#include "ggc.h"
#include "obstack.h"
#include "bitmap.h"
-#include "tree-ssa-structalias.h"
#include "flags.h"
#include "rtl.h"
#include "tm_p.h"
#include "basic-block.h"
#include "output.h"
#include "errors.h"
-#include "expr.h"
#include "diagnostic.h"
#include "tree.h"
#include "c-common.h"
#include "timevar.h"
#include "alloc-pool.h"
#include "splay-tree.h"
+#include "tree-ssa-structalias.h"
/* The idea behind this analyzer is to generate set constraints from the
program, then solve the resulting constraints in order to generate the
static bool use_field_sensitive = true;
static unsigned int create_variable_info_for (tree, const char *);
-static struct constraint_expr get_constraint_for (tree);
+static struct constraint_expr get_constraint_for (tree, bool *);
static void build_constraint_graph (void);
static bitmap_obstack ptabitmap_obstack;
static bitmap_obstack iteration_obstack;
DEF_VEC_P(constraint_t);
-DEF_VEC_ALLOC_P(constraint_t,gc);
+DEF_VEC_ALLOC_P(constraint_t,heap);
static struct constraint_stats
{
/* True if this is a variable created by the constraint analysis, such as
heap variables and constraints we had to break up. */
unsigned int is_artificial_var:1;
+
+ /* True if this is a special variable whose solution set should not be
+ changed. */
+ unsigned int is_special_var:1;
/* True for variables whose size is not known or variable. */
unsigned int is_unknown_size_var:1;
/* True for variables that have unions somewhere in them. */
unsigned int has_union:1;
+ /* True if this is a heap variable. */
+ unsigned int is_heap_var:1;
+
/* Points-to set for this variable. */
bitmap solution;
/* Vector of complex constraints for this node. Complex
constraints are those involving dereferences. */
- VEC(constraint_t,gc) *complex;
+ VEC(constraint_t,heap) *complex;
+
+ /* Variable id this was collapsed to due to type unsafety.
+ This should be unused completely after build_constraint_graph, or
+ something is broken. */
+ struct variable_info *collapsed_to;
};
typedef struct variable_info *varinfo_t;
DEF_VEC_P(varinfo_t);
-DEF_VEC_ALLOC_P(varinfo_t, gc);
+DEF_VEC_ALLOC_P(varinfo_t, heap);
/* Table of variable info structures for constraint variables. Indexed directly
by variable info id. */
-static VEC(varinfo_t,gc) *varmap;
-#define get_varinfo(n) VEC_index(varinfo_t, varmap, n)
+static VEC(varinfo_t,heap) *varmap;
+
+/* Return the varmap element N */
+
+static inline varinfo_t
+get_varinfo (unsigned int n)
+{
+ return VEC_index(varinfo_t, varmap, n);
+}
+
+/* Return the varmap element N, following the collapsed_to link. */
+
+static inline varinfo_t
+get_varinfo_fc (unsigned int n)
+{
+ varinfo_t v = VEC_index(varinfo_t, varmap, n);
+
+ if (v->collapsed_to)
+ return v->collapsed_to;
+ return v;
+}
/* Variable that represents the unknown pointer. */
static varinfo_t var_anything;
static tree integer_tree;
static unsigned int integer_id;
+/* Variable that represents arbitrary offsets into an object. Used to
+ represent pointer arithmetic, which may not legally escape the
+ bounds of an object. */
+static varinfo_t var_anyoffset;
+static tree anyoffset_tree;
+static unsigned int anyoffset_id;
/* Return a new variable info structure consisting for a variable
named NAME, and using constraint graph node NODE. */
ret->address_taken = false;
ret->indirect_target = false;
ret->is_artificial_var = false;
+ ret->is_heap_var = false;
+ ret->is_special_var = false;
ret->is_unknown_size_var = false;
+ ret->has_union = false;
ret->solution = BITMAP_ALLOC (&ptabitmap_obstack);
bitmap_clear (ret->solution);
ret->variables = BITMAP_ALLOC (&ptabitmap_obstack);
bitmap_clear (ret->variables);
ret->complex = NULL;
ret->next = NULL;
+ ret->collapsed_to = NULL;
return ret;
}
/* List of constraints that we use to build the constraint graph from. */
-static VEC(constraint_t,gc) *constraints;
+static VEC(constraint_t,heap) *constraints;
static alloc_pool constraint_pool;
/* An edge in the constraint graph. We technically have no use for
}
DEF_VEC_P(constraint_edge_t);
-DEF_VEC_ALLOC_P(constraint_edge_t,gc);
+DEF_VEC_ALLOC_P(constraint_edge_t,heap);
/* The constraint graph is simply a set of adjacency vectors, one per
IOW, all edges are "forward" edges, which is not like our CFG.
So remember that
preds[x]->src == x, and
- succs[x]->src == x*/
+ succs[x]->src == x. */
struct constraint_graph
{
- VEC(constraint_edge_t,gc) **succs;
- VEC(constraint_edge_t,gc) **preds;
+ VEC(constraint_edge_t,heap) **succs;
+ VEC(constraint_edge_t,heap) **preds;
};
typedef struct constraint_graph *constraint_graph_t;
fprintf (file, "&");
else if (c->lhs.type == DEREF)
fprintf (file, "*");
- fprintf (file, "%s", get_varinfo (c->lhs.var)->name);
+ fprintf (file, "%s", get_varinfo_fc (c->lhs.var)->name);
if (c->lhs.offset != 0)
fprintf (file, " + " HOST_WIDE_INT_PRINT_DEC, c->lhs.offset);
fprintf (file, " = ");
fprintf (file, "&");
else if (c->rhs.type == DEREF)
fprintf (file, "*");
- fprintf (file, "%s", get_varinfo (c->rhs.var)->name);
+ fprintf (file, "%s", get_varinfo_fc (c->rhs.var)->name);
if (c->rhs.offset != 0)
fprintf (file, " + " HOST_WIDE_INT_PRINT_DEC, c->rhs.offset);
fprintf (file, "\n");
/* Find a constraint LOOKFOR in the sorted constraint vector VEC */
static constraint_t
-constraint_vec_find (VEC(constraint_t,gc) *vec,
+constraint_vec_find (VEC(constraint_t,heap) *vec,
struct constraint lookfor)
{
unsigned int place;
/* Union two constraint vectors, TO and FROM. Put the result in TO. */
static void
-constraint_set_union (VEC(constraint_t,gc) **to,
- VEC(constraint_t,gc) **from)
+constraint_set_union (VEC(constraint_t,heap) **to,
+ VEC(constraint_t,heap) **from)
{
int i;
constraint_t c;
{
unsigned int place = VEC_lower_bound (constraint_t, *to, c,
constraint_less);
- VEC_safe_insert (constraint_t, gc, *to, place, c);
+ VEC_safe_insert (constraint_t, heap, *to, place, c);
}
}
}
{
unsigned HOST_WIDE_INT fieldoffset = get_varinfo (i)->offset + offset;
varinfo_t v = first_vi_for_offset (get_varinfo (i), fieldoffset);
+ if (!v)
+ continue;
bitmap_set_bit (result, v->id);
}
else if (get_varinfo (i)->is_artificial_var
+ || get_varinfo (i)->has_union
|| get_varinfo (i)->is_unknown_size_var)
{
bitmap_set_bit (result, i);
varinfo_t vi = get_varinfo (var);
unsigned int place = VEC_lower_bound (constraint_t, vi->complex, c,
constraint_less);
- VEC_safe_insert (constraint_t, gc, vi->complex, place, c);
+ VEC_safe_insert (constraint_t, heap, vi->complex, place, c);
}
Return the edge, if found, NULL otherwise. */
static constraint_edge_t
-constraint_edge_vec_find (VEC(constraint_edge_t,gc) *vec,
