has not been modified, in that case it will
store false to *GUARANTEED_UNMODIFIED, otherwise it will store true there.
INFO and PARMS_AINFO describe parameters of the current function (but the
latter can be NULL), STMT is the load statement. If function returns true,
*INDEX_P, *OFFSET_P and *BY_REF is filled with the parameter index, offset
within the aggregate and whether it is a load from a value passed by
reference respectively. */
bool
ipa_load_from_parm_agg (struct ipa_func_body_info *fbi,
vec<ipa_param_descriptor, va_gc> *descriptors,
gimple *stmt, tree op, int *index_p,
HOST_WIDE_INT *offset_p, poly_int64 *size_p,
bool *by_ref_p, bool *guaranteed_unmodified)
{
int index;
HOST_WIDE_INT size;
bool reverse;
tree base = get_ref_base_and_extent_hwi (op, offset_p, &size, &reverse);
if (!base)
return false;
if (DECL_P (base))
{
int index = ipa_get_param_decl_index_1 (descriptors, base);
if (index >= 0
&& parm_preserved_before_stmt_p (fbi, index, stmt, op))
{
*index_p = index;
*by_ref_p = false;
if (size_p)
*size_p = size;
if (guaranteed_unmodified)
*guaranteed_unmodified = true;
return true;
}
return false;
}
if (TREE_CODE (base) != MEM_REF
|| TREE_CODE (TREE_OPERAND (base, 0)) != SSA_NAME
|| !integer_zerop (TREE_OPERAND (base, 1)))
return false;
if (SSA_NAME_IS_DEFAULT_DEF (TREE_OPERAND (base, 0)))
{
tree parm = SSA_NAME_VAR (TREE_OPERAND (base, 0));
index = ipa_get_param_decl_index_1 (descriptors, parm);
}
else
{
/* This branch catches situations where a pointer parameter is not a
gimple register, for example:
void hip7(S*) (struct S * p)
{
void (*<T2e4>) (struct S *) D.1867;
struct S * p.1;
<bb 2>:
p.1_1 = p;
D.1867_2 = p.1_1->f;
D.1867_2 ();
gdp = &p;
*/
gimple *def = SSA_NAME_DEF_STMT (TREE_OPERAND (base, 0));
index = load_from_unmodified_param (fbi, descriptors, def);
}
if (index >= 0)
{
bool data_preserved = parm_ref_data_preserved_p (fbi, index, stmt, op);
if (!data_preserved && !guaranteed_unmodified)
return false;
*index_p = index;
*by_ref_p = true;
if (size_p)
*size_p = size;
if (guaranteed_unmodified)
*guaranteed_unmodified = data_preserved;
return true;
}
return false;
}
/* If STMT is an assignment that loads a value from a parameter declaration,
or from an aggregate passed as the parameter either by value or reference,
return the index of the parameter in ipa_node_params. Otherwise return -1.
FBI holds gathered information about the function. INFO describes
parameters of the function, STMT is the assignment statement. If it is a
memory load from an aggregate, *OFFSET_P is filled with offset within the
aggregate, and *BY_REF_P specifies whether the aggregate is passed by
reference. */
static int
load_from_unmodified_param_or_agg (struct ipa_func_body_info *fbi,
class ipa_node_params *info,
gimple *stmt,
HOST_WIDE_INT *offset_p,
bool *by_ref_p)
{
int index = load_from_unmodified_param (fbi, info->descriptors, stmt);
poly_int64 size;
/* Load value from a parameter declaration. */
if (index >= 0)
{
*offset_p = -1;
return index;
}
if (!gimple_assign_load_p (stmt))
return -1;
tree rhs = gimple_assign_rhs1 (stmt);
/* Skip memory reference containing VIEW_CONVERT_EXPR. */
for (tree t = rhs; handled_component_p (t); t = TREE_OPERAND (t, 0))
if (TREE_CODE (t) == VIEW_CONVERT_EXPR)
return -1;
/* Skip memory reference containing bit-field. */
if (TREE_CODE (rhs) == BIT_FIELD_REF
|| contains_bitfld_component_ref_p (rhs))
return -1;
if (!ipa_load_from_parm_agg (fbi, info->descriptors, stmt, rhs, &index,
offset_p, &size, by_ref_p))
return -1;
gcc_assert (!maybe_ne (tree_to_poly_int64 (TYPE_SIZE (TREE_TYPE (rhs))),
size));
if (!*by_ref_p)
{
tree param_type = ipa_get_type (info, index);
if (!param_type || !AGGREGATE_TYPE_P (param_type))
return -1;
}
else if (TREE_THIS_VOLATILE (rhs))
return -1;
return index;
}
/* Walk pointer adjustemnts from OP (such as POINTER_PLUS and ADDR_EXPR)
to find original pointer. Initialize RET to the pointer which results from
the walk.
If offset is known return true and initialize OFFSET_RET. */
bool
unadjusted_ptr_and_unit_offset (tree op, tree *ret, poly_int64 *offset_ret)
{
poly_int64 offset = 0;
bool offset_known = true;
int i;
for (i = 0; i < param_ipa_jump_function_lookups; i++)
{
if (TREE_CODE (op) == ADDR_EXPR)
{
poly_int64 extra_offset = 0;
tree base = get_addr_base_and_unit_offset (TREE_OPERAND (op, 0),
&offset);
if (!base)
{
base = get_base_address (TREE_OPERAND (op, 0));
if (TREE_CODE (base) != MEM_REF)
break;
offset_known = false;
}
else
{
if (TREE_CODE (base) != MEM_REF)
break;
offset += extra_offset;
}
op = TREE_OPERAND (base, 0);
if (mem_ref_offset (base).to_shwi (&extra_offset))
offset += extra_offset;
else
offset_known = false;
}
else if (TREE_CODE (op) == SSA_NAME
&& !SSA_NAME_IS_DEFAULT_DEF (op))
{
gimple *pstmt = SSA_NAME_DEF_STMT (op);
if (gimple_assign_single_p (pstmt))
op = gimple_assign_rhs1 (pstmt);
else if (is_gimple_assign (pstmt)
&& gimple_assign_rhs_code (pstmt) == POINTER_PLUS_EXPR)
{
poly_int64 extra_offset = 0;
if (ptrdiff_tree_p (gimple_assign_rhs2 (pstmt),
&extra_offset))
offset += extra_offset;
else
offset_known = false;
op = gimple_assign_rhs1 (pstmt);
}
else
break;
}
else
break;
}
*ret = op;
*offset_ret = offset;
return offset_known;
}
/* Given that an actual argument is an SSA_NAME (given in NAME) and is a result
of an assignment statement STMT, try to determine whether we are actually
handling any of the following cases and construct an appropriate jump
function into JFUNC if so:
1) The passed value is loaded from a formal parameter which is not a gimple
register (most probably because it is addressable, the value has to be
scalar) and we can guarantee the value has not changed. This case can
therefore be described by a simple pass-through jump function. For example:
foo (int a)
{
int a.0;
a.0_2 = a;
bar (a.0_2);
2) The passed value can be described by a simple arithmetic pass-through
jump function. E.g.
