/* Miscellaneous SSA utility functions.
Copyright (C) 2001-2013 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 "tm.h"
#include "tree.h"
#include "flags.h"
#include "tm_p.h"
#include "target.h"
#include "ggc.h"
#include "langhooks.h"
#include "basic-block.h"
#include "function.h"
#include "gimple-pretty-print.h"
#include "pointer-set.h"
#include "gimple.h"
#include "gimple-ssa.h"
#include "tree-phinodes.h"
#include "ssa-iterators.h"
#include "tree-ssanames.h"
#include "tree-ssa-loop-manip.h"
#include "tree-into-ssa.h"
#include "tree-ssa.h"
#include "tree-inline.h"
#include "hashtab.h"
#include "tree-pass.h"
#include "diagnostic-core.h"
#include "cfgloop.h"
/* Pointer map of variable mappings, keyed by edge. */
static struct pointer_map_t *edge_var_maps;
/* Add a mapping with PHI RESULT and PHI DEF associated with edge E. */
void
redirect_edge_var_map_add (edge e, tree result, tree def, source_location locus)
{
void **slot;
edge_var_map_vector *head;
edge_var_map new_node;
if (edge_var_maps == NULL)
edge_var_maps = pointer_map_create ();
slot = pointer_map_insert (edge_var_maps, e);
head = (edge_var_map_vector *) *slot;
if (!head)
vec_safe_reserve (head, 5);
new_node.def = def;
new_node.result = result;
new_node.locus = locus;
vec_safe_push (head, new_node);
*slot = head;
}
/* Clear the var mappings in edge E. */
void
redirect_edge_var_map_clear (edge e)
{
void **slot;
edge_var_map_vector *head;
if (!edge_var_maps)
return;
slot = pointer_map_contains (edge_var_maps, e);
if (slot)
{
head = (edge_var_map_vector *) *slot;
vec_free (head);
*slot = NULL;
}
}
/* Duplicate the redirected var mappings in OLDE in NEWE.
Since we can't remove a mapping, let's just duplicate it. This assumes a
pointer_map can have multiple edges mapping to the same var_map (many to
one mapping), since we don't remove the previous mappings. */
void
redirect_edge_var_map_dup (edge newe, edge olde)
{
void **new_slot, **old_slot;
edge_var_map_vector *head;
if (!edge_var_maps)
return;
new_slot = pointer_map_insert (edge_var_maps, newe);
old_slot = pointer_map_contains (edge_var_maps, olde);
if (!old_slot)
return;
head = (edge_var_map_vector *) *old_slot;
edge_var_map_vector *new_head = NULL;
if (head)
new_head = vec_safe_copy (head);
else
vec_safe_reserve (new_head, 5);
*new_slot = new_head;
}
/* Return the variable mappings for a given edge. If there is none, return
NULL. */
edge_var_map_vector *
redirect_edge_var_map_vector (edge e)
{
void **slot;
/* Hey, what kind of idiot would... you'd be surprised. */
if (!edge_var_maps)
return NULL;
slot = pointer_map_contains (edge_var_maps, e);
if (!slot)
return NULL;
return (edge_var_map_vector *) *slot;
}
/* Used by redirect_edge_var_map_destroy to free all memory. */
static bool
free_var_map_entry (const void *key ATTRIBUTE_UNUSED,
void **value,
void *data ATTRIBUTE_UNUSED)
{
edge_var_map_vector *head = (edge_var_map_vector *) *value;
vec_free (head);
return true;
}
/* Clear the edge variable mappings. */
void
redirect_edge_var_map_destroy (void)
{
if (edge_var_maps)
{
pointer_map_traverse (edge_var_maps, free_var_map_entry, NULL);
pointer_map_destroy (edge_var_maps);
edge_var_maps = NULL;
}
}
/* Remove the corresponding arguments from the PHI nodes in E's
destination block and redirect it to DEST. Return redirected edge.
The list of removed arguments is stored in a vector accessed
through edge_var_maps. */
edge
ssa_redirect_edge (edge e, basic_block dest)
{
gimple_stmt_iterator gsi;
gimple phi;
redirect_edge_var_map_clear (e);
/* Remove the appropriate PHI arguments in E's destination block. */
for (gsi = gsi_start_phis (e->dest); !gsi_end_p (gsi); gsi_next (&gsi))
{
tree def;
source_location locus ;
phi = gsi_stmt (gsi);
def = gimple_phi_arg_def (phi, e->dest_idx);
locus = gimple_phi_arg_location (phi, e->dest_idx);
if (def == NULL_TREE)
continue;
redirect_edge_var_map_add (e, gimple_phi_result (phi), def, locus);
}
e = redirect_edge_succ_nodup (e, dest);
return e;
}
/* Add PHI arguments queued in PENDING_STMT list on edge E to edge
E->dest. */
void
flush_pending_stmts (edge e)
{
gimple phi;
edge_var_map_vector *v;
edge_var_map *vm;
int i;
gimple_stmt_iterator gsi;
v = redirect_edge_var_map_vector (e);
if (!v)
return;
for (gsi = gsi_start_phis (e->dest), i = 0;
!gsi_end_p (gsi) && v->iterate (i, &vm);
gsi_next (&gsi), i++)
{
tree def;
phi = gsi_stmt (gsi);
def = redirect_edge_var_map_def (vm);
add_phi_arg (phi, def, e, redirect_edge_var_map_location (vm));
}
redirect_edge_var_map_clear (e);
}
/* Data structure used to count the number of dereferences to PTR
inside an expression. */
struct count_ptr_d
{
tree ptr;
unsigned num_stores;
unsigned num_loads;
};
/* Helper for count_uses_and_derefs. Called by walk_tree to look for
(ALIGN/MISALIGNED_)INDIRECT_REF nodes for the pointer passed in DATA. */
static tree
count_ptr_derefs (tree *tp, int *walk_subtrees, void *data)
{
struct walk_stmt_info *wi_p = (struct walk_stmt_info *) data;
struct count_ptr_d *count_p = (struct count_ptr_d *) wi_p->info;
/* Do not walk inside ADDR_EXPR nodes. In the expression &ptr->fld,
pointer 'ptr' is *not* dereferenced, it is simply used to compute
the address of 'fld' as 'ptr + offsetof(fld)'. */
if (TREE_CODE (*tp) == ADDR_EXPR)
{
*walk_subtrees = 0;
return NULL_TREE;
}
if (TREE_CODE (*tp) == MEM_REF && TREE_OPERAND (*tp, 0) == count_p->ptr)
{
if (wi_p->is_lhs)
count_p->num_stores++;
else
count_p->num_loads++;
}
return NULL_TREE;
}
/* Count the number of direct and indirect uses for pointer PTR in
statement STMT. The number of direct uses is stored in
*NUM_USES_P. Indirect references are counted separately depending
on whether they are store or load operations. The counts are
stored in *NUM_STORES_P and *NUM_LOADS_P. */
void
count_uses_and_derefs (tree ptr, gimple stmt, unsigned *num_uses_p,
unsigned *num_loads_p, unsigned *num_stores_p)
{
ssa_op_iter i;
tree use;
*num_uses_p = 0;
*num_loads_p = 0;
*num_stores_p = 0;
/* Find out the total number of uses of PTR in STMT. */
FOR_EACH_SSA_TREE_OPERAND (use, stmt, i, SSA_OP_USE)
if (use == ptr)
(*num_uses_p)++;
/* Now count the number of indirect references to PTR. This is
truly awful, but we don't have much choice. There are no parent
pointers inside INDIRECT_REFs, so an expression like
'*x_1 = foo (x_1, *x_1)' needs to be traversed piece by piece to
find all the indirect and direct uses of x_1 inside. The only
shortcut we can take is the fact that GIMPLE only allows
INDIRECT_REFs inside the expressions below. */
if (is_gimple_assign (stmt)
|| gimple_code (stmt) == GIMPLE_RETURN
|| gimple_code (stmt) == GIMPLE_ASM
|| is_gimple_call (stmt))
{
struct walk_stmt_info wi;
struct count_ptr_d count;
count.ptr = ptr;
count.num_stores = 0;
count.num_loads = 0;
memset (&wi, 0, sizeof (wi));
wi.info = &count;
walk_gimple_op (stmt, count_ptr_derefs, &wi);
*num_stores_p = count.num_stores;
*num_loads_p = count.num_loads;
}
gcc_assert (*num_uses_p >= *num_loads_p + *num_stores_p);
}
/* Replace the LHS of STMT, an assignment, either a GIMPLE_ASSIGN or a
GIMPLE_CALL, with NLHS, in preparation for modifying the RHS to an
expression with a different value.