+constraint_edge_vec_find (VEC(constraint_edge_t,heap) *vec,
struct constraint_edge lookfor)
{
unsigned int place;
c->lhs.var = to;
}
constraint_set_union (&tovi->complex, &srcvi->complex);
+ VEC_free (constraint_t, heap, srcvi->complex);
srcvi->complex = NULL;
}
static void
erase_graph_self_edge (constraint_graph_t graph, struct constraint_edge edge)
{
- VEC(constraint_edge_t,gc) *predvec = graph->preds[edge.src];
- VEC(constraint_edge_t,gc) *succvec = graph->succs[edge.dest];
+ VEC(constraint_edge_t,heap) *predvec = graph->preds[edge.src];
+ VEC(constraint_edge_t,heap) *succvec = graph->succs[edge.dest];
unsigned int place;
gcc_assert (edge.src == edge.dest);
static void
clear_edges_for_node (constraint_graph_t graph, unsigned int node)
{
- VEC(constraint_edge_t,gc) *succvec = graph->succs[node];
- VEC(constraint_edge_t,gc) *predvec = graph->preds[node];
+ VEC(constraint_edge_t,heap) *succvec = graph->succs[node];
+ VEC(constraint_edge_t,heap) *predvec = graph->preds[node];
constraint_edge_t c;
int i;
VEC_ordered_remove (constraint_edge_t, graph->succs[c->dest], place);
}
+ VEC_free (constraint_edge_t, heap, graph->preds[node]);
+ VEC_free (constraint_edge_t, heap, graph->succs[node]);
graph->preds[node] = NULL;
graph->succs[node] = NULL;
}
unsigned int place;
unsigned int src = newe.src;
unsigned int dest = newe.dest;
- VEC(constraint_edge_t,gc) *vec;
+ VEC(constraint_edge_t,heap) *vec;
vec = graph->preds[src];
place = VEC_lower_bound (constraint_edge_t, vec, &newe,
weightbitmap = BITMAP_ALLOC (&ptabitmap_obstack);
edge->weights = weightbitmap;
- VEC_safe_insert (constraint_edge_t, gc, graph->preds[edge->src],
+ VEC_safe_insert (constraint_edge_t, heap, graph->preds[edge->src],
place, edge);
edge = new_constraint_edge (dest, src);
edge->weights = weightbitmap;
place = VEC_lower_bound (constraint_edge_t, graph->succs[edge->src],
edge, constraint_edge_less);
- VEC_safe_insert (constraint_edge_t, gc, graph->succs[edge->src],
+ VEC_safe_insert (constraint_edge_t, heap, graph->succs[edge->src],
place, edge);
edge_added = true;
return true;
{
constraint_edge_t edge;
unsigned int src = lookfor.src;
- VEC(constraint_edge_t,gc) *vec;
+ VEC(constraint_edge_t,heap) *vec;
vec = graph->preds[src];
edge = constraint_edge_vec_find (vec, lookfor);
gcc_assert (edge != NULL);
merge_graph_nodes (constraint_graph_t graph, unsigned int to,
unsigned int from)
{
- VEC(constraint_edge_t,gc) *succvec = graph->succs[from];
- VEC(constraint_edge_t,gc) *predvec = graph->preds[from];
+ VEC(constraint_edge_t,heap) *succvec = graph->succs[from];
+ VEC(constraint_edge_t,heap) *predvec = graph->preds[from];
int i;
constraint_edge_t c;
add_graph_edge (graph, newe);
olde.src = from;
olde.dest = c->dest;
+ olde.weights = NULL;
temp = get_graph_weights (graph, olde);
weights = get_graph_weights (graph, newe);
bitmap_ior_into (weights, temp);
add_graph_edge (graph, newe);
olde.src = c->dest;
olde.dest = from;
+ olde.weights = NULL;
temp = get_graph_weights (graph, olde);
weights = get_graph_weights (graph, newe);
bitmap_ior_into (weights, temp);
struct constraint_edge edge;
edge.src = to;
edge.dest = from;
+ edge.weights = NULL;
r = add_graph_edge (graph, edge);
r |= !bitmap_bit_p (get_graph_weights (graph, edge), weight);
bitmap_set_bit (get_graph_weights (graph, edge), weight);
int i = 0;
constraint_t c;
- graph = ggc_alloc (sizeof (struct constraint_graph));
- graph->succs = ggc_alloc_cleared (VEC_length (varinfo_t, varmap) * sizeof (*graph->succs));
- graph->preds = ggc_alloc_cleared (VEC_length (varinfo_t, varmap) * sizeof (*graph->preds));
+ graph = xmalloc (sizeof (struct constraint_graph));
+ graph->succs = xcalloc (VEC_length (varinfo_t, varmap),
+ sizeof (*graph->succs));
+ graph->preds = xcalloc (VEC_length (varinfo_t, varmap),
+ sizeof (*graph->preds));
+
for (i = 0; VEC_iterate (constraint_t, constraints, i, c); i++)
{
struct constraint_expr lhs = c->lhs;
struct constraint_expr rhs = c->rhs;
+ unsigned int lhsvar = get_varinfo_fc (lhs.var)->id;
+ unsigned int rhsvar = get_varinfo_fc (rhs.var)->id;
+
if (lhs.type == DEREF)
{
/* *x = y or *x = &y (complex) */
- if (rhs.type == ADDRESSOF || rhs.var > anything_id)
- insert_into_complex (lhs.var, c);
+ if (rhs.type == ADDRESSOF || rhsvar > anything_id)
+ insert_into_complex (lhsvar, c);
}
else if (rhs.type == DEREF)
{
- /* !ANYTHING = *y */
- if (lhs.var > anything_id)
- insert_into_complex (rhs.var, c);
+ /* !special var= *y */
+ if (!(get_varinfo (lhsvar)->is_special_var))
+ insert_into_complex (rhsvar, c);
}
else if (rhs.type == ADDRESSOF)
{
/* x = &y */
- bitmap_set_bit (get_varinfo (lhs.var)->solution, rhs.var);
+ bitmap_set_bit (get_varinfo (lhsvar)->solution, rhsvar);
}
- else if (rhs.var > anything_id && lhs.var > anything_id)
+ else if (lhsvar > anything_id)
{
/* Ignore 0 weighted self edges, as they can't possibly contribute
anything */
- if (lhs.var != rhs.var || rhs.offset != 0 || lhs.offset != 0)
+ if (lhsvar != rhsvar || rhs.offset != 0 || lhs.offset != 0)
{
struct constraint_edge edge;
- edge.src = lhs.var;
- edge.dest = rhs.var;
+ edge.src = lhsvar;
+ edge.dest = rhsvar;
/* x = y (simple) */
add_graph_edge (graph, edge);
bitmap_set_bit (get_graph_weights (graph, edge),
}
}
}
+
+
/* Changed variables on the last iteration. */
static unsigned int changed_count;
static sbitmap changed;
-DEF_VEC_I(uint);
-DEF_VEC_ALLOC_I(uint,heap);
+DEF_VEC_I(unsigned);
+DEF_VEC_ALLOC_I(unsigned,heap);
/* Strongly Connected Component visitation info. */
sbitmap in_component;
int current_index;
unsigned int *visited_index;
- VEC(uint,heap) *scc_stack;
- VEC(uint,heap) *unification_queue;
+ VEC(unsigned,heap) *scc_stack;
+ VEC(unsigned,heap) *unification_queue;
};
{
unsigned int t = si->visited_index[n];
SET_BIT (si->in_component, n);
- while (VEC_length (uint, si->scc_stack) != 0
- && t < si->visited_index[VEC_last (uint, si->scc_stack)])
+ while (VEC_length (unsigned, si->scc_stack) != 0
+ && t < si->visited_index[VEC_last (unsigned, si->scc_stack)])
{
- unsigned int w = VEC_pop (uint, si->scc_stack);
+ unsigned int w = VEC_pop (unsigned, si->scc_stack);
get_varinfo (w)->node = n;
SET_BIT (si->in_component, w);
/* Mark this node for collapsing. */
- VEC_safe_push (uint, heap, si->unification_queue, w);
+ VEC_safe_push (unsigned, heap, si->unification_queue, w);
}
}
else
- VEC_safe_push (uint, heap, si->scc_stack, n);
+ VEC_safe_push (unsigned, heap, si->scc_stack, n);
}
merge_graph_nodes (graph, to, from);
edge.src = to;
edge.dest = to;
+ edge.weights = NULL;
if (valid_graph_edge (graph, edge))
{
bitmap weights = get_graph_weights (graph, edge);
changed rep's solution.