foo (int a)
{
int D.2064;
D.2064_4 = a.1(D) + 4;
bar (D.2064_4);
This case can also occur in combination of the previous one, e.g.:
foo (int a, int z)
{
int a.0;
int D.2064;
a.0_3 = a;
D.2064_4 = a.0_3 + 4;
foo (D.2064_4);
3) The passed value is an address of an object within another one (which
also passed by reference). Such situations are described by an ancestor
jump function and describe situations such as:
B::foo() (struct B * const this)
{
struct A * D.1845;
D.1845_2 = &this_1(D)->D.1748;
A::bar (D.1845_2);
INFO is the structure describing individual parameters access different
stages of IPA optimizations. PARMS_AINFO contains the information that is
only needed for intraprocedural analysis. */
static void
compute_complex_assign_jump_func (struct ipa_func_body_info *fbi,
class ipa_node_params *info,
struct ipa_jump_func *jfunc,
gcall *call, gimple *stmt, tree name,
tree param_type)
{
HOST_WIDE_INT offset, size;
tree op1, tc_ssa, base, ssa;
bool reverse;
int index;
op1 = gimple_assign_rhs1 (stmt);
if (TREE_CODE (op1) == SSA_NAME)
{
if (SSA_NAME_IS_DEFAULT_DEF (op1))
index = ipa_get_param_decl_index (info, SSA_NAME_VAR (op1));
else
index = load_from_unmodified_param (fbi, info->descriptors,
SSA_NAME_DEF_STMT (op1));
tc_ssa = op1;
}
else
{
index = load_from_unmodified_param (fbi, info->descriptors, stmt);
tc_ssa = gimple_assign_lhs (stmt);
}
if (index >= 0)
{
switch (gimple_assign_rhs_class (stmt))
{
case GIMPLE_BINARY_RHS:
{
tree op2 = gimple_assign_rhs2 (stmt);
if (!is_gimple_ip_invariant (op2)
|| ((TREE_CODE_CLASS (gimple_assign_rhs_code (stmt))
!= tcc_comparison)
&& !useless_type_conversion_p (TREE_TYPE (name),
TREE_TYPE (op1))))
return;
ipa_set_jf_arith_pass_through (jfunc, index, op2,
gimple_assign_rhs_code (stmt));
break;
}
case GIMPLE_SINGLE_RHS:
{
bool agg_p = parm_ref_data_pass_through_p (fbi, index, call,
tc_ssa);
ipa_set_jf_simple_pass_through (jfunc, index, agg_p);
break;
}
case GIMPLE_UNARY_RHS:
if (!CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt)))
ipa_set_jf_unary_pass_through (jfunc, index,
gimple_assign_rhs_code (stmt));
default:;
}
return;
}
if (TREE_CODE (op1) != ADDR_EXPR)
return;
op1 = TREE_OPERAND (op1, 0);
if (TREE_CODE (TREE_TYPE (op1)) != RECORD_TYPE)
return;
base = get_ref_base_and_extent_hwi (op1, &offset, &size, &reverse);
offset_int mem_offset;
if (!base
|| TREE_CODE (base) != MEM_REF
|| !mem_ref_offset (base).is_constant (&mem_offset))
return;
offset += mem_offset.to_short_addr () * BITS_PER_UNIT;
ssa = TREE_OPERAND (base, 0);
if (TREE_CODE (ssa) != SSA_NAME
|| !SSA_NAME_IS_DEFAULT_DEF (ssa)
|| offset < 0)
return;
/* Dynamic types are changed in constructors and destructors. */
index = ipa_get_param_decl_index (info, SSA_NAME_VAR (ssa));
if (index >= 0 && param_type && POINTER_TYPE_P (param_type))
ipa_set_ancestor_jf (jfunc, offset, index,
parm_ref_data_pass_through_p (fbi, index, call, ssa));
}
/* Extract the base, offset and MEM_REF expression from a statement ASSIGN if
it looks like:
iftmp.1_3 = &obj_2(D)->D.1762;
The base of the MEM_REF must be a default definition SSA NAME of a
parameter. Return NULL_TREE if it looks otherwise. If case of success, the
whole MEM_REF expression is returned and the offset calculated from any
handled components and the MEM_REF itself is stored into *OFFSET. The whole
RHS stripped off the ADDR_EXPR is stored into *OBJ_P. */
static tree
get_ancestor_addr_info (gimple *assign, tree *obj_p, HOST_WIDE_INT *offset)
{
HOST_WIDE_INT size;
tree expr, parm, obj;
bool reverse;
if (!gimple_assign_single_p (assign))
return NULL_TREE;
expr = gimple_assign_rhs1 (assign);
if (TREE_CODE (expr) != ADDR_EXPR)
return NULL_TREE;
expr = TREE_OPERAND (expr, 0);
obj = expr;
expr = get_ref_base_and_extent_hwi (expr, offset, &size, &reverse);
offset_int mem_offset;
if (!expr
|| TREE_CODE (expr) != MEM_REF
|| !mem_ref_offset (expr).is_constant (&mem_offset))
return NULL_TREE;
parm = TREE_OPERAND (expr, 0);
if (TREE_CODE (parm) != SSA_NAME
|| !SSA_NAME_IS_DEFAULT_DEF (parm)
|| TREE_CODE (SSA_NAME_VAR (parm)) != PARM_DECL)
return NULL_TREE;
*offset += mem_offset.to_short_addr () * BITS_PER_UNIT;
*obj_p = obj;
return expr;
}
/* Given that an actual argument is an SSA_NAME that is a result of a phi
statement PHI, try to find out whether NAME is in fact a
multiple-inheritance typecast from a descendant into an ancestor of a formal
parameter and thus can be described by an ancestor jump function and if so,
write the appropriate function into JFUNC.
Essentially we want to match the following pattern:
if (obj_2(D) != 0B)
goto <bb 3>;
else
goto <bb 4>;
<bb 3>:
iftmp.1_3 = &obj_2(D)->D.1762;
<bb 4>:
# iftmp.1_1 = PHI <iftmp.1_3(3), 0B(2)>
D.1879_6 = middleman_1 (iftmp.1_1, i_5(D));
return D.1879_6; */
static void
compute_complex_ancestor_jump_func (struct ipa_func_body_info *fbi,
class ipa_node_params *info,
struct ipa_jump_func *jfunc,
gcall *call, gphi *phi)
{
HOST_WIDE_INT offset;
gimple *assign, *cond;
basic_block phi_bb, assign_bb, cond_bb;
tree tmp, parm, expr, obj;
int index, i;
if (gimple_phi_num_args (phi) != 2)
return;
if (integer_zerop (PHI_ARG_DEF (phi, 1)))
tmp = PHI_ARG_DEF (phi, 0);
else if (integer_zerop (PHI_ARG_DEF (phi, 0)))
tmp = PHI_ARG_DEF (phi, 1);
else
return;
if (TREE_CODE (tmp) != SSA_NAME
|| SSA_NAME_IS_DEFAULT_DEF (tmp)
|| !POINTER_TYPE_P (TREE_TYPE (tmp))
|| TREE_CODE (TREE_TYPE (TREE_TYPE (tmp))) != RECORD_TYPE)
return;
assign = SSA_NAME_DEF_STMT (tmp);
assign_bb = gimple_bb (assign);
if (!single_pred_p (assign_bb))
return;
expr = get_ancestor_addr_info (assign, &obj, &offset);
if (!expr)
return;
parm = TREE_OPERAND (expr, 0);
index = ipa_get_param_decl_index (info, SSA_NAME_VAR (parm));
if (index < 0)
return;
cond_bb = single_pred (assign_bb);
cond = last_stmt (cond_bb);
if (!cond
|| gimple_code (cond) != GIMPLE_COND
|| gimple_cond_code (cond) != NE_EXPR
|| gimple_cond_lhs (cond) != parm
|| !integer_zerop (gimple_cond_rhs (cond)))
return;
phi_bb = gimple_bb (phi);
for (i = 0; i < 2; i++)
{
basic_block pred = EDGE_PRED (phi_bb, i)->src;
if (pred != assign_bb && pred != cond_bb)
return;
}
ipa_set_ancestor_jf (jfunc, offset, index,
parm_ref_data_pass_through_p (fbi, index, call, parm));
}
/* Inspect the given TYPE and return true iff it has the same structure (the
same number of fields of the same types) as a C++ member pointer. If
METHOD_PTR and DELTA are non-NULL, store the trees representing the
corresponding fields there. */
static bool
type_like_member_ptr_p (tree type, tree *method_ptr, tree *delta)
{
tree fld;
if (TREE_CODE (type) != RECORD_TYPE)
return false;
fld = TYPE_FIELDS (type);
if (!fld || !POINTER_TYPE_P (TREE_TYPE (fld))
|| TREE_CODE (TREE_TYPE (TREE_TYPE (fld))) != METHOD_TYPE