This will update any annotations (say debug bind stmts) referring
to the original LHS, so that they use the RHS instead. This is
done even if NLHS and LHS are the same, for it is understood that
the RHS will be modified afterwards, and NLHS will not be assigned
an equivalent value.
Adjusting any non-annotation uses of the LHS, if needed, is a
responsibility of the caller.
The effect of this call should be pretty much the same as that of
inserting a copy of STMT before STMT, and then removing the
original stmt, at which time gsi_remove() would have update
annotations, but using this function saves all the inserting,
copying and removing. */
void
gimple_replace_ssa_lhs (gimple stmt, tree nlhs)
{
if (MAY_HAVE_DEBUG_STMTS)
{
tree lhs = gimple_get_lhs (stmt);
gcc_assert (SSA_NAME_DEF_STMT (lhs) == stmt);
insert_debug_temp_for_var_def (NULL, lhs);
}
gimple_set_lhs (stmt, nlhs);
}
/* Given a tree for an expression for which we might want to emit
locations or values in debug information (generally a variable, but
we might deal with other kinds of trees in the future), return the
tree that should be used as the variable of a DEBUG_BIND STMT or
VAR_LOCATION INSN or NOTE. Return NULL if VAR is not to be tracked. */
tree
target_for_debug_bind (tree var)
{
if (!MAY_HAVE_DEBUG_STMTS)
return NULL_TREE;
if (TREE_CODE (var) == SSA_NAME)
{
var = SSA_NAME_VAR (var);
if (var == NULL_TREE)
return NULL_TREE;
}
if ((TREE_CODE (var) != VAR_DECL
|| VAR_DECL_IS_VIRTUAL_OPERAND (var))
&& TREE_CODE (var) != PARM_DECL)
return NULL_TREE;
if (DECL_HAS_VALUE_EXPR_P (var))
return target_for_debug_bind (DECL_VALUE_EXPR (var));
if (DECL_IGNORED_P (var))
return NULL_TREE;
/* var-tracking only tracks registers. */
if (!is_gimple_reg_type (TREE_TYPE (var)))
return NULL_TREE;
return var;
}
/* Called via walk_tree, look for SSA_NAMEs that have already been
released. */
static tree
find_released_ssa_name (tree *tp, int *walk_subtrees, void *data_)
{
struct walk_stmt_info *wi = (struct walk_stmt_info *) data_;
if (wi && wi->is_lhs)
return NULL_TREE;
if (TREE_CODE (*tp) == SSA_NAME)
{
if (SSA_NAME_IN_FREE_LIST (*tp))
return *tp;
*walk_subtrees = 0;
}
else if (IS_TYPE_OR_DECL_P (*tp))
*walk_subtrees = 0;
return NULL_TREE;
}
/* Insert a DEBUG BIND stmt before the DEF of VAR if VAR is referenced
by other DEBUG stmts, and replace uses of the DEF with the
newly-created debug temp. */
void
insert_debug_temp_for_var_def (gimple_stmt_iterator *gsi, tree var)
{
imm_use_iterator imm_iter;
use_operand_p use_p;
gimple stmt;
gimple def_stmt = NULL;
int usecount = 0;
tree value = NULL;
if (!MAY_HAVE_DEBUG_STMTS)
return;
/* If this name has already been registered for replacement, do nothing
as anything that uses this name isn't in SSA form. */
if (name_registered_for_update_p (var))
return;
/* Check whether there are debug stmts that reference this variable and,
if there are, decide whether we should use a debug temp. */
FOR_EACH_IMM_USE_FAST (use_p, imm_iter, var)
{
stmt = USE_STMT (use_p);
if (!gimple_debug_bind_p (stmt))
continue;
if (usecount++)
break;
if (gimple_debug_bind_get_value (stmt) != var)
{
/* Count this as an additional use, so as to make sure we
use a temp unless VAR's definition has a SINGLE_RHS that
can be shared. */
usecount++;
break;
}
}
if (!usecount)
return;
if (gsi)
def_stmt = gsi_stmt (*gsi);
else
def_stmt = SSA_NAME_DEF_STMT (var);
/* If we didn't get an insertion point, and the stmt has already
been removed, we won't be able to insert the debug bind stmt, so
we'll have to drop debug information. */
if (gimple_code (def_stmt) == GIMPLE_PHI)
{
value = degenerate_phi_result (def_stmt);
if (value && walk_tree (&value, find_released_ssa_name, NULL, NULL))
value = NULL;
/* error_mark_node is what fixup_noreturn_call changes PHI arguments
to. */
else if (value == error_mark_node)
value = NULL;
}
else if (is_gimple_assign (def_stmt))
{
bool no_value = false;
if (!dom_info_available_p (CDI_DOMINATORS))
{
struct walk_stmt_info wi;
memset (&wi, 0, sizeof (wi));
/* When removing blocks without following reverse dominance
order, we may sometimes encounter SSA_NAMEs that have
already been released, referenced in other SSA_DEFs that
we're about to release. Consider:
<bb X>:
v_1 = foo;
<bb Y>:
w_2 = v_1 + bar;
# DEBUG w => w_2
If we deleted BB X first, propagating the value of w_2
won't do us any good. It's too late to recover their
original definition of v_1: when it was deleted, it was
only referenced in other DEFs, it couldn't possibly know
it should have been retained, and propagating every
single DEF just in case it might have to be propagated
into a DEBUG STMT would probably be too wasteful.
