This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
patch to fix outstanding problems with analysis of statics.
- From: Kenneth Zadeck <zadeck at naturalbridge dot com>
- To: gcc-patches at gcc dot gnu dot org, "Berlin, Daniel" <dberlin at dberlin dot org>,"Novillo, Diego" <dnovillo at redhat dot com>, Jan Hubicka <jh at suse dot cz>
- Date: Thu, 07 Oct 2004 14:52:34 -0400
- Subject: patch to fix outstanding problems with analysis of statics.
This patch fixes the space blowup associated with analyzing statics that
jan discovered in my previous patch.
This patch also fixes several correctness problems that came to light in
our discussion about the initial patch. These included
some misunderstandings on my part about what the edges meant in the
cgraph structure.
Also, I discovered a problems associated with the scanning of the trees
that have been addressed in this patch.
Lastly, the static analysis code has been broken out to a separate file
(as per the private request of Jan).
The test case should go in gcc.c-torture/execute.
kenny
Index: gcc/Makefile.in
===================================================================
RCS file: /cvs/gcc/gcc/gcc/Makefile.in,v
retrieving revision 1.1408
diff -c -3 -p -r1.1408 Makefile.in
*** gcc/Makefile.in 6 Oct 2004 04:47:25 -0000 1.1408
--- gcc/Makefile.in 7 Oct 2004 18:39:50 -0000
*************** OBJS-common = \
*** 929,935 ****
OBJS-md = $(out_object_file)
OBJS-archive = $(EXTRA_OBJS) $(host_hook_obj) tree-inline.o \
! cgraph.o cgraphunit.o tree-nomudflap.o
OBJS = $(OBJS-common) $(out_object_file) $(OBJS-archive)
--- 929,935 ----
OBJS-md = $(out_object_file)
OBJS-archive = $(EXTRA_OBJS) $(host_hook_obj) tree-inline.o \
! cgraph.o cgraphunit.o cgraph-static-anal.o tree-nomudflap.o
OBJS = $(OBJS-common) $(out_object_file) $(OBJS-archive)
*************** cgraph.o : cgraph.c $(CONFIG_H) $(SYSTEM
*** 1924,1929 ****
--- 1924,1931 ----
cgraphunit.o : cgraphunit.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(TREE_H) \
langhooks.h tree-inline.h toplev.h $(FLAGS_H) $(GGC_H) $(TARGET_H) $(CGRAPH_H) intl.h \
function.h $(TREE_GIMPLE_H) $(TREE_FLOW_H)
+ cgraph-static-anal.o : cgraph-static-anal.c $(CONFIG_H) $(SYSTEM_H) coretypes.h \
+ $(TM_H) $(TREE_H) langhooks.h $(FLAGS_H) $(GGC_H) $(CGRAPH_H)
coverage.o : coverage.c gcov-io.c $(CONFIG_H) $(SYSTEM_H) coretypes.h \
$(TM_H) $(RTL_H) $(TREE_H) $(FLAGS_H) output.h $(REGS_H) $(EXPR_H) function.h \
toplev.h $(GGC_H) $(TARGET_H) langhooks.h $(COVERAGE_H) libfuncs.h \
*************** GTFILES = $(srcdir)/input.h $(srcdir)/co
*** 2405,2411 ****
$(srcdir)/cselib.h $(srcdir)/basic-block.h $(srcdir)/cgraph.h \
$(srcdir)/c-common.h $(srcdir)/c-tree.h $(srcdir)/reload.h \
$(srcdir)/alias.c $(srcdir)/bitmap.c $(srcdir)/cselib.c $(srcdir)/cgraph.c \
! $(srcdir)/cgraphunit.c \
$(srcdir)/dbxout.c $(srcdir)/dwarf2out.c $(srcdir)/dwarf2asm.c \
$(srcdir)/dojump.c \
$(srcdir)/emit-rtl.c $(srcdir)/except.c $(srcdir)/explow.c $(srcdir)/expr.c \
--- 2407,2413 ----
$(srcdir)/cselib.h $(srcdir)/basic-block.h $(srcdir)/cgraph.h \
$(srcdir)/c-common.h $(srcdir)/c-tree.h $(srcdir)/reload.h \
$(srcdir)/alias.c $(srcdir)/bitmap.c $(srcdir)/cselib.c $(srcdir)/cgraph.c \
! $(srcdir)/cgraph-static-anal.c \
$(srcdir)/dbxout.c $(srcdir)/dwarf2out.c $(srcdir)/dwarf2asm.c \
$(srcdir)/dojump.c \
$(srcdir)/emit-rtl.c $(srcdir)/except.c $(srcdir)/explow.c $(srcdir)/expr.c \
cvs diff: gcc/cgraph-static-anal.c is a new entry, no comparison available
Index: gcc/cgraph.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cgraph.c,v
retrieving revision 1.58
diff -c -3 -p -r1.58 cgraph.c
*** gcc/cgraph.c 20 Sep 2004 20:38:16 -0000 1.58
--- gcc/cgraph.c 7 Oct 2004 18:39:51 -0000
*************** cgraph_remove_node (struct cgraph_node *
*** 317,324 ****
slot = htab_find_slot (cgraph_hash, node, NO_INSERT);
if (*slot == node)
{
! if (node->next_clone)
! *slot = node->next_clone;
else
{
htab_clear_slot (cgraph_hash, slot);
--- 317,333 ----
slot = htab_find_slot (cgraph_hash, node, NO_INSERT);
if (*slot == node)
{
! if (node->next_clone)
! {
! struct cgraph_node *new_node = node->next_clone;
! *slot = new_node;
! if ((node->master_clone)
! && (node->master_clone->master_clone == node))
! {
! new_node->master_clone->master_clone = new_node;
! new_node->static_vars_info = node->static_vars_info;
! }
! }
else
{
htab_clear_slot (cgraph_hash, slot);
*************** cgraph_clone_node (struct cgraph_node *n
*** 694,699 ****
--- 703,775 ----
return new;
}
+ /* Return true if N is an master_clone, (see cgraph_master_clone). */
+
+ bool
+ cgraph_is_master_clone (struct cgraph_node *n)
+ {
+ return (n == cgraph_master_clone (n));
+ }
+
+ /* Return true if N is an immortal_master_clone, (see
+ cgraph_immortal_master_clone). */
+
+ bool
+ cgraph_is_immortal_master_clone (struct cgraph_node *n)
+ {
+ return (n == cgraph_immortal_master_clone (n));
+ }
+
+ /* Return pointer to the callgraph node presenting master clone of N.
+ For functions defined outside the compilation unit, NULL is
+ returned. For inline functions that have no out of line clone to
+ be output this the choice of which is the master is random and this
+ node will not exist after inlining has happened. For inline
+ functions that do have an out of line clone to be output, the
+ master clone is a cgraph node that will not be released before any
+ of the clones. */
+
+ struct cgraph_node *
+ cgraph_master_clone (struct cgraph_node *n)
+ {
+ if (n->local.external)
+ return NULL;
+
+ if (!n->master_clone)
+ {
+ struct cgraph_node *mc = cgraph_node (n->decl);
+ if (!mc->master_clone)
+ {
+ mc->master_clone = ggc_alloc (sizeof (struct cgraph_master_clone *));
+ mc->master_clone->master_clone = mc;
+ }
+ n->master_clone = mc->master_clone;
+ }
+
+ return n->master_clone->master_clone;
+ }
+
+ /* Return pointer to the callgraph node presenting immortal master
+ clone of N, if one exists, NULL otherwise. The immortal master
+ clone is a cgraph node that will not be released before any of the
+ clones and thus it is usefull for holding information about
+ function body that is the same for all clones. Inline functions
+ that have no out of line clone to be output have a master node that
+ is not immortal. For functions defined outside the compilation
+ unit, NULL is returned. */
+
+ struct cgraph_node *
+ cgraph_immortal_master_clone (struct cgraph_node *n)
+ {
+ struct cgraph_node *master = cgraph_master_clone (n);
+ if (!master)
+ return NULL;
+
+ if (master->global.inlined_to)
+ return NULL;
+ return master;
+ }
+
/* NODE is no longer nested function; update cgraph accordingly. */
void
cgraph_unnest_node (struct cgraph_node *node)
Index: gcc/cgraph.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cgraph.h,v
retrieving revision 1.38
diff -c -3 -p -r1.38 cgraph.h
*** gcc/cgraph.h 20 Sep 2004 20:38:16 -0000 1.38
--- gcc/cgraph.h 7 Oct 2004 18:39:51 -0000
*************** struct cgraph_local_info GTY(())
*** 40,49 ****
/* Set when function is defined in another compilation unit. */
bool external;
! /* Set when this function calls a function external of the
! compilation unit. In general, such calls are modeled as reading
! and writing all variables (both bits on) but sometime there are
! attributes on the called function so we can do better. */
bool calls_read_all;
bool calls_write_all;
--- 40,50 ----
/* Set when function is defined in another compilation unit. */
bool external;
! /* Set when this function calls another function external to the
! compilation unit or if the function has a asm clobber of memory.
! In general, such calls are modeled as reading and writing all
! variables (both bits on) but sometime there are attributes on the
! called function so we can do better. */
bool calls_read_all;
bool calls_write_all;
*************** struct cgraph_local_info GTY(())
*** 59,68 ****
/* True when the function has been originally extern inline, but it is
redefined now. */
bool redefined_extern_inline;
-
- /* True if statics_read_for_function and
- statics_written_for_function contain valid data. */
- bool for_functions_valid;
};
/* Information about the function that needs to be computed globally
--- 60,65 ----
*************** struct global_static_vars_info_d GTY(())
*** 125,131 ****
bitmap statics_not_read_by_ann_uid;
bitmap statics_not_written_by_ann_uid;
! /* var_anns_valid is reset at the start of compilation for each
function because the indexing that the "_var_anns" is based
on is invalidated between function compilations. This allows for
lazy creation of the "_var_ann" variables. */
--- 122,128 ----
bitmap statics_not_read_by_ann_uid;
bitmap statics_not_written_by_ann_uid;
! /* Var_anns_valid is reset at the start of compilation for each
function because the indexing that the "_var_anns" is based
on is invalidated between function compilations. This allows for
lazy creation of the "_var_ann" variables. */
*************** struct static_vars_info_d GTY(())
*** 152,157 ****
--- 149,161 ----
global_static_vars_info_t global;
};
+ /* Indirect structure to master clone node to allow the master clone
+ to be changed in constant time. */
+ struct cgraph_master_clone GTY(())
+ {
+ struct cgraph_node *master_clone;
+ };
+
typedef struct static_vars_info_d *static_vars_info_t;
/* The cgraph data structure.