|| !tree_fits_uhwi_p (DECL_FIELD_OFFSET (fld)))
return false;
if (method_ptr)
*method_ptr = fld;
fld = DECL_CHAIN (fld);
if (!fld || INTEGRAL_TYPE_P (fld)
|| !tree_fits_uhwi_p (DECL_FIELD_OFFSET (fld)))
return false;
if (delta)
*delta = fld;
if (DECL_CHAIN (fld))
return false;
return true;
}
/* If RHS is an SSA_NAME and it is defined by a simple copy assign statement,
return the rhs of its defining statement, and this statement is stored in
*RHS_STMT. Otherwise return RHS as it is. */
static inline tree
get_ssa_def_if_simple_copy (tree rhs, gimple **rhs_stmt)
{
while (TREE_CODE (rhs) == SSA_NAME && !SSA_NAME_IS_DEFAULT_DEF (rhs))
{
gimple *def_stmt = SSA_NAME_DEF_STMT (rhs);
if (gimple_assign_single_p (def_stmt))
rhs = gimple_assign_rhs1 (def_stmt);
else
break;
*rhs_stmt = def_stmt;
}
return rhs;
}
/* Simple linked list, describing contents of an aggregate before call. */
struct ipa_known_agg_contents_list
{
/* Offset and size of the described part of the aggregate. */
HOST_WIDE_INT offset, size;
/* Type of the described part of the aggregate. */
tree type;
/* Known constant value or jump function data describing contents. */
struct ipa_load_agg_data value;
/* Pointer to the next structure in the list. */
struct ipa_known_agg_contents_list *next;
};
/* Add an aggregate content item into a linked list of
ipa_known_agg_contents_list structure, in which all elements
are sorted ascendingly by offset. */
static inline void
add_to_agg_contents_list (struct ipa_known_agg_contents_list **plist,
struct ipa_known_agg_contents_list *item)
{
struct ipa_known_agg_contents_list *list = *plist;
for (; list; list = list->next)
{
if (list->offset >= item->offset)
break;
plist = &list->next;
}
item->next = list;
*plist = item;
}
/* Check whether a given aggregate content is clobbered by certain element in
a linked list of ipa_known_agg_contents_list. */
static inline bool
clobber_by_agg_contents_list_p (struct ipa_known_agg_contents_list *list,
struct ipa_known_agg_contents_list *item)
{
for (; list; list = list->next)
{
if (list->offset >= item->offset)
return list->offset < item->offset + item->size;
if (list->offset + list->size > item->offset)
return true;
}
return false;
}
/* Build aggregate jump function from LIST, assuming there are exactly
VALUE_COUNT entries there and that offset of the passed argument
is ARG_OFFSET and store it into JFUNC. */
static void
build_agg_jump_func_from_list (struct ipa_known_agg_contents_list *list,
int value_count, HOST_WIDE_INT arg_offset,
struct ipa_jump_func *jfunc)
{
vec_safe_reserve (jfunc->agg.items, value_count, true);
for (; list; list = list->next)
{
struct ipa_agg_jf_item item;
tree operand = list->value.pass_through.operand;
if (list->value.pass_through.formal_id >= 0)
{
/* Content value is derived from some formal paramerter. */
if (list->value.offset >= 0)
item.jftype = IPA_JF_LOAD_AGG;
else
item.jftype = IPA_JF_PASS_THROUGH;
item.value.load_agg = list->value;
if (operand)
item.value.pass_through.operand
= unshare_expr_without_location (operand);
}
else if (operand)
{
/* Content value is known constant. */
item.jftype = IPA_JF_CONST;
item.value.constant = unshare_expr_without_location (operand);
}
else
continue;
item.type = list->type;
gcc_assert (tree_to_shwi (TYPE_SIZE (list->type)) == list->size);
item.offset = list->offset - arg_offset;
gcc_assert ((item.offset % BITS_PER_UNIT) == 0);
jfunc->agg.items->quick_push (item);
}
}
/* Given an assignment statement STMT, try to collect information into
AGG_VALUE that will be used to construct jump function for RHS of the
assignment, from which content value of an aggregate part comes.
Besides constant and simple pass-through jump functions, also try to
identify whether it matches the following pattern that can be described by
a load-value-from-aggregate jump function, which is a derivative of simple
pass-through jump function.
foo (int *p)
{
...
*(q_5 + 4) = *(p_3(D) + 28) op 1;
bar (q_5);
}
Here IPA_LOAD_AGG_DATA data structure is informative enough to describe
constant, simple pass-through and load-vale-from-aggregate. If value
is constant, it will be kept in field OPERAND, and field FORMAL_ID is
set to -1. For simple pass-through and load-value-from-aggregate, field
FORMAL_ID specifies the related formal parameter index, and field
OFFSET can be used to distinguish them, -1 means simple pass-through,
otherwise means load-value-from-aggregate. */
static void
analyze_agg_content_value (struct ipa_func_body_info *fbi,
struct ipa_load_agg_data *agg_value,
gimple *stmt)
{
tree lhs = gimple_assign_lhs (stmt);
tree rhs1 = gimple_assign_rhs1 (stmt);
enum tree_code code;
int index = -1;
/* Initialize jump function data for the aggregate part. */
memset (agg_value, 0, sizeof (*agg_value));
agg_value->pass_through.operation = NOP_EXPR;
agg_value->pass_through.formal_id = -1;
agg_value->offset = -1;
if (AGGREGATE_TYPE_P (TREE_TYPE (lhs)) /* TODO: Support aggregate type. */
|| TREE_THIS_VOLATILE (lhs)
|| TREE_CODE (lhs) == BIT_FIELD_REF
|| contains_bitfld_component_ref_p (lhs))
return;
/* Skip SSA copies. */
while (gimple_assign_rhs_class (stmt) == GIMPLE_SINGLE_RHS)
{
if (TREE_CODE (rhs1) != SSA_NAME || SSA_NAME_IS_DEFAULT_DEF (rhs1))
break;
stmt = SSA_NAME_DEF_STMT (rhs1);
if (!is_gimple_assign (stmt))
break;
rhs1 = gimple_assign_rhs1 (stmt);
}
if (gphi *phi = dyn_cast<gphi *> (stmt))
{
/* Also special case like the following (a is a formal parameter):
_12 = *a_11(D).dim[0].stride;
...
# iftmp.22_9 = PHI <_12(2), 1(3)>
...
parm.6.dim[0].stride = iftmp.22_9;
...
__x_MOD_foo (&parm.6, b_31(D));
The aggregate function describing parm.6.dim[0].stride is encoded as a
PASS-THROUGH jump function with ASSERT_EXPR operation whith operand 1
(the constant from the PHI node). */
if (gimple_phi_num_args (phi) != 2)
return;
tree arg0 = gimple_phi_arg_def (phi, 0);
tree arg1 = gimple_phi_arg_def (phi, 1);
tree operand;
if (is_gimple_ip_invariant (arg1))
{
operand = arg1;
rhs1 = arg0;
}
else if (is_gimple_ip_invariant (arg0))
{
operand = arg0;
rhs1 = arg1;
}
else
return;
rhs1 = get_ssa_def_if_simple_copy (rhs1, &stmt);
if (!is_gimple_assign (stmt))
return;
code = ASSERT_EXPR;
agg_value->pass_through.operand = operand;
}
else if (is_gimple_assign (stmt))
{
code = gimple_assign_rhs_code (stmt);
switch (gimple_assign_rhs_class (stmt))
{
case GIMPLE_SINGLE_RHS:
if (is_gimple_ip_invariant (rhs1))
{
agg_value->pass_through.operand = rhs1;
return;
}
code = NOP_EXPR;
break;
case GIMPLE_UNARY_RHS:
/* NOTE: A GIMPLE_UNARY_RHS operation might not be tcc_unary
(truth_not_expr is example), GIMPLE_BINARY_RHS does not imply
tcc_binary, this subtleness is somewhat misleading.
