/* Tree based points-to analysis
- Copyright (C) 2005 Free Software Foundation, Inc.
+ Copyright (C) 2005, 2006, 2007 Free Software Foundation, Inc.
Contributed by Daniel Berlin <dberlin@dberlin.org>
This file is part of GCC.
#include "timevar.h"
#include "alloc-pool.h"
#include "splay-tree.h"
+#include "params.h"
#include "tree-ssa-structalias.h"
+#include "cgraph.h"
+#include "alias.h"
+#include "pointer-set.h"
/* The idea behind this analyzer is to generate set constraints from the
program, then solve the resulting constraints in order to generate the
- points-to sets.
+ points-to sets.
Set constraints are a way of modeling program analysis problems that
involve sets. They consist of an inclusion constraint language,
Also see "Ultra-fast Aliasing Analysis using CLA: A Million Lines
of C Code in a Second" by ""Nevin Heintze and Olivier Tardieu" at
- http://citeseer.ist.psu.edu/heintze01ultrafast.html
+ http://citeseer.ist.psu.edu/heintze01ultrafast.html
+
+ There are three types of real constraint expressions, DEREF,
+ ADDRESSOF, and SCALAR. Each constraint expression consists
+ of a constraint type, a variable, and an offset.
- There are three types of constraint expressions, DEREF, ADDRESSOF, and
- SCALAR. Each constraint expression consists of a constraint type,
- a variable, and an offset.
-
SCALAR is a constraint expression type used to represent x, whether
it appears on the LHS or the RHS of a statement.
DEREF is a constraint expression type used to represent *x, whether
- it appears on the LHS or the RHS of a statement.
+ it appears on the LHS or the RHS of a statement.
ADDRESSOF is a constraint expression used to represent &x, whether
it appears on the LHS or the RHS of a statement.
-
+
Each pointer variable in the program is assigned an integer id, and
each field of a structure variable is assigned an integer id as well.
-
+
Structure variables are linked to their list of fields through a "next
field" in each variable that points to the next field in offset
- order.
- Each variable for a structure field has
+ order.
+ Each variable for a structure field has
1. "size", that tells the size in bits of that field.
2. "fullsize, that tells the size in bits of the entire structure.
3. "offset", that tells the offset in bits from the beginning of the
structure to this field.
- Thus,
+ Thus,
struct f
{
int a;
foo.b -> id 2, size 32, offset 32, fullsize 64, next NULL
bar -> id 3, size 32, offset 0, fullsize 32, next NULL
-
+
In order to solve the system of set constraints, the following is
done:
1. Each constraint variable x has a solution set associated with it,
Sol(x).
-
+
2. Constraints are separated into direct, copy, and complex.
Direct constraints are ADDRESSOF constraints that require no extra
processing, such as P = &Q
Copy constraints are those of the form P = Q.
- Complex constraints are all the constraints involving dereferences.
-
+ Complex constraints are all the constraints involving dereferences
+ and offsets (including offsetted copies).
+
3. All direct constraints of the form P = &Q are processed, such
- that Q is added to Sol(P)
+ that Q is added to Sol(P)
4. All complex constraints for a given constraint variable are stored in a
- linked list attached to that variable's node.
+ linked list attached to that variable's node.
5. A directed graph is built out of the copy constraints. Each
- constraint variable is a node in the graph, and an edge from
+ constraint variable is a node in the graph, and an edge from
Q to P is added for each copy constraint of the form P = Q
-
+
6. The graph is then walked, and solution sets are
propagated along the copy edges, such that an edge from Q to P
causes Sol(P) <- Sol(P) union Sol(Q).
-
+
7. As we visit each node, all complex constraints associated with
that node are processed by adding appropriate copy edges to the graph, or the
- appropriate variables to the solution set.
+ appropriate variables to the solution set.
8. The process of walking the graph is iterated until no solution
sets change.
Prior to walking the graph in steps 6 and 7, We perform static
- cycle elimination on the constraint graph, as well
+ cycle elimination on the constraint graph, as well
as off-line variable substitution.
-
+
TODO: Adding offsets to pointer-to-structures can be handled (IE not punted
on and turned into anything), but isn't. You can just see what offset
inside the pointed-to struct it's going to access.
-
+
TODO: Constant bounded arrays can be handled as if they were structs of the
- same number of elements.
+ same number of elements.
TODO: Modeling heap and incoming pointers becomes much better if we
add fields to them as we discover them, which we could do.
TODO: We could handle unions, but to be honest, it's probably not
worth the pain or slowdown. */
+static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
+htab_t heapvar_for_stmt;
+
static bool use_field_sensitive = true;
-static unsigned int create_variable_info_for (tree, const char *);
-static struct constraint_expr get_constraint_for (tree, bool *);
-static void build_constraint_graph (void);
+static int in_ipa_mode = 0;
-static bitmap_obstack ptabitmap_obstack;
+/* Used for predecessor bitmaps. */
+static bitmap_obstack predbitmap_obstack;
+
+/* Used for points-to sets. */
+static bitmap_obstack pta_obstack;
+
+/* Used for oldsolution members of variables. */
+static bitmap_obstack oldpta_obstack;
+
+/* Used for per-solver-iteration bitmaps. */
static bitmap_obstack iteration_obstack;
+
+static unsigned int create_variable_info_for (tree, const char *);
+typedef struct constraint_graph *constraint_graph_t;
+static void unify_nodes (constraint_graph_t, unsigned int, unsigned int, bool);
+
DEF_VEC_P(constraint_t);
DEF_VEC_ALLOC_P(constraint_t,heap);
+#define EXECUTE_IF_IN_NONNULL_BITMAP(a, b, c, d) \
+ if (a) \
+ EXECUTE_IF_SET_IN_BITMAP (a, b, c, d)
+
static struct constraint_stats
{
unsigned int total_vars;
- unsigned int collapsed_vars;
+ unsigned int nonpointer_vars;
unsigned int unified_vars_static;
unsigned int unified_vars_dynamic;
unsigned int iterations;
+ unsigned int num_edges;
+ unsigned int num_implicit_edges;
+ unsigned int points_to_sets_created;
} stats;
struct variable_info
tree decl;
/* Offset of this variable, in bits, from the base variable */
- unsigned HOST_WIDE_INT offset;
+ unsigned HOST_WIDE_INT offset;
/* Size of the variable, in bits. */
unsigned HOST_WIDE_INT size;
/* A link to the variable for the next field in this structure. */
struct variable_info *next;
- /* Node in the graph that represents the constraints and points-to
- solution for the variable. */
- unsigned int node;
-
- /* True if the address of this variable is taken. Needed for
- variable substitution. */
- unsigned int address_taken:1;
-
- /* True if this variable is the target of a dereference. Needed for
- variable substitution. */
- unsigned int indirect_target:1;
+ /* True if the variable is directly the target of a dereference.
+ This is used to track which variables are *actually* dereferenced
+ so we can prune their points to listed. */
+ unsigned int directly_dereferenced:1;
/* 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;
+ 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;
+ /* True if we may not use TBAA to prune references to this
+ variable. This is used for C++ placement new. */
+ unsigned int no_tbaa_pruning : 1;
+
/* Points-to set for this variable. */
bitmap solution;
+ /* Old points-to set for this variable. */
+ bitmap oldsolution;
+
/* Variable ids represented by this node. */
bitmap variables;
- /* Vector of complex constraints for this node. Complex
- constraints are those involving dereferences. */
- 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. */
+ /* Variable id this was collapsed to due to type unsafety. This
+ should be unused completely after build_succ_graph, or something
+ is broken. */
struct variable_info *collapsed_to;
};
typedef struct variable_info *varinfo_t;
DEF_VEC_ALLOC_P(varinfo_t, heap);
-/* Table of variable info structures for constraint variables. Indexed directly
- by variable info id. */
+/* Table of variable info structures for constraint variables.
+ Indexed directly by variable info id. */
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 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);
+ varinfo_t v = VEC_index (varinfo_t, varmap, n);
if (v->collapsed_to)
return v->collapsed_to;
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;
+/* Lookup a heap var for FROM, and return it if we find one. */
+
+static tree
+heapvar_lookup (tree from)
+{
+ struct tree_map *h, in;
+ in.base.from = from;
+
+ h = (struct tree_map *) htab_find_with_hash (heapvar_for_stmt, &in,
+ htab_hash_pointer (from));
+ if (h)
+ return h->to;
+ return NULL_TREE;
+}
+
+/* Insert a mapping FROM->TO in the heap var for statement
+ hashtable. */
+
+static void
+heapvar_insert (tree from, tree to)
+{
+ struct tree_map *h;
+ void **loc;
+
+ h = GGC_NEW (struct tree_map);
+ h->hash = htab_hash_pointer (from);
+ h->base.from = from;
+ h->to = to;
+ loc = htab_find_slot_with_hash (heapvar_for_stmt, h, h->hash, INSERT);
+ *(struct tree_map **) loc = h;
+}
/* Return a new variable info structure consisting for a variable
named NAME, and using constraint graph node NODE. */
static varinfo_t
-new_var_info (tree t, unsigned int id, const char *name, unsigned int node)
+new_var_info (tree t, unsigned int id, const char *name)
{
- varinfo_t ret = pool_alloc (variable_info_pool);
+ varinfo_t ret = (varinfo_t) pool_alloc (variable_info_pool);
+ tree var;
ret->id = id;
ret->name = name;
ret->decl = t;
- ret->node = node;
- ret->address_taken = false;
- ret->indirect_target = false;
+ ret->directly_dereferenced = 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;
+ var = t;
+ if (TREE_CODE (var) == SSA_NAME)
+ var = SSA_NAME_VAR (var);
+ ret->no_tbaa_pruning = (DECL_P (var)
+ && POINTER_TYPE_P (TREE_TYPE (var))
+ && DECL_NO_TBAA_P (var));
+ ret->solution = BITMAP_ALLOC (&pta_obstack);
+ ret->oldsolution = BITMAP_ALLOC (&oldpta_obstack);
ret->next = NULL;
ret->collapsed_to = NULL;
return ret;
/* An expression that appears in a constraint. */
-struct constraint_expr
+struct constraint_expr
{
/* Constraint type. */
constraint_expr_type type;
unsigned HOST_WIDE_INT offset;
};
-static struct constraint_expr do_deref (struct constraint_expr);
+typedef struct constraint_expr ce_s;
+DEF_VEC_O(ce_s);
+DEF_VEC_ALLOC_O(ce_s, heap);
+static void get_constraint_for (tree, VEC(ce_s, heap) **);
+static void do_deref (VEC (ce_s, heap) **);
/* Our set constraints are made up of two constraint expressions, one
- LHS, and one RHS.
+ LHS, and one RHS.
As described in the introduction, our set constraints each represent an
operation between set valued variables.
static VEC(constraint_t,heap) *constraints;
static alloc_pool constraint_pool;
-/* An edge in the constraint graph. We technically have no use for
- the src, since it will always be the same node that we are indexing
- into the pred/succ arrays with, but it's nice for checking
- purposes. The edges are weighted, with a bit set in weights for
- each edge from src to dest with that weight. */
-struct constraint_edge
+DEF_VEC_I(int);
+DEF_VEC_ALLOC_I(int, heap);
+
+/* The constraint graph is represented as an array of bitmaps
+ containing successor nodes. */
+
+struct constraint_graph
{
- unsigned int src;
- unsigned int dest;
- bitmap weights;
-};
+ /* Size of this graph, which may be different than the number of
+ nodes in the variable map. */
+ unsigned int size;
-typedef struct constraint_edge *constraint_edge_t;
-static alloc_pool constraint_edge_pool;
+ /* Explicit successors of each node. */
+ bitmap *succs;
-/* Return a new constraint edge from SRC to DEST. */
+ /* Implicit predecessors of each node (Used for variable
+ substitution). */
+ bitmap *implicit_preds;
-static constraint_edge_t
-new_constraint_edge (unsigned int src, unsigned int dest)
-{
- constraint_edge_t ret = pool_alloc (constraint_edge_pool);
- ret->src = src;
- ret->dest = dest;
- ret->weights = NULL;
- return ret;
-}
+ /* Explicit predecessors of each node (Used for variable substitution). */
+ bitmap *preds;
-DEF_VEC_P(constraint_edge_t);
-DEF_VEC_ALLOC_P(constraint_edge_t,heap);
+ /* Indirect cycle representatives, or -1 if the node has no indirect
+ cycles. */
+ int *indirect_cycles;
+ /* Representative node for a node. rep[a] == a unless the node has
+ been unified. */
+ unsigned int *rep;
-/* The constraint graph is simply a set of adjacency vectors, one per
- variable. succs[x] is the vector of successors for variable x, and preds[x]
- is the vector of predecessors for variable x.
- IOW, all edges are "forward" edges, which is not like our CFG.
- So remember that
- preds[x]->src == x, and
- succs[x]->src == x. */
+ /* Equivalence class representative for a node. This is used for
+ variable substitution. */
+ int *eq_rep;
-struct constraint_graph
-{
- VEC(constraint_edge_t,heap) **succs;
- VEC(constraint_edge_t,heap) **preds;
-};
+ /* Label for each node, used during variable substitution. */
+ unsigned int *label;
-typedef struct constraint_graph *constraint_graph_t;
+ /* Bitmap of nodes where the bit is set if the node is a direct
+ node. Used for variable substitution. */
+ sbitmap direct_nodes;
+
+ /* Vector of complex constraints for each graph node. Complex
+ constraints are those involving dereferences or offsets that are
+ not 0. */
+ VEC(constraint_t,heap) **complex;
+};
static constraint_graph_t graph;
+/* During variable substitution and the offline version of indirect
+ cycle finding, we create nodes to represent dereferences and
+ address taken constraints. These represent where these start and
+ end. */
+#define FIRST_REF_NODE (VEC_length (varinfo_t, varmap))
+#define LAST_REF_NODE (FIRST_REF_NODE + (FIRST_REF_NODE - 1))
+#define FIRST_ADDR_NODE (LAST_REF_NODE + 1)
+
+/* Return the representative node for NODE, if NODE has been unioned
+ with another NODE.
+ This function performs path compression along the way to finding
+ the representative. */
+
+static unsigned int
+find (unsigned int node)
+{
+ gcc_assert (node < graph->size);
+ if (graph->rep[node] != node)
+ return graph->rep[node] = find (graph->rep[node]);
+ return node;
+}
+
+/* Union the TO and FROM nodes to the TO nodes.