*************** struct cgraph_node GTY((chain_next ("%h.
*** 176,181 ****
--- 180,188 ----
struct cgraph_node *next_clone;
/* Pointer to next node in a recursive call graph cycle; */
struct cgraph_node *next_cycle;
+ /* Pointer to a single unique cgraph node for this function. If the
+ function is to be output, this is the copy that will survive. */
+ struct cgraph_master_clone *master_clone;
PTR GTY ((skip)) aux;
struct cgraph_local_info local;
*************** extern GTY(()) struct cgraph_node *cgrap
*** 241,246 ****
--- 248,256 ----
extern GTY(()) int cgraph_varpool_n_nodes;
extern GTY(()) struct cgraph_varpool_node *cgraph_varpool_nodes_queue;
+ /* Holds the value of "memory". */
+ extern tree memory_identifier_string;
+
/* In cgraph.c */
void dump_cgraph (FILE *);
void dump_cgraph_node (FILE *, struct cgraph_node *);
*************** bool cgraph_varpool_assemble_pending_dec
*** 266,271 ****
--- 276,286 ----
void cgraph_redirect_edge_callee (struct cgraph_edge *, struct cgraph_node *);
bool cgraph_function_possibly_inlined_p (tree);
+ bool cgraph_is_master_clone (struct cgraph_node *);
+ bool cgraph_is_immortal_master_clone (struct cgraph_node *);
+ struct cgraph_node *cgraph_master_clone (struct cgraph_node *);
+ struct cgraph_node *cgraph_immortal_master_clone (struct cgraph_node *);
+
void cgraph_unnest_node (struct cgraph_node *node);
/* In cgraphunit.c */
*************** void cgraph_mark_inline_edge (struct cgr
*** 284,291 ****
void cgraph_clone_inlined_nodes (struct cgraph_edge *e, bool duplicate);
void cgraph_build_static_cdtor (char which, tree body, int priority);
void cgraph_reset_static_var_maps (void);
bitmap get_global_statics_not_read (tree fn);
bitmap get_global_statics_not_written(tree fn);
- void init_cgraph (void);
#endif /* GCC_CGRAPH_H */
--- 299,309 ----
void cgraph_clone_inlined_nodes (struct cgraph_edge *e, bool duplicate);
void cgraph_build_static_cdtor (char which, tree body, int priority);
void cgraph_reset_static_var_maps (void);
+ void init_cgraph (void);
+
+ /* In cgraph-static-anal.c */
+ void cgraph_characterize_statics (FILE *);
bitmap get_global_statics_not_read (tree fn);
bitmap get_global_statics_not_written(tree fn);
#endif /* GCC_CGRAPH_H */
Index: gcc/cgraphunit.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cgraphunit.c,v
retrieving revision 1.86
diff -c -3 -p -r1.86 cgraphunit.c
*** gcc/cgraphunit.c 1 Oct 2004 15:11:10 -0000 1.86
--- gcc/cgraphunit.c 7 Oct 2004 18:39:51 -0000
*************** Software Foundation, 59 Temple Place - S
*** 164,182 ****
into account, while cgraph_decide_inlining_incrementally considers
only one function at a time and is used in non-unit-at-a-time mode. */
-
- /* Additionally this file gathers information about how local statics
- are used. This is done in cgraph_characterize_statics. After the
- call graph has been built, each function is analyzed to determine
- which local static variables are either read or written or have
- their address taken. Any local static that has its address taken
- is removed from consideration. Once the local read and writes
- are determined, a transitive closure of this information is
- performed over the call graph to determine the worst case set of
- side effects of each call. In a later part of the compiler, these
- local and global sets are examined to make the call clobbering less
- traumatic both with respect to aliasing and to code generation. */
-
#include "config.h"
#include "system.h"
#include "coretypes.h"
--- 164,169 ----
*************** static htab_t visited_nodes;
*** 227,260 ****
static FILE *cgraph_dump_file;
- /* These splay trees contain all of the static variables that are
- being considered by the compilation level alias analysis. For
- module_at_a_time compilation, this is the set of static but not
- public variables. Any variables that either have their address
- taken or participate in otherwise unsavory operations are deleted
- from this list. */
- static GTY((param1_is(tree), param2_is(tree)))
- splay_tree static_vars_to_consider_by_tree;
-
- /* FIXME -- PROFILE-RESTRUCTURE: change comment from DECL_UID to var-ann. */
- /* same as above but indexed by DECL_UID */
- static GTY((param1_is(int), param2_is(tree)))
- splay_tree static_vars_to_consider_by_uid;
-
- /* This bitmap is used to knock out the module static variables whose
- addresses have been taken and passed around. This is indexed by
- uid. */
- static bitmap module_statics_escape;
-
- /* FIXME -- PROFILE-RESTRUCTURE: change comment from DECL_UID to var-ann. */
- /* A bit is set for every module static we are considering and is
- indexed by DECL_UID. This is ored into the local info when asm
- code is found that clobbers all memory. */
- static GTY(()) bitmap all_module_statics;
-
- /* Holds the value of "memory". */
- static tree memory_identifier;
-
/* Determine if function DECL is needed. That is, visible to something
either outside this translation unit, something magic in the system
configury, or (if not doing unit-at-a-time) to something we havn't
--- 214,219 ----
*************** decide_is_function_needed (struct cgraph
*** 321,510 ****
return false;
}
- /* Debugging function for postorder and inorder code. NOTE is a string
- that is printed before the nodes are printed. ORDER is an array of
- cgraph_nodes that has COUNT useful nodes in it. */
-
- static void
- print_order (const char * note, struct cgraph_node** order, int count)
- {
- int i;
- fprintf (cgraph_dump_file, "\n\n ordered call graph: %s\n", note);
-
- for (i = count - 1; i >= 0; i--)
- {
- struct cgraph_edge *edge;
-
- fprintf (cgraph_dump_file, "\n %s<-(", cgraph_node_name (order[i]));
-
- for (edge = order[i]->callers; edge; edge = edge->next_caller)
- fprintf (cgraph_dump_file, " %s", cgraph_node_name (edge->caller));
- fprintf (cgraph_dump_file, ")");
- }
- fprintf (cgraph_dump_file, "\n");
- }
-
- /* FIXME -- PROFILE-RESTRUCTURE: Remove this function, it becomes a nop. */
- /* Convert IN_DECL bitmap which is indexed by DECL_UID to IN_ANN, a
- bitmap indexed by var_ann (VAR_DECL)->uid. */
-
- static void
- convert_UIDs_in_bitmap (bitmap in_ann, bitmap in_decl)
- {
- int index;
- bitmap_iterator bi;
-
- EXECUTE_IF_SET_IN_BITMAP(in_decl, 0, index, bi)
- {
- splay_tree_node n =
- splay_tree_lookup (static_vars_to_consider_by_uid, index);
- if (n != NULL)
- {
- tree t = (tree)n->value;
- var_ann_t va = var_ann (t);
- if (va)
- bitmap_set_bit(in_ann, va->uid);
- }
- }
- }
-
- /* FIXME -- PROFILE-RESTRUCTURE: Delete all stmts initing *_decl_uid
- variables. Add code to create a var_ann for tree node within the
- cgraph_node and have it point to the newly created
- static_vars_info. */
- /* Create a new static_vars_info structure and place it into
- cgraph_node, NODE. INIT_GLOBAL causes the global part of the
- structure to be initialized. */
- static static_vars_info_t
- new_static_vars_info(struct cgraph_node* node,
- bool init_global)
- {
- static_vars_info_t info = ggc_calloc (1, sizeof (struct static_vars_info_d));
- local_static_vars_info_t l
- = ggc_calloc (1, sizeof (struct local_static_vars_info_d));
-
- /* Add the info to the tree's annotation. */
- var_ann_t var_ann = get_var_ann(node->decl);
- node->static_vars_info = info;
- var_ann->static_vars_info = info;
-
- info->local = l;
- l->statics_read_by_decl_uid = BITMAP_GGC_ALLOC ();
- l->statics_written_by_decl_uid = BITMAP_GGC_ALLOC ();
-
- if (init_global)
- {
- global_static_vars_info_t g
- = ggc_calloc (1, sizeof (struct global_static_vars_info_d));
- info->global = g;
- g->statics_read_by_decl_uid = BITMAP_GGC_ALLOC ();
- g->statics_written_by_decl_uid = BITMAP_GGC_ALLOC ();
- g->statics_read_by_ann_uid = BITMAP_GGC_ALLOC ();
- g->statics_written_by_ann_uid = BITMAP_GGC_ALLOC ();
- g->statics_not_read_by_decl_uid = BITMAP_GGC_ALLOC ();
- g->statics_not_written_by_decl_uid = BITMAP_GGC_ALLOC ();
- g->statics_not_read_by_ann_uid = BITMAP_GGC_ALLOC ();
- g->statics_not_written_by_ann_uid = BITMAP_GGC_ALLOC ();
- }
- return info;
- }
-
-
- /* FIXME -- PROFILE-RESTRUCTURE: Remove this function, it becomes a
- nop. */
- /* The bitmaps used to represent the static global variables are
- indexed by DECL_UID however, this is not used inside of functions
- to index the ssa variables. The denser var_ann (VAR_DECL)->uid is
- used there. This function is called from
- tree_dfa:find_referenced_vars after the denser representation is
- built. This function invalidates any cached indexes. */
-
- void
- cgraph_reset_static_var_maps (void)
- {
- struct cgraph_node *node;
-
- for (node = cgraph_nodes; node; node = node->next)
- {
- static_vars_info_t info = node->static_vars_info;
- if (info)
- {
- global_static_vars_info_t g = info->global;
- if (g->var_anns_valid)
- {
- bitmap_clear (g->statics_read_by_ann_uid);
- bitmap_clear (g->statics_written_by_ann_uid);
- bitmap_clear (g->statics_not_read_by_ann_uid);
- bitmap_clear (g->statics_not_written_by_ann_uid);
- g->var_anns_valid = false;
- }
- }
- else
- /* Handle the case where a cgraph node has been inserted
- after the analysis. We know nothing. */
- new_static_vars_info(node, true);
- }
- }
-
- /* Get the global static_vars_info structure for the function FN and
- make sure the ann_uid's bitmaps are properly converted. */
-
- static global_static_vars_info_t
- get_global_static_vars_info (tree fn)
- {
- global_static_vars_info_t g;
-
- /* Was not compiled -O2 or higher. */
- static_vars_info_t info = get_var_ann(fn)->static_vars_info;
- if (!info)
- return NULL;
-
- g = info->global;
- if (!g->var_anns_valid)
- {
- convert_UIDs_in_bitmap (g->statics_read_by_ann_uid,
- g->statics_read_by_decl_uid);
- convert_UIDs_in_bitmap (g->statics_written_by_ann_uid,
- g->statics_written_by_decl_uid);
- convert_UIDs_in_bitmap (g->statics_not_read_by_ann_uid,
- g->statics_not_read_by_decl_uid);
- convert_UIDs_in_bitmap (g->statics_not_written_by_ann_uid,
- g->statics_not_written_by_decl_uid);
- g->var_anns_valid = true;
- }
- return g;
- }
-
- /* Return a bitmap indexed by var_ann (VAR_DECL)->uid for the static
- variables that are not read during the execution of the function
- FN. Returns NULL if no data is available, such as it was not
- compiled with -O2 or higher. */
-
- bitmap
- get_global_statics_not_read (tree fn)
- {
- global_static_vars_info_t g = get_global_static_vars_info (fn);
- if (g)
- return g->statics_not_read_by_ann_uid;
- else
- return NULL;
- }
-
- /* Return a bitmap indexed by var_ann (VAR_DECL)->uid for the static
- variables that are not written during the execution of the function
- FN. Note that variables written may or may not be read during the
- function call. Returns NULL if no data is available, such as it
- was not compiled with -O2 or higher. */
-
- bitmap
- get_global_statics_not_written (tree fn)
- {
- global_static_vars_info_t g = get_global_static_vars_info (fn);
- if (g)
- return g->statics_not_written_by_ann_uid;
- else
- return NULL;
- }
/* When not doing unit-at-a-time, output all functions enqueued.