When dominator information is not readily available, we
check for and accept some loss of debug information. But
if it is available, there's no excuse for us to remove
blocks in the wrong order, so we don't even check for
dead SSA NAMEs. SSA verification shall catch any
errors. */
if ((!gsi && !gimple_bb (def_stmt))
|| walk_gimple_op (def_stmt, find_released_ssa_name, &wi))
no_value = true;
}
if (!no_value)
value = gimple_assign_rhs_to_tree (def_stmt);
}
if (value)
{
/* If there's a single use of VAR, and VAR is the entire debug
expression (usecount would have been incremented again
otherwise), and the definition involves only constants and
SSA names, then we can propagate VALUE into this single use,
avoiding the temp.
We can also avoid using a temp if VALUE can be shared and
propagated into all uses, without generating expressions that
wouldn't be valid gimple RHSs.
Other cases that would require unsharing or non-gimple RHSs
are deferred to a debug temp, although we could avoid temps
at the expense of duplication of expressions. */
if (CONSTANT_CLASS_P (value)
|| gimple_code (def_stmt) == GIMPLE_PHI
|| (usecount == 1
&& (!gimple_assign_single_p (def_stmt)
|| is_gimple_min_invariant (value)))
|| is_gimple_reg (value))
;
else
{
gimple def_temp;
tree vexpr = make_node (DEBUG_EXPR_DECL);
def_temp = gimple_build_debug_bind (vexpr,
unshare_expr (value),
def_stmt);
DECL_ARTIFICIAL (vexpr) = 1;
TREE_TYPE (vexpr) = TREE_TYPE (value);
if (DECL_P (value))
DECL_MODE (vexpr) = DECL_MODE (value);
else
DECL_MODE (vexpr) = TYPE_MODE (TREE_TYPE (value));
if (gsi)
gsi_insert_before (gsi, def_temp, GSI_SAME_STMT);
else
{
gimple_stmt_iterator ngsi = gsi_for_stmt (def_stmt);
gsi_insert_before (&ngsi, def_temp, GSI_SAME_STMT);
}
value = vexpr;
}
}
FOR_EACH_IMM_USE_STMT (stmt, imm_iter, var)
{
if (!gimple_debug_bind_p (stmt))
continue;
if (value)
{
FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter)
/* unshare_expr is not needed here. vexpr is either a
SINGLE_RHS, that can be safely shared, some other RHS
that was unshared when we found it had a single debug
use, or a DEBUG_EXPR_DECL, that can be safely
shared. */
SET_USE (use_p, unshare_expr (value));
/* If we didn't replace uses with a debug decl fold the
resulting expression. Otherwise we end up with invalid IL. */
if (TREE_CODE (value) != DEBUG_EXPR_DECL)
{
gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
fold_stmt_inplace (&gsi);
}
}
else
gimple_debug_bind_reset_value (stmt);
update_stmt (stmt);
}
}
/* Insert a DEBUG BIND stmt before STMT for each DEF referenced by
other DEBUG stmts, and replace uses of the DEF with the
newly-created debug temp. */
void
insert_debug_temps_for_defs (gimple_stmt_iterator *gsi)
{
gimple stmt;
ssa_op_iter op_iter;
def_operand_p def_p;
if (!MAY_HAVE_DEBUG_STMTS)
return;
stmt = gsi_stmt (*gsi);
FOR_EACH_PHI_OR_STMT_DEF (def_p, stmt, op_iter, SSA_OP_DEF)
{
tree var = DEF_FROM_PTR (def_p);
if (TREE_CODE (var) != SSA_NAME)
continue;
insert_debug_temp_for_var_def (gsi, var);
}
}
/* Reset all debug stmts that use SSA_NAME(s) defined in STMT. */
void
reset_debug_uses (gimple stmt)
{
ssa_op_iter op_iter;
def_operand_p def_p;
imm_use_iterator imm_iter;
gimple use_stmt;
if (!MAY_HAVE_DEBUG_STMTS)
return;
FOR_EACH_PHI_OR_STMT_DEF (def_p, stmt, op_iter, SSA_OP_DEF)
{
tree var = DEF_FROM_PTR (def_p);
if (TREE_CODE (var) != SSA_NAME)
continue;
FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, var)
{
if (!gimple_debug_bind_p (use_stmt))
continue;
gimple_debug_bind_reset_value (use_stmt);
update_stmt (use_stmt);
}
}
}
/* Delete SSA DEFs for SSA versions in the TOREMOVE bitmap, removing
dominated stmts before their dominators, so that release_ssa_defs
stands a chance of propagating DEFs into debug bind stmts. */
void
release_defs_bitset (bitmap toremove)
{
unsigned j;
bitmap_iterator bi;
/* Performing a topological sort is probably overkill, this will
most likely run in slightly superlinear time, rather than the
pathological quadratic worst case. */
while (!bitmap_empty_p (toremove))
EXECUTE_IF_SET_IN_BITMAP (toremove, 0, j, bi)
{
bool remove_now = true;
tree var = ssa_name (j);
gimple stmt;
imm_use_iterator uit;
FOR_EACH_IMM_USE_STMT (stmt, uit, var)
{
ssa_op_iter dit;
def_operand_p def_p;
/* We can't propagate PHI nodes into debug stmts. */
if (gimple_code (stmt) == GIMPLE_PHI
|| is_gimple_debug (stmt))
continue;
/* If we find another definition to remove that uses
the one we're looking at, defer the removal of this
one, so that it can be propagated into debug stmts
after the other is. */
FOR_EACH_SSA_DEF_OPERAND (def_p, stmt, dit, SSA_OP_DEF)
{
tree odef = DEF_FROM_PTR (def_p);
if (bitmap_bit_p (toremove, SSA_NAME_VERSION (odef)))
{
remove_now = false;
break;
}
}
if (!remove_now)
BREAK_FROM_IMM_USE_STMT (uit);
}
if (remove_now)
{
gimple def = SSA_NAME_DEF_STMT (var);
gimple_stmt_iterator gsi = gsi_for_stmt (def);
if (gimple_code (def) == GIMPLE_PHI)
remove_phi_node (&gsi, true);
else
{
gsi_remove (&gsi, true);
release_defs (def);
}
bitmap_clear_bit (toremove, j);
}
}
}
/* Return true if SSA_NAME is malformed and mark it visited.