Delete any 0 weighted self-edges we now have for rep. */
- while (i != VEC_length (uint, si->unification_queue))
+ while (i != VEC_length (unsigned, si->unification_queue))
{
- unsigned int tounify = VEC_index (uint, si->unification_queue, i);
+ unsigned int tounify = VEC_index (unsigned, si->unification_queue, i);
unsigned int n = get_varinfo (tounify)->node;
if (dump_file && (dump_flags & TDF_DETAILS))
/* If we've either finished processing the entire queue, or
finished processing all nodes for component n, update the solution for
n. */
- if (i == VEC_length (uint, si->unification_queue)
- || get_varinfo (VEC_index (uint, si->unification_queue, i))->node != n)
+ if (i == VEC_length (unsigned, si->unification_queue)
+ || get_varinfo (VEC_index (unsigned, si->unification_queue, i))->node != n)
{
struct constraint_edge edge;
bitmap_clear (tmp);
edge.src = n;
edge.dest = n;
+ edge.weights = NULL;
if (valid_graph_edge (graph, edge))
{
bitmap weights = get_graph_weights (graph, edge);
sbitmap visited;
/* Array that stores the topological order of the graph, *in
reverse*. */
- VEC(uint,heap) *topo_order;
+ VEC(unsigned,heap) *topo_order;
};
struct topo_info *ti = xmalloc (sizeof (struct topo_info));
ti->visited = sbitmap_alloc (size);
sbitmap_zero (ti->visited);
- ti->topo_order = VEC_alloc (uint, heap, 1);
+ ti->topo_order = VEC_alloc (unsigned, heap, 1);
return ti;
}
free_topo_info (struct topo_info *ti)
{
sbitmap_free (ti->visited);
- VEC_free (uint, heap, ti->topo_order);
+ VEC_free (unsigned, heap, ti->topo_order);
free (ti);
}
topo_visit (constraint_graph_t graph, struct topo_info *ti,
unsigned int n)
{
- VEC(constraint_edge_t,gc) *succs = graph->succs[n];
+ VEC(constraint_edge_t,heap) *succs = graph->succs[n];
constraint_edge_t c;
int i;
SET_BIT (ti->visited, n);
if (!TEST_BIT (ti->visited, c->dest))
topo_visit (graph, ti, c->dest);
}
- VEC_safe_push (uint, heap, ti->topo_order, n);
+ VEC_safe_push (unsigned, heap, ti->topo_order, n);
}
/* Return true if variable N + OFFSET is a legal field of N. */
/* For things we've globbed to single variables, any offset into the
variable acts like the entire variable, so that it becomes offset
0. */
- if (n == anything_id
+ if (ninfo->is_special_var
|| ninfo->is_artificial_var
|| ninfo->is_unknown_size_var)
{
*offset = 0;
return true;
}
- return n > anything_id
- && (get_varinfo (n)->offset + *offset) < get_varinfo (n)->fullsize;
+ return (get_varinfo (n)->offset + *offset) < get_varinfo (n)->fullsize;
}
/* Process a constraint C that represents *x = &y. */
constraint_t c, bitmap delta)
{
unsigned int rhs = c->rhs.var;
- unsigned HOST_WIDE_INT offset = c->lhs.offset;
unsigned int j;
bitmap_iterator bi;
/* For each member j of Delta (Sol(x)), add x to Sol(j) */
EXECUTE_IF_SET_IN_BITMAP (delta, 0, j, bi)
{
- if (type_safe (j, &offset))
+ unsigned HOST_WIDE_INT offset = c->lhs.offset;
+ if (type_safe (j, &offset) && !(get_varinfo (j)->is_special_var))
{
/* *x != NULL && *x != ANYTHING*/
varinfo_t v;
unsigned int t;
bitmap sol;
unsigned HOST_WIDE_INT fieldoffset = get_varinfo (j)->offset + offset;
+
v = first_vi_for_offset (get_varinfo (j), fieldoffset);
+ if (!v)
+ continue;
t = v->node;
sol = get_varinfo (t)->solution;
if (!bitmap_bit_p (sol, rhs))
}
}
}
- else if (dump_file)
+ else if (dump_file && !(get_varinfo (j)->is_special_var))
fprintf (dump_file, "Untypesafe usage in do_da_constraint.\n");
}
bitmap delta)
{
unsigned int lhs = get_varinfo (c->lhs.var)->node;
- unsigned HOST_WIDE_INT roffset = c->rhs.offset;
bool flag = false;
bitmap sol = get_varinfo (lhs)->solution;
unsigned int j;
an edge in the graph from j to x, and union Sol(j) into Sol(x). */
EXECUTE_IF_SET_IN_BITMAP (delta, 0, j, bi)
{
+ unsigned HOST_WIDE_INT roffset = c->rhs.offset;
if (type_safe (j, &roffset))
{
varinfo_t v;
unsigned int t;
v = first_vi_for_offset (get_varinfo (j), fieldoffset);
+ if (!v)
+ continue;
t = v->node;
if (int_add_graph_edge (graph, lhs, t, 0))
flag |= bitmap_ior_into (sol, get_varinfo (t)->solution);
}
- else if (dump_file)
+ else if (dump_file && !(get_varinfo (j)->is_special_var))
fprintf (dump_file, "Untypesafe usage in do_sd_constraint\n");
}
do_ds_constraint (constraint_graph_t graph, constraint_t c, bitmap delta)
{
unsigned int rhs = get_varinfo (c->rhs.var)->node;
- unsigned HOST_WIDE_INT loff = c->lhs.offset;
unsigned HOST_WIDE_INT roff = c->rhs.offset;
bitmap sol = get_varinfo (rhs)->solution;
unsigned int j;
union Sol(y) into Sol(j) */
EXECUTE_IF_SET_IN_BITMAP (delta, 0, j, bi)
{
- if (type_safe (j, &loff))
+ unsigned HOST_WIDE_INT loff = c->lhs.offset;
+ if (type_safe (j, &loff) && !(get_varinfo(j)->is_special_var))
{
varinfo_t v;
unsigned int t;
unsigned HOST_WIDE_INT fieldoffset = get_varinfo (j)->offset + loff;
v = first_vi_for_offset (get_varinfo (j), fieldoffset);
+ if (!v)
+ continue;
t = v->node;
if (int_add_graph_edge (graph, t, rhs, roff))
{
}
}
}
- else if (dump_file)
+ else if (dump_file && !(get_varinfo (j)->is_special_var))
fprintf (dump_file, "Untypesafe usage in do_ds_constraint\n");
}
}
else
{
/* x = *y */
- do_sd_constraint (graph, c, delta);
+ if (!(get_varinfo (c->lhs.var)->is_special_var))
+ do_sd_constraint (graph, c, delta);
}
}
si->in_component = sbitmap_alloc (size);
sbitmap_ones (si->in_component);
si->visited_index = xcalloc (sizeof (unsigned int), size + 1);
- si->scc_stack = VEC_alloc (uint, heap, 1);
- si->unification_queue = VEC_alloc (uint, heap, 1);
+ si->scc_stack = VEC_alloc (unsigned, heap, 1);
+ si->unification_queue = VEC_alloc (unsigned, heap, 1);
return si;
}
sbitmap_free (si->visited);
sbitmap_free (si->in_component);
free (si->visited_index);
- VEC_free (uint, heap, si->scc_stack);
- VEC_free (uint, heap, si->unification_queue);
+ VEC_free (unsigned, heap, si->scc_stack);
+ VEC_free (unsigned, heap, si->unification_queue);
free(si);
}
node in topological order. */
compute_topo_order (graph, ti);
- while (VEC_length (uint, ti->topo_order) != 0)
+ while (VEC_length (unsigned, ti->topo_order) != 0)
{
- unsigned int i = VEC_pop (uint, ti->topo_order);
+ unsigned int i = VEC_pop (unsigned, ti->topo_order);
unsigned int pred;
varinfo_t vi = get_varinfo (i);
bool okay_to_elim = false;
unsigned int root = VEC_length (varinfo_t, varmap);
- VEC(constraint_edge_t,gc) *predvec = graph->preds[i];
+ VEC(constraint_edge_t,heap) *predvec = graph->preds[i];
constraint_edge_t ce;
bitmap tmp;
unsigned int w;
weight = get_graph_weights (graph, *ce);
- /* We can't eliminate variables that have non-zero weighted
+ /* We can't eliminate variables that have nonzero weighted
edges between them. */
if (bitmap_other_than_zero_bit_set (weight))
{
compute_topo_order (graph, ti);
- while (VEC_length (uint, ti->topo_order) != 0)
+ while (VEC_length (unsigned, ti->topo_order) != 0)
{
- i = VEC_pop (uint, ti->topo_order);
+ i = VEC_pop (unsigned, ti->topo_order);
gcc_assert (get_varinfo (i)->node == i);
/* If the node has changed, we need to process the
constraint_t c;
constraint_edge_t e;
bitmap solution;
- VEC(constraint_t,gc) *complex = get_varinfo (i)->complex;
- VEC(constraint_edge_t,gc) *succs;
+ VEC(constraint_t,heap) *complex = get_varinfo (i)->complex;
+ VEC(constraint_edge_t,heap) *succs;
RESET_BIT (changed, i);
changed_count--;
cexpr.type = SCALAR;
- if (TREE_READONLY (t))
+ cexpr.var = get_id_for_tree (t);
+ /* If we determine the result is "anything", and we know this is readonly,
+ say it points to readonly memory instead. */
+ if (cexpr.var == anything_id && TREE_READONLY (t))
{
cexpr.type = ADDRESSOF;
cexpr.var = readonly_id;
}
- else
- cexpr.var = get_id_for_tree (t);
cexpr.offset = 0;
return cexpr;
for (vi = get_varinfo (rhs.var); vi != NULL; vi = vi->next)
vi->address_taken = true;
- VEC_safe_push (constraint_t, gc, constraints, t);
+ VEC_safe_push (constraint_t, heap, constraints, t);
}
else
{
if (lhs.type != DEREF && rhs.type == DEREF)
get_varinfo (lhs.var)->indirect_target = true;
- VEC_safe_push (constraint_t, gc, constraints, t);
+ VEC_safe_push (constraint_t, heap, constraints, t);
}
}
}
+/* Return true if an access to [ACCESSPOS, ACCESSSIZE]
+ overlaps with a field at [FIELDPOS, FIELDSIZE] */
+
+static bool
+offset_overlaps_with_access (const unsigned HOST_WIDE_INT fieldpos,
+ const unsigned HOST_WIDE_INT fieldsize,
+ const unsigned HOST_WIDE_INT accesspos,
+ const unsigned HOST_WIDE_INT accesssize)
+{
+ if (fieldpos == accesspos && fieldsize == accesssize)
+ return true;