Return true when such a functions were found. */
--- 280,285 ----
*************** verify_cgraph_node (struct cgraph_node *
*** 768,773 ****
--- 543,554 ----
cgraph_node_name (e->caller), cgraph_node_name (e->callee));
error_found = true;
}
+ if (!node->global.inlined_to && node != cgraph_node (node->decl))
+ {
+ error ("Out of line copy %s is not the first in the clones list",
+ cgraph_node_name (node));
+ error_found = true;
+ }
for (e = node->callers; e; e = e->next_caller)
{
if (!e->inline_failed)
*************** cgraph_postorder (struct cgraph_node **o
*** 1124,1272 ****
return order_pos;
}
- struct searchc_env {
- struct cgraph_node **stack;
- int stack_size;
- struct cgraph_node **result;
- int order_pos;
- splay_tree nodes_marked_new;
- bool reduce;
- int count;
- };
-
- struct dfs_info {
- int dfn_number;
- int low_link;
- bool new;
- bool on_stack;
- };
-
- /* This is an implementation of Tarjan's strongly connected region
- finder as reprinted in Aho Hopcraft and Ullman's The Design and
- Analysis of Computer Programs (1975) pages 192-193. This version
- has been customized for cgraph_nodes. The env parameter is because
- it is recursive and there are no nested functions here. This
- function should only be called from itself or
- cgraph_reduced_inorder. ENV is a stack env and would be
- unnecessary if C had nested functions. V is the node to start
- searching from. */
-
- static void
- searchc (struct searchc_env* env, struct cgraph_node *v)
- {
- struct cgraph_edge *edge;
- struct dfs_info *v_info = v->aux;
-
- /* mark node as old */
- v_info->new = false;
- splay_tree_remove (env->nodes_marked_new, v->uid);
-
- v_info->dfn_number = env->count;
- v_info->low_link = env->count;
- env->count++;
- env->stack[(env->stack_size)++] = v;
- v_info->on_stack = true;
-
- for (edge = v->callers; edge; edge = edge->next_caller)
- {
- struct dfs_info * w_info;
- struct cgraph_node *w = edge->caller;
- /* skip the nodes that we are supposed to ignore */
- if (w->aux)
- {
- w_info = w->aux;
- if (w_info->new)
- {
- searchc (env, w);
- v_info->low_link =
- (v_info->low_link < w_info->low_link) ?
- v_info->low_link : w_info->low_link;
- }
- else
- if ((w_info->dfn_number < v_info->dfn_number)
- && (w_info->on_stack))
- v_info->low_link =
- (w_info->dfn_number < v_info->low_link) ?
- w_info->dfn_number : v_info->low_link;
- }
- }
-
-
- if (v_info->low_link == v_info->dfn_number)
- {
- struct cgraph_node *last = NULL;
- struct cgraph_node *x;
- struct dfs_info *x_info;
- do {
- x = env->stack[--(env->stack_size)];
- x_info = x->aux;
- x_info->on_stack = false;
-
- if (env->reduce)
- {
- x->next_cycle = last;
- last = x;
- }
- else
- env->result[env->order_pos++] = x;
- }
- while (v != x);
- if (env->reduce)
- env->result[env->order_pos++] = v;
- }
- }
-
- /* Topsort the call graph by caller relation. Put the result in ORDER.
-
- The REDUCE flag is true if you want the cycles reduced to single
- nodes. Only consider nodes that have the output bit set. */
-
- static int
- cgraph_reduced_inorder (struct cgraph_node **order, bool reduce)
- {
- struct cgraph_node *node;
- struct searchc_env env;
- splay_tree_node result;
- env.stack = xcalloc (cgraph_n_nodes, sizeof (struct cgraph_node *));
- env.stack_size = 0;
- env.result = order;
- env.order_pos = 0;
- env.nodes_marked_new = splay_tree_new (splay_tree_compare_ints, 0, 0);
- env.count = 1;
- env.reduce = reduce;
-
- for (node = cgraph_nodes; node; node = node->next)
- if (node->output)
- {
- struct dfs_info *info = xcalloc (1, sizeof (struct dfs_info));
- info->new = true;
- info->on_stack = false;
- node->aux = info;
- node->next_cycle = NULL;
-
- splay_tree_insert (env.nodes_marked_new,
- node->uid, (splay_tree_value)node);
- }
- else
- node->aux = NULL;
- result = splay_tree_min (env.nodes_marked_new);
- while (result)
- {
- node = (struct cgraph_node *)result->value;
- searchc (&env, node);
- result = splay_tree_min (env.nodes_marked_new);
- }
- splay_tree_delete (env.nodes_marked_new);
- free (env.stack);
-
- for (node = cgraph_nodes; node; node = node->next)
- if (node->aux)
- {
- free (node->aux);
- node->aux = NULL;
- }
- return env.order_pos;
- }
/* Perform reachability analysis and reclaim all unreachable nodes.
This function also remove unneeded bodies of extern inline functions
--- 905,910 ----
*************** cgraph_inline_p (struct cgraph_edge *e,
*** 2016,2695 ****
return !e->inline_failed;
}
- /* FIXME this needs to be enhanced. If we are compiling a single
- module this returns true if the variable is a module level static,
- but if we are doing whole program compilation, this could return
- true if TREE_PUBLIC is true. */
- /* Return true if the variable T is the right kind of static variable to
- perform compilation unit scope escape analysis. */
-
- static inline
- bool has_proper_scope_for_analysis (tree t)
- {
- return (TREE_STATIC(t)) && !(TREE_PUBLIC(t)) && !(TREE_THIS_VOLATILE(t));
- }
-
- /* Check to see if T is a read or address of operation on a static var
- we are interested in analyzing. FN is passed in to get access to
- its bit vectors. */
-
- static void
- check_rhs_var (struct cgraph_node *fn, tree t)
- {
- if (TREE_CODE (t) == ADDR_EXPR)
- {
- tree x = TREE_OPERAND (t, 0);
- if ((TREE_CODE (x) == VAR_DECL) && has_proper_scope_for_analysis (x))
- {
- if (cgraph_dump_file)
- fprintf (cgraph_dump_file, "\nadding address:%s",
- lang_hooks.decl_printable_name (x, 2));
-
- /* FIXME -- PROFILE-RESTRUCTURE: Change the call from
- DECL_UID to get the uid from the var_ann field. */
- bitmap_set_bit (module_statics_escape, DECL_UID (x));
- }
- }
- t = get_base_address (t);
- if (!t) return;
- if ((TREE_CODE (t) == VAR_DECL) && has_proper_scope_for_analysis (t))
- {
- if (cgraph_dump_file)
- fprintf (cgraph_dump_file, "\nadding rhs:%s",
- lang_hooks.decl_printable_name (t, 2));
- /* FIXME -- PROFILE-RESTRUCTURE: Change the call from
- DECL_UID to get the uid from the var_ann field. */
- bitmap_set_bit (fn->static_vars_info->local->statics_read_by_decl_uid,
- DECL_UID (t));
- }
- }
-
- /* Check to see if T is an assignment to a static var we are
- interrested in analyzing. FN is passed in to get access to its bit
- vectors.
- */
-
- static void
- check_lhs_var (struct cgraph_node *fn, tree t)
- {
- t = get_base_address (t);
- if (!t) return;
- if ((TREE_CODE (t) == VAR_DECL) && has_proper_scope_for_analysis (t))
- {
- if (cgraph_dump_file)
- fprintf (cgraph_dump_file, "\nadding lhs:%s",
- lang_hooks.decl_printable_name (t, 2));
-
- /* FIXME -- PROFILE-RESTRUCTURE: Change the call from
- DECL_UID to get the uid from the var_ann field. */
- bitmap_set_bit (fn->static_vars_info->local->statics_written_by_decl_uid,
- DECL_UID (t));
- }
- }
-
- /* This is a scaled down version of get_asm_expr_operands from
- tree_ssa_operands.c. The version there runs much later and assumes
- that aliasing information is already available. Here we are just
- trying to find if the set of inputs and outputs contain references
- or address of operations to local static variables. FN is the
- function being analyzed and STMT is the actual asm statement. */
-
- static void
- get_asm_expr_operands (struct cgraph_node * fn, tree stmt)
- {
- int noutputs = list_length (ASM_OUTPUTS (stmt));
- const char **oconstraints
- = (const char **) alloca ((noutputs) * sizeof (const char *));
- int i;
- tree link;
- const char *constraint;
- bool allows_mem, allows_reg, is_inout;
-
- for (i=0, link = ASM_OUTPUTS (stmt); link; ++i, link = TREE_CHAIN (link))
- {
- oconstraints[i] = constraint
- = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
- parse_output_constraint (&constraint, i, 0, 0,
- &allows_mem, &allows_reg, &is_inout);
-
- /* Memory operands are addressable. Note that STMT needs the
- address of this operand. */
- if (!allows_reg && allows_mem)
- {
- check_lhs_var (fn, TREE_VALUE (link));
- }
- }
-
- for (link = ASM_INPUTS (stmt); link; link = TREE_CHAIN (link))
- {
- constraint
- = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
- parse_input_constraint (&constraint, 0, 0, noutputs, 0,
- oconstraints, &allows_mem, &allows_reg);
-
- /* Memory operands are addressable. Note that STMT needs the
- address of this operand. */
- if (!allows_reg && allows_mem)
- {
- check_rhs_var (fn, TREE_VALUE (link));
- }
- }
-
- for (link = ASM_CLOBBERS (stmt); link; link = TREE_CHAIN (link))
- if (TREE_VALUE (link) == memory_identifier)
- {
- /* Abandon all hope, ye who enter here. */
- local_static_vars_info_t l = fn->static_vars_info->local;
- bitmap_a_or_b (l->statics_read_by_decl_uid,
- l->statics_read_by_decl_uid,
- all_module_statics);
- bitmap_a_or_b (l->statics_written_by_decl_uid,
- l->statics_written_by_decl_uid,
- all_module_statics);
-
- }
- }
-
- /* Check the parameters of a function call from CALLER to CALL_EXPR to
- see if any of them are static vars. Also check to see if this is
- either an indirect call, a call outside the compilation unit, or
- has special attributes that effect the clobbers. The caller
- parameter is the tree node for the caller and the second operand is
- the tree node for the entire call expression. */
- static void
- process_call_for_static_vars(struct cgraph_node * caller, tree call_expr)
- {
- int flags = call_expr_flags(call_expr);
- tree operandList = TREE_OPERAND (call_expr, 1);
- tree operand;
-
- for (operand = operandList;
- operand != NULL_TREE;