+ Note that at some point in the future, we may want to do
+ union-by-rank, in which case we are going to have to return the
+ node we unified to. */
+
+static bool
+unite (unsigned int to, unsigned int from)
+{
+ gcc_assert (to < graph->size && from < graph->size);
+ if (to != from && graph->rep[from] != to)
+ {
+ graph->rep[from] = to;
+ return true;
+ }
+ return false;
+}
+
/* Create a new constraint consisting of LHS and RHS expressions. */
-static constraint_t
+static constraint_t
new_constraint (const struct constraint_expr lhs,
const struct constraint_expr rhs)
{
- constraint_t ret = pool_alloc (constraint_pool);
+ constraint_t ret = (constraint_t) pool_alloc (constraint_pool);
ret->lhs = lhs;
ret->rhs = rhs;
return ret;
if (c->lhs.type == ADDRESSOF)
fprintf (file, "&");
else if (c->lhs.type == DEREF)
- fprintf (file, "*");
+ fprintf (file, "*");
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);
dump_constraints (stderr);
}
-/* SOLVER FUNCTIONS
+/* SOLVER FUNCTIONS
The solver is a simple worklist solver, that works on the following
algorithm:
-
- sbitmap changed_nodes = all ones;
- changed_count = number of nodes;
- For each node that was already collapsed:
- changed_count--;
+ sbitmap changed_nodes = all zeroes;
+ changed_count = 0;
+ For each node that is not already collapsed:
+ changed_count++;
+ set bit in changed nodes
while (changed_count > 0)
{
compute topological ordering for constraint graph
-
+
find and collapse cycles in the constraint graph (updating
changed if necessary)
-
+
for each node (n) in the graph in topological order:
changed_count--;
static bool
constraint_expr_equal (struct constraint_expr a, struct constraint_expr b)
{
- return a.type == b.type
- && a.var == b.var
- && a.offset == b.offset;
+ return a.type == b.type && a.var == b.var && a.offset == b.offset;
}
/* Return true if constraint expression A is less than constraint expression
}
/* Return true if two constraints A and B are equal. */
-
+
static bool
constraint_equal (struct constraint a, struct constraint b)
{
- return constraint_expr_equal (a.lhs, b.lhs)
+ return constraint_expr_equal (a.lhs, b.lhs)
&& constraint_expr_equal (a.rhs, b.rhs);
}
constraint_vec_find (VEC(constraint_t,heap) *vec,
struct constraint lookfor)
{
- unsigned int place;
+ unsigned int place;
constraint_t found;
if (vec == NULL)
/* If this is a properly sized variable, only add offset if it's
less than end. Otherwise, it is globbed to a single
variable. */
-
+
if ((get_varinfo (i)->offset + offset) < get_varinfo (i)->fullsize)
{
unsigned HOST_WIDE_INT fieldoffset = get_varinfo (i)->offset + offset;
continue;
bitmap_set_bit (result, v->id);
}
- else if (get_varinfo (i)->is_artificial_var
+ 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);
}
}
-
- bitmap_copy (set, result);
+
+ bitmap_copy (set, result);
BITMAP_FREE (result);
}
}
}
-/* Insert constraint C into the list of complex constraints for VAR. */
+/* Insert constraint C into the list of complex constraints for graph
+ node VAR. */
static void
-insert_into_complex (unsigned int var, constraint_t c)
+insert_into_complex (constraint_graph_t graph,
+ unsigned int var, constraint_t c)
{
- varinfo_t vi = get_varinfo (var);
- unsigned int place = VEC_lower_bound (constraint_t, vi->complex, c,
+ VEC (constraint_t, heap) *complex = graph->complex[var];
+ unsigned int place = VEC_lower_bound (constraint_t, complex, c,
constraint_less);
- VEC_safe_insert (constraint_t, heap, vi->complex, place, c);
-}
-
-
-/* Compare two constraint edges A and B, return true if they are equal. */
-
-static bool
-constraint_edge_equal (struct constraint_edge a, struct constraint_edge b)
-{
- return a.src == b.src && a.dest == b.dest;
-}
-
-/* Compare two constraint edges, return true if A is less than B */
-static bool
-constraint_edge_less (const constraint_edge_t a, const constraint_edge_t b)
-{
- if (a->dest < b->dest)
- return true;
- else if (a->dest == b->dest)
- return a->src < b->src;
- else
- return false;
+ /* Only insert constraints that do not already exist. */
+ if (place >= VEC_length (constraint_t, complex)
+ || !constraint_equal (*c, *VEC_index (constraint_t, complex, place)))
+ VEC_safe_insert (constraint_t, heap, graph->complex[var], place, c);
}
-/* Find the constraint edge that matches LOOKFOR, in VEC.
- Return the edge, if found, NULL otherwise. */
-
-static constraint_edge_t
-constraint_edge_vec_find (VEC(constraint_edge_t,heap) *vec,
- struct constraint_edge lookfor)
-{
- unsigned int place;
- constraint_edge_t edge;
-
- place = VEC_lower_bound (constraint_edge_t, vec, &lookfor,
- constraint_edge_less);
- edge = VEC_index (constraint_edge_t, vec, place);
- if (!constraint_edge_equal (*edge, lookfor))
- return NULL;
- return edge;
-}
/* Condense two variable nodes into a single variable node, by moving
all associated info from SRC to TO. */
-static void
-condense_varmap_nodes (unsigned int to, unsigned int src)
+static void
+merge_node_constraints (constraint_graph_t graph, unsigned int to,
+ unsigned int from)
{
- varinfo_t tovi = get_varinfo (to);
- varinfo_t srcvi = get_varinfo (src);
unsigned int i;
constraint_t c;
- bitmap_iterator bi;
-
- /* the src node, and all its variables, are now the to node. */
- srcvi->node = to;
- EXECUTE_IF_SET_IN_BITMAP (srcvi->variables, 0, i, bi)
- get_varinfo (i)->node = to;
-
- /* Merge the src node variables and the to node variables. */
- bitmap_set_bit (tovi->variables, src);
- bitmap_ior_into (tovi->variables, srcvi->variables);
- bitmap_clear (srcvi->variables);
-
+
+ gcc_assert (find (from) == to);
+
/* Move all complex constraints from src node into to node */
- for (i = 0; VEC_iterate (constraint_t, srcvi->complex, i, c); i++)
+ for (i = 0; VEC_iterate (constraint_t, graph->complex[from], i, c); i++)
{
/* In complex constraints for node src, we may have either
- a = *src, and *src = a. */
-
+ a = *src, and *src = a, or an offseted constraint which are
+ always added to the rhs node's constraints. */
+
if (c->rhs.type == DEREF)
c->rhs.var = to;
- else
+ else if (c->lhs.type == DEREF)
c->lhs.var = to;
+ else
+ c->rhs.var = to;
}
- constraint_set_union (&tovi->complex, &srcvi->complex);
- VEC_free (constraint_t, heap, srcvi->complex);
- srcvi->complex = NULL;
+ constraint_set_union (&graph->complex[to], &graph->complex[from]);
+ VEC_free (constraint_t, heap, graph->complex[from]);
+ graph->complex[from] = NULL;
}
-/* Erase EDGE from GRAPH. This routine only handles self-edges
- (e.g. an edge from a to a). */
-
-static void
-erase_graph_self_edge (constraint_graph_t graph, struct constraint_edge edge)
-{
- 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);
-
- /* Remove from the successors. */
- place = VEC_lower_bound (constraint_edge_t, succvec, &edge,
- constraint_edge_less);
-
- /* Make sure we found the edge. */
-#ifdef ENABLE_CHECKING
- {
- constraint_edge_t tmp = VEC_index (constraint_edge_t, succvec, place);
- gcc_assert (constraint_edge_equal (*tmp, edge));
- }
-#endif
- VEC_ordered_remove (constraint_edge_t, succvec, place);
-
- /* Remove from the predecessors. */
- place = VEC_lower_bound (constraint_edge_t, predvec, &edge,
- constraint_edge_less);
-
- /* Make sure we found the edge. */
-#ifdef ENABLE_CHECKING
- {
- constraint_edge_t tmp = VEC_index (constraint_edge_t, predvec, place);
- gcc_assert (constraint_edge_equal (*tmp, edge));
- }
-#endif
- VEC_ordered_remove (constraint_edge_t, predvec, place);
-}
/* Remove edges involving NODE from GRAPH. */
static void
clear_edges_for_node (constraint_graph_t graph, unsigned int 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;
-
- /* Walk the successors, erase the associated preds. */
- for (i = 0; VEC_iterate (constraint_edge_t, succvec, i, c); i++)
- if (c->dest != node)
- {
- unsigned int place;
- struct constraint_edge lookfor;
- lookfor.src = c->dest;
- lookfor.dest = node;
- place = VEC_lower_bound (constraint_edge_t, graph->preds[c->dest],
- &lookfor, constraint_edge_less);
- VEC_ordered_remove (constraint_edge_t, graph->preds[c->dest], place);
- }
- /* Walk the preds, erase the associated succs. */
- for (i =0; VEC_iterate (constraint_edge_t, predvec, i, c); i++)
- if (c->dest != node)
- {
- unsigned int place;
- struct constraint_edge lookfor;
- lookfor.src = c->dest;
- lookfor.dest = node;
- place = VEC_lower_bound (constraint_edge_t, graph->succs[c->dest],
- &lookfor, constraint_edge_less);
- 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;
+ if (graph->succs[node])
+ BITMAP_FREE (graph->succs[node]);
}
-static bool edge_added = false;
-
-/* Add edge NEWE to the graph. */
+/* Merge GRAPH nodes FROM and TO into node TO. */
-static bool
-add_graph_edge (constraint_graph_t graph, struct constraint_edge newe)
+static void
+merge_graph_nodes (constraint_graph_t graph, unsigned int to,
+ unsigned int from)
{
- unsigned int place;
- unsigned int src = newe.src;
- unsigned int dest = newe.dest;
- VEC(constraint_edge_t,heap) *vec;
-
- vec = graph->preds[src];
- place = VEC_lower_bound (constraint_edge_t, vec, &newe,
- constraint_edge_less);
- if (place == VEC_length (constraint_edge_t, vec)
- || VEC_index (constraint_edge_t, vec, place)->dest != dest)
- {
- constraint_edge_t edge = new_constraint_edge (src, dest);
- bitmap weightbitmap;
-
- weightbitmap = BITMAP_ALLOC (&ptabitmap_obstack);
- edge->weights = weightbitmap;
- 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, heap, graph->succs[edge->src],
- place, edge);
- edge_added = true;
- return true;
+ if (graph->indirect_cycles[from] != -1)
+ {
+ /* If we have indirect cycles with the from node, and we have
+ none on the to node, the to node has indirect cycles from the
+ from node now that they are unified.
+ If indirect cycles exist on both, unify the nodes that they
+ are in a cycle with, since we know they are in a cycle with
+ each other. */
+ if (graph->indirect_cycles[to] == -1)
+ {
+ graph->indirect_cycles[to] = graph->indirect_cycles[from];
+ }
+ else
+ {
+ unsigned int tonode = find (graph->indirect_cycles[to]);
+ unsigned int fromnode = find (graph->indirect_cycles[from]);
+
+ if (unite (tonode, fromnode))
+ unify_nodes (graph, tonode, fromnode, true);
+ }
}
- else
- return false;
+
+ /* Merge all the successor edges. */
+ if (graph->succs[from])
+ {
+ if (!graph->succs[to])
+ graph->succs[to] = BITMAP_ALLOC (&pta_obstack);
+ bitmap_ior_into (graph->succs[to],
+ graph->succs[from]);
+ }
+
+ clear_edges_for_node (graph, from);
}
-/* Return the bitmap representing the weights of edge LOOKFOR */
+/* Add an indirect graph edge to GRAPH, going from TO to FROM if
+ it doesn't exist in the graph already. */
-static bitmap
-get_graph_weights (constraint_graph_t graph, struct constraint_edge lookfor)
+static void
+add_implicit_graph_edge (constraint_graph_t graph, unsigned int to,
+ unsigned int from)
{
- constraint_edge_t edge;
- unsigned int src = lookfor.src;
- VEC(constraint_edge_t,heap) *vec;
- vec = graph->preds[src];
- edge = constraint_edge_vec_find (vec, lookfor);
- gcc_assert (edge != NULL);
- return edge->weights;
-}
+ if (to == from)
+ return;
+ if (!graph->implicit_preds[to])
+ graph->implicit_preds[to] = BITMAP_ALLOC (&predbitmap_obstack);
-/* Merge GRAPH nodes FROM and TO into node TO. */
+ if (!bitmap_bit_p (graph->implicit_preds[to], from))
+ {
+ stats.num_implicit_edges++;
+ bitmap_set_bit (graph->implicit_preds[to], from);
+ }
+}
+
+/* Add a predecessor graph edge to GRAPH, going from TO to FROM if
+ it doesn't exist in the graph already.
+ Return false if the edge already existed, true otherwise. */
static void
-merge_graph_nodes (constraint_graph_t graph, unsigned int to,
- unsigned int from)
+add_pred_graph_edge (constraint_graph_t graph, unsigned int to,
+ unsigned int 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;
-
- /* Merge all the predecessor edges. */
-
- for (i = 0; VEC_iterate (constraint_edge_t, predvec, i, c); i++)
- {
- unsigned int d = c->dest;
- struct constraint_edge olde;
- struct constraint_edge newe;
- bitmap temp;
- bitmap weights;
- if (c->dest == from)
- d = to;
- newe.src = to;
- newe.dest = d;
- 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);
- }
-
- /* Merge all the successor edges. */
- for (i = 0; VEC_iterate (constraint_edge_t, succvec, i, c); i++)
- {
- unsigned int d = c->dest;
- struct constraint_edge olde;
- struct constraint_edge newe;
- bitmap temp;
- bitmap weights;
- if (c->dest == from)
- d = to;
- newe.src = d;
- newe.dest = to;
- 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);
- }
- clear_edges_for_node (graph, from);
+ if (!graph->preds[to])
+ graph->preds[to] = BITMAP_ALLOC (&predbitmap_obstack);
+ if (!bitmap_bit_p (graph->preds[to], from))
+ bitmap_set_bit (graph->preds[to], from);
}
-/* Add a graph edge to GRAPH, going from TO to FROM, with WEIGHT, if
+/* Add a graph edge to GRAPH, going from FROM to TO if
it doesn't exist in the graph already.