+ if (accesspos >= fieldpos && accesspos < (fieldpos + fieldsize))
+ return true;
+ if (accesspos < fieldpos && (accesspos + accesssize > fieldpos))
+ return true;
+
+ return false;
+}
+
/* Given a COMPONENT_REF T, return the constraint_expr for it. */
static struct constraint_expr
-get_constraint_for_component_ref (tree t)
+get_constraint_for_component_ref (tree t, bool *need_anyoffset)
{
struct constraint_expr result;
- HOST_WIDE_INT bitsize;
+ HOST_WIDE_INT bitsize = -1;
HOST_WIDE_INT bitpos;
- tree offset;
+ tree offset = NULL_TREE;
enum machine_mode mode;
int unsignedp;
int volatilep;
t = get_inner_reference (t, &bitsize, &bitpos, &offset, &mode,
&unsignedp, &volatilep, false);
- result = get_constraint_for (t);
+ result = get_constraint_for (t, need_anyoffset);
/* This can also happen due to weird offsetof type macros. */
if (TREE_CODE (t) != ADDR_EXPR && result.type == ADDRESSOF)
{
result.offset = bitpos;
}
+ else if (need_anyoffset)
+ {
+ result.offset = 0;
+ *need_anyoffset = true;
+ }
else
{
result.var = anything_id;
we may have to do something cute here. */
if (result.offset < get_varinfo (result.var)->fullsize)
- result.var = first_vi_for_offset (get_varinfo (result.var),
- result.offset)->id;
+ {
+ /* It's also not true that the constraint will actually start at the
+ right offset, it may start in some padding. We only care about
+ setting the constraint to the first actual field it touches, so
+ walk to find it. */
+ varinfo_t curr;
+ for (curr = get_varinfo (result.var); curr; curr = curr->next)
+ {
+ if (offset_overlaps_with_access (curr->offset, curr->size,
+ result.offset, bitsize))
+ {
+ result.var = curr->id;
+ break;
+
+ }
+ }
+ /* assert that we found *some* field there. The user couldn't be
+ accessing *only* padding. */
+
+ gcc_assert (curr);
+ }
else
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "Access to past the end of variable, ignoring\n");
/* Given a tree T, return the constraint expression for it. */
static struct constraint_expr
-get_constraint_for (tree t)
+get_constraint_for (tree t, bool *need_anyoffset)
{
struct constraint_expr temp;
{
case ADDR_EXPR:
{
- temp = get_constraint_for (TREE_OPERAND (t, 0));
+ temp = get_constraint_for (TREE_OPERAND (t, 0), need_anyoffset);
if (temp.type == DEREF)
temp.type = SCALAR;
else
&ANYTHING added. */
if (call_expr_flags (t) & (ECF_MALLOC | ECF_MAY_BE_ALLOCA))
{
- tree heapvar = create_tmp_var_raw (ptr_type_node, "HEAP");
+ varinfo_t vi;
+ tree heapvar;
+
+ heapvar = create_tmp_var_raw (ptr_type_node, "HEAP");
+ DECL_EXTERNAL (heapvar) = 1;
+ add_referenced_tmp_var (heapvar);
temp.var = create_variable_info_for (heapvar,
alias_get_name (heapvar));
- get_varinfo (temp.var)->is_artificial_var = 1;
+ vi = get_varinfo (temp.var);
+ vi->is_artificial_var = 1;
+ vi->is_heap_var = 1;
temp.type = ADDRESSOF;
temp.offset = 0;
return temp;
{
case INDIRECT_REF:
{
- temp = get_constraint_for (TREE_OPERAND (t, 0));
+ temp = get_constraint_for (TREE_OPERAND (t, 0), need_anyoffset);
temp = do_deref (temp);
return temp;
}
case ARRAY_REF:
case COMPONENT_REF:
- temp = get_constraint_for_component_ref (t);
+ temp = get_constraint_for_component_ref (t, need_anyoffset);
return temp;
default:
{
/* Cast from non-pointer to pointers are bad news for us.
Anything else, we see through */
- if (!(POINTER_TYPE_P (TREE_TYPE (t)) &&
- ! POINTER_TYPE_P (TREE_TYPE (op))))
- return get_constraint_for (op);
+ if (!(POINTER_TYPE_P (TREE_TYPE (t))
+ && ! POINTER_TYPE_P (TREE_TYPE (op))))
+ return get_constraint_for (op, need_anyoffset);
+
+ /* FALLTHRU */
}
default:
{
switch (TREE_CODE (t))
{
case PHI_NODE:
- return get_constraint_for (PHI_RESULT (t));
+ return get_constraint_for (PHI_RESULT (t), need_anyoffset);
case SSA_NAME:
return get_constraint_exp_from_ssa_var (t);
default:
For each field of the lhs variable (lhsfield)
For each field of the rhs variable at lhsfield.offset (rhsfield)
add the constraint lhsfield = rhsfield
-*/
-static void
+ If we fail due to some kind of type unsafety or other thing we
+ can't handle, return false. We expect the caller to collapse the
+ variable in that case. */
+
+static bool
do_simple_structure_copy (const struct constraint_expr lhs,
const struct constraint_expr rhs,
const unsigned HOST_WIDE_INT size)
q = get_varinfo (temprhs.var);
fieldoffset = p->offset - pstart;
q = first_vi_for_offset (q, q->offset + fieldoffset);
+ if (!q)
+ return false;
temprhs.var = q->id;
process_constraint (new_constraint (templhs, temprhs));
}
+ return true;
}
}
}
+/* Sometimes, frontends like to give us bad type information. This
+ function will collapse all the fields from VAR to the end of VAR,
+ into VAR, so that we treat those fields as a single variable.
+ We return the variable they were collapsed into. */
+
+static unsigned int
+collapse_rest_of_var (unsigned int var)
+{
+ varinfo_t currvar = get_varinfo (var);
+ varinfo_t field;
+
+ for (field = currvar->next; field; field = field->next)
+ {
+ if (dump_file)
+ fprintf (dump_file, "Type safety: Collapsing var %s into %s\n",
+ field->name, currvar->name);
+
+ gcc_assert (!field->collapsed_to);
+ field->collapsed_to = currvar;
+ }
+
+ currvar->next = NULL;
+ currvar->size = currvar->fullsize - currvar->offset;
+
+ return currvar->id;
+}
/* Handle aggregate copies by expanding into copies of the respective
fields of the structures. */
unsigned HOST_WIDE_INT lhssize;
unsigned HOST_WIDE_INT rhssize;
- lhs = get_constraint_for (lhsop);
- rhs = get_constraint_for (rhsop);
+ lhs = get_constraint_for (lhsop, NULL);
+ rhs = get_constraint_for (rhsop, NULL);
/* If we have special var = x, swap it around. */
- if (lhs.var <= integer_id && rhs.var > integer_id)
+ if (lhs.var <= integer_id && !(get_varinfo (rhs.var)->is_special_var))
{
tmp = lhs;
lhs = rhs;
possible it's something we could handle. However, most cases falling
into this are dealing with transparent unions, which are slightly
weird. */
- if (rhs.type == ADDRESSOF && rhs.var > integer_id)
+ if (rhs.type == ADDRESSOF && !(get_varinfo (rhs.var)->is_special_var))
{
rhs.type = ADDRESSOF;
rhs.var = anything_id;
}
else
{
+ tree rhstype = TREE_TYPE (rhsop);
+ tree lhstype = TREE_TYPE (lhsop);
+ tree rhstypesize = TYPE_SIZE (rhstype);
+ tree lhstypesize = TYPE_SIZE (lhstype);
+
+ /* If we have a variably sized types on the rhs or lhs, and a deref
+ constraint, add the constraint, lhsconstraint = &ANYTHING.
+ This is conservatively correct because either the lhs is an unknown
+ sized var (if the constraint is SCALAR), or the lhs is a DEREF
+ constraint, and every variable it can point to must be unknown sized
+ anyway, so we don't need to worry about fields at all. */
+ if ((rhs.type == DEREF && TREE_CODE (rhstypesize) != INTEGER_CST)
+ || (lhs.type == DEREF && TREE_CODE (lhstypesize) != INTEGER_CST))
+ {
+ rhs.var = anything_id;
+ rhs.type = ADDRESSOF;
+ rhs.offset = 0;
+ process_constraint (new_constraint (lhs, rhs));
+ return;
+ }
+
/* The size only really matters insofar as we don't set more or less of
the variable. If we hit an unknown size var, the size should be the
whole darn thing. */
if (get_varinfo (rhs.var)->is_unknown_size_var)
rhssize = ~0;
else
- rhssize = TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (rhsop)));
+ rhssize = TREE_INT_CST_LOW (rhstypesize);
if (get_varinfo (lhs.var)->is_unknown_size_var)
lhssize = ~0;
else
- lhssize = TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (lhsop)));
+ lhssize = TREE_INT_CST_LOW (lhstypesize);
if (rhs.type == SCALAR && lhs.type == SCALAR)
- do_simple_structure_copy (lhs, rhs, MIN (lhssize, rhssize));
+ {
+ if (!do_simple_structure_copy (lhs, rhs, MIN (lhssize, rhssize)))
+ {
+ lhs.var = collapse_rest_of_var (lhs.var);
+ rhs.var = collapse_rest_of_var (rhs.var);
+ lhs.offset = 0;
+ rhs.offset = 0;
+ lhs.type = SCALAR;
+ rhs.type = SCALAR;
+ process_constraint (new_constraint (lhs, rhs));
+ }
+ }
else if (lhs.type != DEREF && rhs.type == DEREF)
do_rhs_deref_structure_copy (lhs, rhs, MIN (lhssize, rhssize));
else if (lhs.type == DEREF && rhs.type != DEREF)
do_lhs_deref_structure_copy (lhs, rhs, MIN (lhssize, rhssize));
else
{
- tree rhsdecl = get_varinfo (rhs.var)->decl;
- tree pointertype = TREE_TYPE (rhsdecl);
- tree pointedtotype = TREE_TYPE (pointertype);
+ tree pointedtotype = lhstype;
tree tmpvar;
gcc_assert (rhs.type == DEREF && lhs.type == DEREF);
}
}
+/* Update related alias information kept in AI. This is used when
+ building name tags, alias sets and deciding grouping heuristics.