- operand = TREE_CHAIN (operand))
- {
- tree argument = TREE_VALUE (operand);
- check_rhs_var (caller, argument);
- }
-
- /* Const and pure functions have less clobber effects than other
- functions so we process these first. Otherwise if it is a call
- outside the compilation unit or an indirect call we punt. This
- leaves local calls which will be processed by following the call
- graph. */
- if (flags & ECF_CONST)
- return;
- else if (flags & ECF_PURE)
- caller->local.calls_write_all = true;
- else
- {
- tree callee_t = get_callee_fndecl (call_expr);
- if (callee_t == NULL)
- {
- /* Indirect call. */
- caller->local.calls_read_all = true;
- caller->local.calls_write_all = true;
- }
- else
- {
- struct cgraph_node* callee = cgraph_node(callee_t);
-
- if (callee->local.external)
- {
- caller->local.calls_read_all = true;
- caller->local.calls_write_all = true;
- }
- }
- }
- }
-
- /* FIXME -- PROFILE-RESTRUCTURE: Change to walk by explicitly walking
- the basic blocks rather than calling walktree. */
-
- /* Walk tree and record all calls. Called via walk_tree. FIXME When
- this is moved into the tree-profiling-branch, and is dealing with
- low GIMPLE, this routine should be changed to use tree iterators
- rather than being a walk_tree callback. The data is the function
- that is being scanned. */
- /* TP is the part of the tree currently under the
- microscope. WALK_SUBTREES is part of the walk_tree api but is
- unused here. DATA is cgraph_node of the function being walked. */
-
- static tree
- scan_for_static_refs (tree *tp,
- int *walk_subtrees ATTRIBUTE_UNUSED,
- void *data)
- {
- struct cgraph_node *fn = data;
- tree t = *tp;
-
- switch (TREE_CODE (t))
- {
- case MODIFY_EXPR:
- {
- /* First look on the lhs and see what variable is stored to */
- tree rhs = TREE_OPERAND (t, 1);
- check_lhs_var (fn, TREE_OPERAND (t, 0));
- /* Next check the operands on the rhs to see if they are ok. */
- switch (TREE_CODE_CLASS (TREE_CODE (rhs))) {
- case tcc_binary:
- check_rhs_var (fn, TREE_OPERAND (rhs, 0));
- check_rhs_var (fn, TREE_OPERAND (rhs, 1));
- break;
- case tcc_unary:
- case tcc_reference:
- check_rhs_var (fn, TREE_OPERAND (rhs, 0));
- break;
- case tcc_declaration:
- check_rhs_var (fn, rhs);
- break;
- case tcc_expression:
- switch (TREE_CODE (rhs)) {
- case ADDR_EXPR:
- check_rhs_var (fn, rhs);
- break;
- case CALL_EXPR:
- process_call_for_static_vars (fn, rhs);
- break;
- default:
- break;
- }
- break;
- default:
- break;
- }
- }
- break;
-
-
- case CALL_EXPR:
- process_call_for_static_vars (fn, t);
- break;
-
- case ASM_EXPR:
- get_asm_expr_operands (fn, t);
- break;
-
- default:
- break;
- }
- return NULL;
- }
-
-
- /* This is the main routine for finding the reference patterns for
- global variables within a function FN */
- static void
- cgraph_characterize_statics_local (struct cgraph_node *fn)
- {
- tree decl = fn->decl;
- static_vars_info_t info = new_static_vars_info(fn, false);
- local_static_vars_info_t l = info->local;
-
-
- /* The nodes we're interested in are never shared, so walk
- the tree ignoring duplicates. */
- visited_nodes = htab_create (37, htab_hash_pointer,
- htab_eq_pointer, NULL);
-
- /* FIXME -- PROFILE-RESTRUCTURE: Remove creation of _decl_uid vars. */
- l->statics_read_by_decl_uid = BITMAP_GGC_ALLOC ();
- l->statics_written_by_decl_uid = BITMAP_GGC_ALLOC ();
-
- if (cgraph_dump_file)
- fprintf (cgraph_dump_file, "\n local analysis of %s", cgraph_node_name (fn));
-
- walk_tree (&DECL_SAVED_TREE (decl), scan_for_static_refs, fn, visited_nodes);
- htab_delete (visited_nodes);
- visited_nodes = NULL;
- }
-
- /* Lookup the tree node for the static variable that has UID and
- conver the name to a string for debugging. */
- static const char *
- cgraph_get_static_name_by_uid (int index)
- {
- splay_tree_node stn = splay_tree_lookup (static_vars_to_consider_by_uid, index);
- if (stn)
- return lang_hooks.decl_printable_name ((tree)(stn->value), 2);
- return NULL;
- }
-
- /* Clear out any the static variable with uid INDEX from further
- consideration because it escapes (i.e. has had its address
- taken). */
- static void
- clear_static_vars_maps (int index)
- {
- splay_tree_node stn = splay_tree_lookup (static_vars_to_consider_by_uid, index);
- if (stn)
- {
- splay_tree_remove (static_vars_to_consider_by_tree, stn->value);
- splay_tree_remove (static_vars_to_consider_by_uid, index);
- }
- }
-
- /* FIXME -- PROFILE-RESTRUCTURE: Change all *_decl_uid to *_ann_uid. */
-
- /* Or in all of the bits from every callee into X, the caller's, bit
- vector. There are several cases to check to avoid the sparse
- bitmap oring. */
- static void
- cgraph_propagate_bits (struct cgraph_node *x)
- {
- static_vars_info_t x_info = x->static_vars_info;
- global_static_vars_info_t x_global = x_info->global;
-
- struct cgraph_edge *e;
- for (e = x->callees; e; e = e->next_callee)
- {
- struct cgraph_node *y = e->callee;
-
- /* We are only going to look at edges that point to nodes that
- have their output bit set. */
- if (y->output)
- {
- static_vars_info_t y_info;
- global_static_vars_info_t y_global;
- y_info = y->static_vars_info;
- y_global = y_info->global;
-
- if (x_global->statics_read_by_decl_uid != all_module_statics)
- {
- if (y_global->statics_read_by_decl_uid == all_module_statics)
- x_global->statics_read_by_decl_uid = all_module_statics;
- /* Skip bitmaps that are pointer equal to node's bitmap
- (no reason to spin within the cycle). */
- else if (x_global->statics_read_by_decl_uid != y_global->statics_read_by_decl_uid)
- bitmap_a_or_b (x_global->statics_read_by_decl_uid,
- x_global->statics_read_by_decl_uid,
- y_global->statics_read_by_decl_uid);
- }
-
- if (x_global->statics_written_by_decl_uid != all_module_statics)
- {
- if (y_global->statics_written_by_decl_uid == all_module_statics)
- x_global->statics_written_by_decl_uid = all_module_statics;
- /* Skip bitmaps that are pointer equal to node's bitmap
- (no reason to spin within the cycle). */
- else if (x_global->statics_written_by_decl_uid != y_global->statics_written_by_decl_uid)
- bitmap_a_or_b (x_global->statics_written_by_decl_uid,
- x_global->statics_written_by_decl_uid,
- y_global->statics_written_by_decl_uid);
- }
- }
- }
- }
-
- /* FIXME -- PROFILE-RESTRUCTURE: Change all *_decl_uid to *_ann_uid
- except where noted below. */
-
- /* The main routine for analyzing global static variable usage. See
- comments at top for description. */
-
- static void
- cgraph_characterize_statics (void)
- {
- struct cgraph_node *node;
- struct cgraph_node *w;
- struct cgraph_node **order =
- xcalloc (cgraph_n_nodes, sizeof (struct cgraph_node *));
- int order_pos = 0;
- int i;
-
- struct cgraph_varpool_node *vnode;
- tree global;
-
- /* get rid of the splay trees from the previous compilation unit. */
-
- static_vars_to_consider_by_tree =
- splay_tree_new_ggc (splay_tree_compare_pointers);
- static_vars_to_consider_by_uid =
- splay_tree_new_ggc (splay_tree_compare_ints);
-
- if (module_statics_escape)
- {
- bitmap_clear (module_statics_escape);
- bitmap_clear (all_module_statics);
- }
- else
- {
- module_statics_escape = BITMAP_XMALLOC ();
- all_module_statics = BITMAP_GGC_ALLOC ();
- }
-
- /* Find all of the global variables that we wish to analyze. */
- for (vnode = cgraph_varpool_nodes_queue; vnode; vnode = vnode->next_needed)
- {
- global = vnode->decl;
- if ((TREE_CODE (global) == VAR_DECL) &&
- has_proper_scope_for_analysis (global))
- {
- splay_tree_insert (static_vars_to_consider_by_tree,
- (splay_tree_key) global,
- (splay_tree_value) global);
- /* FIXME -- PROFILE-RESTRUCTURE: Change the call from
- DECL_UID to get the uid from the var_ann field. */
- splay_tree_insert (static_vars_to_consider_by_uid,
- DECL_UID (global), (splay_tree_value)global);
-
- if (cgraph_dump_file)
- fprintf (cgraph_dump_file, "\nConsidering global:%s",
- lang_hooks.decl_printable_name (global, 2));
- /* FIXME -- PROFILE-RESTRUCTURE: Change the call from
- DECL_UID to get the uid from the var_ann field. */
- bitmap_set_bit (all_module_statics, DECL_UID (global));
- }
- }
-
- order_pos = cgraph_reduced_inorder (order, false);
- if (cgraph_dump_file)
- print_order("new", order, order_pos);
-
- for (i = order_pos - 1; i >= 0; i--)
- {
- node = order[i];
-
- /* Scan each function to determine the variable usage
- patterns. */
- cgraph_characterize_statics_local (node);
- }
-
- /* Prune out the variables that were found to behave badly
- (i.e. have there address taken). */
- {
- int index;
- bitmap_iterator bi;
-
- EXECUTE_IF_SET_IN_BITMAP (module_statics_escape, 0, index, bi)
- {
- clear_static_vars_maps (index);
- }
- bitmap_operation (all_module_statics, all_module_statics,
- module_statics_escape, BITMAP_AND_COMPL);
-
- for (i = order_pos - 1; i >= 0; i--)
- {
- local_static_vars_info_t l;
- node = order[i];
- l = node->static_vars_info->local;
-
- bitmap_operation (l->statics_read_by_decl_uid,
- l->statics_read_by_decl_uid,
- module_statics_escape,
- BITMAP_AND_COMPL);
- bitmap_operation (l->statics_written_by_decl_uid,
- l->statics_written_by_decl_uid,
- module_statics_escape,
- BITMAP_AND_COMPL);
- }
- }
-
- if (cgraph_dump_file)
- {
- for (i = order_pos - 1; i >= 0; i--)
- {
- int index;
- local_static_vars_info_t l;
- bitmap_iterator bi;
-
- node = order[i];
- l = node->static_vars_info->local;
- fprintf (cgraph_dump_file,
- "\nFunction name:%s/%i:",
- cgraph_node_name (node), node->uid);