Since tcc_unary is widely used in IPA-CP code to check an operation
with one operand, here we only allow tc_unary operation to avoid
possible problem. Then we can use (opclass == tc_unary) or not to
distinguish unary and binary. */
if (TREE_CODE_CLASS (code) != tcc_unary || CONVERT_EXPR_CODE_P (code))
return;
rhs1 = get_ssa_def_if_simple_copy (rhs1, &stmt);
break;
case GIMPLE_BINARY_RHS:
{
gimple *rhs1_stmt = stmt;
gimple *rhs2_stmt = stmt;
tree rhs2 = gimple_assign_rhs2 (stmt);
rhs1 = get_ssa_def_if_simple_copy (rhs1, &rhs1_stmt);
rhs2 = get_ssa_def_if_simple_copy (rhs2, &rhs2_stmt);
if (is_gimple_ip_invariant (rhs2))
{
agg_value->pass_through.operand = rhs2;
stmt = rhs1_stmt;
}
else if (is_gimple_ip_invariant (rhs1))
{
if (TREE_CODE_CLASS (code) == tcc_comparison)
code = swap_tree_comparison (code);
else if (!commutative_tree_code (code))
return;
agg_value->pass_through.operand = rhs1;
stmt = rhs2_stmt;
rhs1 = rhs2;
}
else
return;
if (TREE_CODE_CLASS (code) != tcc_comparison
&& !useless_type_conversion_p (TREE_TYPE (lhs),
TREE_TYPE (rhs1)))
return;
}
break;
default:
return;
}
}
else
return;
if (TREE_CODE (rhs1) != SSA_NAME)
index = load_from_unmodified_param_or_agg (fbi, fbi->info, stmt,
&agg_value->offset,
&agg_value->by_ref);
else if (SSA_NAME_IS_DEFAULT_DEF (rhs1))
index = ipa_get_param_decl_index (fbi->info, SSA_NAME_VAR (rhs1));
if (index >= 0)
{
if (agg_value->offset >= 0)
agg_value->type = TREE_TYPE (rhs1);
agg_value->pass_through.formal_id = index;
agg_value->pass_through.operation = code;
}
else
agg_value->pass_through.operand = NULL_TREE;
}
/* If STMT is a memory store to the object whose address is BASE, extract
information (offset, size, and value) into CONTENT, and return true,
otherwise we conservatively assume the whole object is modified with
unknown content, and return false. CHECK_REF means that access to object
is expected to be in form of MEM_REF expression. */
static bool
extract_mem_content (struct ipa_func_body_info *fbi,
gimple *stmt, tree base, bool check_ref,
struct ipa_known_agg_contents_list *content)
{
HOST_WIDE_INT lhs_offset, lhs_size;
bool reverse;
if (!is_gimple_assign (stmt))
return false;
tree lhs = gimple_assign_lhs (stmt);
tree lhs_base = get_ref_base_and_extent_hwi (lhs, &lhs_offset, &lhs_size,
&reverse);
if (!lhs_base)
return false;
if (check_ref)
{
if (TREE_CODE (lhs_base) != MEM_REF
|| TREE_OPERAND (lhs_base, 0) != base
|| !integer_zerop (TREE_OPERAND (lhs_base, 1)))
return false;
}
else if (lhs_base != base)
return false;
content->offset = lhs_offset;
content->size = lhs_size;
content->type = TREE_TYPE (lhs);
content->next = NULL;
analyze_agg_content_value (fbi, &content->value, stmt);
return true;
}
/* Traverse statements from CALL backwards, scanning whether an aggregate given
in ARG is filled in constants or values that are derived from caller's
formal parameter in the way described by some kinds of jump functions. FBI
is the context of the caller function for interprocedural analysis. ARG can
either be an aggregate expression or a pointer to an aggregate. ARG_TYPE is
the type of the aggregate, JFUNC is the jump function for the aggregate. */
static void
determine_known_aggregate_parts (struct ipa_func_body_info *fbi,
gcall *call, tree arg,
tree arg_type,
struct ipa_jump_func *jfunc)
{
struct ipa_known_agg_contents_list *list = NULL, *all_list = NULL;
bitmap visited = NULL;
int item_count = 0, value_count = 0;
HOST_WIDE_INT arg_offset, arg_size;
tree arg_base;
bool check_ref, by_ref;
ao_ref r;
int max_agg_items = opt_for_fn (fbi->node->decl, param_ipa_max_agg_items);
if (max_agg_items == 0)
return;
/* The function operates in three stages. First, we prepare check_ref, r,
arg_base and arg_offset based on what is actually passed as an actual
argument. */
if (POINTER_TYPE_P (arg_type))
{
by_ref = true;
if (TREE_CODE (arg) == SSA_NAME)
{
tree type_size;
if (!tree_fits_uhwi_p (TYPE_SIZE (TREE_TYPE (arg_type)))
|| !POINTER_TYPE_P (TREE_TYPE (arg)))
return;
check_ref = true;
arg_base = arg;
arg_offset = 0;
type_size = TYPE_SIZE (TREE_TYPE (arg_type));
arg_size = tree_to_uhwi (type_size);
ao_ref_init_from_ptr_and_size (&r, arg_base, NULL_TREE);
}
else if (TREE_CODE (arg) == ADDR_EXPR)
{
bool reverse;
arg = TREE_OPERAND (arg, 0);
arg_base = get_ref_base_and_extent_hwi (arg, &arg_offset,
&arg_size, &reverse);
if (!arg_base)
return;
if (DECL_P (arg_base))
{
check_ref = false;
ao_ref_init (&r, arg_base);
}
else
return;
}
else
return;
}
else
{
bool reverse;
gcc_checking_assert (AGGREGATE_TYPE_P (TREE_TYPE (arg)));
by_ref = false;
check_ref = false;
arg_base = get_ref_base_and_extent_hwi (arg, &arg_offset,
&arg_size, &reverse);
if (!arg_base)
return;
ao_ref_init (&r, arg);
}
/* Second stage traverses virtual SSA web backwards starting from the call
statement, only looks at individual dominating virtual operand (its
definition dominates the call), as long as it is confident that content
of the aggregate is affected by definition of the virtual operand, it
builds a sorted linked list of ipa_agg_jf_list describing that. */
for (tree dom_vuse = gimple_vuse (call);
dom_vuse && fbi->aa_walk_budget > 0;)
{
gimple *stmt = SSA_NAME_DEF_STMT (dom_vuse);
if (gimple_code (stmt) == GIMPLE_PHI)
{
dom_vuse = get_continuation_for_phi (stmt, &r, true,
fbi->aa_walk_budget,
&visited, false, NULL, NULL);
continue;
}
fbi->aa_walk_budget--;
if (stmt_may_clobber_ref_p_1 (stmt, &r))
{
struct ipa_known_agg_contents_list *content
= XALLOCA (struct ipa_known_agg_contents_list);
if (!extract_mem_content (fbi, stmt, arg_base, check_ref, content))
break;
/* Now we get a dominating virtual operand, and need to check
whether its value is clobbered any other dominating one. */
if ((content->value.pass_through.formal_id >= 0
|| content->value.pass_through.operand)
&& !clobber_by_agg_contents_list_p (all_list, content))
{
struct ipa_known_agg_contents_list *copy
= XALLOCA (struct ipa_known_agg_contents_list);
/* Add to the list consisting of only dominating virtual
operands, whose definitions can finally reach the call. */
add_to_agg_contents_list (&list, (*copy = *content, copy));
if (++value_count == max_agg_items)
break;
}
/* Add to the list consisting of all dominating virtual operands. */
add_to_agg_contents_list (&all_list, content);
if (++item_count == 2 * max_agg_items)
break;
}
dom_vuse = gimple_vuse (stmt);
}
if (visited)
BITMAP_FREE (visited);
/* Third stage just goes over the list and creates an appropriate vector of
ipa_agg_jf_item structures out of it, of course only if there are
any meaningful items to begin with. */
if (value_count)
{
jfunc->agg.by_ref = by_ref;
build_agg_jump_func_from_list (list, value_count, arg_offset, jfunc);
}
}
/* Return the Ith param type of callee associated with call graph
edge E. */
tree
ipa_get_callee_param_type (struct cgraph_edge *e, int i)
{
int n;
tree type = (e->callee
? TREE_TYPE (e->callee->decl)