+ STMT is the statement to process. This function also updates
+ ADDRESSABLE_VARS. */
-/* Return true if REF, a COMPONENT_REF, has an INDIRECT_REF somewhere
- in it. */
-
-static inline bool
-ref_contains_indirect_ref (tree ref)
+static void
+update_alias_info (tree stmt, struct alias_info *ai)
{
- while (handled_component_p (ref))
+ bitmap addr_taken;
+ use_operand_p use_p;
+ ssa_op_iter iter;
+ bool stmt_escapes_p = is_escape_site (stmt, ai);
+ tree op;
+
+ /* Mark all the variables whose address are taken by the statement. */
+ addr_taken = addresses_taken (stmt);
+ if (addr_taken)
{
- if (TREE_CODE (ref) == INDIRECT_REF)
- return true;
- ref = TREE_OPERAND (ref, 0);
+ bitmap_ior_into (addressable_vars, addr_taken);
+
+ /* If STMT is an escape point, all the addresses taken by it are
+ call-clobbered. */
+ if (stmt_escapes_p)
+ {
+ bitmap_iterator bi;
+ unsigned i;
+
+ EXECUTE_IF_SET_IN_BITMAP (addr_taken, 0, i, bi)
+ mark_call_clobbered (referenced_var (i));
+ }
+ }
+
+ /* Process each operand use. If an operand may be aliased, keep
+ track of how many times it's being used. For pointers, determine
+ whether they are dereferenced by the statement, or whether their
+ value escapes, etc. */
+ FOR_EACH_PHI_OR_STMT_USE (use_p, stmt, iter, SSA_OP_USE)
+ {
+ tree op, var;
+ var_ann_t v_ann;
+ struct ptr_info_def *pi;
+ bool is_store, is_potential_deref;
+ unsigned num_uses, num_derefs;
+
+ op = USE_FROM_PTR (use_p);
+
+ /* If STMT is a PHI node, OP may be an ADDR_EXPR. If so, add it
+ to the set of addressable variables. */
+ if (TREE_CODE (op) == ADDR_EXPR)
+ {
+ gcc_assert (TREE_CODE (stmt) == PHI_NODE);
+
+ /* PHI nodes don't have annotations for pinning the set
+ of addresses taken, so we collect them here.
+
+ FIXME, should we allow PHI nodes to have annotations
+ so that they can be treated like regular statements?
+ Currently, they are treated as second-class
+ statements. */
+ add_to_addressable_set (TREE_OPERAND (op, 0), &addressable_vars);
+ continue;
+ }
+
+ /* Ignore constants. */
+ if (TREE_CODE (op) != SSA_NAME)
+ continue;
+
+ var = SSA_NAME_VAR (op);
+ v_ann = var_ann (var);
+
+ /* If the operand's variable may be aliased, keep track of how
+ many times we've referenced it. This is used for alias
+ grouping in compute_flow_insensitive_aliasing. */
+ if (may_be_aliased (var))
+ NUM_REFERENCES_INC (v_ann);
+
+ /* We are only interested in pointers. */
+ if (!POINTER_TYPE_P (TREE_TYPE (op)))
+ continue;
+
+ pi = get_ptr_info (op);
+
+ /* Add OP to AI->PROCESSED_PTRS, if it's not there already. */
+ if (!TEST_BIT (ai->ssa_names_visited, SSA_NAME_VERSION (op)))
+ {
+ SET_BIT (ai->ssa_names_visited, SSA_NAME_VERSION (op));
+ VARRAY_PUSH_TREE (ai->processed_ptrs, op);
+ }
+
+ /* If STMT is a PHI node, then it will not have pointer
+ dereferences and it will not be an escape point. */
+ if (TREE_CODE (stmt) == PHI_NODE)
+ continue;
+
+ /* Determine whether OP is a dereferenced pointer, and if STMT
+ is an escape point, whether OP escapes. */
+ count_uses_and_derefs (op, stmt, &num_uses, &num_derefs, &is_store);
+
+ /* Handle a corner case involving address expressions of the
+ form '&PTR->FLD'. The problem with these expressions is that
+ they do not represent a dereference of PTR. However, if some
+ other transformation propagates them into an INDIRECT_REF
+ expression, we end up with '*(&PTR->FLD)' which is folded
+ into 'PTR->FLD'.
+
+ So, if the original code had no other dereferences of PTR,
+ the aliaser will not create memory tags for it, and when
+ &PTR->FLD gets propagated to INDIRECT_REF expressions, the
+ memory operations will receive no V_MAY_DEF/VUSE operands.
+
+ One solution would be to have count_uses_and_derefs consider
+ &PTR->FLD a dereference of PTR. But that is wrong, since it
+ is not really a dereference but an offset calculation.
+
+ What we do here is to recognize these special ADDR_EXPR
+ nodes. Since these expressions are never GIMPLE values (they
+ are not GIMPLE invariants), they can only appear on the RHS
+ of an assignment and their base address is always an
+ INDIRECT_REF expression. */
+ is_potential_deref = false;
+ if (TREE_CODE (stmt) == MODIFY_EXPR
+ && TREE_CODE (TREE_OPERAND (stmt, 1)) == ADDR_EXPR
+ && !is_gimple_val (TREE_OPERAND (stmt, 1)))
+ {
+ /* If the RHS if of the form &PTR->FLD and PTR == OP, then
+ this represents a potential dereference of PTR. */
+ tree rhs = TREE_OPERAND (stmt, 1);
+ tree base = get_base_address (TREE_OPERAND (rhs, 0));
+ if (TREE_CODE (base) == INDIRECT_REF
+ && TREE_OPERAND (base, 0) == op)
+ is_potential_deref = true;
+ }
+
+ if (num_derefs > 0 || is_potential_deref)
+ {
+ /* Mark OP as dereferenced. In a subsequent pass,
+ dereferenced pointers that point to a set of
+ variables will be assigned a name tag to alias
+ all the variables OP points to. */
+ pi->is_dereferenced = 1;
+
+ /* Keep track of how many time we've dereferenced each
+ pointer. */
+ NUM_REFERENCES_INC (v_ann);
+
+ /* If this is a store operation, mark OP as being
+ dereferenced to store, otherwise mark it as being
+ dereferenced to load. */
+ if (is_store)
+ bitmap_set_bit (ai->dereferenced_ptrs_store, DECL_UID (var));
+ else
+ bitmap_set_bit (ai->dereferenced_ptrs_load, DECL_UID (var));
+ }
+
+ if (stmt_escapes_p && num_derefs < num_uses)
+ {
+ /* If STMT is an escape point and STMT contains at
+ least one direct use of OP, then the value of OP
+ escapes and so the pointed-to variables need to
+ be marked call-clobbered. */
+ pi->value_escapes_p = 1;
+
+ /* If the statement makes a function call, assume
+ that pointer OP will be dereferenced in a store
+ operation inside the called function. */
+ if (get_call_expr_in (stmt))
+ {
+ bitmap_set_bit (ai->dereferenced_ptrs_store, DECL_UID (var));
+ pi->is_dereferenced = 1;
+ }
+ }
+ }
+
+ if (TREE_CODE (stmt) == PHI_NODE)
+ return;
+
+ /* Update reference counter for definitions to any
+ potentially aliased variable. This is used in the alias
+ grouping heuristics. */
+ FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_DEF)
+ {
+ tree var = SSA_NAME_VAR (op);
+ var_ann_t ann = var_ann (var);
+ bitmap_set_bit (ai->written_vars, DECL_UID (var));
+ if (may_be_aliased (var))
+ NUM_REFERENCES_INC (ann);
+
+ }
+
+ /* Mark variables in V_MAY_DEF operands as being written to. */
+ FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_VIRTUAL_DEFS)
+ {
+ tree var = DECL_P (op) ? op : SSA_NAME_VAR (op);
+ bitmap_set_bit (ai->written_vars, DECL_UID (var));
}
- return false;
}
-/* Tree walker that is the heart of the aliasing infrastructure.
- TP is a pointer to the current tree.
- WALK_SUBTREES specifies whether to continue traversing subtrees or
- not.
- Returns NULL_TREE when we should stop.
-
- This function is the main part of the constraint builder. It
- walks the trees, calling the appropriate building functions
- to process various statements. */
+/* Handle pointer arithmetic EXPR when creating aliasing constraints.
+ Expressions of the type PTR + CST can be handled in two ways:
+
+ 1- If the constraint for PTR is ADDRESSOF for a non-structure
+ variable, then we can use it directly because adding or
+ subtracting a constant may not alter the original ADDRESSOF
+ constraint (i.e., pointer arithmetic may not legally go outside
+ an object's boundaries).
+
+ 2- If the constraint for PTR is ADDRESSOF for a structure variable,
+ then if CST is a compile-time constant that can be used as an
+ offset, we can determine which sub-variable will be pointed-to
+ by the expression.