- fprintf (cgraph_dump_file, "\n locals read: ");
- EXECUTE_IF_SET_IN_BITMAP (l->statics_read_by_decl_uid,
- 0, index, bi)
- {
- fprintf (cgraph_dump_file, "%s ",
- cgraph_get_static_name_by_uid (index));
- }
- fprintf (cgraph_dump_file, "\n locals written: ");
- EXECUTE_IF_SET_IN_BITMAP (l->statics_written_by_decl_uid,
- 0, index, bi)
- {
- fprintf(cgraph_dump_file, "%s ",
- cgraph_get_static_name_by_uid (index));
- }
- }
- }
-
- /* Propagate the local information thru the call graph to produce
- the global information. All the nodes within a cycle will have
- the same info so we collapse cycles first. Then we can do the
- propagation in one pass from the leaves to the roots. */
- order_pos = cgraph_reduced_inorder (order, true);
- for (i = order_pos - 1; i >= 0; i--)
- {
- static_vars_info_t node_info;
- global_static_vars_info_t node_g =
- ggc_calloc (1, sizeof (struct global_static_vars_info_d));
- local_static_vars_info_t node_l;
-
-
- bool read_all;
- bool write_all;
-
- node = order[i];
- node_info = node->static_vars_info;
- node_info->global = node_g;
- node_l = node_info->local;
-
- read_all = node->local.calls_read_all;
- write_all = node->local.calls_write_all;
-
- /* If any node in a cycle is calls_read_all or calls_write_all
- they all are. */
- w = node->next_cycle;
- while (w)
- {
- read_all |= w->local.calls_read_all;
- write_all |= w->local.calls_write_all;
- w = w->next_cycle;
- }
-
- /* Initialized the bitmaps for the reduced nodes */
- if (read_all)
- node_g->statics_read_by_decl_uid = all_module_statics;
- else
- {
- node_g->statics_read_by_decl_uid = BITMAP_GGC_ALLOC ();
- bitmap_copy (node_g->statics_read_by_decl_uid,
- node_l->statics_read_by_decl_uid);
- }
-
- if (write_all)
- node_g->statics_written_by_decl_uid = all_module_statics;
- else
- {
- node_g->statics_written_by_decl_uid = BITMAP_GGC_ALLOC ();
- bitmap_copy (node_g->statics_written_by_decl_uid,
- node_l->statics_written_by_decl_uid);
- }
-
- w = node->next_cycle;
- while (w)
- {
- /* All nodes within a cycle share the same global info bitmaps. */
- static_vars_info_t w_info = w->static_vars_info;
- local_static_vars_info_t w_l;
-
- w_info->global = node_g;
- w_l = w_info->local;
-
- /* These global bitmaps are initialized from the local info
- of all of the nodes in the region. However there is no
- need to do any work if the bitmaps were set to
- all_module_statics. */
- if (!read_all)
- bitmap_a_or_b (node_g->statics_read_by_decl_uid,
- node_g->statics_read_by_decl_uid,
- w_l->statics_read_by_decl_uid);
- if (!write_all)
- bitmap_a_or_b (node_g->statics_written_by_decl_uid,
- node_g->statics_written_by_decl_uid,
- w_l->statics_written_by_decl_uid);
- w = w->next_cycle;
- }
-
- cgraph_propagate_bits (node);
-
- w = node->next_cycle;
- while (w)
- {
- cgraph_propagate_bits (w);
- w = w->next_cycle;
- }
- }
-
- if (cgraph_dump_file)
- {
- for (i = order_pos - 1; i >= 0; i--)
- {
- static_vars_info_t node_info;
- global_static_vars_info_t node_g;
- int index;
- bitmap_iterator bi;
-
- node = order[i];
- node_info = node->static_vars_info;
- node_g = node_info->global;
- fprintf (cgraph_dump_file,
- "\nFunction name:%s/%i:",
- cgraph_node_name (node), node->uid);
- w = node->next_cycle;
- while (w)
- {
- fprintf (cgraph_dump_file, "\n next cycle: %s/%i ",
- cgraph_node_name (w), w->uid);
- w = w->next_cycle;
- }
- fprintf (cgraph_dump_file, "\n globals read: ");
- EXECUTE_IF_SET_IN_BITMAP (node_g->statics_read_by_decl_uid,
- 0, index, bi)
- {
- fprintf (cgraph_dump_file, "%s ",
- cgraph_get_static_name_by_uid (index));
- }
- fprintf (cgraph_dump_file, "\n globals written: ");
- EXECUTE_IF_SET_IN_BITMAP (node_g->statics_written_by_decl_uid,
- 0, index, bi)
- {
- fprintf (cgraph_dump_file, "%s ",
- cgraph_get_static_name_by_uid (index));
- }
- }
- }
-
- /* Cleanup. */
- for (i = order_pos - 1; i >= 0; i--)
- {
- static_vars_info_t node_info;
- global_static_vars_info_t node_g;
- node = order[i];
- node_info = node->static_vars_info;
- node_g = node_info->global;
-
- node_g->var_anns_valid = false;
-
- /* Create the complimentary sets. These are more useful for
- certain apis. */
- node_g->statics_not_read_by_decl_uid = BITMAP_GGC_ALLOC ();
- node_g->statics_not_written_by_decl_uid = BITMAP_GGC_ALLOC ();
-
- /* FIXME -- PROFILE-RESTRUCTURE: Delete next 4 assignments. */
- node_g->statics_read_by_ann_uid = BITMAP_GGC_ALLOC ();
- node_g->statics_written_by_ann_uid = BITMAP_GGC_ALLOC ();
- node_g->statics_not_read_by_ann_uid = BITMAP_GGC_ALLOC ();
- node_g->statics_not_written_by_ann_uid = BITMAP_GGC_ALLOC ();
-
- if (node_g->statics_read_by_decl_uid != all_module_statics)
- {
- bitmap_operation (node_g->statics_not_read_by_decl_uid,
- all_module_statics,
- node_g->statics_read_by_decl_uid,
- BITMAP_AND_COMPL);
- }
-
- if (node_g->statics_written_by_decl_uid != all_module_statics)
- bitmap_operation (node_g->statics_not_written_by_decl_uid,
- all_module_statics,
- node_g->statics_written_by_decl_uid,
- BITMAP_AND_COMPL);
-
- w = node->next_cycle;
-
- while (w)
- {
- struct cgraph_node * last = w;
- w = w->next_cycle;
- last->next_cycle = NULL;
- }
- }
-
- free (order);
- }
-
/* Expand all functions that must be output.
Attempt to topologically sort the nodes so function is output when
--- 1654,1659 ----
*************** cgraph_optimize (void)
*** 2834,2840 ****
cgraph_mark_functions_to_output ();
! cgraph_characterize_statics ();
cgraph_expand_all_functions ();
if (cgraph_dump_file)
--- 1798,1804 ----
cgraph_mark_functions_to_output ();
! cgraph_characterize_statics (cgraph_dump_file);
cgraph_expand_all_functions ();
if (cgraph_dump_file)
*************** void
*** 2943,2948 ****
init_cgraph (void)
{
cgraph_dump_file = dump_begin (TDI_cgraph, NULL);
- memory_identifier = get_identifier("memory");
}
! #include "gt-cgraphunit.h"
--- 1907,1911 ----
init_cgraph (void)
{
cgraph_dump_file = dump_begin (TDI_cgraph, NULL);
}
!
Index: gcc/tree-gimple.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-gimple.c,v
retrieving revision 2.28
diff -c -3 -p -r2.28 tree-gimple.c
*** gcc/tree-gimple.c 30 Sep 2004 01:22:05 -0000 2.28
--- gcc/tree-gimple.c 7 Oct 2004 18:39:51 -0000
*************** get_call_expr_in (tree t)
*** 429,434 ****
--- 429,454 ----
return NULL_TREE;
}
+ /* Given a memory reference T, will return the variable at the bottom
+ of the access. Unlike get_base_address below, this will recurse
+ thru INDIRECT_REFS. */
+
+ tree
+ get_base_var (tree t)
+ {
+ if ((TREE_CODE (t) == EXC_PTR_EXPR) || (TREE_CODE (t) == FILTER_EXPR))
+ return t;
+
+ while (!SSA_VAR_P (t)
+ && (!CONSTANT_CLASS_P (t))
+ && TREE_CODE (t) != LABEL_DECL
+ && TREE_CODE (t) != FUNCTION_DECL)
+ {
+ t = TREE_OPERAND (t, 0);
+ }
+ return t;
+ }
+
/* Given a memory reference expression, return the base address. Note that,
in contrast with get_base_var, this will not recurse inside INDIRECT_REF
expressions. Therefore, given the reference PTR->FIELD, this function
Index: gcc/tree-ssa-operands.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-ssa-operands.c,v
retrieving revision 2.49
diff -c -3 -p -r2.49 tree-ssa-operands.c
*** gcc/tree-ssa-operands.c 5 Oct 2004 22:42:34 -0000 2.49
--- gcc/tree-ssa-operands.c 7 Oct 2004 18:39:51 -0000
*************** add_call_clobber_ops (tree stmt, tree ca
*** 1598,1616 ****
else
{
size_t i;
- bitmap not_read_b = NULL, not_written_b = NULL;
bitmap_iterator bi;
/* Get info for module level statics. There is a bit set for
each static if the call being processed does not read or
write that variable. */
! /* ??? Turn off the optimization until it gets fixed. */
! if (0 && callee)
! {
! not_read_b = get_global_statics_not_read (callee);
! not_written_b = get_global_statics_not_written (callee);
! }
EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, i, bi)
{
--- 1598,1613 ----
else
{
size_t i;
bitmap_iterator bi;
/* Get info for module level statics. There is a bit set for
each static if the call being processed does not read or
write that variable. */
! bitmap not_read_b = callee
! ? get_global_statics_not_read (callee) : NULL;
! bitmap not_written_b = callee
! ? get_global_statics_not_written (callee) : NULL;
EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, i, bi)
{
Index: gcc/tree.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree.c,v
retrieving revision 1.437
diff -c -3 -p -r1.437 tree.c
*** gcc/tree.c 29 Sep 2004 13:07:44 -0000 1.437
--- gcc/tree.c 7 Oct 2004 18:39:51 -0000
*************** make_node_stat (enum tree_code code MEM_
*** 259,265 ****
enum tree_code_class type = TREE_CODE_CLASS (code);
size_t length = tree_code_size (code);
#ifdef GATHER_STATISTICS
! tree_node_kind kind;
switch (type)
{
--- 259,265 ----
enum tree_code_class type = TREE_CODE_CLASS (code);
size_t length = tree_code_size (code);
#ifdef GATHER_STATISTICS
! tree_node_kind kind = all_kinds;
switch (type)
{
Index: gcc/tree.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree.h,v
retrieving revision 1.635
diff -c -3 -p -r1.635 tree.h
*** gcc/tree.h 1 Oct 2004 07:42:49 -0000 1.635
--- gcc/tree.h 7 Oct 2004 18:39:51 -0000
*************** tree upper_bound_in_type (tree, tree);
*** 3933,3938 ****
--- 3933,3939 ----
extern bool thread_through_all_blocks (void);
/* In tree-gimple.c. */
+ extern tree get_base_var (tree t);
extern tree get_base_address (tree t);
#endif /* GCC_TREE_H */
/* Callgraph based analysis of static variables.
Copyright (C) 2004 Free Software Foundation, Inc.