IS_VIRTUAL is true if this SSA_NAME was found inside a virtual
operand. */
static bool
verify_ssa_name (tree ssa_name, bool is_virtual)
{
if (TREE_CODE (ssa_name) != SSA_NAME)
{
error ("expected an SSA_NAME object");
return true;
}
if (SSA_NAME_IN_FREE_LIST (ssa_name))
{
error ("found an SSA_NAME that had been released into the free pool");
return true;
}
if (SSA_NAME_VAR (ssa_name) != NULL_TREE
&& TREE_TYPE (ssa_name) != TREE_TYPE (SSA_NAME_VAR (ssa_name)))
{
error ("type mismatch between an SSA_NAME and its symbol");
return true;
}
if (is_virtual && !virtual_operand_p (ssa_name))
{
error ("found a virtual definition for a GIMPLE register");
return true;
}
if (is_virtual && SSA_NAME_VAR (ssa_name) != gimple_vop (cfun))
{
error ("virtual SSA name for non-VOP decl");
return true;
}
if (!is_virtual && virtual_operand_p (ssa_name))
{
error ("found a real definition for a non-register");
return true;
}
if (SSA_NAME_IS_DEFAULT_DEF (ssa_name)
&& !gimple_nop_p (SSA_NAME_DEF_STMT (ssa_name)))
{
error ("found a default name with a non-empty defining statement");
return true;
}
return false;
}
/* Return true if the definition of SSA_NAME at block BB is malformed.
STMT is the statement where SSA_NAME is created.
DEFINITION_BLOCK is an array of basic blocks indexed by SSA_NAME
version numbers. If DEFINITION_BLOCK[SSA_NAME_VERSION] is set,
it means that the block in that array slot contains the
definition of SSA_NAME.
IS_VIRTUAL is true if SSA_NAME is created by a VDEF. */
static bool
verify_def (basic_block bb, basic_block *definition_block, tree ssa_name,
gimple stmt, bool is_virtual)
{
if (verify_ssa_name (ssa_name, is_virtual))
goto err;
if (SSA_NAME_VAR (ssa_name)
&& TREE_CODE (SSA_NAME_VAR (ssa_name)) == RESULT_DECL
&& DECL_BY_REFERENCE (SSA_NAME_VAR (ssa_name)))
{
error ("RESULT_DECL should be read only when DECL_BY_REFERENCE is set");
goto err;
}
if (definition_block[SSA_NAME_VERSION (ssa_name)])
{
error ("SSA_NAME created in two different blocks %i and %i",
definition_block[SSA_NAME_VERSION (ssa_name)]->index, bb->index);
goto err;
}
definition_block[SSA_NAME_VERSION (ssa_name)] = bb;
if (SSA_NAME_DEF_STMT (ssa_name) != stmt)
{
error ("SSA_NAME_DEF_STMT is wrong");
fprintf (stderr, "Expected definition statement:\n");
print_gimple_stmt (stderr, SSA_NAME_DEF_STMT (ssa_name), 4, TDF_VOPS);
fprintf (stderr, "\nActual definition statement:\n");
print_gimple_stmt (stderr, stmt, 4, TDF_VOPS);
goto err;
}
return false;
err:
fprintf (stderr, "while verifying SSA_NAME ");
print_generic_expr (stderr, ssa_name, 0);
fprintf (stderr, " in statement\n");
print_gimple_stmt (stderr, stmt, 4, TDF_VOPS);
return true;
}
/* Return true if the use of SSA_NAME at statement STMT in block BB is
malformed.
DEF_BB is the block where SSA_NAME was found to be created.
IDOM contains immediate dominator information for the flowgraph.
CHECK_ABNORMAL is true if the caller wants to check whether this use
is flowing through an abnormal edge (only used when checking PHI
arguments).
If NAMES_DEFINED_IN_BB is not NULL, it contains a bitmap of ssa names
that are defined before STMT in basic block BB. */
static bool
verify_use (basic_block bb, basic_block def_bb, use_operand_p use_p,
gimple stmt, bool check_abnormal, bitmap names_defined_in_bb)
{
bool err = false;
tree ssa_name = USE_FROM_PTR (use_p);
if (!TREE_VISITED (ssa_name))
if (verify_imm_links (stderr, ssa_name))
err = true;
TREE_VISITED (ssa_name) = 1;
if (gimple_nop_p (SSA_NAME_DEF_STMT (ssa_name))
&& SSA_NAME_IS_DEFAULT_DEF (ssa_name))
; /* Default definitions have empty statements. Nothing to do. */
else if (!def_bb)
{
error ("missing definition");
err = true;
}
else if (bb != def_bb
&& !dominated_by_p (CDI_DOMINATORS, bb, def_bb))
{
error ("definition in block %i does not dominate use in block %i",
def_bb->index, bb->index);
err = true;
}
else if (bb == def_bb
&& names_defined_in_bb != NULL
&& !bitmap_bit_p (names_defined_in_bb, SSA_NAME_VERSION (ssa_name)))
{
error ("definition in block %i follows the use", def_bb->index);
err = true;
}
if (check_abnormal
&& !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ssa_name))
{
error ("SSA_NAME_OCCURS_IN_ABNORMAL_PHI should be set");
err = true;
}
/* Make sure the use is in an appropriate list by checking the previous
element to make sure it's the same. */
if (use_p->prev == NULL)
{
error ("no immediate_use list");
err = true;
}
else
{
tree listvar;
if (use_p->prev->use == NULL)
listvar = use_p->prev->loc.ssa_name;
else
listvar = USE_FROM_PTR (use_p->prev);
if (listvar != ssa_name)
{
error ("wrong immediate use list");
err = true;
}
}
if (err)
{
fprintf (stderr, "for SSA_NAME: ");
print_generic_expr (stderr, ssa_name, TDF_VOPS);
fprintf (stderr, " in statement:\n");
print_gimple_stmt (stderr, stmt, 0, TDF_VOPS);
}
return err;
}
/* Return true if any of the arguments for PHI node PHI at block BB is
malformed.