Return false if the edge already existed, true otherwise. */
static bool
-int_add_graph_edge (constraint_graph_t graph, unsigned int to,
- unsigned int from, unsigned HOST_WIDE_INT weight)
+add_graph_edge (constraint_graph_t graph, unsigned int to,
+ unsigned int from)
{
- if (to == from && weight == 0)
+ if (to == from)
{
return false;
}
else
{
- bool r;
- 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);
+ bool r = false;
+
+ if (!graph->succs[from])
+ graph->succs[from] = BITMAP_ALLOC (&pta_obstack);
+ if (!bitmap_bit_p (graph->succs[from], to))
+ {
+ r = true;
+ if (to < FIRST_REF_NODE && from < FIRST_REF_NODE)
+ stats.num_edges++;
+ bitmap_set_bit (graph->succs[from], to);
+ }
return r;
}
}
-/* Return true if LOOKFOR is an existing graph edge. */
+/* Return true if {DEST.SRC} is an existing graph edge in GRAPH. */
static bool
-valid_graph_edge (constraint_graph_t graph, struct constraint_edge lookfor)
+valid_graph_edge (constraint_graph_t graph, unsigned int src,
+ unsigned int dest)
{
- return constraint_edge_vec_find (graph->preds[lookfor.src], lookfor) != NULL;
+ return (graph->succs[dest]
+ && bitmap_bit_p (graph->succs[dest], src));
}
-
-/* Build the constraint graph. */
+/* Build the constraint graph, adding only predecessor edges right now. */
static void
-build_constraint_graph (void)
+build_pred_graph (void)
{
- int i = 0;
+ int i;
constraint_t c;
+ unsigned int j;
+
+ graph = XNEW (struct constraint_graph);
+ graph->size = (VEC_length (varinfo_t, varmap)) * 3;
+ graph->succs = XCNEWVEC (bitmap, graph->size);
+ graph->implicit_preds = XCNEWVEC (bitmap, graph->size);
+ graph->preds = XCNEWVEC (bitmap, graph->size);
+ graph->indirect_cycles = XNEWVEC (int, VEC_length (varinfo_t, varmap));
+ graph->label = XCNEWVEC (unsigned int, graph->size);
+ graph->rep = XNEWVEC (unsigned int, graph->size);
+ graph->eq_rep = XNEWVEC (int, graph->size);
+ graph->complex = XCNEWVEC (VEC(constraint_t, heap) *,
+ VEC_length (varinfo_t, varmap));
+ graph->direct_nodes = sbitmap_alloc (graph->size);
+ sbitmap_zero (graph->direct_nodes);
+
+ for (j = 0; j < FIRST_REF_NODE; j++)
+ {
+ if (!get_varinfo (j)->is_special_var)
+ SET_BIT (graph->direct_nodes, j);
+ }
- 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 (j = 0; j < graph->size; j++)
+ {
+ graph->rep[j] = j;
+ graph->eq_rep[j] = -1;
+ }
+
+ for (j = 0; j < VEC_length (varinfo_t, varmap); j++)
+ graph->indirect_cycles[j] = -1;
for (i = 0; VEC_iterate (constraint_t, constraints, i, c); i++)
{
if (lhs.type == DEREF)
{
- /* *x = y or *x = &y (complex) */
- if (rhs.type == ADDRESSOF || rhsvar > anything_id)
- insert_into_complex (lhsvar, c);
+ /* *x = y. */
+ if (rhs.offset == 0 && lhs.offset == 0 && rhs.type == SCALAR)
+ add_pred_graph_edge (graph, FIRST_REF_NODE + lhsvar, rhsvar);
+ if (rhs.type == ADDRESSOF)
+ RESET_BIT (graph->direct_nodes, rhsvar);
}
else if (rhs.type == DEREF)
{
- /* !special var= *y */
- if (!(get_varinfo (lhsvar)->is_special_var))
- insert_into_complex (rhsvar, c);
+ /* x = *y */
+ if (rhs.offset == 0 && lhs.offset == 0 && lhs.type == SCALAR)
+ add_pred_graph_edge (graph, lhsvar, FIRST_REF_NODE + rhsvar);
+ else
+ RESET_BIT (graph->direct_nodes, lhsvar);
+ }
+ else if (rhs.type == ADDRESSOF)
+ {
+ /* x = &y */
+ add_pred_graph_edge (graph, lhsvar, FIRST_ADDR_NODE + rhsvar);
+ /* Implicitly, *x = y */
+ add_implicit_graph_edge (graph, FIRST_REF_NODE + lhsvar, rhsvar);
+
+ RESET_BIT (graph->direct_nodes, rhsvar);
+ }
+ else if (lhsvar > anything_id
+ && lhsvar != rhsvar && lhs.offset == 0 && rhs.offset == 0)
+ {
+ /* x = y */
+ add_pred_graph_edge (graph, lhsvar, rhsvar);
+ /* Implicitly, *x = *y */
+ add_implicit_graph_edge (graph, FIRST_REF_NODE + lhsvar,
+ FIRST_REF_NODE + rhsvar);
+ }
+ else if (lhs.offset != 0 || rhs.offset != 0)
+ {
+ if (rhs.offset != 0)
+ RESET_BIT (graph->direct_nodes, lhs.var);
+ if (lhs.offset != 0)
+ RESET_BIT (graph->direct_nodes, rhs.var);
+ }
+ }
+}
+
+/* Build the constraint graph, adding successor edges. */
+
+static void
+build_succ_graph (void)
+{
+ int i;
+ constraint_t c;
+
+ for (i = 0; VEC_iterate (constraint_t, constraints, i, c); i++)
+ {
+ struct constraint_expr lhs;
+ struct constraint_expr rhs;
+ unsigned int lhsvar;
+ unsigned int rhsvar;
+
+ if (!c)
+ continue;
+
+ lhs = c->lhs;
+ rhs = c->rhs;
+ lhsvar = find (get_varinfo_fc (lhs.var)->id);
+ rhsvar = find (get_varinfo_fc (rhs.var)->id);
+
+ if (lhs.type == DEREF)
+ {
+ if (rhs.offset == 0 && lhs.offset == 0 && rhs.type == SCALAR)
+ add_graph_edge (graph, FIRST_REF_NODE + lhsvar, rhsvar);
+ }
+ else if (rhs.type == DEREF)
+ {
+ if (rhs.offset == 0 && lhs.offset == 0 && lhs.type == SCALAR)
+ add_graph_edge (graph, lhsvar, FIRST_REF_NODE + rhsvar);
}
else if (rhs.type == ADDRESSOF)
{
/* x = &y */
+ gcc_assert (find (get_varinfo_fc (rhs.var)->id)
+ == get_varinfo_fc (rhs.var)->id);
bitmap_set_bit (get_varinfo (lhsvar)->solution, rhsvar);
}
- else if (lhsvar > anything_id)
+ else if (lhsvar > anything_id
+ && lhsvar != rhsvar && lhs.offset == 0 && rhs.offset == 0)
{
- /* Ignore 0 weighted self edges, as they can't possibly contribute
- anything */
- if (lhsvar != rhsvar || rhs.offset != 0 || lhs.offset != 0)
- {
-
- struct constraint_edge edge;
- edge.src = lhsvar;
- edge.dest = rhsvar;
- /* x = y (simple) */
- add_graph_edge (graph, edge);
- bitmap_set_bit (get_graph_weights (graph, edge),
- rhs.offset);
- }
-
+ add_graph_edge (graph, lhsvar, rhsvar);
}
}
}
struct scc_info
{
sbitmap visited;
- sbitmap in_component;
+ sbitmap roots;
+ unsigned int *dfs;
+ unsigned int *node_mapping;
int current_index;
- unsigned int *visited_index;
VEC(unsigned,heap) *scc_stack;
- VEC(unsigned,heap) *unification_queue;
};
/* Recursive routine to find strongly connected components in GRAPH.
SI is the SCC info to store the information in, and N is the id of current
graph node we are processing.
-
+
This is Tarjan's strongly connected component finding algorithm, as
- modified by Nuutila to keep only non-root nodes on the stack.
+ modified by Nuutila to keep only non-root nodes on the stack.
The algorithm can be found in "On finding the strongly connected
connected components in a directed graph" by Esko Nuutila and Eljas
Soisalon-Soininen, in Information Processing Letters volume 49,
static void
scc_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n)
{
- constraint_edge_t c;
- int i;
+ unsigned int i;
+ bitmap_iterator bi;
+ unsigned int my_dfs;
- gcc_assert (get_varinfo (n)->node == n);
SET_BIT (si->visited, n);
- RESET_BIT (si->in_component, n);
- si->visited_index[n] = si->current_index ++;
-
+ si->dfs[n] = si->current_index ++;
+ my_dfs = si->dfs[n];
+
/* Visit all the successors. */
- for (i = 0; VEC_iterate (constraint_edge_t, graph->succs[n], i, c); i++)
+ EXECUTE_IF_IN_NONNULL_BITMAP (graph->succs[n], 0, i, bi)
{
- /* We only want to find and collapse the zero weight edges. */
- if (bitmap_bit_p (c->weights, 0))
- {
- unsigned int w = c->dest;
- if (!TEST_BIT (si->visited, w))
- scc_visit (graph, si, w);
- if (!TEST_BIT (si->in_component, w))
- {
- unsigned int t = get_varinfo (w)->node;
- unsigned int nnode = get_varinfo (n)->node;
- if (si->visited_index[t] < si->visited_index[nnode])
- get_varinfo (n)->node = t;
- }
- }
+ unsigned int w;
+
+ if (i > LAST_REF_NODE)
+ break;
+
+ w = find (i);
+ if (TEST_BIT (si->roots, w))
+ continue;
+
+ if (!TEST_BIT (si->visited, w))
+ scc_visit (graph, si, w);
+ {
+ unsigned int t = find (w);
+ unsigned int nnode = find (n);
+ gcc_assert (nnode == n);
+
+ if (si->dfs[t] < si->dfs[nnode])
+ si->dfs[n] = si->dfs[t];
+ }
}
-
+
/* See if any components have been identified. */
- if (get_varinfo (n)->node == n)
+ if (si->dfs[n] == my_dfs)
{
- unsigned int t = si->visited_index[n];
- SET_BIT (si->in_component, n);
- while (VEC_length (unsigned, si->scc_stack) != 0
- && t < si->visited_index[VEC_last (unsigned, si->scc_stack)])
+ if (VEC_length (unsigned, si->scc_stack) > 0
+ && si->dfs[VEC_last (unsigned, si->scc_stack)] >= my_dfs)
{
- 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 (unsigned, heap, si->unification_queue, w);
- }
+ bitmap scc = BITMAP_ALLOC (NULL);
+ bool have_ref_node = n >= FIRST_REF_NODE;
+ unsigned int lowest_node;
+ bitmap_iterator bi;
+
+ bitmap_set_bit (scc, n);
+
+ while (VEC_length (unsigned, si->scc_stack) != 0
+ && si->dfs[VEC_last (unsigned, si->scc_stack)] >= my_dfs)
+ {
+ unsigned int w = VEC_pop (unsigned, si->scc_stack);
+
+ bitmap_set_bit (scc, w);
+ if (w >= FIRST_REF_NODE)
+ have_ref_node = true;
+ }
+
+ lowest_node = bitmap_first_set_bit (scc);
+ gcc_assert (lowest_node < FIRST_REF_NODE);
+ EXECUTE_IF_SET_IN_BITMAP (scc, 0, i, bi)
+ {
+ if (i < FIRST_REF_NODE)
+ {
+ /* Mark this node for collapsing. */
+ if (unite (lowest_node, i))
+ unify_nodes (graph, lowest_node, i, false);
+ }
+ else
+ {
+ unite (lowest_node, i);
+ graph->indirect_cycles[i - FIRST_REF_NODE] = lowest_node;
+ }
+ }
+ }
+ SET_BIT (si->roots, n);
}
else
VEC_safe_push (unsigned, heap, si->scc_stack, n);
}
-
-/* Collapse two variables into one variable. */
+/* Unify node FROM into node TO, updating the changed count if
+ necessary when UPDATE_CHANGED is true. */
static void
-collapse_nodes (constraint_graph_t graph, unsigned int to, unsigned int from)
+unify_nodes (constraint_graph_t graph, unsigned int to, unsigned int from,
+ bool update_changed)
{
- bitmap tosol, fromsol;
- struct constraint_edge edge;
+ gcc_assert (to != from && find (to) == to);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Unifying %s to %s\n",
+ get_varinfo (from)->name,
+ get_varinfo (to)->name);
- condense_varmap_nodes (to, from);
- tosol = get_varinfo (to)->solution;
- fromsol = get_varinfo (from)->solution;
- bitmap_ior_into (tosol, fromsol);
- 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);
- bitmap_clear_bit (weights, 0);
- if (bitmap_empty_p (weights))
- erase_graph_self_edge (graph, edge);
- }
- bitmap_clear (fromsol);
- get_varinfo (to)->address_taken |= get_varinfo (from)->address_taken;
- get_varinfo (to)->indirect_target |= get_varinfo (from)->indirect_target;
-}
-
-
-/* Unify nodes in GRAPH that we have found to be part of a cycle.
- SI is the Strongly Connected Components information structure that tells us
- what components to unify.
- UPDATE_CHANGED should be set to true if the changed sbitmap and changed
- count should be updated to reflect the unification. */
-
-static void
-process_unification_queue (constraint_graph_t graph, struct scc_info *si,
- bool update_changed)
-{
- size_t i = 0;
- bitmap tmp = BITMAP_ALLOC (update_changed ? &iteration_obstack : NULL);
- bitmap_clear (tmp);
-
- /* We proceed as follows:
-
- For each component in the queue (components are delineated by
- when current_queue_element->node != next_queue_element->node):
-
- rep = representative node for component
-
- For each node (tounify) to be unified in the component,
- merge the solution for tounify into tmp bitmap
-
- clear solution for tounify
-
- merge edges from tounify into rep
+ if (update_changed)
+ stats.unified_vars_dynamic++;
+ else
+ stats.unified_vars_static++;
- merge complex constraints from tounify into rep
+ merge_graph_nodes (graph, to, from);
+ merge_node_constraints (graph, to, from);
- update changed count to note that tounify will never change
- again
+ if (get_varinfo (from)->no_tbaa_pruning)
+ get_varinfo (to)->no_tbaa_pruning = true;
- Merge tmp into solution for rep, marking rep changed if this
- changed rep's solution.
-
- Delete any 0 weighted self-edges we now have for rep. */
- while (i != VEC_length (unsigned, si->unification_queue))
+ if (update_changed && TEST_BIT (changed, from))
{
- unsigned int tounify = VEC_index (unsigned, si->unification_queue, i);
- unsigned int n = get_varinfo (tounify)->node;
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "Unifying %s to %s\n",
- get_varinfo (tounify)->name,
- get_varinfo (n)->name);
- if (update_changed)
- stats.unified_vars_dynamic++;
+ RESET_BIT (changed, from);
+ if (!TEST_BIT (changed, to))
+ SET_BIT (changed, to);
else
- stats.unified_vars_static++;
- bitmap_ior_into (tmp, get_varinfo (tounify)->solution);
- merge_graph_nodes (graph, n, tounify);
- condense_varmap_nodes (n, tounify);
-
- if (update_changed && TEST_BIT (changed, tounify))
- {
- RESET_BIT (changed, tounify);
- if (!TEST_BIT (changed, n))
- SET_BIT (changed, n);
- else
- {
- gcc_assert (changed_count > 0);
- changed_count--;
- }
+ {
+ gcc_assert (changed_count > 0);
+ changed_count--;
}
+ }
- bitmap_clear (get_varinfo (tounify)->solution);
- ++i;
-
- /* 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 (unsigned, si->unification_queue)
- || get_varinfo (VEC_index (unsigned, si->unification_queue, i))->node != n)
+ /* If the solution changes because of the merging, we need to mark
+ the variable as changed. */
+ if (bitmap_ior_into (get_varinfo (to)->solution,
+ get_varinfo (from)->solution))
+ {
+ if (update_changed && !TEST_BIT (changed, to))
{
- struct constraint_edge edge;
-
- /* If the solution changes because of the merging, we need to mark
- the variable as changed. */
- if (bitmap_ior_into (get_varinfo (n)->solution, tmp))
- {
- if (update_changed && !TEST_BIT (changed, n))
- {
- SET_BIT (changed, n);
- changed_count++;
- }
- }
- 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);
- bitmap_clear_bit (weights, 0);
- if (bitmap_empty_p (weights))
- erase_graph_self_edge (graph, edge);
- }
+ SET_BIT (changed, to);
+ changed_count++;
}
}
- BITMAP_FREE (tmp);
-}
+ BITMAP_FREE (get_varinfo (from)->solution);
+ BITMAP_FREE (get_varinfo (from)->oldsolution);
+
+ if (stats.iterations > 0)
+ {
+ BITMAP_FREE (get_varinfo (to)->oldsolution);
+ get_varinfo (to)->oldsolution = BITMAP_ALLOC (&oldpta_obstack);
+ }
+
+ if (valid_graph_edge (graph, to, to))
+ {
+ if (graph->succs[to])
+ bitmap_clear_bit (graph->succs[to], to);
+ }
+}
/* Information needed to compute the topological ordering of a graph. */
init_topo_info (void)
{
size_t size = VEC_length (varinfo_t, varmap);
- struct topo_info *ti = xmalloc (sizeof (struct topo_info));
+ struct topo_info *ti = XNEW (struct topo_info);
ti->visited = sbitmap_alloc (size);
sbitmap_zero (ti->visited);
ti->topo_order = VEC_alloc (unsigned, heap, 1);
topo_visit (constraint_graph_t graph, struct topo_info *ti,
unsigned int n)
{
- VEC(constraint_edge_t,heap) *succs = graph->succs[n];
- constraint_edge_t c;
- int i;
+ bitmap_iterator bi;
+ unsigned int j;
+
SET_BIT (ti->visited, n);
- for (i = 0; VEC_iterate (constraint_edge_t, succs, i, c); i++)
- {
- if (!TEST_BIT (ti->visited, c->dest))
- topo_visit (graph, ti, c->dest);
- }
+
+ if (graph->succs[n])
+ EXECUTE_IF_SET_IN_BITMAP (graph->succs[n], 0, j, bi)
+ {
+ if (!TEST_BIT (ti->visited, j))
+ topo_visit (graph, ti, j);
+ }
+
VEC_safe_push (unsigned, heap, ti->topo_order, n);
}
/* Return true if variable N + OFFSET is a legal field of N. */
-static bool
+static bool
type_safe (unsigned int n, unsigned HOST_WIDE_INT *offset)
{
varinfo_t ninfo = get_varinfo (n);
v = first_vi_for_offset (get_varinfo (j), fieldoffset);
if (!v)
continue;
- t = v->node;
+ t = find (v->id);
sol = get_varinfo (t)->solution;
if (!bitmap_bit_p (sol, rhs))
- {
+ {
bitmap_set_bit (sol, rhs);
if (!TEST_BIT (changed, t))
{
}
}
}
- else if (dump_file && !(get_varinfo (j)->is_special_var))
+ else if (0 && dump_file && !(get_varinfo (j)->is_special_var))
fprintf (dump_file, "Untypesafe usage in do_da_constraint.\n");
-
+
}
}
do_sd_constraint (constraint_graph_t graph, constraint_t c,
bitmap delta)
{
- unsigned int lhs = get_varinfo (c->lhs.var)->node;
+ unsigned int lhs = find (c->lhs.var);
bool flag = false;
bitmap sol = get_varinfo (lhs)->solution;
unsigned int j;
bitmap_iterator bi;
-
- /* For each variable j in delta (Sol(y)), add
+
+ if (bitmap_bit_p (delta, anything_id))
+ {
+ flag = !bitmap_bit_p (sol, anything_id);
+ if (flag)
+ bitmap_set_bit (sol, anything_id);
+ goto done;
+ }
+ /* For each variable j in delta (Sol(y)), add
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 fieldoffset = get_varinfo (j)->offset + roffset;
unsigned int t;
- v = first_vi_for_offset (get_varinfo (j), fieldoffset);
+ 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);
+ t = find (v->id);
+
+ /* Adding edges from the special vars is pointless.