: gimple_call_fntype (e->call_stmt));
tree t = TYPE_ARG_TYPES (type);
for (n = 0; n < i; n++)
{
if (!t)
break;
t = TREE_CHAIN (t);
}
if (t)
return TREE_VALUE (t);
if (!e->callee)
return NULL;
t = DECL_ARGUMENTS (e->callee->decl);
for (n = 0; n < i; n++)
{
if (!t)
return NULL;
t = TREE_CHAIN (t);
}
if (t)
return TREE_TYPE (t);
return NULL;
}
/* Return ipa_bits with VALUE and MASK values, which can be either a newly
allocated structure or a previously existing one shared with other jump
functions and/or transformation summaries. */
ipa_bits *
ipa_get_ipa_bits_for_value (const widest_int &value, const widest_int &mask)
{
ipa_bits tmp;
tmp.value = value;
tmp.mask = mask;
ipa_bits **slot = ipa_bits_hash_table->find_slot (&tmp, INSERT);
if (*slot)
return *slot;
ipa_bits *res = ggc_alloc<ipa_bits> ();
res->value = value;
res->mask = mask;
*slot = res;
return res;
}
/* Assign to JF a pointer to ipa_bits structure with VALUE and MASK. Use hash
table in order to avoid creating multiple same ipa_bits structures. */
static void
ipa_set_jfunc_bits (ipa_jump_func *jf, const widest_int &value,
const widest_int &mask)
{
jf->bits = ipa_get_ipa_bits_for_value (value, mask);
}
/* Return a pointer to a value_range just like *TMP, but either find it in
ipa_vr_hash_table or allocate it in GC memory. TMP->equiv must be NULL. */
static value_range *
ipa_get_value_range (value_range *tmp)
{
value_range **slot = ipa_vr_hash_table->find_slot (tmp, INSERT);
if (*slot)
return *slot;
value_range *vr = new (ggc_alloc<value_range> ()) value_range;
*vr = *tmp;
*slot = vr;
return vr;
}
/* Return a pointer to a value range consisting of TYPE, MIN, MAX and an empty
equiv set. Use hash table in order to avoid creating multiple same copies of
value_ranges. */
static value_range *
ipa_get_value_range (enum value_range_kind kind, tree min, tree max)
{
value_range tmp (min, max, kind);
return ipa_get_value_range (&tmp);
}
/* Assign to JF a pointer to a value_range structure with TYPE, MIN and MAX and
a NULL equiv bitmap. Use hash table in order to avoid creating multiple
same value_range structures. */
static void
ipa_set_jfunc_vr (ipa_jump_func *jf, enum value_range_kind type,
tree min, tree max)
{
jf->m_vr = ipa_get_value_range (type, min, max);
}
/* Assign to JF a pointer to a value_range just like TMP but either fetch a
copy from ipa_vr_hash_table or allocate a new on in GC memory. */
static void
ipa_set_jfunc_vr (ipa_jump_func *jf, value_range *tmp)
{
jf->m_vr = ipa_get_value_range (tmp);
}
/* Compute jump function for all arguments of callsite CS and insert the
information in the jump_functions array in the ipa_edge_args corresponding
to this callsite. */
static void
ipa_compute_jump_functions_for_edge (struct ipa_func_body_info *fbi,
struct cgraph_edge *cs)
{
ipa_node_params *info = ipa_node_params_sum->get (cs->caller);
ipa_edge_args *args = ipa_edge_args_sum->get_create (cs);
gcall *call = cs->call_stmt;
int n, arg_num = gimple_call_num_args (call);
bool useful_context = false;
value_range vr;
if (arg_num == 0 || args->jump_functions)
return;
vec_safe_grow_cleared (args->jump_functions, arg_num, true);
if (flag_devirtualize)
vec_safe_grow_cleared (args->polymorphic_call_contexts, arg_num, true);
if (gimple_call_internal_p (call))
return;
if (ipa_func_spec_opts_forbid_analysis_p (cs->caller))
return;
for (n = 0; n < arg_num; n++)
{
struct ipa_jump_func *jfunc = ipa_get_ith_jump_func (args, n);
tree arg = gimple_call_arg (call, n);
tree param_type = ipa_get_callee_param_type (cs, n);
if (flag_devirtualize && POINTER_TYPE_P (TREE_TYPE (arg)))
{
tree instance;
class ipa_polymorphic_call_context context (cs->caller->decl,
arg, cs->call_stmt,
&instance);
context.get_dynamic_type (instance, arg, NULL, cs->call_stmt,
&fbi->aa_walk_budget);
*ipa_get_ith_polymorhic_call_context (args, n) = context;
if (!context.useless_p ())
useful_context = true;
}
if (POINTER_TYPE_P (TREE_TYPE (arg)))
{
bool addr_nonzero = false;
bool strict_overflow = false;
if (TREE_CODE (arg) == SSA_NAME
&& param_type
&& get_range_query (cfun)->range_of_expr (vr, arg)
&& vr.nonzero_p ())
addr_nonzero = true;
else if (tree_single_nonzero_warnv_p (arg, &strict_overflow))
addr_nonzero = true;
if (addr_nonzero)
{
tree z = build_int_cst (TREE_TYPE (arg), 0);
ipa_set_jfunc_vr (jfunc, VR_ANTI_RANGE, z, z);
}
else
gcc_assert (!jfunc->m_vr);
}
else
{
if (TREE_CODE (arg) == SSA_NAME
&& param_type
&& get_range_query (cfun)->range_of_expr (vr, arg)
&& !vr.undefined_p ())
{
value_range resvr;
range_fold_unary_expr (&resvr, NOP_EXPR, param_type,
&vr, TREE_TYPE (arg));
if (!resvr.undefined_p () && !resvr.varying_p ())
ipa_set_jfunc_vr (jfunc, &resvr);
else
gcc_assert (!jfunc->m_vr);
}
else
gcc_assert (!jfunc->m_vr);
}
if (INTEGRAL_TYPE_P (TREE_TYPE (arg))
&& (TREE_CODE (arg) == SSA_NAME || TREE_CODE (arg) == INTEGER_CST))
{
if (TREE_CODE (arg) == SSA_NAME)
ipa_set_jfunc_bits (jfunc, 0,
widest_int::from (get_nonzero_bits (arg),
TYPE_SIGN (TREE_TYPE (arg))));
else
ipa_set_jfunc_bits (jfunc, wi::to_widest (arg), 0);
}
else if (POINTER_TYPE_P (TREE_TYPE (arg)))
{
unsigned HOST_WIDE_INT bitpos;
unsigned align;
get_pointer_alignment_1 (arg, &align, &bitpos);
widest_int mask = wi::bit_and_not
(wi::mask<widest_int> (TYPE_PRECISION (TREE_TYPE (arg)), false),
align / BITS_PER_UNIT - 1);
widest_int value = bitpos / BITS_PER_UNIT;
ipa_set_jfunc_bits (jfunc, value, mask);
}
else
gcc_assert (!jfunc->bits);
if (is_gimple_ip_invariant (arg)
|| (VAR_P (arg)
&& is_global_var (arg)
&& TREE_READONLY (arg)))
ipa_set_jf_constant (jfunc, arg, cs);
else if (!is_gimple_reg_type (TREE_TYPE (arg))
&& TREE_CODE (arg) == PARM_DECL)
{
int index = ipa_get_param_decl_index (info, arg);
gcc_assert (index >=0);
/* Aggregate passed by value, check for pass-through, otherwise we
will attempt to fill in aggregate contents later in this
for cycle. */
if (parm_preserved_before_stmt_p (fbi, index, call, arg))
{
ipa_set_jf_simple_pass_through (jfunc, index, false);
continue;
}
}
else if (TREE_CODE (arg) == SSA_NAME)
{
if (SSA_NAME_IS_DEFAULT_DEF (arg))
{
int index = ipa_get_param_decl_index (info, SSA_NAME_VAR (arg));
if (index >= 0)
{
bool agg_p;
agg_p = parm_ref_data_pass_through_p (fbi, index, call, arg);
ipa_set_jf_simple_pass_through (jfunc, index, agg_p);
}
}
else
{
gimple *stmt = SSA_NAME_DEF_STMT (arg);
if (is_gimple_assign (stmt))
compute_complex_assign_jump_func (fbi, info, jfunc,
call, stmt, arg, param_type);
else if (gimple_code (stmt) == GIMPLE_PHI)
compute_complex_ancestor_jump_func (fbi, info, jfunc,
call,
as_a <gphi *> (stmt));
}
}
/* If ARG is pointer, we cannot use its type to determine the type of aggregate
passed (because type conversions are ignored in gimple). Usually we can
safely get type from function declaration, but in case of K&R prototypes or
variadic functions we can try our luck with type of the pointer passed.