DEFINITION_BLOCK is an array of basic blocks indexed by SSA_NAME
version numbers. If DEFINITION_BLOCK[SSA_NAME_VERSION] is set,
it means that the block in that array slot contains the
definition of SSA_NAME. */
static bool
verify_phi_args (gimple phi, basic_block bb, basic_block *definition_block)
{
edge e;
bool err = false;
size_t i, phi_num_args = gimple_phi_num_args (phi);
if (EDGE_COUNT (bb->preds) != phi_num_args)
{
error ("incoming edge count does not match number of PHI arguments");
err = true;
goto error;
}
for (i = 0; i < phi_num_args; i++)
{
use_operand_p op_p = gimple_phi_arg_imm_use_ptr (phi, i);
tree op = USE_FROM_PTR (op_p);
e = EDGE_PRED (bb, i);
if (op == NULL_TREE)
{
error ("PHI argument is missing for edge %d->%d",
e->src->index,
e->dest->index);
err = true;
goto error;
}
if (TREE_CODE (op) != SSA_NAME && !is_gimple_min_invariant (op))
{
error ("PHI argument is not SSA_NAME, or invariant");
err = true;
}
if (TREE_CODE (op) == SSA_NAME)
{
err = verify_ssa_name (op, virtual_operand_p (gimple_phi_result (phi)));
err |= verify_use (e->src, definition_block[SSA_NAME_VERSION (op)],
op_p, phi, e->flags & EDGE_ABNORMAL, NULL);
}
if (TREE_CODE (op) == ADDR_EXPR)
{
tree base = TREE_OPERAND (op, 0);
while (handled_component_p (base))
base = TREE_OPERAND (base, 0);
if ((TREE_CODE (base) == VAR_DECL
|| TREE_CODE (base) == PARM_DECL
|| TREE_CODE (base) == RESULT_DECL)
&& !TREE_ADDRESSABLE (base))
{
error ("address taken, but ADDRESSABLE bit not set");
err = true;
}
}
if (e->dest != bb)
{
error ("wrong edge %d->%d for PHI argument",
e->src->index, e->dest->index);
err = true;
}
if (err)
{
fprintf (stderr, "PHI argument\n");
print_generic_stmt (stderr, op, TDF_VOPS);
goto error;
}
}
error:
if (err)
{
fprintf (stderr, "for PHI node\n");
print_gimple_stmt (stderr, phi, 0, TDF_VOPS|TDF_MEMSYMS);
}
return err;
}
/* Verify common invariants in the SSA web.
TODO: verify the variable annotations. */
DEBUG_FUNCTION void
verify_ssa (bool check_modified_stmt)
{
size_t i;
basic_block bb;
basic_block *definition_block = XCNEWVEC (basic_block, num_ssa_names);
ssa_op_iter iter;
tree op;
enum dom_state orig_dom_state = dom_info_state (CDI_DOMINATORS);
bitmap names_defined_in_bb = BITMAP_ALLOC (NULL);
gcc_assert (!need_ssa_update_p (cfun));
timevar_push (TV_TREE_SSA_VERIFY);
/* Keep track of SSA names present in the IL. */
for (i = 1; i < num_ssa_names; i++)
{
tree name = ssa_name (i);
if (name)
{
gimple stmt;
TREE_VISITED (name) = 0;
verify_ssa_name (name, virtual_operand_p (name));
stmt = SSA_NAME_DEF_STMT (name);
if (!gimple_nop_p (stmt))
{
basic_block bb = gimple_bb (stmt);
verify_def (bb, definition_block,
name, stmt, virtual_operand_p (name));
}
}
}
calculate_dominance_info (CDI_DOMINATORS);
/* Now verify all the uses and make sure they agree with the definitions
found in the previous pass. */
FOR_EACH_BB (bb)
{
edge e;
gimple phi;
edge_iterator ei;
gimple_stmt_iterator gsi;
/* Make sure that all edges have a clear 'aux' field. */
FOR_EACH_EDGE (e, ei, bb->preds)
{
if (e->aux)
{
error ("AUX pointer initialized for edge %d->%d", e->src->index,
e->dest->index);
goto err;
}
}
/* Verify the arguments for every PHI node in the block. */
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
phi = gsi_stmt (gsi);
if (verify_phi_args (phi, bb, definition_block))
goto err;
bitmap_set_bit (names_defined_in_bb,
SSA_NAME_VERSION (gimple_phi_result (phi)));
}
/* Now verify all the uses and vuses in every statement of the block. */
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
gimple stmt = gsi_stmt (gsi);
use_operand_p use_p;
if (check_modified_stmt && gimple_modified_p (stmt))
{
error ("stmt (%p) marked modified after optimization pass: ",
(void *)stmt);
print_gimple_stmt (stderr, stmt, 0, TDF_VOPS);
goto err;
}
if (verify_ssa_operands (stmt))
{
print_gimple_stmt (stderr, stmt, 0, TDF_VOPS);
goto err;
}
if (gimple_debug_bind_p (stmt)
&& !gimple_debug_bind_has_value_p (stmt))
continue;
FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE|SSA_OP_VUSE)
{
op = USE_FROM_PTR (use_p);
if (verify_use (bb, definition_block[SSA_NAME_VERSION (op)],
use_p, stmt, false, names_defined_in_bb))
goto err;
}
FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_ALL_DEFS)
{
if (SSA_NAME_DEF_STMT (op) != stmt)
{
error ("SSA_NAME_DEF_STMT is wrong");
fprintf (stderr, "Expected definition statement:\n");
print_gimple_stmt (stderr, stmt, 4, TDF_VOPS);
fprintf (stderr, "\nActual definition statement:\n");
print_gimple_stmt (stderr, SSA_NAME_DEF_STMT (op),
4, TDF_VOPS);
goto err;
}
bitmap_set_bit (names_defined_in_bb, SSA_NAME_VERSION (op));
}
}
bitmap_clear (names_defined_in_bb);
}
free (definition_block);
/* Restore the dominance information to its prior known state, so
that we do not perturb the compiler's subsequent behavior. */
if (orig_dom_state == DOM_NONE)
free_dominance_info (CDI_DOMINATORS);
else
set_dom_info_availability (CDI_DOMINATORS, orig_dom_state);
BITMAP_FREE (names_defined_in_bb);
timevar_pop (TV_TREE_SSA_VERIFY);
return;
err:
internal_error ("verify_ssa failed");
}
/* Return true if the DECL_UID in both trees are equal. */
static int
uid_ssaname_map_eq (const void *va, const void *vb)
{
const_tree a = (const_tree) va;
const_tree b = (const_tree) vb;
return (a->ssa_name.var->decl_minimal.uid == b->ssa_name.var->decl_minimal.uid);
}
/* Hash a tree in a uid_decl_map. */
static unsigned int
uid_ssaname_map_hash (const void *item)
{
return ((const_tree)item)->ssa_name.var->decl_minimal.uid;
}
/* Initialize global DFA and SSA structures. */
void
init_tree_ssa (struct function *fn)
{
fn->gimple_df = ggc_alloc_cleared_gimple_df ();
fn->gimple_df->default_defs = htab_create_ggc (20, uid_ssaname_map_hash,
uid_ssaname_map_eq, NULL);
pt_solution_reset (&fn->gimple_df->escaped);
init_ssanames (fn, 0);
}
/* Do the actions required to initialize internal data structures used
in tree-ssa optimization passes. */
static unsigned int
execute_init_datastructures (void)