+ They don't have sets that can change. */
+ if (get_varinfo (t) ->is_special_var)
+ flag |= bitmap_ior_into (sol, get_varinfo (t)->solution);
+ else if (add_graph_edge (graph, lhs, t))
+ flag |= bitmap_ior_into (sol, get_varinfo (t)->solution);
}
- else if (dump_file && !(get_varinfo (j)->is_special_var))
+ else if (0 && dump_file && !(get_varinfo (j)->is_special_var))
fprintf (dump_file, "Untypesafe usage in do_sd_constraint\n");
-
+
}
+done:
/* If the LHS solution changed, mark the var as changed. */
if (flag)
{
SET_BIT (changed, lhs);
changed_count++;
}
- }
+ }
}
/* Process a constraint C that represents *x = y. */
static void
-do_ds_constraint (constraint_graph_t graph, constraint_t c, bitmap delta)
+do_ds_constraint (constraint_t c, bitmap delta)
{
- unsigned int rhs = get_varinfo (c->rhs.var)->node;
+ unsigned int rhs = find (c->rhs.var);
unsigned HOST_WIDE_INT roff = c->rhs.offset;
bitmap sol = get_varinfo (rhs)->solution;
unsigned int j;
bitmap_iterator bi;
+ if (bitmap_bit_p (sol, anything_id))
+ {
+ EXECUTE_IF_SET_IN_BITMAP (delta, 0, j, bi)
+ {
+ varinfo_t jvi = get_varinfo (j);
+ unsigned int t;
+ unsigned int loff = c->lhs.offset;
+ unsigned HOST_WIDE_INT fieldoffset = jvi->offset + loff;
+ varinfo_t v;
+
+ v = first_vi_for_offset (get_varinfo (j), fieldoffset);
+ if (!v)
+ continue;
+ t = find (v->id);
+
+ if (!bitmap_bit_p (get_varinfo (t)->solution, anything_id))
+ {
+ bitmap_set_bit (get_varinfo (t)->solution, anything_id);
+ if (!TEST_BIT (changed, t))
+ {
+ SET_BIT (changed, t);
+ changed_count++;
+ }
+ }
+ }
+ return;
+ }
+
/* For each member j of delta (Sol(x)), add an edge from y to j and
union Sol(y) into Sol(j) */
EXECUTE_IF_SET_IN_BITMAP (delta, 0, j, bi)
{
unsigned HOST_WIDE_INT loff = c->lhs.offset;
- if (type_safe (j, &loff) && !(get_varinfo(j)->is_special_var))
+ 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;
+ bitmap tmp;
v = first_vi_for_offset (get_varinfo (j), fieldoffset);
if (!v)
continue;
- t = v->node;
- if (int_add_graph_edge (graph, t, rhs, roff))
+ t = find (v->id);
+ tmp = get_varinfo (t)->solution;
+
+ if (set_union_with_increment (tmp, sol, roff))
{
- bitmap tmp = get_varinfo (t)->solution;
- if (set_union_with_increment (tmp, sol, roff))
+ get_varinfo (t)->solution = tmp;
+ if (t == rhs)
+ sol = get_varinfo (rhs)->solution;
+ if (!TEST_BIT (changed, t))
{
- get_varinfo (t)->solution = tmp;
- if (t == rhs)
- {
- sol = get_varinfo (rhs)->solution;
- }
- if (!TEST_BIT (changed, t))
- {
- SET_BIT (changed, t);
- changed_count++;
- }
+ SET_BIT (changed, t);
+ changed_count++;
}
}
- }
- else if (dump_file && !(get_varinfo (j)->is_special_var))
+ }
+ else if (0 && dump_file && !(get_varinfo (j)->is_special_var))
fprintf (dump_file, "Untypesafe usage in do_ds_constraint\n");
}
}
-/* Handle a non-simple (simple meaning requires no iteration), non-copy
- constraint (IE *x = &y, x = *y, and *x = y). */
-
+/* Handle a non-simple (simple meaning requires no iteration),
+ constraint (IE *x = &y, x = *y, *x = y, and x = y with offsets involved). */
+
static void
do_complex_constraint (constraint_graph_t graph, constraint_t c, bitmap delta)
{
else
{
/* *x = y */
- do_ds_constraint (graph, c, delta);
+ do_ds_constraint (c, delta);
}
}
- else
+ else if (c->rhs.type == DEREF)
{
/* x = *y */
if (!(get_varinfo (c->lhs.var)->is_special_var))
do_sd_constraint (graph, c, delta);
}
+ else
+ {
+ bitmap tmp;
+ bitmap solution;
+ bool flag = false;
+ unsigned int t;
+
+ gcc_assert (c->rhs.type == SCALAR && c->lhs.type == SCALAR);
+ t = find (c->rhs.var);
+ solution = get_varinfo (t)->solution;
+ t = find (c->lhs.var);
+ tmp = get_varinfo (t)->solution;
+
+ flag = set_union_with_increment (tmp, solution, c->rhs.offset);
+
+ if (flag)
+ {
+ get_varinfo (t)->solution = tmp;
+ if (!TEST_BIT (changed, t))
+ {
+ SET_BIT (changed, t);
+ changed_count++;
+ }
+ }
+ }
}
/* Initialize and return a new SCC info structure. */
static struct scc_info *
-init_scc_info (void)
+init_scc_info (size_t size)
{
- struct scc_info *si = xmalloc (sizeof (struct scc_info));
- size_t size = VEC_length (varinfo_t, varmap);
+ struct scc_info *si = XNEW (struct scc_info);
+ size_t i;
si->current_index = 0;
si->visited = sbitmap_alloc (size);
sbitmap_zero (si->visited);
- si->in_component = sbitmap_alloc (size);
- sbitmap_ones (si->in_component);
- si->visited_index = xcalloc (sizeof (unsigned int), size + 1);
+ si->roots = sbitmap_alloc (size);
+ sbitmap_zero (si->roots);
+ si->node_mapping = XNEWVEC (unsigned int, size);
+ si->dfs = XCNEWVEC (unsigned int, size);
+
+ for (i = 0; i < size; i++)
+ si->node_mapping[i] = i;
+
si->scc_stack = VEC_alloc (unsigned, heap, 1);
- si->unification_queue = VEC_alloc (unsigned, heap, 1);
return si;
}
static void
free_scc_info (struct scc_info *si)
-{
+{
sbitmap_free (si->visited);
- sbitmap_free (si->in_component);
- free (si->visited_index);
+ sbitmap_free (si->roots);
+ free (si->node_mapping);
+ free (si->dfs);
VEC_free (unsigned, heap, si->scc_stack);
- VEC_free (unsigned, heap, si->unification_queue);
- free(si);
+ free (si);
}
-/* Find cycles in GRAPH that occur, using strongly connected components, and
- collapse the cycles into a single representative node. if UPDATE_CHANGED
- is true, then update the changed sbitmap to note those nodes whose
- solutions have changed as a result of collapsing. */
+/* Find indirect cycles in GRAPH that occur, using strongly connected
+ components, and note them in the indirect cycles map.
+
+ This technique comes from Ben Hardekopf and Calvin Lin,
+ "It Pays to be Lazy: Fast and Accurate Pointer Analysis for Millions of
+ Lines of Code", submitted to PLDI 2007. */
static void
-find_and_collapse_graph_cycles (constraint_graph_t graph, bool update_changed)
+find_indirect_cycles (constraint_graph_t graph)
{
unsigned int i;
- unsigned int size = VEC_length (varinfo_t, varmap);
- struct scc_info *si = init_scc_info ();
+ unsigned int size = graph->size;
+ struct scc_info *si = init_scc_info (size);
- for (i = 0; i != size; ++i)
- if (!TEST_BIT (si->visited, i) && get_varinfo (i)->node == i)
+ for (i = 0; i < MIN (LAST_REF_NODE, size); i ++ )
+ if (!TEST_BIT (si->visited, i) && find (i) == i)
scc_visit (graph, si, i);
- process_unification_queue (graph, si, update_changed);
+
free_scc_info (si);
}
/* Compute a topological ordering for GRAPH, and store the result in the
topo_info structure TI. */
-static void
+static void
compute_topo_order (constraint_graph_t graph,
struct topo_info *ti)
{
unsigned int i;
unsigned int size = VEC_length (varinfo_t, varmap);
-
+
for (i = 0; i != size; ++i)
- if (!TEST_BIT (ti->visited, i) && get_varinfo (i)->node == i)
+ if (!TEST_BIT (ti->visited, i) && find (i) == i)
topo_visit (graph, ti, i);
}
-/* Return true if bitmap B is empty, or a bitmap other than bit 0 is set. */
-
-static bool
-bitmap_other_than_zero_bit_set (bitmap b)
-{
- unsigned int i;
- bitmap_iterator bi;
-
- if (bitmap_empty_p (b))
- return false;
- EXECUTE_IF_SET_IN_BITMAP (b, 1, i, bi)
- return true;
- return false;
-}
-
/* Perform offline variable substitution.
-
+
This is a linear time way of identifying variables that must have
equivalent points-to sets, including those caused by static cycles,
and single entry subgraphs, in the constraint graph.
The technique is described in "Off-line variable substitution for
scaling points-to analysis" by Atanas Rountev and Satish Chandra,
- in "ACM SIGPLAN Notices" volume 35, number 5, pages 47-56. */
+ in "ACM SIGPLAN Notices" volume 35, number 5, pages 47-56.
+
+ There is an optimal way to do this involving hash based value
+ numbering, once the technique is published i will implement it
+ here.
+
+ The general method of finding equivalence classes is as follows:
+ Add fake nodes (REF nodes) and edges for *a = b and a = *b constraints.
+ Add fake nodes (ADDRESS nodes) and edges for a = &b constraints.
+ Initialize all non-REF/ADDRESS nodes to be direct nodes
+ For each SCC in the predecessor graph:
+ for each member (x) of the SCC
+ if x is not a direct node:
+ set rootnode(SCC) to be not a direct node
+ collapse node x into rootnode(SCC).
+ if rootnode(SCC) is not a direct node:
+ label rootnode(SCC) with a new equivalence class
+ else:
+ if all labeled predecessors of rootnode(SCC) have the same
+ label:
+ label rootnode(SCC) with this label
+ else:
+ label rootnode(SCC) with a new equivalence class
+
+ All direct nodes with the same equivalence class can be replaced
+ with a single representative node.
+ All unlabeled nodes (label == 0) are not pointers and all edges
+ involving them can be eliminated.
+ We perform these optimizations during move_complex_constraints.
+*/
+
+static int equivalence_class;
+
+/* Recursive routine to find strongly connected components in GRAPH,
+ and label it's nodes with equivalence classes.
+ This is used during variable substitution to find cycles involving
+ the regular or implicit predecessors, and label them as equivalent.
+ The SCC finding algorithm used is the same as that for scc_visit. */
static void
-perform_var_substitution (constraint_graph_t graph)
+label_visit (constraint_graph_t graph, struct scc_info *si, unsigned int n)
{
- struct topo_info *ti = init_topo_info ();
-
- /* Compute the topological ordering of the graph, then visit each
- node in topological order. */
- compute_topo_order (graph, ti);
-
- while (VEC_length (unsigned, ti->topo_order) != 0)
- {
- 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,heap) *predvec = graph->preds[i];
- constraint_edge_t ce;
- bitmap tmp;
+ unsigned int i;
+ bitmap_iterator bi;
+ unsigned int my_dfs;
- /* We can't eliminate things whose address is taken, or which is
- the target of a dereference. */
- if (vi->address_taken || vi->indirect_target)
- continue;
+ gcc_assert (si->node_mapping[n] == n);
+ SET_BIT (si->visited, n);
+ si->dfs[n] = si->current_index ++;
+ my_dfs = si->dfs[n];
- /* See if all predecessors of I are ripe for elimination */
- for (pred = 0; VEC_iterate (constraint_edge_t, predvec, pred, ce); pred++)
- {
- bitmap weight;
- unsigned int w;
- weight = get_graph_weights (graph, *ce);
-
- /* We can't eliminate variables that have nonzero weighted
- edges between them. */
- if (bitmap_other_than_zero_bit_set (weight))
- {
- okay_to_elim = false;
- break;
- }
- w = get_varinfo (ce->dest)->node;
+ /* Visit all the successors. */
+ EXECUTE_IF_IN_NONNULL_BITMAP (graph->preds[n], 0, i, bi)
+ {
+ unsigned int w = si->node_mapping[i];
- /* We can't eliminate the node if one of the predecessors is
- part of a different strongly connected component. */
- if (!okay_to_elim)
- {
- root = w;
- okay_to_elim = true;
- }
- else if (w != root)
- {
- okay_to_elim = false;
- break;
- }
+ if (TEST_BIT (si->roots, w))
+ continue;
- /* Theorem 4 in Rountev and Chandra: If i is a direct node,
- then Solution(i) is a subset of Solution (w), where w is a
- predecessor in the graph.
- Corollary: If all predecessors of i have the same
- points-to set, then i has that same points-to set as
- those predecessors. */
- tmp = BITMAP_ALLOC (NULL);
- bitmap_and_compl (tmp, get_varinfo (i)->solution,
- get_varinfo (w)->solution);
- if (!bitmap_empty_p (tmp))
- {
- okay_to_elim = false;
- BITMAP_FREE (tmp);
- break;
- }
- BITMAP_FREE (tmp);
- }
+ if (!TEST_BIT (si->visited, w))
+ label_visit (graph, si, w);
+ {
+ unsigned int t = si->node_mapping[w];
+ unsigned int nnode = si->node_mapping[n];
+ gcc_assert (nnode == n);
- /* See if the root is different than the original node.
- If so, we've found an equivalence. */
- if (root != get_varinfo (i)->node && okay_to_elim)
- {
- /* Found an equivalence */
- get_varinfo (i)->node = root;
- collapse_nodes (graph, root, i);
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "Collapsing %s into %s\n",
- get_varinfo (i)->name,
- get_varinfo (root)->name);
- stats.collapsed_vars++;
- }
+ if (si->dfs[t] < si->dfs[nnode])
+ si->dfs[n] = si->dfs[t];
+ }
}
- free_topo_info (ti);
-}
+ /* Visit all the implicit predecessors. */
+ EXECUTE_IF_IN_NONNULL_BITMAP (graph->implicit_preds[n], 0, i, bi)
+ {
+ unsigned int w = si->node_mapping[i];
+ if (TEST_BIT (si->roots, w))
+ continue;
-/* Solve the constraint graph GRAPH using our worklist solver.
- This is based on the PW* family of solvers from the "Efficient Field
- Sensitive Pointer Analysis for C" paper.