TODO: Since we look for actual initialization of the memory object, we may better
work out the type based on the memory stores we find. */
if (!param_type)
param_type = TREE_TYPE (arg);
if ((jfunc->type != IPA_JF_PASS_THROUGH
|| !ipa_get_jf_pass_through_agg_preserved (jfunc))
&& (jfunc->type != IPA_JF_ANCESTOR
|| !ipa_get_jf_ancestor_agg_preserved (jfunc))
&& (AGGREGATE_TYPE_P (TREE_TYPE (arg))
|| POINTER_TYPE_P (param_type)))
determine_known_aggregate_parts (fbi, call, arg, param_type, jfunc);
}
if (!useful_context)
vec_free (args->polymorphic_call_contexts);
}
/* Compute jump functions for all edges - both direct and indirect - outgoing
from BB. */
static void
ipa_compute_jump_functions_for_bb (struct ipa_func_body_info *fbi, basic_block bb)
{
struct ipa_bb_info *bi = ipa_get_bb_info (fbi, bb);
int i;
struct cgraph_edge *cs;
FOR_EACH_VEC_ELT_REVERSE (bi->cg_edges, i, cs)
{
struct cgraph_node *callee = cs->callee;
if (callee)
{
callee = callee->ultimate_alias_target ();
/* We do not need to bother analyzing calls to unknown functions
unless they may become known during lto/whopr. */
if (!callee->definition && !flag_lto
&& !gimple_call_fnspec (cs->call_stmt).known_p ())
continue;
}
ipa_compute_jump_functions_for_edge (fbi, cs);
}
}
/* If STMT looks like a statement loading a value from a member pointer formal
parameter, return that parameter and store the offset of the field to
*OFFSET_P, if it is non-NULL. Otherwise return NULL (but *OFFSET_P still
might be clobbered). If USE_DELTA, then we look for a use of the delta
field rather than the pfn. */
static tree
ipa_get_stmt_member_ptr_load_param (gimple *stmt, bool use_delta,
HOST_WIDE_INT *offset_p)
{
tree rhs, rec, ref_field, ref_offset, fld, ptr_field, delta_field;
if (!gimple_assign_single_p (stmt))
return NULL_TREE;
rhs = gimple_assign_rhs1 (stmt);
if (TREE_CODE (rhs) == COMPONENT_REF)
{
ref_field = TREE_OPERAND (rhs, 1);
rhs = TREE_OPERAND (rhs, 0);
}
else
ref_field = NULL_TREE;
if (TREE_CODE (rhs) != MEM_REF)
return NULL_TREE;
rec = TREE_OPERAND (rhs, 0);
if (TREE_CODE (rec) != ADDR_EXPR)
return NULL_TREE;
rec = TREE_OPERAND (rec, 0);
if (TREE_CODE (rec) != PARM_DECL
|| !type_like_member_ptr_p (TREE_TYPE (rec), &ptr_field, &delta_field))
return NULL_TREE;
ref_offset = TREE_OPERAND (rhs, 1);
if (use_delta)
fld = delta_field;
else
fld = ptr_field;
if (offset_p)
*offset_p = int_bit_position (fld);
if (ref_field)
{
if (integer_nonzerop (ref_offset))
return NULL_TREE;
return ref_field == fld ? rec : NULL_TREE;
}
else
return tree_int_cst_equal (byte_position (fld), ref_offset) ? rec
: NULL_TREE;
}
/* Returns true iff T is an SSA_NAME defined by a statement. */
static bool
ipa_is_ssa_with_stmt_def (tree t)
{
if (TREE_CODE (t) == SSA_NAME
&& !SSA_NAME_IS_DEFAULT_DEF (t))
return true;
else
return false;
}
/* Find the indirect call graph edge corresponding to STMT and mark it as a
call to a parameter number PARAM_INDEX. NODE is the caller. Return the
indirect call graph edge.
If POLYMORPHIC is true record is as a destination of polymorphic call. */
static struct cgraph_edge *
ipa_note_param_call (struct cgraph_node *node, int param_index,
gcall *stmt, bool polymorphic)
{
struct cgraph_edge *cs;
cs = node->get_edge (stmt);
cs->indirect_info->param_index = param_index;
cs->indirect_info->agg_contents = 0;
cs->indirect_info->member_ptr = 0;
cs->indirect_info->guaranteed_unmodified = 0;
ipa_node_params *info = ipa_node_params_sum->get (node);
ipa_set_param_used_by_indirect_call (info, param_index, true);
if (cs->indirect_info->polymorphic || polymorphic)
ipa_set_param_used_by_polymorphic_call (info, param_index, true);
return cs;
}
/* Analyze the CALL and examine uses of formal parameters of the caller NODE
(described by INFO). PARMS_AINFO is a pointer to a vector containing
intermediate information about each formal parameter. Currently it checks
whether the call calls a pointer that is a formal parameter and if so, the
parameter is marked with the called flag and an indirect call graph edge
describing the call is created. This is very simple for ordinary pointers
represented in SSA but not-so-nice when it comes to member pointers. The
ugly part of this function does nothing more than trying to match the
pattern of such a call. An example of such a pattern is the gimple dump
below, the call is on the last line:
<bb 2>:
f$__delta_5 = f.__delta;
f$__pfn_24 = f.__pfn;
or
<bb 2>:
f$__delta_5 = MEM[(struct *)&f];
f$__pfn_24 = MEM[(struct *)&f + 4B];
and a few lines below:
<bb 5>
D.2496_3 = (int) f$__pfn_24;
D.2497_4 = D.2496_3 & 1;
if (D.2497_4 != 0)
goto <bb 3>;
else
goto <bb 4>;
<bb 6>:
D.2500_7 = (unsigned int) f$__delta_5;
D.2501_8 = &S + D.2500_7;
D.2502_9 = (int (*__vtbl_ptr_type) (void) * *) D.2501_8;
D.2503_10 = *D.2502_9;
D.2504_12 = f$__pfn_24 + -1;
D.2505_13 = (unsigned int) D.2504_12;
D.2506_14 = D.2503_10 + D.2505_13;
D.2507_15 = *D.2506_14;
iftmp.11_16 = (String:: *) D.2507_15;
<bb 7>:
# iftmp.11_1 = PHI <iftmp.11_16(3), f$__pfn_24(2)>
D.2500_19 = (unsigned int) f$__delta_5;
D.2508_20 = &S + D.2500_19;
D.2493_21 = iftmp.11_1 (D.2508_20, 4);
Such patterns are results of simple calls to a member pointer:
int doprinting (int (MyString::* f)(int) const)
{
MyString S ("somestring");
return (S.*f)(4);
}
Moreover, the function also looks for called pointers loaded from aggregates
passed by value or reference. */
static void
ipa_analyze_indirect_call_uses (struct ipa_func_body_info *fbi, gcall *call,
tree target)
{
class ipa_node_params *info = fbi->info;
HOST_WIDE_INT offset;
bool by_ref;
if (SSA_NAME_IS_DEFAULT_DEF (target))
{
tree var = SSA_NAME_VAR (target);
int index = ipa_get_param_decl_index (info, var);
if (index >= 0)
ipa_note_param_call (fbi->node, index, call, false);
return;
}
int index;
gimple *def = SSA_NAME_DEF_STMT (target);
bool guaranteed_unmodified;
if (gimple_assign_single_p (def)
&& ipa_load_from_parm_agg (fbi, info->descriptors, def,
gimple_assign_rhs1 (def), &index, &offset,
NULL, &by_ref, &guaranteed_unmodified))
{
struct cgraph_edge *cs = ipa_note_param_call (fbi->node, index,
call, false);