{
/* Allocate hash tables, arrays and other structures. */
gcc_assert (!cfun->gimple_df);
init_tree_ssa (cfun);
return 0;
}
/* Gate for IPCP optimization. */
static bool
gate_init_datastructures (void)
{
/* Do nothing for funcions that was produced already in SSA form. */
return !(cfun->curr_properties & PROP_ssa);
}
namespace {
const pass_data pass_data_init_datastructures =
{
GIMPLE_PASS, /* type */
"*init_datastructures", /* name */
OPTGROUP_NONE, /* optinfo_flags */
true, /* has_gate */
true, /* has_execute */
TV_NONE, /* tv_id */
PROP_cfg, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
0, /* todo_flags_finish */
};
class pass_init_datastructures : public gimple_opt_pass
{
public:
pass_init_datastructures (gcc::context *ctxt)
: gimple_opt_pass (pass_data_init_datastructures, ctxt)
{}
/* opt_pass methods: */
bool gate () { return gate_init_datastructures (); }
unsigned int execute () { return execute_init_datastructures (); }
}; // class pass_init_datastructures
} // anon namespace
gimple_opt_pass *
make_pass_init_datastructures (gcc::context *ctxt)
{
return new pass_init_datastructures (ctxt);
}
/* Deallocate memory associated with SSA data structures for FNDECL. */
void
delete_tree_ssa (void)
{
fini_ssanames ();
/* We no longer maintain the SSA operand cache at this point. */
if (ssa_operands_active (cfun))
fini_ssa_operands ();
htab_delete (cfun->gimple_df->default_defs);
cfun->gimple_df->default_defs = NULL;
pt_solution_reset (&cfun->gimple_df->escaped);
if (cfun->gimple_df->decls_to_pointers != NULL)
pointer_map_destroy (cfun->gimple_df->decls_to_pointers);
cfun->gimple_df->decls_to_pointers = NULL;
cfun->gimple_df->modified_noreturn_calls = NULL;
cfun->gimple_df = NULL;
/* We no longer need the edge variable maps. */
redirect_edge_var_map_destroy ();
}
/* Return true if EXPR is a useless type conversion, otherwise return
false. */
bool
tree_ssa_useless_type_conversion (tree expr)
{
/* If we have an assignment that merely uses a NOP_EXPR to change
the top of the RHS to the type of the LHS and the type conversion
is "safe", then strip away the type conversion so that we can
enter LHS = RHS into the const_and_copies table. */
if (CONVERT_EXPR_P (expr)
|| TREE_CODE (expr) == VIEW_CONVERT_EXPR
|| TREE_CODE (expr) == NON_LVALUE_EXPR)
return useless_type_conversion_p
(TREE_TYPE (expr),
TREE_TYPE (TREE_OPERAND (expr, 0)));
return false;
}
/* Strip conversions from EXP according to
tree_ssa_useless_type_conversion and return the resulting
expression. */
tree
tree_ssa_strip_useless_type_conversions (tree exp)
{
while (tree_ssa_useless_type_conversion (exp))
exp = TREE_OPERAND (exp, 0);
return exp;
}
/* Return true if T, an SSA_NAME, has an undefined value. */
bool
ssa_undefined_value_p (tree t)
{
tree var = SSA_NAME_VAR (t);
if (!var)
;
/* Parameters get their initial value from the function entry. */
else if (TREE_CODE (var) == PARM_DECL)
return false;
/* When returning by reference the return address is actually a hidden
parameter. */
else if (TREE_CODE (var) == RESULT_DECL && DECL_BY_REFERENCE (var))
return false;
/* Hard register variables get their initial value from the ether. */
else if (TREE_CODE (var) == VAR_DECL && DECL_HARD_REGISTER (var))
return false;
/* The value is undefined iff its definition statement is empty. */
return gimple_nop_p (SSA_NAME_DEF_STMT (t));
}
/* If necessary, rewrite the base of the reference tree *TP from
a MEM_REF to a plain or converted symbol. */
static void
maybe_rewrite_mem_ref_base (tree *tp, bitmap suitable_for_renaming)
{
tree sym;
while (handled_component_p (*tp))
tp = &TREE_OPERAND (*tp, 0);
if (TREE_CODE (*tp) == MEM_REF
&& TREE_CODE (TREE_OPERAND (*tp, 0)) == ADDR_EXPR
&& (sym = TREE_OPERAND (TREE_OPERAND (*tp, 0), 0))
&& DECL_P (sym)
&& !TREE_ADDRESSABLE (sym)
&& bitmap_bit_p (suitable_for_renaming, DECL_UID (sym)))
{
if (TREE_CODE (TREE_TYPE (sym)) == VECTOR_TYPE
&& useless_type_conversion_p (TREE_TYPE (*tp),
TREE_TYPE (TREE_TYPE (sym)))
&& multiple_of_p (sizetype, TREE_OPERAND (*tp, 1),
TYPE_SIZE_UNIT (TREE_TYPE (*tp))))
{
*tp = build3 (BIT_FIELD_REF, TREE_TYPE (*tp), sym,
TYPE_SIZE (TREE_TYPE (*tp)),
int_const_binop (MULT_EXPR,
bitsize_int (BITS_PER_UNIT),
TREE_OPERAND (*tp, 1)));
}
else if (TREE_CODE (TREE_TYPE (sym)) == COMPLEX_TYPE
&& useless_type_conversion_p (TREE_TYPE (*tp),
TREE_TYPE (TREE_TYPE (sym))))
{
*tp = build1 (integer_zerop (TREE_OPERAND (*tp, 1))
? REALPART_EXPR : IMAGPART_EXPR,
TREE_TYPE (*tp), sym);
}
else if (integer_zerop (TREE_OPERAND (*tp, 1)))
{
if (!useless_type_conversion_p (TREE_TYPE (*tp),
TREE_TYPE (sym)))
*tp = build1 (VIEW_CONVERT_EXPR,
TREE_TYPE (*tp), sym);
else
*tp = sym;
}
}
}
/* For a tree REF return its base if it is the base of a MEM_REF
that cannot be rewritten into SSA form. Otherwise return NULL_TREE. */
static tree
non_rewritable_mem_ref_base (tree ref)
{
tree base = ref;
/* A plain decl does not need it set. */
if (DECL_P (ref))
return NULL_TREE;
while (handled_component_p (base))
base = TREE_OPERAND (base, 0);
/* But watch out for MEM_REFs we cannot lower to a
VIEW_CONVERT_EXPR or a BIT_FIELD_REF. */
if (TREE_CODE (base) == MEM_REF
&& TREE_CODE (TREE_OPERAND (base, 0)) == ADDR_EXPR)
{
tree decl = TREE_OPERAND (TREE_OPERAND (base, 0), 0);
if ((TREE_CODE (TREE_TYPE (decl)) == VECTOR_TYPE
|| TREE_CODE (TREE_TYPE (decl)) == COMPLEX_TYPE)
&& useless_type_conversion_p (TREE_TYPE (base),
TREE_TYPE (TREE_TYPE (decl)))
&& mem_ref_offset (base).fits_uhwi ()
&& tree_to_double_int (TYPE_SIZE_UNIT (TREE_TYPE (decl)))
.ugt (mem_ref_offset (base))
&& multiple_of_p (sizetype, TREE_OPERAND (base, 1),
TYPE_SIZE_UNIT (TREE_TYPE (base))))
return NULL_TREE;
if (DECL_P (decl)
&& (!integer_zerop (TREE_OPERAND (base, 1))
|| (DECL_SIZE (decl)
!= TYPE_SIZE (TREE_TYPE (base)))
|| TREE_THIS_VOLATILE (decl) != TREE_THIS_VOLATILE (base)))
return decl;
}
return NULL_TREE;
}
/* For an lvalue tree LHS return true if it cannot be rewritten into SSA form.