- It works by iterating over all the graph nodes, processing the complex
- constraints and propagating the copy constraints, until everything stops
- changed. This corresponds to steps 6-8 in the solving list given above. */
+ if (!TEST_BIT (si->visited, w))
+ label_visit (graph, si, w);
+ {
+ unsigned int t = si->node_mapping[w];
+ unsigned int nnode = si->node_mapping[n];
+ gcc_assert (nnode == n);
-static void
-solve_graph (constraint_graph_t graph)
-{
- unsigned int size = VEC_length (varinfo_t, varmap);
- unsigned int i;
+ if (si->dfs[t] < si->dfs[nnode])
+ si->dfs[n] = si->dfs[t];
+ }
+ }
- changed_count = size;
- changed = sbitmap_alloc (size);
- sbitmap_ones (changed);
-
- /* The already collapsed/unreachable nodes will never change, so we
- need to account for them in changed_count. */
- for (i = 0; i < size; i++)
- if (get_varinfo (i)->node != i)
- changed_count--;
-
- while (changed_count > 0)
+ /* See if any components have been identified. */
+ if (si->dfs[n] == my_dfs)
{
- unsigned int i;
- struct topo_info *ti = init_topo_info ();
- stats.iterations++;
-
- bitmap_obstack_initialize (&iteration_obstack);
-
- if (edge_added)
- {
- /* We already did cycle elimination once, when we did
- variable substitution, so we don't need it again for the
- first iteration. */
- if (stats.iterations > 1)
- find_and_collapse_graph_cycles (graph, true);
-
- edge_added = false;
- }
+ while (VEC_length (unsigned, si->scc_stack) != 0
+ && si->dfs[VEC_last (unsigned, si->scc_stack)] >= my_dfs)
+ {
+ unsigned int w = VEC_pop (unsigned, si->scc_stack);
+ si->node_mapping[w] = n;
- compute_topo_order (graph, ti);
+ if (!TEST_BIT (graph->direct_nodes, w))
+ RESET_BIT (graph->direct_nodes, n);
+ }
+ SET_BIT (si->roots, n);
- while (VEC_length (unsigned, ti->topo_order) != 0)
+ if (!TEST_BIT (graph->direct_nodes, n))
{
- i = VEC_pop (unsigned, ti->topo_order);
- gcc_assert (get_varinfo (i)->node == i);
+ graph->label[n] = equivalence_class++;
+ }
+ else
+ {
+ unsigned int size = 0;
+ unsigned int firstlabel = ~0;
- /* If the node has changed, we need to process the
- complex constraints and outgoing edges again. */
- if (TEST_BIT (changed, i))
+ EXECUTE_IF_IN_NONNULL_BITMAP (graph->preds[n], 0, i, bi)
{
- unsigned int j;
- constraint_t c;
- constraint_edge_t e;
- bitmap solution;
- VEC(constraint_t,heap) *complex = get_varinfo (i)->complex;
- VEC(constraint_edge_t,heap) *succs;
-
- RESET_BIT (changed, i);
- changed_count--;
+ unsigned int j = si->node_mapping[i];
- /* Process the complex constraints */
- solution = get_varinfo (i)->solution;
- for (j = 0; VEC_iterate (constraint_t, complex, j, c); j++)
- do_complex_constraint (graph, c, solution);
+ if (j == n || graph->label[j] == 0)
+ continue;
- /* Propagate solution to all successors. */
- succs = graph->succs[i];
- for (j = 0; VEC_iterate (constraint_edge_t, succs, j, e); j++)
+ if (firstlabel == (unsigned int)~0)
{
- bitmap tmp = get_varinfo (e->dest)->solution;
- bool flag = false;
- unsigned int k;
- bitmap weights = e->weights;
- bitmap_iterator bi;
-
- gcc_assert (!bitmap_empty_p (weights));
- EXECUTE_IF_SET_IN_BITMAP (weights, 0, k, bi)
- flag |= set_union_with_increment (tmp, solution, k);
-
- if (flag)
- {
- get_varinfo (e->dest)->solution = tmp;
- if (!TEST_BIT (changed, e->dest))
- {
- SET_BIT (changed, e->dest);
- changed_count++;
- }
- }
+ firstlabel = graph->label[j];
+ size++;
}
+ else if (graph->label[j] != firstlabel)
+ size++;
}
+
+ if (size == 0)
+ graph->label[n] = 0;
+ else if (size == 1)
+ graph->label[n] = firstlabel;
+ else
+ graph->label[n] = equivalence_class++;
}
- free_topo_info (ti);
- bitmap_obstack_release (&iteration_obstack);
}
-
- sbitmap_free (changed);
+ else
+ VEC_safe_push (unsigned, heap, si->scc_stack, n);
}
+/* Perform offline variable substitution, discovering equivalence
+ classes, and eliminating non-pointer variables. */
-/* CONSTRAINT AND VARIABLE GENERATION FUNCTIONS */
+static struct scc_info *
+perform_var_substitution (constraint_graph_t graph)
+{
+ unsigned int i;
+ unsigned int size = graph->size;
+ struct scc_info *si = init_scc_info (size);
-/* Map from trees to variable ids. */
-static htab_t id_for_tree;
+ bitmap_obstack_initialize (&iteration_obstack);
+ equivalence_class = 0;
-typedef struct tree_id
-{
- tree t;
- unsigned int id;
-} *tree_id_t;
+ /* We only need to visit the non-address nodes for labeling
+ purposes, as the address nodes will never have any predecessors,
+ because &x never appears on the LHS of a constraint. */
+ for (i = 0; i < LAST_REF_NODE; i++)
+ if (!TEST_BIT (si->visited, si->node_mapping[i]))
+ label_visit (graph, si, si->node_mapping[i]);
-/* Hash a tree id structure. */
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ for (i = 0; i < FIRST_REF_NODE; i++)
+ {
+ bool direct_node = TEST_BIT (graph->direct_nodes, i);
+ fprintf (dump_file,
+ "Equivalence class for %s node id %d:%s is %d\n",
+ direct_node ? "Direct node" : "Indirect node", i,
+ get_varinfo (i)->name,
+ graph->label[si->node_mapping[i]]);
+ }
-static hashval_t
-tree_id_hash (const void *p)
-{
- const tree_id_t ta = (tree_id_t) p;
- return htab_hash_pointer (ta->t);
-}
+ /* Quickly eliminate our non-pointer variables. */
-/* Return true if the tree in P1 and the tree in P2 are the same. */
+ for (i = 0; i < FIRST_REF_NODE; i++)
+ {
+ unsigned int node = si->node_mapping[i];
-static int
-tree_id_eq (const void *p1, const void *p2)
-{
- const tree_id_t ta1 = (tree_id_t) p1;
- const tree_id_t ta2 = (tree_id_t) p2;
- return ta1->t == ta2->t;
+ if (graph->label[node] == 0 && TEST_BIT (graph->direct_nodes, node))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "%s is a non-pointer variable, eliminating edges.\n",
+ get_varinfo (node)->name);
+ stats.nonpointer_vars++;
+ clear_edges_for_node (graph, node);
+ }
+ }
+ return si;
}
-/* Insert ID as the variable id for tree T in the hashtable. */
+/* Free information that was only necessary for variable
+ substitution. */
-static void
-insert_id_for_tree (tree t, int id)
+static void
+free_var_substitution_info (struct scc_info *si)
{
- void **slot;
- struct tree_id finder;
- tree_id_t new_pair;
-
- finder.t = t;
- slot = htab_find_slot (id_for_tree, &finder, INSERT);
- gcc_assert (*slot == NULL);
- new_pair = xmalloc (sizeof (struct tree_id));
- new_pair->t = t;
- new_pair->id = id;
- *slot = (void *)new_pair;
+ free_scc_info (si);
+ free (graph->label);
+ free (graph->eq_rep);
+ sbitmap_free (graph->direct_nodes);
+ bitmap_obstack_release (&iteration_obstack);
}
-/* Find the variable id for tree T in ID_FOR_TREE. If T does not
- exist in the hash table, return false, otherwise, return true and
- set *ID to the id we found. */
+/* Return an existing node that is equivalent to NODE, which has
+ equivalence class LABEL, if one exists. Return NODE otherwise. */
-static bool
-lookup_id_for_tree (tree t, unsigned int *id)
+static unsigned int
+find_equivalent_node (constraint_graph_t graph,
+ unsigned int node, unsigned int label)
{
- tree_id_t pair;
- struct tree_id finder;
+ /* If the address version of this variable is unused, we can
+ substitute it for anything else with the same label.
+ Otherwise, we know the pointers are equivalent, but not the
+ locations. */
- finder.t = t;
- pair = htab_find (id_for_tree, &finder);
- if (pair == NULL)
- return false;
- *id = pair->id;
- return true;
+ if (graph->label[FIRST_ADDR_NODE + node] == 0)
+ {
+ gcc_assert (label < graph->size);
+
+ if (graph->eq_rep[label] != -1)
+ {
+ /* Unify the two variables since we know they are equivalent. */
+ if (unite (graph->eq_rep[label], node))
+ unify_nodes (graph, graph->eq_rep[label], node, false);
+ return graph->eq_rep[label];
+ }
+ else
+ {
+ graph->eq_rep[label] = node;
+ }
+ }
+ return node;
}
-/* Return a printable name for DECL */
+/* Move complex constraints to the appropriate nodes, and collapse
+ variables we've discovered are equivalent during variable
+ substitution. SI is the SCC_INFO that is the result of
+ perform_variable_substitution. */
-static const char *
-alias_get_name (tree decl)
+static void
+move_complex_constraints (constraint_graph_t graph,
+ struct scc_info *si)
{
- const char *res = get_name (decl);
- char *temp;
- int num_printed = 0;
+ int i;
+ unsigned int j;
+ constraint_t c;
- if (res != NULL)
- return res;
+ for (j = 0; j < graph->size; j++)
+ gcc_assert (find (j) == j);
+
+ 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 = find (get_varinfo_fc (lhs.var)->id);
+ unsigned int rhsvar = find (get_varinfo_fc (rhs.var)->id);
+ unsigned int lhsnode, rhsnode;
+ unsigned int lhslabel, rhslabel;
+
+ lhsnode = si->node_mapping[lhsvar];
+ rhsnode = si->node_mapping[rhsvar];
+ lhslabel = graph->label[lhsnode];
+ rhslabel = graph->label[rhsnode];
+
+ /* See if it is really a non-pointer variable, and if so, ignore
+ the constraint. */
+ if (lhslabel == 0)
+ {
+ if (!TEST_BIT (graph->direct_nodes, lhsnode))
+ lhslabel = graph->label[lhsnode] = equivalence_class++;
+ else
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+
+ fprintf (dump_file, "%s is a non-pointer variable,"
+ "ignoring constraint:",
+ get_varinfo (lhs.var)->name);
+ dump_constraint (dump_file, c);
+ }
+ VEC_replace (constraint_t, constraints, i, NULL);
+ continue;
+ }
+ }
+
+ if (rhslabel == 0)
+ {
+ if (!TEST_BIT (graph->direct_nodes, rhsnode))
+ rhslabel = graph->label[rhsnode] = equivalence_class++;
+ else
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+
+ fprintf (dump_file, "%s is a non-pointer variable,"
+ "ignoring constraint:",
+ get_varinfo (rhs.var)->name);
+ dump_constraint (dump_file, c);
+ }
+ VEC_replace (constraint_t, constraints, i, NULL);
+ continue;
+ }
+ }
+
+ lhsvar = find_equivalent_node (graph, lhsvar, lhslabel);
+ rhsvar = find_equivalent_node (graph, rhsvar, rhslabel);
+ c->lhs.var = lhsvar;
+ c->rhs.var = rhsvar;
+
+ if (lhs.type == DEREF)
+ {
+ if (rhs.type == ADDRESSOF || rhsvar > anything_id)
+ insert_into_complex (graph, lhsvar, c);
+ }
+ else if (rhs.type == DEREF)
+ {
+ if (!(get_varinfo (lhsvar)->is_special_var))
+ insert_into_complex (graph, rhsvar, c);
+ }
+ else if (rhs.type != ADDRESSOF && lhsvar > anything_id
+ && (lhs.offset != 0 || rhs.offset != 0))
+ {
+ insert_into_complex (graph, rhsvar, c);
+ }
+
+ }
+}
+
+/* Eliminate indirect cycles involving NODE. Return true if NODE was
+ part of an SCC, false otherwise. */
+
+static bool
+eliminate_indirect_cycles (unsigned int node)
+{
+ if (graph->indirect_cycles[node] != -1
+ && !bitmap_empty_p (get_varinfo (node)->solution))
+ {
+ unsigned int i;
+ VEC(unsigned,heap) *queue = NULL;
+ int queuepos;
+ unsigned int to = find (graph->indirect_cycles[node]);
+ bitmap_iterator bi;
+
+ /* We can't touch the solution set and call unify_nodes
+ at the same time, because unify_nodes is going to do
+ bitmap unions into it. */
+
+ EXECUTE_IF_SET_IN_BITMAP (get_varinfo (node)->solution, 0, i, bi)
+ {
+ if (find (i) == i && i != to)
+ {
+ if (unite (to, i))
+ VEC_safe_push (unsigned, heap, queue, i);
+ }
+ }
+
+ for (queuepos = 0;
+ VEC_iterate (unsigned, queue, queuepos, i);
+ queuepos++)
+ {
+ unify_nodes (graph, to, i, true);
+ }
+ VEC_free (unsigned, heap, queue);
+ return true;
+ }
+ return false;
+}
+
+/* Solve the constraint graph GRAPH using our worklist solver.
+ This is based on the PW* family of solvers from the "Efficient Field
+ Sensitive Pointer Analysis for C" paper.