Contributed by Kenneth Zadeck <zadeck@naturalbridge.com>
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, 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 COPYING. If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
/* Additionally this file gathers information about how local statics
are used. This is done in cgraph_characterize_statics. After the
call graph has been built, each function is analyzed to determine
which local static variables are either read or written or have
their address taken. Any local static that has its address taken
is removed from consideration. Once the local read and writes
are determined, a transitive closure of this information is
performed over the call graph to determine the worst case set of
side effects of each call. In a later part of the compiler, these
local and global sets are examined to make the call clobbering less
traumatic both with respect to aliasing and to code generation. */
/* The code in this module is called from cgraphunit. It is tightly
intertwined in that modules operation. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
#include "rtl.h"
#include "tree-flow.h"
#include "tree-inline.h"
#include "langhooks.h"
#include "hashtab.h"
#include "toplev.h"
#include "flags.h"
#include "ggc.h"
#include "debug.h"
#include "target.h"
#include "cgraph.h"
#include "diagnostic.h"
#include "timevar.h"
#include "params.h"
#include "fibheap.h"
#include "c-common.h"
#include "intl.h"
#include "function.h"
#include "tree-gimple.h"
/*
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
#include "langhooks.h"
#include "hashtab.h"
#include "flags.h"
#include "ggc.h"
#include "debug.h"
#include "cgraph.h"
*/
tree memory_identifier_string;
/* These splay trees contain all of the static variables that are
being considered by the compilation level alias analysis. For
module_at_a_time compilation, this is the set of static but not
public variables. Any variables that either have their address
taken or participate in otherwise unsavory operations are deleted
from this list. */
static GTY((param1_is(tree), param2_is(tree)))
splay_tree static_vars_to_consider_by_tree;
/* FIXME -- PROFILE-RESTRUCTURE: change comment from DECL_UID to var-ann. */
/* same as above but indexed by DECL_UID */
static GTY((param1_is(int), param2_is(tree)))
splay_tree static_vars_to_consider_by_uid;
/* This bitmap is used to knock out the module static variables whose
addresses have been taken and passed around. This is indexed by
uid. */
static bitmap module_statics_escape;
/* FIXME -- PROFILE-RESTRUCTURE: change comment from DECL_UID to var-ann. */
/* A bit is set for every module static we are considering and is
indexed by DECL_UID. This is ored into the local info when asm
code is found that clobbers all memory. */
static GTY(()) bitmap all_module_statics;
static FILE * dump_file;
/* Records tree nodes seen in cgraph_create_edges. Simply using
walk_tree_without_duplicates doesn't guarantee each node is visited
once because it gets a new htab upon each recursive call from
record_calls_1. */
static htab_t visited_nodes;
/* Debugging function for postorder and inorder code. NOTE is a string
that is printed before the nodes are printed. ORDER is an array of
cgraph_nodes that has COUNT useful nodes in it. */
static void
print_order (FILE* out,
const char * note,
struct cgraph_node** order,
int count)
{
int i;
struct cgraph_node* node;
fprintf (out, "\n\n ordered call graph: %s\n", note);
for (i = count - 1; i >= 0; i--)
{
struct cgraph_edge *edge;
fprintf (out, "\n %s->(", cgraph_node_name (order[i]));
for (edge = order[i]->callees; edge; edge = edge->next_callee)
fprintf (out, " %s", cgraph_node_name (edge->callee));
fprintf (out, ")");
fprintf (out, "\n %s<->[", cgraph_node_name (order[i]));
for (node = order[i]->next_cycle; node; node = node->next_cycle)
fprintf (out, " %s", cgraph_node_name (node));
fprintf (out, "]");
}
fprintf (out, "\n");
fflush(out);
}
/* FIXME -- PROFILE-RESTRUCTURE: Remove this function, it becomes a nop. */
/* Convert IN_DECL bitmap which is indexed by DECL_UID to IN_ANN, a
bitmap indexed by var_ann (VAR_DECL)->uid. */
static void
convert_UIDs_in_bitmap (bitmap in_ann, bitmap in_decl)
{
int index;
bitmap_iterator bi;
EXECUTE_IF_SET_IN_BITMAP(in_decl, 0, index, bi)
{
splay_tree_node n =
splay_tree_lookup (static_vars_to_consider_by_uid, index);
if (n != NULL)
{
tree t = (tree)n->value;
var_ann_t va = var_ann (t);
if (va)
bitmap_set_bit(in_ann, va->uid);
}
}
}
/* FIXME -- PROFILE-RESTRUCTURE: Delete all stmts initing *_decl_uid
variables. Add code to create a var_ann for tree node within the
cgraph_node and have it point to the newly created
static_vars_info. */
/* Create a new static_vars_info structure and place it into
cgraph_node, NODE. INIT_GLOBAL causes the global part of the
structure to be initialized. */
static static_vars_info_t
new_static_vars_info(struct cgraph_node* node,
bool init_global)
{
static_vars_info_t info = ggc_calloc (1, sizeof (struct static_vars_info_d));
local_static_vars_info_t l
= ggc_calloc (1, sizeof (struct local_static_vars_info_d));
/* Add the info to the tree's annotation. */
var_ann_t var_ann = get_var_ann (node->decl);
node->static_vars_info = info;
var_ann->static_vars_info = info;
info->local = l;
l->statics_read_by_decl_uid = BITMAP_GGC_ALLOC ();
l->statics_written_by_decl_uid = BITMAP_GGC_ALLOC ();
if (init_global)
{
global_static_vars_info_t g
= ggc_calloc (1, sizeof (struct global_static_vars_info_d));
info->global = g;
g->statics_read_by_decl_uid = BITMAP_GGC_ALLOC ();
g->statics_written_by_decl_uid = BITMAP_GGC_ALLOC ();
g->statics_read_by_ann_uid = BITMAP_GGC_ALLOC ();
g->statics_written_by_ann_uid = BITMAP_GGC_ALLOC ();
g->statics_not_read_by_decl_uid = BITMAP_GGC_ALLOC ();
g->statics_not_written_by_decl_uid = BITMAP_GGC_ALLOC ();
g->statics_not_read_by_ann_uid = BITMAP_GGC_ALLOC ();
g->statics_not_written_by_ann_uid = BITMAP_GGC_ALLOC ();
}
return info;
}
/* FIXME -- PROFILE-RESTRUCTURE: Remove this function, it becomes a
nop. */
/* The bitmaps used to represent the static global variables are
indexed by DECL_UID however, this is not used inside of functions
to index the ssa variables. The denser var_ann (VAR_DECL)->uid is
used there. This function is called from
tree_dfa:find_referenced_vars after the denser representation is
built. This function invalidates any cached indexes. */
void
cgraph_reset_static_var_maps (void)
{
struct cgraph_node *node;
for (node = cgraph_nodes; node; node = node->next)
{
static_vars_info_t info = node->static_vars_info;
if (info)
{
global_static_vars_info_t g = info->global;
if (g->var_anns_valid)
{
bitmap_clear (g->statics_read_by_ann_uid);
bitmap_clear (g->statics_written_by_ann_uid);
bitmap_clear (g->statics_not_read_by_ann_uid);
bitmap_clear (g->statics_not_written_by_ann_uid);
g->var_anns_valid = false;
}
}
}
}
/* Get the global static_vars_info structure for the function FN and
make sure the ann_uid's bitmaps are properly converted. */
static global_static_vars_info_t
get_global_static_vars_info (tree fn)
{
global_static_vars_info_t g;
/* Was not compiled -O2 or higher. */
static_vars_info_t info = get_var_ann (fn)->static_vars_info;
if (!info)
return NULL;
g = info->global;
if (!g->var_anns_valid)
{
convert_UIDs_in_bitmap (g->statics_read_by_ann_uid,
g->statics_read_by_decl_uid);
convert_UIDs_in_bitmap (g->statics_written_by_ann_uid,
g->statics_written_by_decl_uid);
convert_UIDs_in_bitmap (g->statics_not_read_by_ann_uid,
g->statics_not_read_by_decl_uid);
convert_UIDs_in_bitmap (g->statics_not_written_by_ann_uid,
g->statics_not_written_by_decl_uid);
g->var_anns_valid = true;
}
return g;
}
/* Return a bitmap indexed by var_ann (VAR_DECL)->uid for the static
variables that are not read during the execution of the function
FN. Returns NULL if no data is available, such as it was not
compiled with -O2 or higher. */
bitmap
get_global_statics_not_read (tree fn)
{
global_static_vars_info_t g = get_global_static_vars_info (fn);
if (g)
return g->statics_not_read_by_ann_uid;
else
return NULL;
}
/* Return a bitmap indexed by var_ann (VAR_DECL)->uid for the static
variables that are not written during the execution of the function
FN. Note that variables written may or may not be read during the
function call. Returns NULL if no data is available, such as it
was not compiled with -O2 or higher. */
bitmap
get_global_statics_not_written (tree fn)
{
global_static_vars_info_t g = get_global_static_vars_info (fn);
if (g)
return g->statics_not_written_by_ann_uid;
else
return NULL;
}
struct searchc_env {
struct cgraph_node **stack;
int stack_size;
struct cgraph_node **result;
int order_pos;
splay_tree nodes_marked_new;
bool reduce;
int count;
};
struct dfs_info {
int dfn_number;
int low_link;
bool new;
bool on_stack;
};
/* This is an implementation of Tarjan's strongly connected region
finder as reprinted in Aho Hopcraft and Ullman's The Design and
Analysis of Computer Programs (1975) pages 192-193. This version
has been customized for cgraph_nodes. The env parameter is because
it is recursive and there are no nested functions here. This
function should only be called from itself or
cgraph_reduced_inorder. ENV is a stack env and would be
unnecessary if C had nested functions. V is the node to start
searching from. */
static void
searchc (struct searchc_env* env, struct cgraph_node *v)
{
struct cgraph_edge *edge;
struct dfs_info *v_info = v->aux;
/* mark node as old */
v_info->new = false;
splay_tree_remove (env->nodes_marked_new, v->uid);
v_info->dfn_number = env->count;
v_info->low_link = env->count;
env->count++;
env->stack[(env->stack_size)++] = v;
v_info->on_stack = true;
for (edge = v->callees; edge; edge = edge->next_callee)
{
struct dfs_info * w_info;
struct cgraph_node *w = edge->callee;
/* Bypass the clones and only look at the master node. Skip
external nodes. */
w = cgraph_master_clone (w);
if (w)
{
w_info = w->aux;
if (w_info->new)
{
searchc (env, w);
v_info->low_link =
(v_info->low_link < w_info->low_link) ?
v_info->low_link : w_info->low_link;
}
else
if ((w_info->dfn_number < v_info->dfn_number)
&& (w_info->on_stack))
v_info->low_link =
(w_info->dfn_number < v_info->low_link) ?
w_info->dfn_number : v_info->low_link;
}
}
if (v_info->low_link == v_info->dfn_number)
{
struct cgraph_node *last = NULL;
struct cgraph_node *x;
struct dfs_info *x_info;
do {
x = env->stack[--(env->stack_size)];
x_info = x->aux;
x_info->on_stack = false;
if (env->reduce)
{
x->next_cycle = last;
last = x;
}
else
env->result[env->order_pos++] = x;
}
while (v != x);
if (env->reduce)
env->result[env->order_pos++] = v;
}
}
/* Topsort the call graph by caller relation. Put the result in ORDER.
The REDUCE flag is true if you want the cycles reduced to single
nodes. Only consider nodes that have the output bit set. */
static int
cgraph_reduced_inorder (struct cgraph_node **order, bool reduce)
{
struct cgraph_node *node;
struct searchc_env env;
splay_tree_node result;
env.stack = xcalloc (cgraph_n_nodes, sizeof (struct cgraph_node *));
env.stack_size = 0;
env.result = order;
env.order_pos = 0;
env.nodes_marked_new = splay_tree_new (splay_tree_compare_ints, 0, 0);
env.count = 1;
env.reduce = reduce;
for (node = cgraph_nodes; node; node = node->next)
if (cgraph_is_master_clone (node))
{
struct dfs_info *info = xcalloc (1, sizeof (struct dfs_info));
info->new = true;
info->on_stack = false;
node->aux = info;
node->next_cycle = NULL;
splay_tree_insert (env.nodes_marked_new,
node->uid, (splay_tree_value)node);
}
else
node->aux = NULL;
result = splay_tree_min (env.nodes_marked_new);
while (result)
{
node = (struct cgraph_node *)result->value;
searchc (&env, node);
result = splay_tree_min (env.nodes_marked_new);
}
splay_tree_delete (env.nodes_marked_new);
free (env.stack);
for (node = cgraph_nodes; node; node = node->next)
if (node->aux)
{
free (node->aux);
node->aux = NULL;
}
return env.order_pos;
}
/* FIXME this needs to be enhanced. If we are compiling a single
module this returns true if the variable is a module level static,
but if we are doing whole program compilation, this could return
true if TREE_PUBLIC is true. */
/* Return true if the variable T is the right kind of static variable to
perform compilation unit scope escape analysis. */
static inline
bool has_proper_scope_for_analysis (tree t)
{
return (TREE_STATIC(t)) && !(TREE_PUBLIC(t)) && !(TREE_THIS_VOLATILE(t));
}
/* If T is a VAR_DECL for a static that we are interrested in, add the
uid to the bitmap. */
static void
check_operand (tree t, bitmap bm)
{
if (!t) return;
/* FIXME -- PROFILE-RESTRUCTURE: Change the call from DECL_UID to
get the uid from the var_ann field. */
if ((TREE_CODE (t) == VAR_DECL) && has_proper_scope_for_analysis (t))
bitmap_set_bit (bm, DECL_UID (t));
}
/* Examine tree T for references to static variables. All internal
references like array references or indirect references are added
to the INTERNAL_BM. Direct references are added to BASE_BM. When
this is called from the rhs or recursively, both bitmap operands
are for the read bitmap. When called from the lhs, the BASE_BM is
the write bitmap. */
static void
check_tree (tree t, bitmap base_bm, bitmap internal_bm)
{
if ((TREE_CODE (t) == EXC_PTR_EXPR) || (TREE_CODE (t) == FILTER_EXPR))
return;
while (TREE_CODE (t) == REALPART_EXPR
|| TREE_CODE (t) == IMAGPART_EXPR
|| handled_component_p (t))
{
if (TREE_CODE (t) == ARRAY_REF)
check_operand (TREE_OPERAND (t, 1), internal_bm);
t = TREE_OPERAND (t, 0);
}
/* The bottom of an indirect reference can only be read, not
written. So just recurse and but what ever we find, check it
against the read bitmaps. */
if (INDIRECT_REF_P (t))
check_tree (TREE_OPERAND (t, 0), internal_bm, internal_bm);
if (SSA_VAR_P (t))
check_operand (t, base_bm);
}
static void
look_for_address_of (tree t)
{
if (TREE_CODE (t) == ADDR_EXPR)
{
tree x = get_base_var (t);
if ((TREE_CODE (x) == VAR_DECL) && has_proper_scope_for_analysis (x))
{
if (dump_file)
fprintf (dump_file, "\nadding address:%s",
lang_hooks.decl_printable_name (x, 2));
/* FIXME -- PROFILE-RESTRUCTURE: Change the call from
DECL_UID to get the uid from the var_ann field. */
bitmap_set_bit (module_statics_escape, DECL_UID (x));
}
}
}
/* Check to see if T is a read or address of operation on a static var
we are interested in analyzing. FN is passed in to get access to
its bit vectors. */
static void
check_rhs_var (struct cgraph_node *fn, tree t)
{
look_for_address_of (t);
if (fn == NULL)
return;
/* FIXME -- PROFILE-RESTRUCTURE: Change the call from DECL_UID to
get the uid from the var_ann field. */
check_tree(t,
fn->static_vars_info->local->statics_read_by_decl_uid,
fn->static_vars_info->local->statics_read_by_decl_uid);
}
/* Check to see if T is an assignment to a static var we are
interrested in analyzing. FN is passed in to get access to its bit
vectors.