+
+ Return true if the expression is handled. For any other kind of
+ expression, return false so that each operand can be added as a
+ separate constraint by the caller. */
+
+static bool
+handle_ptr_arith (struct constraint_expr lhs, tree expr)
+{
+ tree op0, op1;
+ struct constraint_expr base, offset;
+
+ if (TREE_CODE (expr) != PLUS_EXPR)
+ return false;
+
+ op0 = TREE_OPERAND (expr, 0);
+ op1 = TREE_OPERAND (expr, 1);
+
+ base = get_constraint_for (op0, NULL);
+
+ offset.var = anyoffset_id;
+ offset.type = ADDRESSOF;
+ offset.offset = 0;
+
+ process_constraint (new_constraint (lhs, base));
+ process_constraint (new_constraint (lhs, offset));
+
+ return true;
+}
+
+
+/* Walk statement T setting up aliasing constraints according to the
+ references found in T. This function is the main part of the
+ constraint builder. AI points to auxiliary alias information used
+ when building alias sets and computing alias grouping heuristics. */
static void
-find_func_aliases (tree t)
+find_func_aliases (tree t, struct alias_info *ai)
{
struct constraint_expr lhs, rhs;
- switch (TREE_CODE (t))
- {
- case PHI_NODE:
- {
- int i;
- /* Only care about pointers and structures containing
- pointers. */
- if (POINTER_TYPE_P (TREE_TYPE (PHI_RESULT (t)))
- || AGGREGATE_TYPE_P (TREE_TYPE (PHI_RESULT (t))))
- {
- lhs = get_constraint_for (PHI_RESULT (t));
- for (i = 0; i < PHI_NUM_ARGS (t); i++)
- {
- rhs = get_constraint_for (PHI_ARG_DEF (t, i));
- process_constraint (new_constraint (lhs, rhs));
- }
- }
- }
- break;
+ /* Update various related attributes like escaped addresses, pointer
+ dereferences for loads and stores. This is used when creating
+ name tags and alias sets. */
+ update_alias_info (t, ai);
- case MODIFY_EXPR:
- {
- tree lhsop = TREE_OPERAND (t, 0);
- tree rhsop = TREE_OPERAND (t, 1);
- int i;
+ /* Now build constraints expressions. */
+ if (TREE_CODE (t) == PHI_NODE)
+ {
+ /* Only care about pointers and structures containing
+ pointers. */
+ if (POINTER_TYPE_P (TREE_TYPE (PHI_RESULT (t)))
+ || AGGREGATE_TYPE_P (TREE_TYPE (PHI_RESULT (t))))
+ {
+ int i;
- if (AGGREGATE_TYPE_P (TREE_TYPE (lhsop))
- && AGGREGATE_TYPE_P (TREE_TYPE (rhsop)))
- {
- do_structure_copy (lhsop, rhsop);
- }
- else
- {
- /* Only care about operations with pointers, structures
- containing pointers, dereferences, and call
- expressions. */
- if (POINTER_TYPE_P (TREE_TYPE (lhsop))
- || AGGREGATE_TYPE_P (TREE_TYPE (lhsop))
- || ref_contains_indirect_ref (lhsop)
- || TREE_CODE (rhsop) == CALL_EXPR)
- {
- lhs = get_constraint_for (lhsop);
- switch (TREE_CODE_CLASS (TREE_CODE (rhsop)))
- {
- /* RHS that consist of unary operations,
- exceptional types, or bare decls/constants, get
- handled directly by get_constraint_for. */
+ lhs = get_constraint_for (PHI_RESULT (t), NULL);
+ for (i = 0; i < PHI_NUM_ARGS (t); i++)
+ {
+ rhs = get_constraint_for (PHI_ARG_DEF (t, i), NULL);
+ process_constraint (new_constraint (lhs, rhs));
+ }
+ }
+ }
+ else if (TREE_CODE (t) == MODIFY_EXPR)
+ {
+ tree lhsop = TREE_OPERAND (t, 0);
+ tree rhsop = TREE_OPERAND (t, 1);
+ int i;
+
+ if (AGGREGATE_TYPE_P (TREE_TYPE (lhsop))
+ && AGGREGATE_TYPE_P (TREE_TYPE (rhsop)))
+ {
+ do_structure_copy (lhsop, rhsop);
+ }
+ else
+ {
+ /* Only care about operations with pointers, structures
+ containing pointers, dereferences, and call expressions. */
+ if (POINTER_TYPE_P (TREE_TYPE (lhsop))
+ || AGGREGATE_TYPE_P (TREE_TYPE (lhsop))
+ || TREE_CODE (rhsop) == CALL_EXPR)
+ {
+ lhs = get_constraint_for (lhsop, NULL);
+ switch (TREE_CODE_CLASS (TREE_CODE (rhsop)))
+ {
+ /* RHS that consist of unary operations,
+ exceptional types, or bare decls/constants, get
+ handled directly by get_constraint_for. */
case tcc_reference:
case tcc_declaration:
case tcc_constant:
case tcc_exceptional:
case tcc_expression:
case tcc_unary:
- {
- rhs = get_constraint_for (rhsop);
- process_constraint (new_constraint (lhs, rhs));
- }
+ {
+ tree anyoffsetrhs = rhsop;
+ bool need_anyoffset = false;
+ rhs = get_constraint_for (rhsop, &need_anyoffset);
+ process_constraint (new_constraint (lhs, rhs));
+
+ STRIP_NOPS (anyoffsetrhs);
+ /* When taking the address of an aggregate
+ type, from the LHS we can access any field
+ of the RHS. */
+ if (need_anyoffset || (rhs.type == ADDRESSOF
+ && !(get_varinfo (rhs.var)->is_special_var)
+ && AGGREGATE_TYPE_P (TREE_TYPE (TREE_TYPE (anyoffsetrhs)))))
+ {
+ rhs.var = anyoffset_id;
+ rhs.type = ADDRESSOF;
+ rhs.offset = 0;
+ process_constraint (new_constraint (lhs, rhs));
+ }
+ }
break;
- /* Otherwise, walk each operand. */
+ case tcc_binary:
+ {
+ /* For pointer arithmetic of the form
+ PTR + CST, we can simply use PTR's
+ constraint because pointer arithmetic is
+ not allowed to go out of bounds. */
+ if (handle_ptr_arith (lhs, rhsop))
+ break;
+ }
+ /* FALLTHRU */
+
+ /* Otherwise, walk each operand. Notice that we
+ can't use the operand interface because we need
+ to process expressions other than simple operands
+ (e.g. INDIRECT_REF, ADDR_EXPR, CALL_EXPR). */
default:
for (i = 0; i < TREE_CODE_LENGTH (TREE_CODE (rhsop)); i++)
{
tree op = TREE_OPERAND (rhsop, i);
- rhs = get_constraint_for (op);
+ rhs = get_constraint_for (op, NULL);
process_constraint (new_constraint (lhs, rhs));
}
- }
- }
- }
- }
- break;
-
- default:
- break;
+ }
+ }
+ }
}
+
+ /* After promoting variables and computing aliasing we will
+ need to re-scan most statements. FIXME: Try to minimize the
+ number of statements re-scanned. It's not really necessary to
+ re-scan *all* statements. */
+ mark_stmt_modified (t);
}
OFFSET.
Effectively, walk the chain of fields for the variable START to find the
first field that overlaps with OFFSET.
- Abort if we can't find one. */
+ Return NULL if we can't find one. */
static varinfo_t
first_vi_for_offset (varinfo_t start, unsigned HOST_WIDE_INT offset)
return curr;
curr = curr->next;
}
-
- gcc_unreachable ();
+ return NULL;
}
if (TREE_CODE (field) == FIELD_DECL)
{
bool push = false;
+ int pushed = 0;
if (has_union
&& (TREE_CODE (TREE_TYPE (field)) == QUAL_UNION_TYPE
if (!var_can_have_subvars (field))
push = true;
- else if (!(push_fields_onto_fieldstack
+ else if (!(pushed = push_fields_onto_fieldstack
(TREE_TYPE (field), fieldstack,
offset + bitpos_of_field (field), has_union))
&& DECL_SIZE (field)
pair->offset = offset + bitpos_of_field (field);
count++;
}
+ else
+ count += pushed;
}
return count;
process_constraint (new_constraint (lhs, rhs));
}
+
+/* Return true if FIELDSTACK contains fields that overlap.
+ FIELDSTACK is assumed to be sorted by offset. */
+
+static bool
+check_for_overlaps (VEC (fieldoff_s,heap) *fieldstack)
+{
+ fieldoff_s *fo = NULL;
+ unsigned int i;
+ HOST_WIDE_INT lastoffset = -1;
+
+ for (i = 0; VEC_iterate (fieldoff_s, fieldstack, i, fo); i++)
+ {
+ if (fo->offset == lastoffset)
+ return true;
+ lastoffset = fo->offset;
+ }
+ return false;
+}
+
/* Create a varinfo structure for NAME and DECL, and add it to VARMAP.
This will also create any varinfo structures necessary for fields
of DECL. */
tree decltype = TREE_TYPE (decl);
bool notokay = false;
bool hasunion;
- subvar_t svars;
bool is_global = DECL_P (decl) ? is_global_var (decl) : false;
VEC (fieldoff_s,heap) *fieldstack = NULL;
- hasunion = TREE_CODE (decltype) == UNION_TYPE || TREE_CODE (decltype) == QUAL_UNION_TYPE;
+ hasunion = TREE_CODE (decltype) == UNION_TYPE
+ || TREE_CODE (decltype) == QUAL_UNION_TYPE;
if (var_can_have_subvars (decl) && use_field_sensitive && !hasunion)
{
push_fields_onto_fieldstack (decltype, &fieldstack, 0, &hasunion);
notokay = true;
}
}
-
- /* If this variable already has subvars, just create the variables for the
- subvars and we are done.