+ It works by iterating over all the graph nodes, processing the complex
+ constraints and propagating the copy constraints, until everything stops
+ changed. This corresponds to steps 6-8 in the solving list given above. */
+
+static void
+solve_graph (constraint_graph_t graph)
+{
+ unsigned int size = VEC_length (varinfo_t, varmap);
+ unsigned int i;
+ bitmap pts;
+
+ changed_count = 0;
+ changed = sbitmap_alloc (size);
+ sbitmap_zero (changed);
+
+ /* Mark all initial non-collapsed nodes as changed. */
+ for (i = 0; i < size; i++)
+ {
+ varinfo_t ivi = get_varinfo (i);
+ if (find (i) == i && !bitmap_empty_p (ivi->solution)
+ && ((graph->succs[i] && !bitmap_empty_p (graph->succs[i]))
+ || VEC_length (constraint_t, graph->complex[i]) > 0))
+ {
+ SET_BIT (changed, i);
+ changed_count++;
+ }
+ }
+
+ /* Allocate a bitmap to be used to store the changed bits. */
+ pts = BITMAP_ALLOC (&pta_obstack);
+
+ while (changed_count > 0)
+ {
+ unsigned int i;
+ struct topo_info *ti = init_topo_info ();
+ stats.iterations++;
+
+ bitmap_obstack_initialize (&iteration_obstack);
+
+ compute_topo_order (graph, ti);
+
+ while (VEC_length (unsigned, ti->topo_order) != 0)
+ {
+
+ i = VEC_pop (unsigned, ti->topo_order);
+
+ /* If this variable is not a representative, skip it. */
+ if (find (i) != i)
+ continue;
+
+ /* In certain indirect cycle cases, we may merge this
+ variable to another. */
+ if (eliminate_indirect_cycles (i) && find (i) != i)
+ continue;
+
+ /* If the node has changed, we need to process the
+ complex constraints and outgoing edges again. */
+ if (TEST_BIT (changed, i))
+ {
+ unsigned int j;
+ constraint_t c;
+ bitmap solution;
+ VEC(constraint_t,heap) *complex = graph->complex[i];
+ bool solution_empty;
+
+ RESET_BIT (changed, i);
+ changed_count--;
+
+ /* Compute the changed set of solution bits. */
+ bitmap_and_compl (pts, get_varinfo (i)->solution,
+ get_varinfo (i)->oldsolution);
+
+ if (bitmap_empty_p (pts))
+ continue;
+
+ bitmap_ior_into (get_varinfo (i)->oldsolution, pts);
+
+ solution = get_varinfo (i)->solution;
+ solution_empty = bitmap_empty_p (solution);
+
+ /* Process the complex constraints */
+ for (j = 0; VEC_iterate (constraint_t, complex, j, c); j++)
+ {
+ /* The only complex constraint that can change our
+ solution to non-empty, given an empty solution,
+ is a constraint where the lhs side is receiving
+ some set from elsewhere. */
+ if (!solution_empty || c->lhs.type != DEREF)
+ do_complex_constraint (graph, c, pts);
+ }
+
+ solution_empty = bitmap_empty_p (solution);
+
+ if (!solution_empty)
+ {
+ bitmap_iterator bi;
+
+ /* Propagate solution to all successors. */
+ EXECUTE_IF_IN_NONNULL_BITMAP (graph->succs[i],
+ 0, j, bi)
+ {
+ bitmap tmp;
+ bool flag;
+
+ unsigned int to = find (j);
+ tmp = get_varinfo (to)->solution;
+ flag = false;
+
+ /* Don't try to propagate to ourselves. */
+ if (to == i)
+ continue;
+
+ flag = set_union_with_increment (tmp, pts, 0);
+
+ if (flag)
+ {
+ get_varinfo (to)->solution = tmp;
+ if (!TEST_BIT (changed, to))
+ {
+ SET_BIT (changed, to);
+ changed_count++;
+ }
+ }
+ }
+ }
+ }
+ }
+ free_topo_info (ti);
+ bitmap_obstack_release (&iteration_obstack);
+ }
+
+ BITMAP_FREE (pts);
+ sbitmap_free (changed);
+ bitmap_obstack_release (&oldpta_obstack);
+}
+
+/* Map from trees to variable infos. */
+static struct pointer_map_t *vi_for_tree;
+
+
+/* Insert ID as the variable id for tree T in the vi_for_tree map. */
+
+static void
+insert_vi_for_tree (tree t, varinfo_t vi)
+{
+ void **slot = pointer_map_insert (vi_for_tree, t);
+ gcc_assert (vi);
+ gcc_assert (*slot == NULL);
+ *slot = vi;
+}
+
+/* Find the variable info for tree T in VI_FOR_TREE. If T does not
+ exist in the map, return NULL, otherwise, return the varinfo we found. */
+
+static varinfo_t
+lookup_vi_for_tree (tree t)
+{
+ void **slot = pointer_map_contains (vi_for_tree, t);
+ if (slot == NULL)
+ return NULL;
+
+ return (varinfo_t) *slot;
+}
+
+/* Return a printable name for DECL */
+
+static const char *
+alias_get_name (tree decl)
+{
+ const char *res = get_name (decl);
+ char *temp;
+ int num_printed = 0;
+
+ if (res != NULL)
+ return res;
res = "NULL";
+ if (!dump_file)
+ return res;
+
if (TREE_CODE (decl) == SSA_NAME)
{
- num_printed = asprintf (&temp, "%s_%u",
+ num_printed = asprintf (&temp, "%s_%u",
alias_get_name (SSA_NAME_VAR (decl)),
SSA_NAME_VERSION (decl));
}
return res;
}
-/* Find the variable id for tree T in the hashtable.
- If T doesn't exist in the hash table, create an entry for it. */
+/* Find the variable id for tree T in the map.
+ If T doesn't exist in the map, create an entry for it and return it. */
-static unsigned int
-get_id_for_tree (tree t)
+static varinfo_t
+get_vi_for_tree (tree t)
{
- tree_id_t pair;
- struct tree_id finder;
+ void **slot = pointer_map_contains (vi_for_tree, t);
+ if (slot == NULL)
+ return get_varinfo (create_variable_info_for (t, alias_get_name (t)));
- finder.t = t;
- pair = htab_find (id_for_tree, &finder);
- if (pair == NULL)
- return create_variable_info_for (t, alias_get_name (t));
-
- return pair->id;
+ return (varinfo_t) *slot;
}
/* Get a constraint expression from an SSA_VAR_P node. */
/* For parameters, get at the points-to set for the actual parm
decl. */
- if (TREE_CODE (t) == SSA_NAME
- && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL
- && default_def (SSA_NAME_VAR (t)) == t)
+ if (TREE_CODE (t) == SSA_NAME
+ && TREE_CODE (SSA_NAME_VAR (t)) == PARM_DECL
+ && SSA_NAME_IS_DEFAULT_DEF (t))
return get_constraint_exp_from_ssa_var (SSA_NAME_VAR (t));
cexpr.type = SCALAR;
-
- cexpr.var = get_id_for_tree (t);
+
+ cexpr.var = get_vi_for_tree (t)->id;
/* 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;
}
-
+
cexpr.offset = 0;
return cexpr;
}
{
struct constraint_expr rhs = t->rhs;
struct constraint_expr lhs = t->lhs;
-
+
gcc_assert (rhs.var < VEC_length (varinfo_t, varmap));
gcc_assert (lhs.var < VEC_length (varinfo_t, varmap));
+ if (lhs.type == DEREF)
+ get_varinfo (lhs.var)->directly_dereferenced = true;
+ if (rhs.type == DEREF)
+ get_varinfo (rhs.var)->directly_dereferenced = true;
+
+ if (!use_field_sensitive)
+ {
+ t->rhs.offset = 0;
+ t->lhs.offset = 0;
+ }
+
/* ANYTHING == ANYTHING is pointless. */
if (lhs.var == anything_id && rhs.var == anything_id)
return;
t->lhs = t->rhs;
t->rhs = rhs;
process_constraint (t);
- }
+ }
/* This can happen in our IR with things like n->a = *p */
else if (rhs.type == DEREF && lhs.type == DEREF && rhs.var != anything_id)
{
tree pointedtotype = TREE_TYPE (pointertype);
tree tmpvar = create_tmp_var_raw (pointedtotype, "doubledereftmp");
struct constraint_expr tmplhs = get_constraint_exp_from_ssa_var (tmpvar);
-
+
/* If this is an aggregate of known size, we should have passed
this off to do_structure_copy, and it should have broken it
up. */
- gcc_assert (!AGGREGATE_TYPE_P (pointedtotype)
+ gcc_assert (!AGGREGATE_TYPE_P (pointedtotype)
|| get_varinfo (rhs.var)->is_unknown_size_var);
-
+
process_constraint (new_constraint (tmplhs, rhs));
process_constraint (new_constraint (lhs, tmplhs));
}
- else if (rhs.type == ADDRESSOF)
- {
- varinfo_t vi;
- gcc_assert (rhs.offset == 0);
-
- for (vi = get_varinfo (rhs.var); vi != NULL; vi = vi->next)
- vi->address_taken = true;
-
- VEC_safe_push (constraint_t, heap, constraints, t);
- }
else
{
- if (lhs.type != DEREF && rhs.type == DEREF)
- get_varinfo (lhs.var)->indirect_target = true;
+ gcc_assert (rhs.type != ADDRESSOF || rhs.offset == 0);
VEC_safe_push (constraint_t, heap, constraints, t);
}
}
+/* Return true if T is a variable of a type that could contain
+ pointers. */
+
+static bool
+could_have_pointers (tree t)
+{
+ tree type = TREE_TYPE (t);
+
+ if (POINTER_TYPE_P (type)
+ || AGGREGATE_TYPE_P (type)
+ || TREE_CODE (type) == COMPLEX_TYPE)
+ return true;
+
+ return false;
+}
/* Return the position, in bits, of FIELD_DECL from the beginning of its
structure. */
if (TREE_CODE (DECL_FIELD_OFFSET (fdecl)) != INTEGER_CST
|| TREE_CODE (DECL_FIELD_BIT_OFFSET (fdecl)) != INTEGER_CST)
return -1;
-
- return (tree_low_cst (DECL_FIELD_OFFSET (fdecl), 1) * 8)
- + tree_low_cst (DECL_FIELD_BIT_OFFSET (fdecl), 1);
+
+ return (tree_low_cst (DECL_FIELD_OFFSET (fdecl), 1) * 8)
+ + tree_low_cst (DECL_FIELD_BIT_OFFSET (fdecl), 1);
}
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, bool *need_anyoffset)
+static void
+get_constraint_for_component_ref (tree t, VEC(ce_s, heap) **results)
{
- struct constraint_expr result;
+ tree orig_t = t;
HOST_WIDE_INT bitsize = -1;
+ HOST_WIDE_INT bitmaxsize = -1;
HOST_WIDE_INT bitpos;
- tree offset = NULL_TREE;
- enum machine_mode mode;
- int unsignedp;
- int volatilep;
tree forzero;
-
- result.offset = 0;
- result.type = SCALAR;
- result.var = 0;
+ struct constraint_expr *result;
+ unsigned int beforelength = VEC_length (ce_s, *results);
/* Some people like to do cute things like take the address of
&0->a.b */
forzero = t;
while (!SSA_VAR_P (forzero) && !CONSTANT_CLASS_P (forzero))
- forzero = TREE_OPERAND (forzero, 0);
+ forzero = TREE_OPERAND (forzero, 0);
- if (CONSTANT_CLASS_P (forzero) && integer_zerop (forzero))
+ if (CONSTANT_CLASS_P (forzero) && integer_zerop (forzero))
{
- result.offset = 0;
- result.var = integer_id;
- result.type = SCALAR;
- return result;
+ struct constraint_expr temp;
+
+ temp.offset = 0;
+ temp.var = integer_id;
+ temp.type = SCALAR;
+ VEC_safe_push (ce_s, heap, *results, &temp);
+ return;
}
-
- t = get_inner_reference (t, &bitsize, &bitpos, &offset, &mode,
- &unsignedp, &volatilep, false);
- 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.type = SCALAR;
-
- /* If we know where this goes, then yay. Otherwise, booo. */
+ t = get_ref_base_and_extent (t, &bitpos, &bitsize, &bitmaxsize);
- if (offset == NULL && bitsize != -1)
- {
- result.offset = bitpos;
- }
- else if (need_anyoffset)
- {
- result.offset = 0;
- *need_anyoffset = true;
- }
- else
- {
- result.var = anything_id;
- result.offset = 0;
- }
+ /* String constants are readonly, so there is nothing to really do
+ here. */
+ if (TREE_CODE (t) == STRING_CST)
+ return;
+
+ get_constraint_for (t, results);
+ result = VEC_last (ce_s, *results);
+ result->offset = bitpos;
+
+ gcc_assert (beforelength + 1 == VEC_length (ce_s, *results));
+
+ /* This can also happen due to weird offsetof type macros. */
+ if (TREE_CODE (t) != ADDR_EXPR && result->type == ADDRESSOF)
+ result->type = SCALAR;
- if (result.type == SCALAR)
+ if (result->type == SCALAR)
{
/* In languages like C, you can access one past the end of an
array. You aren't allowed to dereference it, so we can
ignore this constraint. When we handle pointer subtraction,
we may have to do something cute here. */
-
- if (result.offset < get_varinfo (result.var)->fullsize)
+
+ if (result->offset < get_varinfo (result->var)->fullsize
+ && bitmaxsize != 0)
{
/* 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. */
+ walk to find it. */
varinfo_t curr;
- for (curr = get_varinfo (result.var); curr; curr = curr->next)
+ for (curr = get_varinfo (result->var); curr; curr = curr->next)
{
if (offset_overlaps_with_access (curr->offset, curr->size,
- result.offset, bitsize))
+ result->offset, bitmaxsize))
{
- result.var = curr->id;
+ result->var = curr->id;
break;
-
}
}
/* assert that we found *some* field there. The user couldn't be
accessing *only* padding. */
-
- gcc_assert (curr);
+ /* Still the user could access one past the end of an array
+ embedded in a struct resulting in accessing *only* padding. */
+ gcc_assert (curr || ref_contains_array_ref (orig_t));
+ }
+ else if (bitmaxsize == 0)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Access to zero-sized part of variable,"
+ "ignoring\n");
}
else
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "Access to past the end of variable, ignoring\n");
- result.offset = 0;
+ result->offset = 0;
}
-
- return result;
}
DEREF (DEREF) = (temp = DEREF1; result = DEREF(temp))
This is needed so that we can handle dereferencing DEREF constraints. */
-static struct constraint_expr
-do_deref (struct constraint_expr cons)
+static void
+do_deref (VEC (ce_s, heap) **constraints)
{
- if (cons.type == SCALAR)
- {
- cons.type = DEREF;
- return cons;
- }
- else if (cons.type == ADDRESSOF)
- {
- cons.type = SCALAR;
- return cons;
- }
- else if (cons.type == DEREF)
+ struct constraint_expr *c;
+ unsigned int i = 0;
+
+ for (i = 0; VEC_iterate (ce_s, *constraints, i, c); i++)
{
- tree tmpvar = create_tmp_var_raw (ptr_type_node, "derefmp");
- struct constraint_expr tmplhs = get_constraint_exp_from_ssa_var (tmpvar);
- process_constraint (new_constraint (tmplhs, cons));
- cons.var = tmplhs.var;
- return cons;
+ if (c->type == SCALAR)
+ c->type = DEREF;
+ else if (c->type == ADDRESSOF)
+ c->type = SCALAR;
+ else if (c->type == DEREF)
+ {
+ tree tmpvar = create_tmp_var_raw (ptr_type_node, "dereftmp");
+ struct constraint_expr tmplhs = get_constraint_exp_from_ssa_var (tmpvar);
+ process_constraint (new_constraint (tmplhs, *c));
+ c->var = tmplhs.var;
+ }
+ else
+ gcc_unreachable ();
}
- gcc_unreachable ();
}
-
/* Given a tree T, return the constraint expression for it. */
-static struct constraint_expr
-get_constraint_for (tree t, bool *need_anyoffset)
+static void
+get_constraint_for (tree t, VEC (ce_s, heap) **results)
{
struct constraint_expr temp;
temp.var = integer_id;
temp.type = SCALAR;
temp.offset = 0;
- return temp;
+ VEC_safe_push (ce_s, heap, *results, &temp);
+ return;
}
else if (TREE_CODE (t) == INTEGER_CST
&& integer_zerop (t))
temp.var = nothing_id;
temp.type = ADDRESSOF;
temp.offset = 0;
- return temp;
+ VEC_safe_push (ce_s, heap, *results, &temp);
+ return;
}
switch (TREE_CODE_CLASS (TREE_CODE (t)))
{
case tcc_expression:
+ case tcc_vl_exp:
{
switch (TREE_CODE (t))
{
case ADDR_EXPR:
{
- temp = get_constraint_for (TREE_OPERAND (t, 0), need_anyoffset);
- if (temp.type == DEREF)
- temp.type = SCALAR;
- else
- temp.type = ADDRESSOF;
- return temp;
+ struct constraint_expr *c;
+ unsigned int i;
+ tree exp = TREE_OPERAND (t, 0);
+ tree pttype = TREE_TYPE (TREE_TYPE (t));
+
+ get_constraint_for (exp, results);
+
+ /* Make sure we capture constraints to all elements