*/
static void
check_lhs_var (struct cgraph_node *fn, tree t)
{
if (fn == NULL)
return;
/* FIXME -- PROFILE-RESTRUCTURE: Change the call from DECL_UID to
get the uid from the var_ann field. */
check_tree(t,
fn->static_vars_info->local->statics_written_by_decl_uid,
fn->static_vars_info->local->statics_read_by_decl_uid);
}
/* This is a scaled down version of get_asm_expr_operands from
tree_ssa_operands.c. The version there runs much later and assumes
that aliasing information is already available. Here we are just
trying to find if the set of inputs and outputs contain references
or address of operations to local static variables. FN is the
function being analyzed and STMT is the actual asm statement. */
static void
get_asm_expr_operands (struct cgraph_node * fn, tree stmt)
{
int noutputs = list_length (ASM_OUTPUTS (stmt));
const char **oconstraints
= (const char **) alloca ((noutputs) * sizeof (const char *));
int i;
tree link;
const char *constraint;
bool allows_mem, allows_reg, is_inout;
for (i=0, link = ASM_OUTPUTS (stmt); link; ++i, link = TREE_CHAIN (link))
{
oconstraints[i] = constraint
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
parse_output_constraint (&constraint, i, 0, 0,
&allows_mem, &allows_reg, &is_inout);
/* Memory operands are addressable. Note that STMT needs the
address of this operand. */
if (!allows_reg && allows_mem)
check_lhs_var (fn, TREE_VALUE (link));
}
for (link = ASM_INPUTS (stmt); link; link = TREE_CHAIN (link))
{
constraint
= TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
parse_input_constraint (&constraint, 0, 0, noutputs, 0,
oconstraints, &allows_mem, &allows_reg);
/* Memory operands are addressable. Note that STMT needs the
address of this operand. */
if (!allows_reg && allows_mem)
check_rhs_var (fn, TREE_VALUE (link));
}
for (link = ASM_CLOBBERS (stmt); link; link = TREE_CHAIN (link))
if (simple_cst_equal(TREE_VALUE (link), memory_identifier_string) == 1)
{
/* Abandon all hope, ye who enter here. */
fn->local.calls_read_all = true;
fn->local.calls_write_all = true;
}
}
/* Check the parameters of a function call from CALLER to CALL_EXPR to
see if any of them are static vars. Also check to see if this is
either an indirect call, a call outside the compilation unit, or
has special attributes that effect the clobbers. The caller
parameter is the tree node for the caller and the second operand is
the tree node for the entire call expression. */
static void
process_call_for_static_vars(struct cgraph_node * caller, tree call_expr)
{
int flags = call_expr_flags(call_expr);
tree operandList = TREE_OPERAND (call_expr, 1);
tree operand;
for (operand = operandList;
operand != NULL_TREE;
operand = TREE_CHAIN (operand))
{
tree argument = TREE_VALUE (operand);
check_rhs_var (caller, argument);
}
/* Const and pure functions have less clobber effects than other
functions so we process these first. Otherwise if it is a call
outside the compilation unit or an indirect call we punt. This
leaves local calls which will be processed by following the call
graph. */
if (flags & ECF_CONST)
return;
else if (flags & ECF_PURE)
caller->local.calls_write_all = true;
else
{
tree callee_t = get_callee_fndecl (call_expr);
if (callee_t == NULL)
{
/* Indirect call. */
caller->local.calls_read_all = true;
caller->local.calls_write_all = true;
}
else
{
struct cgraph_node* callee = cgraph_node(callee_t);
if (callee->local.external)
{
caller->local.calls_read_all = true;
caller->local.calls_write_all = true;
}
}
}
}
/* FIXME -- PROFILE-RESTRUCTURE: Change to walk by explicitly walking
the basic blocks rather than calling walktree. */
/* Walk tree and record all calls. Called via walk_tree. FIXME When
this is moved into the tree-profiling-branch, and is dealing with
low GIMPLE, this routine should be changed to use tree iterators
rather than being a walk_tree callback. The data is the function
that is being scanned. */
/* TP is the part of the tree currently under the
microscope. WALK_SUBTREES is part of the walk_tree api but is
unused here. DATA is cgraph_node of the function being walked. */
static tree
scan_for_static_refs (tree *tp,
int *walk_subtrees ATTRIBUTE_UNUSED,
void *data)
{
struct cgraph_node *fn = data;
tree t = *tp;
switch (TREE_CODE (t))
{
case MODIFY_EXPR:
{
/* First look on the lhs and see what variable is stored to */
tree rhs = TREE_OPERAND (t, 1);
check_lhs_var (fn, TREE_OPERAND (t, 0));
/* Next check the operands on the rhs to see if they are ok. */
switch (TREE_CODE_CLASS (TREE_CODE (rhs)))
{
case tcc_binary:
check_rhs_var (fn, TREE_OPERAND (rhs, 0));
check_rhs_var (fn, TREE_OPERAND (rhs, 1));
break;
case tcc_unary:
case tcc_reference:
check_rhs_var (fn, TREE_OPERAND (rhs, 0));
break;
case tcc_declaration:
check_rhs_var (fn, rhs);
break;
case tcc_expression:
switch (TREE_CODE (rhs))
{
case ADDR_EXPR:
check_rhs_var (fn, rhs);
break;
case CALL_EXPR:
process_call_for_static_vars (fn, rhs);
break;
default:
break;
}
break;
default:
break;
}
}
break;
case CALL_EXPR:
process_call_for_static_vars (fn, t);
break;
case ASM_EXPR:
get_asm_expr_operands (fn, t);
break;
default:
break;
}
return NULL;
}
/* This is the main routine for finding the reference patterns for
global variables within a function FN */
static void
cgraph_characterize_statics_local (struct cgraph_node *fn)
{
tree decl = fn->decl;
static_vars_info_t info = new_static_vars_info(fn, false);
local_static_vars_info_t l = info->local;
/* The nodes we're interested in are never shared, so walk
the tree ignoring duplicates. */
visited_nodes = htab_create (37, htab_hash_pointer,
htab_eq_pointer, NULL);
/* FIXME -- PROFILE-RESTRUCTURE: Remove creation of _decl_uid vars. */
l->statics_read_by_decl_uid = BITMAP_GGC_ALLOC ();
l->statics_written_by_decl_uid = BITMAP_GGC_ALLOC ();
if (dump_file)
fprintf (dump_file, "\n local analysis of %s", cgraph_node_name (fn));
walk_tree (&DECL_SAVED_TREE (decl), scan_for_static_refs, fn, visited_nodes);
htab_delete (visited_nodes);
visited_nodes = NULL;
}
/* Lookup the tree node for the static variable that has UID and
conver the name to a string for debugging. */
static const char *
cgraph_get_static_name_by_uid (int index)
{
splay_tree_node stn = splay_tree_lookup (static_vars_to_consider_by_uid, index);
if (stn)
return lang_hooks.decl_printable_name ((tree)(stn->value), 2);
return NULL;
}
/* Clear out any the static variable with uid INDEX from further
consideration because it escapes (i.e. has had its address
taken). */
static void
clear_static_vars_maps (int index)
{
splay_tree_node stn = splay_tree_lookup (static_vars_to_consider_by_uid, index);
if (stn)
{
splay_tree_remove (static_vars_to_consider_by_tree, stn->value);
splay_tree_remove (static_vars_to_consider_by_uid, index);
}
}
/* FIXME -- PROFILE-RESTRUCTURE: Change all *_decl_uid to *_ann_uid. */
/* Or in all of the bits from every callee into X, the caller's, bit
vector. There are several cases to check to avoid the sparse
bitmap oring. */
static void
cgraph_propagate_bits (struct cgraph_node *x)
{
static_vars_info_t x_info = x->static_vars_info;
global_static_vars_info_t x_global = x_info->global;
struct cgraph_edge *e;
for (e = x->callees; e; e = e->next_callee)
{
struct cgraph_node *y = e->callee;
/* Only look at the master nodes and skip external nodes. */
y = cgraph_master_clone (y);
if (y)
{
static_vars_info_t y_info;
global_static_vars_info_t y_global;
y_info = y->static_vars_info;
y_global = y_info->global;
if (x_global->statics_read_by_decl_uid != all_module_statics)
{
if (y_global->statics_read_by_decl_uid == all_module_statics)
x_global->statics_read_by_decl_uid = all_module_statics;
/* Skip bitmaps that are pointer equal to node's bitmap
(no reason to spin within the cycle). */
else if (x_global->statics_read_by_decl_uid
!= y_global->statics_read_by_decl_uid)
bitmap_a_or_b (x_global->statics_read_by_decl_uid,
x_global->statics_read_by_decl_uid,
y_global->statics_read_by_decl_uid);
}
if (x_global->statics_written_by_decl_uid != all_module_statics)
{
if (y_global->statics_written_by_decl_uid == all_module_statics)
x_global->statics_written_by_decl_uid = all_module_statics;
/* Skip bitmaps that are pointer equal to node's bitmap
(no reason to spin within the cycle). */
else if (x_global->statics_written_by_decl_uid
!= y_global->statics_written_by_decl_uid)
bitmap_a_or_b (x_global->statics_written_by_decl_uid,
x_global->statics_written_by_decl_uid,
y_global->statics_written_by_decl_uid);
}
}
}
}
/* FIXME -- PROFILE-RESTRUCTURE: Change all *_decl_uid to *_ann_uid. */
/* Look at all of the callees of X to see which ones represent inlined
calls. For each of these callees, merge their local info into TARGET
and check their children recursively. */
static void
merge_callee_local_info (struct cgraph_node *target,
struct cgraph_node *x)
{
struct cgraph_edge *e;
local_static_vars_info_t info = target->static_vars_info->local;
/* Make the world safe for tail recursion. */
if (x->aux)
return;
x->aux = x;
for (e = x->callees; e; e = e->next_callee)
{
struct cgraph_node *y = e->callee;
if (y->global.inlined_to)
{
static_vars_info_t y_info;
local_static_vars_info_t y_l;
y = cgraph_master_clone (y);
y_info = y->static_vars_info;
y_l = y_info->local;
bitmap_a_or_b (info->statics_read_by_decl_uid,
info->statics_read_by_decl_uid,
y_l->statics_read_by_decl_uid);
bitmap_a_or_b (info->statics_written_by_decl_uid,