- NOTE: This assumes things haven't generated uses of previously
- unused structure fields. */
- if (use_field_sensitive
- && !notokay
- && var_can_have_subvars (decl)
- && var_ann (decl)
- && (svars = get_subvars_for_var (decl)))
- {
- subvar_t sv;
- varinfo_t base = NULL;
- unsigned int firstindex = index;
-
- for (sv = svars; sv; sv = sv->next)
- {
- /* For debugging purposes, this will print the names of the
- fields as "<var>.<offset>.<size>"
- This is only for debugging purposes. */
-#define PRINT_LONG_NAMES
-#ifdef PRINT_LONG_NAMES
- char *tempname;
- const char *newname;
-
- asprintf (&tempname,
- "%s." HOST_WIDE_INT_PRINT_DEC "." HOST_WIDE_INT_PRINT_DEC,
- alias_get_name (decl), sv->offset, sv->size);
- newname = ggc_strdup (tempname);
- free (tempname);
- vi = new_var_info (sv->var, index, newname, index);
-#else
- vi = new_var_info (sv->var, index, alias_get_name (sv->var), index);
-#endif
- vi->decl = sv->var;
- vi->fullsize = TREE_INT_CST_LOW (TYPE_SIZE (decltype));
- vi->size = sv->size;
- vi->offset = sv->offset;
- if (!base)
- {
- base = vi;
- insert_id_for_tree (decl, index);
- }
- else
- {
- insert_into_field_list (base, vi);
- }
- insert_id_for_tree (sv->var, index);
- VEC_safe_push (varinfo_t, gc, varmap, vi);
- if (is_global)
- make_constraint_to_anything (vi);
- index++;
-
- }
- return firstindex;
- }
/* If the variable doesn't have subvars, we may end up needing to
}
insert_id_for_tree (vi->decl, index);
- VEC_safe_push (varinfo_t, gc, varmap, vi);
+ VEC_safe_push (varinfo_t, heap, varmap, vi);
if (is_global)
make_constraint_to_anything (vi);
which will make notokay = true. In that case, we are going to return
without creating varinfos for the fields anyway, so sorting them is a
waste to boot. */
- if (!notokay)
- sort_fieldstack (fieldstack);
+ if (!notokay)
+ {
+ sort_fieldstack (fieldstack);
+ /* Due to some C++ FE issues, like PR 22488, we might end up
+ what appear to be overlapping fields even though they,
+ in reality, do not overlap. Until the C++ FE is fixed,
+ we will simply disable field-sensitivity for these cases. */
+ notokay = check_for_overlaps (fieldstack);
+ }
+
if (VEC_length (fieldoff_s, fieldstack) != 0)
fo = VEC_index (fieldoff_s, fieldstack, 0);
field = fo->field;
vi->size = TREE_INT_CST_LOW (DECL_SIZE (field));
+ vi->offset = fo->offset;
for (i = 1; VEC_iterate (fieldoff_s, fieldstack, i, fo); i++)
{
varinfo_t newvi;
newvi->size = TREE_INT_CST_LOW (DECL_SIZE (field));
newvi->fullsize = vi->fullsize;
insert_into_field_list (vi, newvi);
- VEC_safe_push (varinfo_t, gc, varmap, newvi);
+ VEC_safe_push (varinfo_t, heap, varmap, newvi);
if (is_global)
make_constraint_to_anything (newvi);
lhs.type = SCALAR;
lhs.var = create_variable_info_for (t, alias_get_name (t));
- get_varinfo (lhs.var)->is_artificial_var = true;
rhs.var = anything_id;
rhs.type = ADDRESSOF;
rhs.offset = 0;
{
unsigned int i;
bitmap_iterator bi;
+ bool found_anyoffset = false;
+ subvar_t sv;
EXECUTE_IF_SET_IN_BITMAP (from, 0, i, bi)
{
varinfo_t vi = get_varinfo (i);
+
+ /* If we find ANYOFFSET in the solution and the solution
+ includes SFTs for some structure, then all the SFTs in that
+ structure will need to be added to the alias set. */
+ if (vi->id == anyoffset_id)
+ {
+ found_anyoffset = true;
+ continue;
+ }
+
+ /* The only artificial variables that are allowed in a may-alias
+ set are heap variables. */
+ if (vi->is_artificial_var && !vi->is_heap_var)
+ continue;
- /* Variables containing unions may need to be converted to their
- SFT's, because SFT's can have unions and we cannot. */
if (vi->has_union && get_subvars_for_var (vi->decl) != NULL)
{
- subvar_t svars = get_subvars_for_var (vi->decl);
- subvar_t sv;
- for (sv = svars; sv; sv = sv->next)
- bitmap_set_bit (into, var_ann (sv->var)->uid);
+ /* Variables containing unions may need to be converted to
+ their SFT's, because SFT's can have unions and we cannot. */
+ for (sv = get_subvars_for_var (vi->decl); sv; sv = sv->next)
+ bitmap_set_bit (into, DECL_UID (sv->var));
}
- /* We may end up with labels in the points-to set because people
- take their address, and they are _DECL's. */
else if (TREE_CODE (vi->decl) == VAR_DECL
- || TREE_CODE (vi->decl) == PARM_DECL)
- bitmap_set_bit (into, var_ann (vi->decl)->uid);
-
-
+ || TREE_CODE (vi->decl) == PARM_DECL)
+ {
+ if (found_anyoffset
+ && var_can_have_subvars (vi->decl)
+ && get_subvars_for_var (vi->decl))
+ {
+ /* If ANYOFFSET is in the solution set and VI->DECL is
+ an aggregate variable with sub-variables, then any of
+ the SFTs inside VI->DECL may have been accessed. Add
+ all the sub-vars for VI->DECL. */
+ for (sv = get_subvars_for_var (vi->decl); sv; sv = sv->next)
+ bitmap_set_bit (into, DECL_UID (sv->var));
+ }
+ else if (var_can_have_subvars (vi->decl)
+ && get_subvars_for_var (vi->decl))
+ {
+ /* If VI->DECL is an aggregate for which we created
+ SFTs, add the SFT corresponding to VI->OFFSET. */
+ tree sft = get_subvar_at (vi->decl, vi->offset);
+ bitmap_set_bit (into, DECL_UID (sft));
+ }
+ else
+ {
+ /* Otherwise, just add VI->DECL to the alias set. */
+ bitmap_set_bit (into, DECL_UID (vi->decl));
+ }
+ }
}
}
-static int have_alias_info = false;
+
+
+static bool have_alias_info = false;
/* Given a pointer variable P, fill in its points-to set, or return
false if we can't. */
find_what_p_points_to (tree p)
{
unsigned int id = 0;
+
if (!have_alias_info)
return false;
+
if (lookup_id_for_tree (p, &id))
{
varinfo_t vi = get_varinfo (id);
if (vi->is_artificial_var)
return false;
- /* See if this is a field or a structure */
+ /* See if this is a field or a structure. */
if (vi->size != vi->fullsize)
{
+ /* Nothing currently asks about structure fields directly,
+ but when they do, we need code here to hand back the
+ points-to set. */
if (!var_can_have_subvars (vi->decl)
|| get_subvars_for_var (vi->decl) == NULL)
return false;
- /* Nothing currently asks about structure fields directly, but when
- they do, we need code here to hand back the points-to set. */
}
else
{
variable. */
vi = get_varinfo (vi->node);
- /* Make sure there aren't any artificial vars in the points to set.