cs->indirect_info->offset = offset;
cs->indirect_info->agg_contents = 1;
cs->indirect_info->by_ref = by_ref;
cs->indirect_info->guaranteed_unmodified = guaranteed_unmodified;
return;
}
/* Now we need to try to match the complex pattern of calling a member
pointer. */
if (gimple_code (def) != GIMPLE_PHI
|| gimple_phi_num_args (def) != 2
|| !POINTER_TYPE_P (TREE_TYPE (target))
|| TREE_CODE (TREE_TYPE (TREE_TYPE (target))) != METHOD_TYPE)
return;
/* First, we need to check whether one of these is a load from a member
pointer that is a parameter to this function. */
tree n1 = PHI_ARG_DEF (def, 0);
tree n2 = PHI_ARG_DEF (def, 1);
if (!ipa_is_ssa_with_stmt_def (n1) || !ipa_is_ssa_with_stmt_def (n2))
return;
gimple *d1 = SSA_NAME_DEF_STMT (n1);
gimple *d2 = SSA_NAME_DEF_STMT (n2);
tree rec;
basic_block bb, virt_bb;
basic_block join = gimple_bb (def);
if ((rec = ipa_get_stmt_member_ptr_load_param (d1, false, &offset)))
{
if (ipa_get_stmt_member_ptr_load_param (d2, false, NULL))
return;
bb = EDGE_PRED (join, 0)->src;
virt_bb = gimple_bb (d2);
}
else if ((rec = ipa_get_stmt_member_ptr_load_param (d2, false, &offset)))
{
bb = EDGE_PRED (join, 1)->src;
virt_bb = gimple_bb (d1);
}
else
return;
/* Second, we need to check that the basic blocks are laid out in the way
corresponding to the pattern. */
if (!single_pred_p (virt_bb) || !single_succ_p (virt_bb)
|| single_pred (virt_bb) != bb
|| single_succ (virt_bb) != join)
return;
/* Third, let's see that the branching is done depending on the least
significant bit of the pfn. */
gimple *branch = last_stmt (bb);
if (!branch || gimple_code (branch) != GIMPLE_COND)
return;
if ((gimple_cond_code (branch) != NE_EXPR
&& gimple_cond_code (branch) != EQ_EXPR)
|| !integer_zerop (gimple_cond_rhs (branch)))
return;
tree cond = gimple_cond_lhs (branch);
if (!ipa_is_ssa_with_stmt_def (cond))
return;
def = SSA_NAME_DEF_STMT (cond);
if (!is_gimple_assign (def)
|| gimple_assign_rhs_code (def) != BIT_AND_EXPR
|| !integer_onep (gimple_assign_rhs2 (def)))
return;
cond = gimple_assign_rhs1 (def);
if (!ipa_is_ssa_with_stmt_def (cond))
return;
def = SSA_NAME_DEF_STMT (cond);
if (is_gimple_assign (def)
&& CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def)))
{
cond = gimple_assign_rhs1 (def);
if (!ipa_is_ssa_with_stmt_def (cond))
return;
def = SSA_NAME_DEF_STMT (cond);
}
tree rec2;
rec2 = ipa_get_stmt_member_ptr_load_param (def,
(TARGET_PTRMEMFUNC_VBIT_LOCATION
== ptrmemfunc_vbit_in_delta),
NULL);
if (rec != rec2)
return;
index = ipa_get_param_decl_index (info, rec);
if (index >= 0
&& parm_preserved_before_stmt_p (fbi, index, call, rec))
{
struct cgraph_edge *cs = ipa_note_param_call (fbi->node, index,
call, false);
cs->indirect_info->offset = offset;
cs->indirect_info->agg_contents = 1;
cs->indirect_info->member_ptr = 1;
cs->indirect_info->guaranteed_unmodified = 1;
}
return;
}
/* Analyze a CALL to an OBJ_TYPE_REF which is passed in TARGET and if the
object referenced in the expression is a formal parameter of the caller
FBI->node (described by FBI->info), create a call note for the
statement. */
static void
ipa_analyze_virtual_call_uses (struct ipa_func_body_info *fbi,
gcall *call, tree target)
{
tree obj = OBJ_TYPE_REF_OBJECT (target);
int index;
HOST_WIDE_INT anc_offset;
if (!flag_devirtualize)
return;
if (TREE_CODE (obj) != SSA_NAME)
return;
class ipa_node_params *info = fbi->info;
if (SSA_NAME_IS_DEFAULT_DEF (obj))
{
if (TREE_CODE (SSA_NAME_VAR (obj)) != PARM_DECL)
return;
anc_offset = 0;
index = ipa_get_param_decl_index (info, SSA_NAME_VAR (obj));
gcc_assert (index >= 0);
if (detect_type_change_ssa (fbi, obj, obj_type_ref_class (target),
call))
return;
}
else
{
gimple *stmt = SSA_NAME_DEF_STMT (obj);
tree expr;
expr = get_ancestor_addr_info (stmt, &obj, &anc_offset);
if (!expr)
return;
index = ipa_get_param_decl_index (info,
SSA_NAME_VAR (TREE_OPERAND (expr, 0)));
gcc_assert (index >= 0);
if (detect_type_change (fbi, obj, expr, obj_type_ref_class (target),
call, anc_offset))
return;
}
struct cgraph_edge *cs = ipa_note_param_call (fbi->node, index,
call, true);
class cgraph_indirect_call_info *ii = cs->indirect_info;
ii->offset = anc_offset;
ii->otr_token = tree_to_uhwi (OBJ_TYPE_REF_TOKEN (target));
ii->otr_type = obj_type_ref_class (target);
ii->polymorphic = 1;
}
/* Analyze a call statement CALL whether and how it utilizes formal parameters
of the caller (described by INFO). PARMS_AINFO is a pointer to a vector
containing intermediate information about each formal parameter. */
static void
ipa_analyze_call_uses (struct ipa_func_body_info *fbi, gcall *call)
{
tree target = gimple_call_fn (call);
if (!target
|| (TREE_CODE (target) != SSA_NAME
&& !virtual_method_call_p (target)))
return;
struct cgraph_edge *cs = fbi->node->get_edge (call);
/* If we previously turned the call into a direct call, there is
no need to analyze. */
if (cs && !cs->indirect_unknown_callee)
return;
if (cs->indirect_info->polymorphic && flag_devirtualize)
{
tree instance;
tree target = gimple_call_fn (call);
ipa_polymorphic_call_context context (current_function_decl,
target, call, &instance);
gcc_checking_assert (cs->indirect_info->otr_type
== obj_type_ref_class (target));
gcc_checking_assert (cs->indirect_info->otr_token
== tree_to_shwi (OBJ_TYPE_REF_TOKEN (target)));
cs->indirect_info->vptr_changed
= !context.get_dynamic_type (instance,
OBJ_TYPE_REF_OBJECT (target),
obj_type_ref_class (target), call,
&fbi->aa_walk_budget);
cs->indirect_info->context = context;
}
if (TREE_CODE (target) == SSA_NAME)
ipa_analyze_indirect_call_uses (fbi, call, target);
else if (virtual_method_call_p (target))
ipa_analyze_virtual_call_uses (fbi, call, target);
}
/* Analyze the call statement STMT with respect to formal parameters (described
in INFO) of caller given by FBI->NODE. Currently it only checks whether
formal parameters are called. */
static void
ipa_analyze_stmt_uses (struct ipa_func_body_info *fbi, gimple *stmt)
{
if (is_gimple_call (stmt))
ipa_analyze_call_uses (fbi, as_a <gcall *> (stmt));
}
/* Callback of walk_stmt_load_store_addr_ops for the visit_load.