info->statics_written_by_decl_uid,
y_l->statics_written_by_decl_uid);
target->local.calls_read_all |= y->local.calls_read_all;
target->local.calls_write_all |= y->local.calls_write_all;
merge_callee_local_info (target, y);
}
}
x->aux = NULL;
}
/* FIXME -- PROFILE-RESTRUCTURE: Change all *_decl_uid to *_ann_uid
except where noted below. */
/* The main routine for analyzing global static variable usage. See
comments at top for description. */
void
cgraph_characterize_statics (FILE * f)
{
struct cgraph_node *node;
struct cgraph_node *w;
struct cgraph_node **order =
xcalloc (cgraph_n_nodes, sizeof (struct cgraph_node *));
int order_pos = 0;
int i;
struct cgraph_varpool_node *vnode;
tree global;
dump_file = f;
memory_identifier_string = build_string(7, "memory");
/* get rid of the splay trees from the previous compilation unit. */
static_vars_to_consider_by_tree =
splay_tree_new_ggc (splay_tree_compare_pointers);
static_vars_to_consider_by_uid =
splay_tree_new_ggc (splay_tree_compare_ints);
if (module_statics_escape)
{
bitmap_clear (module_statics_escape);
bitmap_clear (all_module_statics);
}
else
{
module_statics_escape = BITMAP_XMALLOC ();
all_module_statics = BITMAP_GGC_ALLOC ();
}
/* Find all of the global variables that we wish to analyze. */
for (vnode = cgraph_varpool_nodes_queue; vnode; vnode = vnode->next_needed)
{
global = vnode->decl;
if ((TREE_CODE (global) == VAR_DECL) &&
has_proper_scope_for_analysis (global))
{
splay_tree_insert (static_vars_to_consider_by_tree,
(splay_tree_key) global,
(splay_tree_value) global);
/* FIXME -- PROFILE-RESTRUCTURE: Change the call from
DECL_UID to get the uid from the var_ann field. */
splay_tree_insert (static_vars_to_consider_by_uid,
DECL_UID (global), (splay_tree_value)global);
if (dump_file)
fprintf (dump_file, "\nConsidering global:%s",
lang_hooks.decl_printable_name (global, 2));
/* FIXME -- PROFILE-RESTRUCTURE: Change the call from
DECL_UID to get the uid from the var_ann field. */
bitmap_set_bit (all_module_statics, DECL_UID (global));
}
}
visited_nodes = htab_create (37, htab_hash_pointer,
htab_eq_pointer, NULL);
/* Check out the rhs of static and global initializations to see if
any of them contain addressof operations. */
for (vnode = cgraph_varpool_nodes_queue; vnode; vnode = vnode->next_needed)
{
global = vnode->decl;
if (TREE_CODE (global) == VAR_DECL)
{
if (DECL_INITIAL (global))
walk_tree (&DECL_INITIAL (global), scan_for_static_refs, NULL, visited_nodes);
}
}
htab_delete (visited_nodes);
visited_nodes = NULL;
order_pos = cgraph_reduced_inorder (order, false);
if (dump_file)
print_order(stderr, "big", order, order_pos);
/* Scan each function to determine the variable usage patterns. */
for (i = 0; i < order_pos; i++ )
{
node = order[i];
cgraph_characterize_statics_local (node);
}
/* Prune out the variables that were found to behave badly
(i.e. have there address taken). */
{
int index;
bitmap_iterator bi;
EXECUTE_IF_SET_IN_BITMAP (module_statics_escape, 0, index, bi)
{
clear_static_vars_maps (index);
}
bitmap_operation (all_module_statics, all_module_statics,
module_statics_escape, BITMAP_AND_COMPL);
for (i = 0; i < order_pos; i++ )
{
local_static_vars_info_t l;
node = order[i];
l = node->static_vars_info->local;
bitmap_operation (l->statics_read_by_decl_uid,
l->statics_read_by_decl_uid,
module_statics_escape,
BITMAP_AND_COMPL);
bitmap_operation (l->statics_written_by_decl_uid,
l->statics_written_by_decl_uid,
module_statics_escape,
BITMAP_AND_COMPL);
}
}
if (dump_file)
{
for (i = 0; i < order_pos; i++ )
{
int index;
local_static_vars_info_t l;
bitmap_iterator bi;
node = order[i];
l = node->static_vars_info->local;
fprintf (dump_file,
"\nFunction name:%s/%i:",
cgraph_node_name (node), node->uid);
fprintf (dump_file, "\n locals read: ");
EXECUTE_IF_SET_IN_BITMAP (l->statics_read_by_decl_uid,
0, index, bi)
{
fprintf (dump_file, "%s ",
cgraph_get_static_name_by_uid (index));
}
fprintf (dump_file, "\n locals written: ");
EXECUTE_IF_SET_IN_BITMAP (l->statics_written_by_decl_uid,
0, index, bi)
{
fprintf(dump_file, "%s ",
cgraph_get_static_name_by_uid (index));
}
}
}
/* Propagate the local information thru the call graph to produce
the global information. All the nodes within a cycle will have
the same info so we collapse cycles first. Then we can do the
propagation in one pass from the leaves to the roots. */
order_pos = cgraph_reduced_inorder (order, true);
if (dump_file)
print_order(stderr, "reduced", order, order_pos);
for (i = 0; i < order_pos; i++ )
{
static_vars_info_t node_info;
global_static_vars_info_t node_g =
ggc_calloc (1, sizeof (struct global_static_vars_info_d));
local_static_vars_info_t node_l;
bool read_all;
bool write_all;
node = order[i];
node_info = node->static_vars_info;
node_info->global = node_g;
node_l = node_info->local;
read_all = node->local.calls_read_all;
write_all = node->local.calls_write_all;
/* If any node in a cycle is calls_read_all or calls_write_all
they all are. */
w = node->next_cycle;
while (w)
{
read_all |= w->local.calls_read_all;
write_all |= w->local.calls_write_all;
w = w->next_cycle;
}
/* Initialized the bitmaps for the reduced nodes */
if (read_all)
node_g->statics_read_by_decl_uid = all_module_statics;
else
{
node_g->statics_read_by_decl_uid = BITMAP_GGC_ALLOC ();
bitmap_copy (node_g->statics_read_by_decl_uid,
node_l->statics_read_by_decl_uid);
}
if (write_all)
node_g->statics_written_by_decl_uid = all_module_statics;
else
{
node_g->statics_written_by_decl_uid = BITMAP_GGC_ALLOC ();
bitmap_copy (node_g->statics_written_by_decl_uid,
node_l->statics_written_by_decl_uid);
}
w = node->next_cycle;
while (w)
{
/* All nodes within a cycle share the same global info bitmaps. */
static_vars_info_t w_info = w->static_vars_info;
local_static_vars_info_t w_l;
w_info->global = node_g;
w_l = w_info->local;
/* These global bitmaps are initialized from the local info
of all of the nodes in the region. However there is no
need to do any work if the bitmaps were set to
all_module_statics. */
if (!read_all)
bitmap_a_or_b (node_g->statics_read_by_decl_uid,
node_g->statics_read_by_decl_uid,
w_l->statics_read_by_decl_uid);
if (!write_all)
bitmap_a_or_b (node_g->statics_written_by_decl_uid,
node_g->statics_written_by_decl_uid,
w_l->statics_written_by_decl_uid);
w = w->next_cycle;
}
cgraph_propagate_bits (node);
w = node->next_cycle;
while (w)
{
cgraph_propagate_bits (w);
w = w->next_cycle;
}
}
if (dump_file)
{
for (i = 0; i < order_pos; i++ )
{
static_vars_info_t node_info;
global_static_vars_info_t node_g;
int index;
bitmap_iterator bi;
node = order[i];
node_info = node->static_vars_info;
node_g = node_info->global;
fprintf (dump_file,
"\nFunction name:%s/%i:",
cgraph_node_name (node), node->uid);
w = node->next_cycle;
while (w)
{
fprintf (dump_file, "\n next cycle: %s/%i ",
cgraph_node_name (w), w->uid);
w = w->next_cycle;
}
fprintf (dump_file, "\n globals read: ");
EXECUTE_IF_SET_IN_BITMAP (node_g->statics_read_by_decl_uid,
0, index, bi)
{
fprintf (dump_file, "%s ",
cgraph_get_static_name_by_uid (index));
}
fprintf (dump_file, "\n globals written: ");
EXECUTE_IF_SET_IN_BITMAP (node_g->statics_written_by_decl_uid,
0, index, bi)
{
fprintf (dump_file, "%s ",
cgraph_get_static_name_by_uid (index));
}
}
}
/* Need to fix up the local information sets. The information that
has been gathered so far is preinlining. However, the
compilation will progress post inlining so the local sets for the
inlined calls need to be merged into the callers. */
for (i = 0; i < order_pos; i++ )
{
node = order[i];
if (cgraph_is_immortal_master_clone (node))
merge_callee_local_info (node, node);
}
/* Cleanup. */
for (i = 0; i < order_pos; i++ )
{
static_vars_info_t node_info;
global_static_vars_info_t node_g;
node = order[i];
node_info = node->static_vars_info;
node_g = node_info->global;
node_g->var_anns_valid = false;
/* Create the complimentary sets. These are more useful for
certain apis. */
node_g->statics_not_read_by_decl_uid = BITMAP_GGC_ALLOC ();
node_g->statics_not_written_by_decl_uid = BITMAP_GGC_ALLOC ();
/* FIXME -- PROFILE-RESTRUCTURE: Delete next 4 assignments. */
node_g->statics_read_by_ann_uid = BITMAP_GGC_ALLOC ();
node_g->statics_written_by_ann_uid = BITMAP_GGC_ALLOC ();
node_g->statics_not_read_by_ann_uid = BITMAP_GGC_ALLOC ();
node_g->statics_not_written_by_ann_uid = BITMAP_GGC_ALLOC ();
if (node_g->statics_read_by_decl_uid != all_module_statics)
{
bitmap_operation (node_g->statics_not_read_by_decl_uid,
all_module_statics,
node_g->statics_read_by_decl_uid,
BITMAP_AND_COMPL);
}
if (node_g->statics_written_by_decl_uid != all_module_statics)
bitmap_operation (node_g->statics_not_written_by_decl_uid,
all_module_statics,
node_g->statics_written_by_decl_uid,
BITMAP_AND_COMPL);
w = node;
while (w)
{
struct cgraph_node * last = w;
w = w->next_cycle;
last->next_cycle = NULL;
}
}
free (order);
}
#include "gt-cgraph-static-anal.h"
/* This program tests the effects of initialized static variables on in cgraph. */
static int foo1 = 1;
static int * foop = &foo1;
static int foo2;
static int foo3;
static int bar1 ()
{
foo1 = 10;
foo2 = 2;
return foo2;
}
static int (*barp) () = bar1;
static int bar2 ()
{
foo1 = 12;
foo3 = 3;
return foo3;
}
int main()
{
int x;
foo1 = 0;
foo2 = 0;
x = (barp)();
if (foo2 != x) abort();
if (foo1 != 10) abort();
x = bar2();
if (foo3 != x) abort();
if (foo1 != 12) abort();
return 0;
}