Otherwise return true. */
static bool
non_rewritable_lvalue_p (tree lhs)
{
/* A plain decl is always rewritable. */
if (DECL_P (lhs))
return false;
/* A decl that is wrapped inside a MEM-REF that covers
it full is also rewritable.
??? The following could be relaxed allowing component
references that do not change the access size. */
if (TREE_CODE (lhs) == MEM_REF
&& TREE_CODE (TREE_OPERAND (lhs, 0)) == ADDR_EXPR
&& integer_zerop (TREE_OPERAND (lhs, 1)))
{
tree decl = TREE_OPERAND (TREE_OPERAND (lhs, 0), 0);
if (DECL_P (decl)
&& DECL_SIZE (decl) == TYPE_SIZE (TREE_TYPE (lhs))
&& (TREE_THIS_VOLATILE (decl) == TREE_THIS_VOLATILE (lhs)))
return false;
}
return true;
}
/* When possible, clear TREE_ADDRESSABLE bit or set DECL_GIMPLE_REG_P bit and
mark the variable VAR for conversion into SSA. Return true when updating
stmts is required. */
static void
maybe_optimize_var (tree var, bitmap addresses_taken, bitmap not_reg_needs,
bitmap suitable_for_renaming)
{
/* Global Variables, result decls cannot be changed. */
if (is_global_var (var)
|| TREE_CODE (var) == RESULT_DECL
|| bitmap_bit_p (addresses_taken, DECL_UID (var)))
return;
if (TREE_ADDRESSABLE (var)
/* Do not change TREE_ADDRESSABLE if we need to preserve var as
a non-register. Otherwise we are confused and forget to
add virtual operands for it. */
&& (!is_gimple_reg_type (TREE_TYPE (var))
|| TREE_CODE (TREE_TYPE (var)) == VECTOR_TYPE
|| TREE_CODE (TREE_TYPE (var)) == COMPLEX_TYPE
|| !bitmap_bit_p (not_reg_needs, DECL_UID (var))))
{
TREE_ADDRESSABLE (var) = 0;
if (is_gimple_reg (var))
bitmap_set_bit (suitable_for_renaming, DECL_UID (var));
if (dump_file)
{
fprintf (dump_file, "No longer having address taken: ");
print_generic_expr (dump_file, var, 0);
fprintf (dump_file, "\n");
}
}
if (!DECL_GIMPLE_REG_P (var)
&& !bitmap_bit_p (not_reg_needs, DECL_UID (var))
&& (TREE_CODE (TREE_TYPE (var)) == COMPLEX_TYPE
|| TREE_CODE (TREE_TYPE (var)) == VECTOR_TYPE)
&& !TREE_THIS_VOLATILE (var)
&& (TREE_CODE (var) != VAR_DECL || !DECL_HARD_REGISTER (var)))
{
DECL_GIMPLE_REG_P (var) = 1;
bitmap_set_bit (suitable_for_renaming, DECL_UID (var));
if (dump_file)
{
fprintf (dump_file, "Now a gimple register: ");
print_generic_expr (dump_file, var, 0);
fprintf (dump_file, "\n");
}
}
}
/* Compute TREE_ADDRESSABLE and DECL_GIMPLE_REG_P for local variables. */
void
execute_update_addresses_taken (void)
{
gimple_stmt_iterator gsi;
basic_block bb;
bitmap addresses_taken = BITMAP_ALLOC (NULL);
bitmap not_reg_needs = BITMAP_ALLOC (NULL);
bitmap suitable_for_renaming = BITMAP_ALLOC (NULL);
tree var;
unsigned i;
timevar_push (TV_ADDRESS_TAKEN);
/* Collect into ADDRESSES_TAKEN all variables whose address is taken within
the function body. */
FOR_EACH_BB (bb)
{
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
gimple stmt = gsi_stmt (gsi);
enum gimple_code code = gimple_code (stmt);
tree decl;
/* Note all addresses taken by the stmt. */
gimple_ior_addresses_taken (addresses_taken, stmt);
/* If we have a call or an assignment, see if the lhs contains
a local decl that requires not to be a gimple register. */
if (code == GIMPLE_ASSIGN || code == GIMPLE_CALL)
{
tree lhs = gimple_get_lhs (stmt);
if (lhs
&& TREE_CODE (lhs) != SSA_NAME
&& non_rewritable_lvalue_p (lhs))
{
decl = get_base_address (lhs);
if (DECL_P (decl))
bitmap_set_bit (not_reg_needs, DECL_UID (decl));
}
}
if (gimple_assign_single_p (stmt))
{
tree rhs = gimple_assign_rhs1 (stmt);
if ((decl = non_rewritable_mem_ref_base (rhs)))
bitmap_set_bit (not_reg_needs, DECL_UID (decl));
}
else if (code == GIMPLE_CALL)
{
for (i = 0; i < gimple_call_num_args (stmt); ++i)
{
tree arg = gimple_call_arg (stmt, i);
if ((decl = non_rewritable_mem_ref_base (arg)))
bitmap_set_bit (not_reg_needs, DECL_UID (decl));
}
}
else if (code == GIMPLE_ASM)
{
for (i = 0; i < gimple_asm_noutputs (stmt); ++i)
{
tree link = gimple_asm_output_op (stmt, i);
tree lhs = TREE_VALUE (link);
if (TREE_CODE (lhs) != SSA_NAME)
{
decl = get_base_address (lhs);
if (DECL_P (decl)
&& (non_rewritable_lvalue_p (lhs)
/* We cannot move required conversions from
the lhs to the rhs in asm statements, so
require we do not need any. */
|| !useless_type_conversion_p
(TREE_TYPE (lhs), TREE_TYPE (decl))))
bitmap_set_bit (not_reg_needs, DECL_UID (decl));
}
}
for (i = 0; i < gimple_asm_ninputs (stmt); ++i)
{
tree link = gimple_asm_input_op (stmt, i);
if ((decl = non_rewritable_mem_ref_base (TREE_VALUE (link))))
bitmap_set_bit (not_reg_needs, DECL_UID (decl));
}
}
}
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
size_t i;
gimple phi = gsi_stmt (gsi);
for (i = 0; i < gimple_phi_num_args (phi); i++)
{