- XXX: Note that we need to translate our heap variables to
- something. */
+ /* Translate artificial variables into SSA_NAME_PTR_INFO
+ attributes. */
EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
{
- if (get_varinfo (i)->is_artificial_var)
- return false;
+ varinfo_t vi = get_varinfo (i);
+
+ if (vi->is_artificial_var)
+ {
+ /* FIXME. READONLY should be handled better so that
+ flow insensitive aliasing can disregard writable
+ aliases. */
+ if (vi->id == nothing_id)
+ pi->pt_null = 1;
+ else if (vi->id == anything_id)
+ pi->pt_anything = 1;
+ else if (vi->id == readonly_id)
+ pi->pt_anything = 1;
+ else if (vi->id == integer_id)
+ pi->pt_anything = 1;
+ else if (vi->is_heap_var)
+ pi->pt_global_mem = 1;
+ }
}
- pi->pt_anything = false;
+
+ if (pi->pt_anything)
+ return false;
+
if (!pi->pt_vars)
pi->pt_vars = BITMAP_GGC_ALLOC ();
+
set_uids_in_ptset (pi->pt_vars, vi->solution);
+
+ if (bitmap_empty_p (pi->pt_vars))
+ pi->pt_vars = NULL;
+
return true;
}
}
+
return false;
}
{
unsigned int i;
- fprintf (outfile, "\nPoints-to information\n\n");
+ fprintf (outfile, "\nPoints-to sets\n\n");
if (dump_flags & TDF_STATS)
{
var_nothing->offset = 0;
var_nothing->size = ~0;
var_nothing->fullsize = ~0;
+ var_nothing->is_special_var = 1;
nothing_id = 0;
- VEC_safe_push (varinfo_t, gc, varmap, var_nothing);
+ VEC_safe_push (varinfo_t, heap, varmap, var_nothing);
/* Create the ANYTHING variable, used to represent that a variable
points to some unknown piece of memory. */
var_anything->offset = 0;
var_anything->next = NULL;
var_anything->fullsize = ~0;
+ var_anything->is_special_var = 1;
anything_id = 1;
/* Anything points to anything. This makes deref constraints just
work in the presence of linked list and other p = *p type loops,
by saying that *ANYTHING = ANYTHING. */
- VEC_safe_push (varinfo_t, gc, varmap, var_anything);
+ VEC_safe_push (varinfo_t, heap, varmap, var_anything);
lhs.type = SCALAR;
lhs.var = anything_id;
lhs.offset = 0;
rhs.var = anything_id;
rhs.offset = 0;
var_anything->address_taken = true;
+
/* This specifically does not use process_constraint because
process_constraint ignores all anything = anything constraints, since all
but this one are redundant. */
- VEC_safe_push (constraint_t, gc, constraints, new_constraint (lhs, rhs));
+ VEC_safe_push (constraint_t, heap, constraints, new_constraint (lhs, rhs));
/* Create the READONLY variable, used to represent that a variable
points to readonly memory. */
var_readonly->size = ~0;
var_readonly->fullsize = ~0;
var_readonly->next = NULL;
+ var_readonly->is_special_var = 1;
insert_id_for_tree (readonly_tree, 2);
readonly_id = 2;
- VEC_safe_push (varinfo_t, gc, varmap, var_readonly);
+ VEC_safe_push (varinfo_t, heap, varmap, var_readonly);
/* readonly memory points to anything, in order to make deref
easier. In reality, it points to anything the particular
var_integer->fullsize = ~0;
var_integer->offset = 0;
var_integer->next = NULL;
+ var_integer->is_special_var = 1;
integer_id = 3;
- VEC_safe_push (varinfo_t, gc, varmap, var_integer);
+ VEC_safe_push (varinfo_t, heap, varmap, var_integer);
/* *INTEGER = ANYTHING, because we don't know where a dereference of a random
integer will point to. */
rhs.var = anything_id;
rhs.offset = 0;
process_constraint (new_constraint (lhs, rhs));
+
+ /* Create the ANYOFFSET variable, used to represent an arbitrary offset
+ inside an object. This is similar to ANYTHING, but less drastic.
+ It means that the pointer can point anywhere inside an object,
+ but not outside of it. */
+ anyoffset_tree = create_tmp_var_raw (void_type_node, "ANYOFFSET");
+ anyoffset_id = 4;
+ var_anyoffset = new_var_info (anyoffset_tree, anyoffset_id, "ANYOFFSET",
+ anyoffset_id);
+ insert_id_for_tree (anyoffset_tree, anyoffset_id);
+ var_anyoffset->is_artificial_var = 1;
+ var_anyoffset->size = ~0;
+ var_anyoffset->offset = 0;
+ var_anyoffset->next = NULL;
+ var_anyoffset->fullsize = ~0;
+ var_anyoffset->is_special_var = 1;
+ VEC_safe_push (varinfo_t, heap, varmap, var_anyoffset);
+
+ /* ANYOFFSET points to ANYOFFSET. */
+ lhs.type = SCALAR;
+ lhs.var = anyoffset_id;
+ lhs.offset = 0;
+ rhs.type = ADDRESSOF;
+ rhs.var = anyoffset_id;
+ rhs.offset = 0;
+ process_constraint (new_constraint (lhs, rhs));
}
+/* Return true if we actually need to solve the constraint graph in order to
+ get our points-to sets. This is false when, for example, no addresses are
+ taken other than special vars, or all points-to sets with members already
+ contain the anything variable and there are no predecessors for other
+ sets. */
+
+static bool
+need_to_solve (void)
+{
+ int i;
+ varinfo_t v;
+ bool found_address_taken = false;
+ bool found_non_anything = false;
+
+ for (i = 0; VEC_iterate (varinfo_t, varmap, i, v); i++)
+ {
+ if (v->is_special_var)
+ continue;
+
+ if (v->address_taken)
+ found_address_taken = true;
+
+ if (v->solution
+ && !bitmap_empty_p (v->solution)
+ && !bitmap_bit_p (v->solution, anything_id))
+ found_non_anything = true;
+ else if (bitmap_empty_p (v->solution)
+ && VEC_length (constraint_edge_t, graph->preds[v->id]) != 0)
+ found_non_anything = true;
+
+ if (found_address_taken && found_non_anything)
+ return true;
+ }
+
+ return false;
+}
/* Create points-to sets for the current function. See the comments
at the start of the file for an algorithmic overview. */
-static void
-create_alias_vars (void)
+void
+compute_points_to_sets (struct alias_info *ai)
{
basic_block bb;
-
+
+ timevar_push (TV_TREE_PTA);
+
init_alias_vars ();
constraint_pool = create_alloc_pool ("Constraint pool",
constraint_edge_pool = create_alloc_pool ("Constraint edges",
sizeof (struct constraint_edge), 30);
- constraints = VEC_alloc (constraint_t, gc, 8);
- varmap = VEC_alloc (varinfo_t, gc, 8);
+ constraints = VEC_alloc (constraint_t, heap, 8);
+ varmap = VEC_alloc (varinfo_t, heap, 8);
id_for_tree = htab_create (10, tree_id_hash, tree_id_eq, free);
memset (&stats, 0, sizeof (stats));
-
+
init_base_vars ();
intra_create_variable_infos ();
for (phi = phi_nodes (bb); phi; phi = TREE_CHAIN (phi))
if (is_gimple_reg (PHI_RESULT (phi)))
- find_func_aliases (phi);
+ find_func_aliases (phi, ai);
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
- find_func_aliases (bsi_stmt (bsi));
+ find_func_aliases (bsi_stmt (bsi), ai);
}
build_constraint_graph ();
if (dump_file)
{
- fprintf (dump_file, "Constraints:\n");
+ fprintf (dump_file, "Points-to analysis\n\nConstraints:\n\n");
dump_constraints (dump_file);
}
-
- if (dump_file)
- fprintf (dump_file, "Collapsing static cycles and doing variable substitution:\n");
-
- find_and_collapse_graph_cycles (graph, false);
- perform_var_substitution (graph);
-
- if (dump_file)
- fprintf (dump_file, "Solving graph:\n");
-
- solve_graph (graph);
-
+
+ if (need_to_solve ())
+ {
+ if (dump_file)
+ fprintf (dump_file, "\nCollapsing static cycles and doing variable "
+ "substitution:\n");
+
+ find_and_collapse_graph_cycles (graph, false);
+ perform_var_substitution (graph);
+
+ if (dump_file)
+ fprintf (dump_file, "\nSolving graph:\n");
+
+ solve_graph (graph);
+ }
+
if (dump_file)
dump_sa_points_to_info (dump_file);
have_alias_info = true;
+
+ timevar_pop (TV_TREE_PTA);
}
-struct tree_opt_pass pass_build_pta =
-{
- "pta", /* name */
- NULL, /* gate */
- create_alias_vars, /* execute */
- NULL, /* sub */
- NULL, /* next */
- 0, /* static_pass_number */
- TV_TREE_PTA, /* tv_id */
- PROP_cfg, /* properties_required */
- PROP_pta, /* properties_provided */
- 0, /* properties_destroyed */
- 0, /* todo_flags_start */
- 0, /* todo_flags_finish */
- 0 /* letter */
-};
-
/* Delete created points-to sets. */
-static void
-delete_alias_vars (void)
+void
+delete_points_to_sets (void)
{
+ varinfo_t v;
+ int i;
+
htab_delete (id_for_tree);
+ bitmap_obstack_release (&ptabitmap_obstack);
+ VEC_free (constraint_t, heap, constraints);
+
+ for (i = 0; VEC_iterate (varinfo_t, varmap, i, v); i++)
+ {
+ VEC_free (constraint_edge_t, heap, graph->succs[i]);
+ VEC_free (constraint_edge_t, heap, graph->preds[i]);
+ VEC_free (constraint_t, heap, v->complex);
+ }
+ free (graph->succs);
+ free (graph->preds);
+ free (graph);
+
+ VEC_free (varinfo_t, heap, varmap);
free_alloc_pool (variable_info_pool);
free_alloc_pool (constraint_pool);
free_alloc_pool (constraint_edge_pool);
- bitmap_obstack_release (&ptabitmap_obstack);
+
have_alias_info = false;
}
-
-struct tree_opt_pass pass_del_pta =
-{
- NULL, /* name */
- NULL, /* gate */
- delete_alias_vars, /* execute */
- NULL, /* sub */
- NULL, /* next */
- 0, /* static_pass_number */
- TV_TREE_PTA, /* tv_id */
- PROP_pta, /* properties_required */
- 0, /* properties_provided */
- PROP_pta, /* properties_destroyed */
- 0, /* todo_flags_start */
- 0, /* todo_flags_finish */
- 0 /* letter */
-};
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