If OP is a parameter declaration, mark it as used in the info structure
passed in DATA. */
static bool
visit_ref_for_mod_analysis (gimple *, tree op, tree, void *data)
{
class ipa_node_params *info = (class ipa_node_params *) data;
op = get_base_address (op);
if (op
&& TREE_CODE (op) == PARM_DECL)
{
int index = ipa_get_param_decl_index (info, op);
gcc_assert (index >= 0);
ipa_set_param_used (info, index, true);
}
return false;
}
/* Scan the statements in BB and inspect the uses of formal parameters. Store
the findings in various structures of the associated ipa_node_params
structure, such as parameter flags, notes etc. FBI holds various data about
the function being analyzed. */
static void
ipa_analyze_params_uses_in_bb (struct ipa_func_body_info *fbi, basic_block bb)
{
gimple_stmt_iterator gsi;
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
gimple *stmt = gsi_stmt (gsi);
if (is_gimple_debug (stmt))
continue;
ipa_analyze_stmt_uses (fbi, stmt);
walk_stmt_load_store_addr_ops (stmt, fbi->info,
visit_ref_for_mod_analysis,
visit_ref_for_mod_analysis,
visit_ref_for_mod_analysis);
}
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
walk_stmt_load_store_addr_ops (gsi_stmt (gsi), fbi->info,
visit_ref_for_mod_analysis,
visit_ref_for_mod_analysis,
visit_ref_for_mod_analysis);
}
/* Return true EXPR is a load from a dereference of SSA_NAME NAME. */
static bool
load_from_dereferenced_name (tree expr, tree name)
{
tree base = get_base_address (expr);
return (TREE_CODE (base) == MEM_REF
&& TREE_OPERAND (base, 0) == name);
}
/* Calculate controlled uses of parameters of NODE. */
static void
ipa_analyze_controlled_uses (struct cgraph_node *node)
{
ipa_node_params *info = ipa_node_params_sum->get (node);
for (int i = 0; i < ipa_get_param_count (info); i++)
{
tree parm = ipa_get_param (info, i);
int call_uses = 0;
bool load_dereferenced = false;
/* For SSA regs see if parameter is used. For non-SSA we compute
the flag during modification analysis. */
if (is_gimple_reg (parm))
{
tree ddef = ssa_default_def (DECL_STRUCT_FUNCTION (node->decl),
parm);
if (ddef && !has_zero_uses (ddef))
{
imm_use_iterator imm_iter;
gimple *stmt;
ipa_set_param_used (info, i, true);
FOR_EACH_IMM_USE_STMT (stmt, imm_iter, ddef)
{
if (is_gimple_debug (stmt))
continue;
int all_stmt_uses = 0;
use_operand_p use_p;
FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter)
all_stmt_uses++;
if (is_gimple_call (stmt))
{
if (gimple_call_internal_p (stmt))
{
call_uses = IPA_UNDESCRIBED_USE;
break;
}
int recognized_stmt_uses;
if (gimple_call_fn (stmt) == ddef)
recognized_stmt_uses = 1;
else
recognized_stmt_uses = 0;
unsigned arg_count = gimple_call_num_args (stmt);
for (unsigned i = 0; i < arg_count; i++)
{
tree arg = gimple_call_arg (stmt, i);
if (arg == ddef)
recognized_stmt_uses++;
else if (load_from_dereferenced_name (arg, ddef))
{
load_dereferenced = true;
recognized_stmt_uses++;
}
}
if (recognized_stmt_uses != all_stmt_uses)
{
call_uses = IPA_UNDESCRIBED_USE;
break;
}
if (call_uses >= 0)
call_uses += all_stmt_uses;
}
else if (gimple_assign_single_p (stmt))
{
tree rhs = gimple_assign_rhs1 (stmt);
if (all_stmt_uses != 1
|| !load_from_dereferenced_name (rhs, ddef))
{
call_uses = IPA_UNDESCRIBED_USE;
break;
}
load_dereferenced = true;
}
else
{
call_uses = IPA_UNDESCRIBED_USE;
break;
}
}
}
else
call_uses = 0;
}
else
call_uses = IPA_UNDESCRIBED_USE;
ipa_set_controlled_uses (info, i, call_uses);
ipa_set_param_load_dereferenced (info, i, load_dereferenced);
}
}
/* Free stuff in BI. */
static void
free_ipa_bb_info (struct ipa_bb_info *bi)
{
bi->cg_edges.release ();
bi->param_aa_statuses.release ();
}
/* Dominator walker driving the analysis. */
class analysis_dom_walker : public dom_walker
{
public:
analysis_dom_walker (struct ipa_func_body_info *fbi)
: dom_walker (CDI_DOMINATORS), m_fbi (fbi) {}
virtual edge before_dom_children (basic_block);
private:
struct ipa_func_body_info *m_fbi;
};
edge
analysis_dom_walker::before_dom_children (basic_block bb)
{
ipa_analyze_params_uses_in_bb (m_fbi, bb);
ipa_compute_jump_functions_for_bb (m_fbi, bb);
return NULL;
}
/* Release body info FBI. */
void
ipa_release_body_info (struct ipa_func_body_info *fbi)
{
int i;
struct ipa_bb_info *bi;
FOR_EACH_VEC_ELT (fbi->bb_infos, i, bi)
free_ipa_bb_info (bi);
fbi->bb_infos.release ();
}
/* Initialize the array describing properties of formal parameters
of NODE, analyze their uses and compute jump functions associated
with actual arguments of calls from within NODE. */
void
ipa_analyze_node (struct cgraph_node *node)
{
struct ipa_func_body_info fbi;
class ipa_node_params *info;
ipa_check_create_node_params ();
ipa_check_create_edge_args ();
info = ipa_node_params_sum->get_create (node);
if (info->analysis_done)
return;
info->analysis_done = 1;
if (ipa_func_spec_opts_forbid_analysis_p (node))
{
for (int i = 0; i < ipa_get_param_count (info); i++)
{
ipa_set_param_used (info, i, true);
ipa_set_controlled_uses (info, i, IPA_UNDESCRIBED_USE);
}
return;
}
struct function *func = DECL_STRUCT_FUNCTION (node->decl);
push_cfun (func);
calculate_dominance_info (CDI_DOMINATORS);
ipa_initialize_node_params (node);
ipa_analyze_controlled_uses (node);
fbi.node = node;
fbi.info = info;
fbi.bb_infos = vNULL;
fbi.bb_infos.safe_grow_cleared (last_basic_block_for_fn (cfun), true);
fbi.param_count = ipa_get_param_count (info);
fbi.aa_walk_budget = opt_for_fn (node->decl, param_ipa_max_aa_steps);
for (struct cgraph_edge *cs = node->callees; cs; cs = cs->next_callee)
{
ipa_bb_info *bi = ipa_get_bb_info (&fbi, gimple_bb (cs->call_stmt));
bi->cg_edges.safe_push (cs);
}
for (struct cgraph_edge *cs = node->indirect_calls; cs; cs = cs->next_callee)
{
ipa_bb_info *bi = ipa_get_bb_info (&fbi, gimple_bb (cs->call_stmt));
bi->cg_edges.safe_push (cs);
}
analysis_dom_walker (&fbi).walk (ENTRY_BLOCK_PTR_FOR_FN (cfun));
ipa_release_body_info (&fbi);
free_dominance_info (CDI_DOMINATORS);
pop_cfun ();
}
/* Update the jump functions associated with call graph edge E when the call
graph edge CS is being inlined, assuming that E->caller is already (possibly
indirectly) inlined into CS->callee and that E has not been inlined. */
static void
update_jump_functions_after_inlining (struct cgraph_edge *cs,
struct cgraph_edge *e)
{
ipa_edge_args *top = ipa_edge_args_sum->get (cs);
ipa_edge_args *args = ipa_edge_args_sum->get (e);
if (!args)
return;
int count = ipa_get_cs_argument_count (args);
int i;
for (i = 0; i < count; i++)
{
struct ipa_jump_func *dst = ipa_get_ith_jump_func (args, i);
class ipa_polymorphic_call_context *dst_ctx
= ipa_get_ith_polymorhic_call_context (args, i);
if (dst->agg.items)
{
struct ipa_agg_jf_item *item;
int j;
FOR_EACH_VEC_ELT (*dst->agg.items, j, item)
{
int dst_fid;
struct ipa_jump_func *src;
if (item->jftype != IPA_JF_PASS_THROUGH
&& item->jftype != IPA_JF_LOAD_AGG)
continue;
dst_fid = item->value.pass_through.formal_id;
if (!top || dst_fid >= ipa_get_cs_argument_count (top))
{
item->jftype = IPA_JF_UNKNOWN;
continue;
}
item->value.pass_through.formal_id = -1;
src = ipa_get_ith_jump_func (top, dst_fid);
if (src->type == IPA_JF_CONST)
{
if (item->jftype == IPA_JF_PASS_THROUGH
&& item->value.pass_through.operation == NOP_EXPR)
{
item->jftype = IPA_JF_CONST;
item->value.constant = src->value.constant.value;
continue;
}
}
else if (src->type == IPA_JF_PASS_THROUGH
&& src->value.pass_through.operation == NOP_EXPR)
{
if (item->jftype == IPA_JF_PASS_THROUGH
|| !item->value.load_agg.by_ref
|| src->value.pass_through.agg_preserved)
item->value.pass_through.formal_id
= src->value.pass_through.formal_id;
}
else if (src->type == IPA_JF_ANCESTOR)
{
if (item->jftype == IPA_JF_PASS_THROUGH)
{
if (!src->value.ancestor.offset)
item->value.pass_through.formal_id
= src->value.ancestor.formal_id;
}
else if (src->value.ancestor.agg_preserved)
{
gcc_checking_assert (item->value.load_agg.by_ref);
item->value.pass_through.formal_id
= src->value.ancestor.formal_id;
item->value.load_agg.offset
+= src->value.ancestor.offset;
}
}
if (item->value.pass_through.formal_id < 0)
item->jftype = IPA_JF_UNKNOWN;
}
}