tree op = PHI_ARG_DEF (phi, i), var;
if (TREE_CODE (op) == ADDR_EXPR
&& (var = get_base_address (TREE_OPERAND (op, 0))) != NULL
&& DECL_P (var))
bitmap_set_bit (addresses_taken, DECL_UID (var));
}
}
}
/* We cannot iterate over all referenced vars because that can contain
unused vars from BLOCK trees, which causes code generation differences
for -g vs. -g0. */
for (var = DECL_ARGUMENTS (cfun->decl); var; var = DECL_CHAIN (var))
maybe_optimize_var (var, addresses_taken, not_reg_needs,
suitable_for_renaming);
FOR_EACH_VEC_SAFE_ELT (cfun->local_decls, i, var)
maybe_optimize_var (var, addresses_taken, not_reg_needs,
suitable_for_renaming);
/* Operand caches need to be recomputed for operands referencing the updated
variables and operands need to be rewritten to expose bare symbols. */
if (!bitmap_empty_p (suitable_for_renaming))
{
FOR_EACH_BB (bb)
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi);)
{
gimple stmt = gsi_stmt (gsi);
/* Re-write TARGET_MEM_REFs of symbols we want to
rewrite into SSA form. */
if (gimple_assign_single_p (stmt))
{
tree lhs = gimple_assign_lhs (stmt);
tree rhs, *rhsp = gimple_assign_rhs1_ptr (stmt);
tree sym;
/* We shouldn't have any fancy wrapping of
component-refs on the LHS, but look through
VIEW_CONVERT_EXPRs as that is easy. */
while (TREE_CODE (lhs) == VIEW_CONVERT_EXPR)
lhs = TREE_OPERAND (lhs, 0);
if (TREE_CODE (lhs) == MEM_REF
&& TREE_CODE (TREE_OPERAND (lhs, 0)) == ADDR_EXPR
&& integer_zerop (TREE_OPERAND (lhs, 1))
&& (sym = TREE_OPERAND (TREE_OPERAND (lhs, 0), 0))
&& DECL_P (sym)
&& !TREE_ADDRESSABLE (sym)
&& bitmap_bit_p (suitable_for_renaming, DECL_UID (sym)))
lhs = sym;
else
lhs = gimple_assign_lhs (stmt);
/* Rewrite the RHS and make sure the resulting assignment
is validly typed. */
maybe_rewrite_mem_ref_base (rhsp, suitable_for_renaming);
rhs = gimple_assign_rhs1 (stmt);
if (gimple_assign_lhs (stmt) != lhs
&& !useless_type_conversion_p (TREE_TYPE (lhs),
TREE_TYPE (rhs)))
rhs = fold_build1 (VIEW_CONVERT_EXPR,
TREE_TYPE (lhs), rhs);
if (gimple_assign_lhs (stmt) != lhs)
gimple_assign_set_lhs (stmt, lhs);
/* For var ={v} {CLOBBER}; where var lost
TREE_ADDRESSABLE just remove the stmt. */
if (DECL_P (lhs)
&& TREE_CLOBBER_P (rhs)
&& bitmap_bit_p (suitable_for_renaming, DECL_UID (lhs)))
{
unlink_stmt_vdef (stmt);
gsi_remove (&gsi, true);
release_defs (stmt);
continue;
}
if (gimple_assign_rhs1 (stmt) != rhs)
{
gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
gimple_assign_set_rhs_from_tree (&gsi, rhs);
}
}
else if (gimple_code (stmt) == GIMPLE_CALL)
{
unsigned i;
for (i = 0; i < gimple_call_num_args (stmt); ++i)
{
tree *argp = gimple_call_arg_ptr (stmt, i);
maybe_rewrite_mem_ref_base (argp, suitable_for_renaming);
}
}
else if (gimple_code (stmt) == GIMPLE_ASM)
{
unsigned i;
for (i = 0; i < gimple_asm_noutputs (stmt); ++i)
{
tree link = gimple_asm_output_op (stmt, i);
maybe_rewrite_mem_ref_base (&TREE_VALUE (link),
suitable_for_renaming);
}
for (i = 0; i < gimple_asm_ninputs (stmt); ++i)
{
tree link = gimple_asm_input_op (stmt, i);
maybe_rewrite_mem_ref_base (&TREE_VALUE (link),
suitable_for_renaming);
}
}
else if (gimple_debug_bind_p (stmt)
&& gimple_debug_bind_has_value_p (stmt))
{
tree *valuep = gimple_debug_bind_get_value_ptr (stmt);
tree decl;
maybe_rewrite_mem_ref_base (valuep, suitable_for_renaming);
decl = non_rewritable_mem_ref_base (*valuep);
if (decl
&& bitmap_bit_p (suitable_for_renaming, DECL_UID (decl)))
gimple_debug_bind_reset_value (stmt);
}
if (gimple_references_memory_p (stmt)
|| is_gimple_debug (stmt))
update_stmt (stmt);
gsi_next (&gsi);
}
/* Update SSA form here, we are called as non-pass as well. */
if (number_of_loops (cfun) > 1
&& loops_state_satisfies_p (LOOP_CLOSED_SSA))
rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
else
update_ssa (TODO_update_ssa);
}
BITMAP_FREE (not_reg_needs);
BITMAP_FREE (addresses_taken);
BITMAP_FREE (suitable_for_renaming);
timevar_pop (TV_ADDRESS_TAKEN);
}
namespace {
const pass_data pass_data_update_address_taken =
{
GIMPLE_PASS, /* type */
"addressables", /* name */
OPTGROUP_NONE, /* optinfo_flags */
false, /* has_gate */
false, /* has_execute */
TV_ADDRESS_TAKEN, /* tv_id */
PROP_ssa, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
TODO_update_address_taken, /* todo_flags_finish */
};
class pass_update_address_taken : public gimple_opt_pass
{
public:
pass_update_address_taken (gcc::context *ctxt)
: gimple_opt_pass (pass_data_update_address_taken, ctxt)
{}
/* opt_pass methods: */
}; // class pass_update_address_taken
} // anon namespace
gimple_opt_pass *
make_pass_update_address_taken (gcc::context *ctxt)
{
return new pass_update_address_taken (ctxt);
}