+ of an array. */
+ if ((handled_component_p (exp)
+ && ref_contains_array_ref (exp))
+ || TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE)
+ {
+ struct constraint_expr *origrhs;
+ varinfo_t origvar;
+ struct constraint_expr tmp;
+
+ if (VEC_length (ce_s, *results) == 0)
+ return;
+
+ gcc_assert (VEC_length (ce_s, *results) == 1);
+ origrhs = VEC_last (ce_s, *results);
+ tmp = *origrhs;
+ VEC_pop (ce_s, *results);
+ origvar = get_varinfo (origrhs->var);
+ for (; origvar; origvar = origvar->next)
+ {
+ tmp.var = origvar->id;
+ VEC_safe_push (ce_s, heap, *results, &tmp);
+ }
+ }
+ else if (VEC_length (ce_s, *results) == 1
+ && (AGGREGATE_TYPE_P (pttype)
+ || TREE_CODE (pttype) == COMPLEX_TYPE))
+ {
+ struct constraint_expr *origrhs;
+ varinfo_t origvar;
+ struct constraint_expr tmp;
+
+ gcc_assert (VEC_length (ce_s, *results) == 1);
+ origrhs = VEC_last (ce_s, *results);
+ tmp = *origrhs;
+ VEC_pop (ce_s, *results);
+ origvar = get_varinfo (origrhs->var);
+ for (; origvar; origvar = origvar->next)
+ {
+ tmp.var = origvar->id;
+ VEC_safe_push (ce_s, heap, *results, &tmp);
+ }
+ }
+
+ for (i = 0; VEC_iterate (ce_s, *results, i, c); i++)
+ {
+ if (c->type == DEREF)
+ c->type = SCALAR;
+ else
+ c->type = ADDRESSOF;
+ }
+ return;
}
break;
case CALL_EXPR:
-
/* XXX: In interprocedural mode, if we didn't have the
body, we would need to do *each pointer argument =
&ANYTHING added. */
if (call_expr_flags (t) & (ECF_MALLOC | ECF_MAY_BE_ALLOCA))
{
varinfo_t vi;
- tree heapvar;
-
- heapvar = create_tmp_var_raw (ptr_type_node, "HEAP");
- DECL_EXTERNAL (heapvar) = 1;
- add_referenced_tmp_var (heapvar);
+ tree heapvar = heapvar_lookup (t);
+
+ if (heapvar == NULL)
+ {
+ heapvar = create_tmp_var_raw (ptr_type_node, "HEAP");
+ DECL_EXTERNAL (heapvar) = 1;
+ get_var_ann (heapvar)->is_heapvar = 1;
+ if (gimple_referenced_vars (cfun))
+ add_referenced_var (heapvar);
+ heapvar_insert (t, heapvar);
+ }
+
temp.var = create_variable_info_for (heapvar,
alias_get_name (heapvar));
-
+
vi = get_varinfo (temp.var);
vi->is_artificial_var = 1;
vi->is_heap_var = 1;
temp.type = ADDRESSOF;
temp.offset = 0;
- return temp;
+ VEC_safe_push (ce_s, heap, *results, &temp);
+ return;
+ }
+ else
+ {
+ temp.var = anything_id;
+ temp.type = SCALAR;
+ temp.offset = 0;
+ VEC_safe_push (ce_s, heap, *results, &temp);
+ return;
}
- /* FALLTHRU */
+ break;
default:
{
temp.type = ADDRESSOF;
temp.var = anything_id;
temp.offset = 0;
- return temp;
+ VEC_safe_push (ce_s, heap, *results, &temp);
+ return;
}
}
}
{
case INDIRECT_REF:
{
- temp = get_constraint_for (TREE_OPERAND (t, 0), need_anyoffset);
- temp = do_deref (temp);
- return temp;
+ get_constraint_for (TREE_OPERAND (t, 0), results);
+ do_deref (results);
+ return;
}
case ARRAY_REF:
+ case ARRAY_RANGE_REF:
case COMPONENT_REF:
- temp = get_constraint_for_component_ref (t, need_anyoffset);
- return temp;
+ get_constraint_for_component_ref (t, results);
+ return;
default:
{
temp.type = ADDRESSOF;
temp.var = anything_id;
temp.offset = 0;
- return temp;
+ VEC_safe_push (ce_s, heap, *results, &temp);
+ return;
}
}
}
case NON_LVALUE_EXPR:
{
tree op = TREE_OPERAND (t, 0);
-
+
/* 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, need_anyoffset);
+ {
+ get_constraint_for (op, results);
+ return;
+ }
/* FALLTHRU */
}
temp.type = ADDRESSOF;
temp.var = anything_id;
temp.offset = 0;
- return temp;
+ VEC_safe_push (ce_s, heap, *results, &temp);
+ return;
}
}
}
{
switch (TREE_CODE (t))
{
- case PHI_NODE:
- return get_constraint_for (PHI_RESULT (t), need_anyoffset);
+ case PHI_NODE:
+ {
+ get_constraint_for (PHI_RESULT (t), results);
+ return;
+ }
+ break;
case SSA_NAME:
- return get_constraint_exp_from_ssa_var (t);
+ {
+ struct constraint_expr temp;
+ temp = get_constraint_exp_from_ssa_var (t);
+ VEC_safe_push (ce_s, heap, *results, &temp);
+ return;
+ }
+ break;
default:
{
temp.type = ADDRESSOF;
temp.var = anything_id;
temp.offset = 0;
- return temp;
+ VEC_safe_push (ce_s, heap, *results, &temp);
+ return;
}
}
}
case tcc_declaration:
- return get_constraint_exp_from_ssa_var (t);
+ {
+ struct constraint_expr temp;
+ temp = get_constraint_exp_from_ssa_var (t);
+ VEC_safe_push (ce_s, heap, *results, &temp);
+ return;
+ }
default:
{
temp.type = ADDRESSOF;
temp.var = anything_id;
temp.offset = 0;
- return temp;
+ VEC_safe_push (ce_s, heap, *results, &temp);
+ return;
}
}
}
/* Handle the structure copy case where we have a simple structure copy
- between LHS and RHS that is of SIZE (in bits)
-
+ between LHS and RHS that is of SIZE (in bits)
+
For each field of the lhs variable (lhsfield)
For each field of the rhs variable at lhsfield.offset (rhsfield)
add the constraint lhsfield = rhsfield
struct constraint_expr temprhs = rhs;
unsigned HOST_WIDE_INT fieldoffset;
- templhs.var = p->id;
+ templhs.var = p->id;
q = get_varinfo (temprhs.var);
fieldoffset = p->offset - pstart;
q = first_vi_for_offset (q, q->offset + fieldoffset);
/* Handle the structure copy case where we have a structure copy between a
aggregate on the LHS and a dereference of a pointer on the RHS
- that is of SIZE (in bits)
-
+ that is of SIZE (in bits)
+
For each field of the lhs variable (lhsfield)
rhs.offset = lhsfield->offset
add the constraint lhsfield = rhs
if (templhs.type == SCALAR)
- templhs.var = p->id;
+ templhs.var = p->id;
else
templhs.offset = p->offset;
-
+
q = get_varinfo (temprhs.var);
- fieldoffset = p->offset - pstart;
+ fieldoffset = p->offset - pstart;
temprhs.offset += fieldoffset;
process_constraint (new_constraint (templhs, temprhs));
}
}
/* Handle the structure copy case where we have a structure copy
- between a aggregate on the RHS and a dereference of a pointer on
- the LHS that is of SIZE (in bits)
+ between an aggregate on the RHS and a dereference of a pointer on
+ the LHS that is of SIZE (in bits)
For each field of the rhs variable (rhsfield)
lhs.offset = rhsfield->offset
if (temprhs.type == SCALAR)
- temprhs.var = p->id;
+ temprhs.var = p->id;
else
temprhs.offset = p->offset;
-
+
q = get_varinfo (templhs.var);
- fieldoffset = p->offset - pstart;
+ fieldoffset = p->offset - pstart;
templhs.offset += fieldoffset;
process_constraint (new_constraint (templhs, temprhs));
}
/* 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.
+ into VAR, so that we treat those fields as a single variable.
We return the variable they were collapsed into. */
static unsigned int
for (field = currvar->next; field; field = field->next)
{
if (dump_file)
- fprintf (dump_file, "Type safety: Collapsing var %s into %s\n",
+ 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;
}
do_structure_copy (tree lhsop, tree rhsop)
{
struct constraint_expr lhs, rhs, tmp;
+ VEC (ce_s, heap) *lhsc = NULL, *rhsc = NULL;
varinfo_t p;
unsigned HOST_WIDE_INT lhssize;
unsigned HOST_WIDE_INT rhssize;
- lhs = get_constraint_for (lhsop, NULL);
- rhs = get_constraint_for (rhsop, NULL);
-
+ get_constraint_for (lhsop, &lhsc);
+ get_constraint_for (rhsop, &rhsc);
+ gcc_assert (VEC_length (ce_s, lhsc) == 1);
+ gcc_assert (VEC_length (ce_s, rhsc) == 1);
+ lhs = *(VEC_last (ce_s, lhsc));
+ rhs = *(VEC_last (ce_s, rhsc));
+
+ VEC_free (ce_s, heap, lhsc);
+ VEC_free (ce_s, heap, rhsc);
+
/* If we have special var = x, swap it around. */
if (lhs.var <= integer_id && !(get_varinfo (rhs.var)->is_special_var))
{
lhs = rhs;
rhs = tmp;
}
-
+
/* This is fairly conservative for the RHS == ADDRESSOF case, in that it's
possible it's something we could handle. However, most cases falling
into this are dealing with transparent unions, which are slightly
{
struct constraint_expr templhs = lhs;
struct constraint_expr temprhs = rhs;
+
if (templhs.type == SCALAR )
templhs.var = p->id;
else
{
tree rhstype = TREE_TYPE (rhsop);
tree lhstype = TREE_TYPE (lhsop);
- tree rhstypesize = TYPE_SIZE (rhstype);
- tree lhstypesize = TYPE_SIZE (lhstype);
+ tree rhstypesize;
+ tree lhstypesize;
+
+ lhstypesize = DECL_P (lhsop) ? DECL_SIZE (lhsop) : TYPE_SIZE (lhstype);
+ rhstypesize = DECL_P (rhsop) ? DECL_SIZE (rhsop) : TYPE_SIZE (rhstype);
/* If we have a variably sized types on the rhs or lhs, and a deref
constraint, add the constraint, lhsconstraint = &ANYTHING.
else
lhssize = TREE_INT_CST_LOW (lhstypesize);
-
- if (rhs.type == SCALAR && lhs.type == SCALAR)
+
+ if (rhs.type == SCALAR && lhs.type == SCALAR)
{
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;
else
{
tree pointedtotype = lhstype;
- tree tmpvar;
+ tree tmpvar;
gcc_assert (rhs.type == DEREF && lhs.type == DEREF);
tmpvar = create_tmp_var_raw (pointedtotype, "structcopydereftmp");
}
}
+
/* 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
bitmap addr_taken;
use_operand_p use_p;
ssa_op_iter iter;
- bool stmt_escapes_p = is_escape_site (stmt, ai);
- tree op;
+ bool stmt_dereferences_ptr_p;
+ enum escape_type stmt_escape_type = is_escape_site (stmt);
+ struct mem_ref_stats_d *mem_ref_stats = gimple_mem_ref_stats (cfun);
+
+ stmt_dereferences_ptr_p = false;
+
+ if (stmt_escape_type == ESCAPE_TO_CALL
+ || stmt_escape_type == ESCAPE_TO_PURE_CONST)
+ {
+ mem_ref_stats->num_call_sites++;
+ if (stmt_escape_type == ESCAPE_TO_PURE_CONST)
+ mem_ref_stats->num_pure_const_call_sites++;
+ }
+ else if (stmt_escape_type == ESCAPE_TO_ASM)
+ mem_ref_stats->num_asm_sites++;
/* Mark all the variables whose address are taken by the statement. */
addr_taken = addresses_taken (stmt);
if (addr_taken)
{
- bitmap_ior_into (addressable_vars, addr_taken);
+ bitmap_ior_into (gimple_addressable_vars (cfun), addr_taken);
/* If STMT is an escape point, all the addresses taken by it are
call-clobbered. */
- if (stmt_escapes_p)
+ if (stmt_escape_type != NO_ESCAPE)
{
bitmap_iterator bi;
unsigned i;
EXECUTE_IF_SET_IN_BITMAP (addr_taken, 0, i, bi)
- mark_call_clobbered (referenced_var (i));
+ {
+ tree rvar = referenced_var (i);
+ if (!unmodifiable_var_p (rvar))
+ mark_call_clobbered (rvar, stmt_escape_type);
+ }
}
}
- /* 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. */
+ /* Process each operand use. 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;
+ unsigned num_uses, num_loads, num_stores;
op = USE_FROM_PTR (use_p);
to the set of addressable variables. */
if (TREE_CODE (op) == ADDR_EXPR)
{
+ bitmap addressable_vars = gimple_addressable_vars (cfun);
+
gcc_assert (TREE_CODE (stmt) == PHI_NODE);
+ gcc_assert (addressable_vars);
/* PHI nodes don't have annotations for pinning the set
of addresses taken, so we collect them here.
continue;
}
- /* Ignore constants. */
+ /* Ignore constants (they may occur in PHI node arguments). */
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);
+ /* The base variable of an SSA name must be a GIMPLE register, and thus
+ it cannot be aliased. */
+ gcc_assert (!may_be_aliased (var));
/* We are only interested in pointers. */
if (!POINTER_TYPE_P (TREE_TYPE (op)))
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);
+ VEC_safe_push (tree, heap, ai->processed_ptrs, op);
}
/* If STMT is a PHI node, then it will not have pointer
/* 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);
+ count_uses_and_derefs (op, stmt, &num_uses, &num_loads, &num_stores);
/* Handle a corner case involving address expressions of the
form '&PTR->FLD'. The problem with these expressions is that
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.
+ memory operations will receive no VDEF/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
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 (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT
+ && TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 1)) == ADDR_EXPR
+ && !is_gimple_val (GIMPLE_STMT_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 rhs = GIMPLE_STMT_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;
+ num_loads++;
}
- if (num_derefs > 0 || is_potential_deref)
+ if (num_loads + num_stores > 0)
{
/* Mark OP as dereferenced. In a subsequent pass,
dereferenced pointers that point to a set of
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));
+ if (num_stores > 0)
+ pointer_set_insert (ai->dereferenced_ptrs_store, var);
else
- bitmap_set_bit (ai->dereferenced_ptrs_load, DECL_UID (var));
+ pointer_set_insert (ai->dereferenced_ptrs_load, var);
+
+ /* Update the frequency estimate for all the dereferences of
+ pointer OP. */
+ update_mem_sym_stats_from_stmt (op, stmt, num_loads, num_stores);
+
+ /* Indicate that STMT contains pointer dereferences. */
+ stmt_dereferences_ptr_p = true;
}
- if (stmt_escapes_p && num_derefs < num_uses)
+ if (stmt_escape_type != NO_ESCAPE && num_loads + num_stores < 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;
+ pi->escape_mask |= stmt_escape_type;
/* 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))
+ if (get_call_expr_in (stmt)
+ || stmt_escape_type == ESCAPE_STORED_IN_GLOBAL)
{
- bitmap_set_bit (ai->dereferenced_ptrs_store, DECL_UID (var));
+ pointer_set_insert (ai->dereferenced_ptrs_store, 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)
+ /* Mark stored variables in STMT as being written to and update the
+ memory reference stats for all memory symbols referenced by STMT. */
+ if (stmt_references_memory_p (stmt))
{
- 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));
+ unsigned i;
+ bitmap_iterator bi;
+
+ mem_ref_stats->num_mem_stmts++;
+
+ /* Notice that we only update memory reference stats for symbols
+ loaded and stored by the statement if the statement does not
+ contain pointer dereferences and it is not a call/asm site.
+ This is to avoid double accounting problems when creating
+ memory partitions. After computing points-to information,
+ pointer dereference statistics are used to update the
+ reference stats of the pointed-to variables, so here we
+ should only update direct references to symbols.
+
+ Indirect references are not updated here for two reasons: (1)
+ The first time we compute alias information, the sets
+ LOADED/STORED are empty for pointer dereferences, (2) After
+ partitioning, LOADED/STORED may have references to
+ partitions, not the original pointed-to variables. So, if we
+ always counted LOADED/STORED here and during partitioning, we
+ would count many symbols more than once.
+
+ This does cause some imprecision when a statement has a
+ combination of direct symbol references and pointer
+ dereferences (e.g., MEMORY_VAR = *PTR) or if a call site has
+ memory symbols in its argument list, but these cases do not
+ occur so frequently as to constitute a serious problem. */
+ if (STORED_SYMS (stmt))
+ EXECUTE_IF_SET_IN_BITMAP (STORED_SYMS (stmt), 0, i, bi)
+ {
+ tree sym = referenced_var (i);
+ pointer_set_insert (ai->written_vars, sym);
+ if (!stmt_dereferences_ptr_p
+ && stmt_escape_type != ESCAPE_TO_CALL
+ && stmt_escape_type != ESCAPE_TO_PURE_CONST
+ && stmt_escape_type != ESCAPE_TO_ASM)
+ update_mem_sym_stats_from_stmt (sym, stmt, 0, 1);
+ }
+
+ if (!stmt_dereferences_ptr_p
+ && LOADED_SYMS (stmt)
+ && stmt_escape_type != ESCAPE_TO_CALL
+ && stmt_escape_type != ESCAPE_TO_PURE_CONST
+ && stmt_escape_type != ESCAPE_TO_ASM)
+ EXECUTE_IF_SET_IN_BITMAP (LOADED_SYMS (stmt), 0, i, bi)
+ update_mem_sym_stats_from_stmt (referenced_var (i), stmt, 1, 0);
}
}
separate constraint by the caller. */
static bool
-handle_ptr_arith (struct constraint_expr lhs, tree expr)
+handle_ptr_arith (VEC (ce_s, heap) *lhsc, tree expr)
{
tree op0, op1;
- struct constraint_expr base, offset;
+ struct constraint_expr *c, *c2;
+ unsigned int i = 0;
+ unsigned int j = 0;
+ VEC (ce_s, heap) *temp = NULL;
+ unsigned HOST_WIDE_INT rhsoffset = 0;
- if (TREE_CODE (expr) != PLUS_EXPR)
+ if (TREE_CODE (expr) != POINTER_PLUS_EXPR)
return false;
op0 = TREE_OPERAND (expr, 0);
op1 = TREE_OPERAND (expr, 1);
+ gcc_assert (POINTER_TYPE_P (TREE_TYPE (op0)));
- base = get_constraint_for (op0, NULL);
+ get_constraint_for (op0, &temp);
- offset.var = anyoffset_id;
- offset.type = ADDRESSOF;
- offset.offset = 0;
+ /* We can only handle positive offsets that do not overflow
+ if we multiply it by BITS_PER_UNIT. */
+ if (host_integerp (op1, 1))
+ {
+ rhsoffset = TREE_INT_CST_LOW (op1) * BITS_PER_UNIT;
- process_constraint (new_constraint (lhs, base));
- process_constraint (new_constraint (lhs, offset));
+ if (rhsoffset / BITS_PER_UNIT != TREE_INT_CST_LOW (op1))
+ return false;
+ }
+
+ for (i = 0; VEC_iterate (ce_s, lhsc, i, c); i++)
+ for (j = 0; VEC_iterate (ce_s, temp, j, c2); j++)
+ {
+ if (c2->type == ADDRESSOF && rhsoffset != 0)
+ {
+ varinfo_t temp = get_varinfo (c2->var);
+
+ /* An access one after the end of an array is valid,
+ so simply punt on accesses we cannot resolve. */
+ temp = first_vi_for_offset (temp, rhsoffset);
+ if (temp == NULL)
+ continue;
+ c2->var = temp->id;
+ c2->offset = 0;
+ }
+ else
+ c2->offset = rhsoffset;
+ process_constraint (new_constraint (*c, *c2));
+ }
+
+ VEC_free (ce_s, heap, temp);
return true;
}
when building alias sets and computing alias grouping heuristics. */
static void
-find_func_aliases (tree t, struct alias_info *ai)
+find_func_aliases (tree origt)
{
- struct constraint_expr lhs, rhs;
+ tree t = origt;
+ VEC(ce_s, heap) *lhsc = NULL;
+ VEC(ce_s, heap) *rhsc = NULL;
+ struct constraint_expr *c;
- /* 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);
+ if (TREE_CODE (t) == RETURN_EXPR && TREE_OPERAND (t, 0))
+ t = TREE_OPERAND (t, 0);
/* Now build constraints expressions. */
if (TREE_CODE (t) == PHI_NODE)
{
+ gcc_assert (!AGGREGATE_TYPE_P (TREE_TYPE (PHI_RESULT (t))));
+
/* 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))))
+ if (could_have_pointers (PHI_RESULT (t)))
{
int i;
+ unsigned int j;
- lhs = get_constraint_for (PHI_RESULT (t), NULL);
+ /* For a phi node, assign all the arguments to
+ the result. */
+ get_constraint_for (PHI_RESULT (t), &lhsc);
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));
+ tree rhstype;
+ tree strippedrhs = PHI_ARG_DEF (t, i);
+
+ STRIP_NOPS (strippedrhs);
+ rhstype = TREE_TYPE (strippedrhs);
+ get_constraint_for (PHI_ARG_DEF (t, i), &rhsc);
+
+ for (j = 0; VEC_iterate (ce_s, lhsc, j, c); j++)
+ {
+ struct constraint_expr *c2;
+ while (VEC_length (ce_s, rhsc) > 0)
+ {
+ c2 = VEC_last (ce_s, rhsc);
+ process_constraint (new_constraint (*c, *c2));
+ VEC_pop (ce_s, rhsc);
+ }
+ }
}
}
}
- else if (TREE_CODE (t) == MODIFY_EXPR)
+ /* In IPA mode, we need to generate constraints to pass call
+ arguments through their calls. There are two cases, either a
+ GIMPLE_MODIFY_STMT when we are returning a value, or just a plain
+ CALL_EXPR when we are not. */
+ else if (in_ipa_mode
+ && ((TREE_CODE (t) == GIMPLE_MODIFY_STMT
+ && TREE_CODE (GIMPLE_STMT_OPERAND (t, 1)) == CALL_EXPR
+ && !(call_expr_flags (GIMPLE_STMT_OPERAND (t, 1))
+ & (ECF_MALLOC | ECF_MAY_BE_ALLOCA)))
+ || (TREE_CODE (t) == CALL_EXPR
+ && !(call_expr_flags (t)
+ & (ECF_MALLOC | ECF_MAY_BE_ALLOCA)))))
{
- tree lhsop = TREE_OPERAND (t, 0);
- tree rhsop = TREE_OPERAND (t, 1);
- int i;
+ tree lhsop;
+ tree rhsop;
+ tree arg;
+ call_expr_arg_iterator iter;
+ varinfo_t fi;
+ int i = 1;
+ tree decl;
+ if (TREE_CODE (t) == GIMPLE_MODIFY_STMT)
+ {
+ lhsop = GIMPLE_STMT_OPERAND (t, 0);
+ rhsop = GIMPLE_STMT_OPERAND (t, 1);
+ }
+ else
+ {
+ lhsop = NULL;
+ rhsop = t;
+ }
+ decl = get_callee_fndecl (rhsop);
+
+ /* If we can directly resolve the function being called, do so.
+ Otherwise, it must be some sort of indirect expression that
+ we should still be able to handle. */
+ if (decl)
+ {
+ fi = get_vi_for_tree (decl);
+ }
+ else
+ {
+ decl = CALL_EXPR_FN (rhsop);
+ fi = get_vi_for_tree (decl);
+ }
+
+ /* Assign all the passed arguments to the appropriate incoming
+ parameters of the function. */
+
+ FOR_EACH_CALL_EXPR_ARG (arg, iter, rhsop)
+ {
+ struct constraint_expr lhs ;
+ struct constraint_expr *rhsp;
+
+ get_constraint_for (arg, &rhsc);
+ if (TREE_CODE (decl) != FUNCTION_DECL)
+ {
+ lhs.type = DEREF;
+ lhs.var = fi->id;
+ lhs.offset = i;
+ }
+ else
+ {
+ lhs.type = SCALAR;
+ lhs.var = first_vi_for_offset (fi, i)->id;
+ lhs.offset = 0;
+ }
+ while (VEC_length (ce_s, rhsc) != 0)
+ {
+ rhsp = VEC_last (ce_s, rhsc);
+ process_constraint (new_constraint (lhs, *rhsp));
+ VEC_pop (ce_s, rhsc);
+ }
+ i++;
+ }
+
+ /* If we are returning a value, assign it to the result. */
+ if (lhsop)
+ {
+ struct constraint_expr rhs;
+ struct constraint_expr *lhsp;
+ unsigned int j = 0;
- if (AGGREGATE_TYPE_P (TREE_TYPE (lhsop))
- && AGGREGATE_TYPE_P (TREE_TYPE (rhsop)))
+ get_constraint_for (lhsop, &lhsc);
+ if (TREE_CODE (decl) != FUNCTION_DECL)
+ {
+ rhs.type = DEREF;
+ rhs.var = fi->id;
+ rhs.offset = i;
+ }
+ else
+ {
+ rhs.type = SCALAR;
+ rhs.var = first_vi_for_offset (fi, i)->id;
+ rhs.offset = 0;
+ }
+ for (j = 0; VEC_iterate (ce_s, lhsc, j, lhsp); j++)
+ process_constraint (new_constraint (*lhsp, rhs));
+ }
+ }
+ /* Otherwise, just a regular assignment statement. */
+ else if (TREE_CODE (t) == GIMPLE_MODIFY_STMT)
+ {
+ tree lhsop = GIMPLE_STMT_OPERAND (t, 0);
+ tree rhsop = GIMPLE_STMT_OPERAND (t, 1);
+ int i;
+
+ if ((AGGREGATE_TYPE_P (TREE_TYPE (lhsop))
+ || TREE_CODE (TREE_TYPE (lhsop)) == COMPLEX_TYPE)
+ && (AGGREGATE_TYPE_P (TREE_TYPE (rhsop))
+ || TREE_CODE (TREE_TYPE (lhsop)) == COMPLEX_TYPE))
{
do_structure_copy (lhsop, rhsop);
}
{
/* 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))
+ if (could_have_pointers (lhsop)
|| TREE_CODE (rhsop) == CALL_EXPR)
{
- lhs = get_constraint_for (lhsop, NULL);
+ get_constraint_for (lhsop, &lhsc);
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. */
+ handled directly by get_constraint_for. */
case tcc_reference:
case tcc_declaration:
case tcc_constant:
case tcc_exceptional:
case tcc_expression:
+ case tcc_vl_exp:
case tcc_unary:
{
- 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)))))
+ unsigned int j;
+
+ get_constraint_for (rhsop, &rhsc);
+ for (j = 0; VEC_iterate (ce_s, lhsc, j, c); j++)
{
- rhs.var = anyoffset_id;
- rhs.type = ADDRESSOF;
- rhs.offset = 0;
- process_constraint (new_constraint (lhs, rhs));
+ struct constraint_expr *c2;
+ unsigned int k;
+
+ for (k = 0; VEC_iterate (ce_s, rhsc, k, c2); k++)
+ process_constraint (new_constraint (*c, *c2));
}
+
}
break;
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))
+ if (handle_ptr_arith (lhsc, rhsop))
break;
}
/* FALLTHRU */
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++)
+ for (i = 0; i < TREE_OPERAND_LENGTH (rhsop); i++)
{
tree op = TREE_OPERAND (rhsop, i);
- rhs = get_constraint_for (op, NULL);
- process_constraint (new_constraint (lhs, rhs));
+ unsigned int j;
+
+ gcc_assert (VEC_length (ce_s, rhsc) == 0);
+ get_constraint_for (op, &rhsc);
+ for (j = 0; VEC_iterate (ce_s, lhsc, j, c); j++)
+ {
+ struct constraint_expr *c2;
+ while (VEC_length (ce_s, rhsc) > 0)
+ {
+ c2 = VEC_last (ce_s, rhsc);
+ process_constraint (new_constraint (*c, *c2));
+ VEC_pop (ce_s, rhsc);
+ }
+ }
}
- }
+ }
}
}
}
+ else if (TREE_CODE (t) == CHANGE_DYNAMIC_TYPE_EXPR)
+ {
+ unsigned int j;
+
+ get_constraint_for (CHANGE_DYNAMIC_TYPE_LOCATION (t), &lhsc);
+ for (j = 0; VEC_iterate (ce_s, lhsc, j, c); ++j)
+ get_varinfo (c->var)->no_tbaa_pruning = true;
+ }
/* 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);
+ mark_stmt_modified (origt);
+ VEC_free (ce_s, heap, rhsc);
+ VEC_free (ce_s, heap, lhsc);
}
first field that overlaps with OFFSET.
Return NULL if we can't find one. */
-static varinfo_t
+static varinfo_t
first_vi_for_offset (varinfo_t start, unsigned HOST_WIDE_INT offset)
{
varinfo_t curr = start;
}
+/* Insert the varinfo FIELD into the field list for BASE, at the front
+ of the list. */
+
+static void
+insert_into_field_list (varinfo_t base, varinfo_t field)
+{
+ varinfo_t prev = base;
+ varinfo_t curr = base->next;
+
+ field->next = curr;
+ prev->next = field;
+}
+
/* Insert the varinfo FIELD into the field list for BASE, ordered by
offset. */
static void
-insert_into_field_list (varinfo_t base, varinfo_t field)
+insert_into_field_list_sorted (varinfo_t base, varinfo_t field)
{
varinfo_t prev = base;
varinfo_t curr = base->next;
-
+
if (curr == NULL)
{
prev->next = field;
/* qsort comparison function for two fieldoff's PA and PB */
-static int
+static int
fieldoff_compare (const void *pa, const void *pb)
{
const fieldoff_s *foa = (const fieldoff_s *)pa;
const fieldoff_s *fob = (const fieldoff_s *)pb;
HOST_WIDE_INT foasize, fobsize;
-
+
if (foa->offset != fob->offset)
return foa->offset - fob->offset;
- foasize = TREE_INT_CST_LOW (DECL_SIZE (foa->field));
- fobsize = TREE_INT_CST_LOW (DECL_SIZE (fob->field));
+ foasize = TREE_INT_CST_LOW (foa->size);
+ fobsize = TREE_INT_CST_LOW (fob->size);
return foasize - fobsize;
}
/* Sort a fieldstack according to the field offset and sizes. */
-void sort_fieldstack (VEC(fieldoff_s,heap) *fieldstack)
+void
+sort_fieldstack (VEC(fieldoff_s,heap) *fieldstack)
{
- qsort (VEC_address (fieldoff_s, fieldstack),
- VEC_length (fieldoff_s, fieldstack),
+ qsort (VEC_address (fieldoff_s, fieldstack),
+ VEC_length (fieldoff_s, fieldstack),
sizeof (fieldoff_s),
fieldoff_compare);
}
than just the immediately containing structure. Returns the number
of fields pushed.
HAS_UNION is set to true if we find a union type as a field of
- TYPE. */
+ TYPE. ADDRESSABLE_TYPE is the type of the outermost object that could have
+ its address taken. */
int
-push_fields_onto_fieldstack (tree type, VEC(fieldoff_s,heap) **fieldstack,
- HOST_WIDE_INT offset, bool *has_union)
+push_fields_onto_fieldstack (tree type, VEC(fieldoff_s,heap) **fieldstack,
+ HOST_WIDE_INT offset, bool *has_union,
+ tree addressable_type)
{
tree field;
int count = 0;
+ if (TREE_CODE (type) == COMPLEX_TYPE)
+ {
+ fieldoff_s *real_part, *img_part;
+ real_part = VEC_safe_push (fieldoff_s, heap, *fieldstack, NULL);
+ real_part->type = TREE_TYPE (type);
+ real_part->size = TYPE_SIZE (TREE_TYPE (type));
+ real_part->offset = offset;
+ real_part->decl = NULL_TREE;
+ real_part->alias_set = -1;
+
+ img_part = VEC_safe_push (fieldoff_s, heap, *fieldstack, NULL);
+ img_part->type = TREE_TYPE (type);
+ img_part->size = TYPE_SIZE (TREE_TYPE (type));
+ img_part->offset = offset + TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (type)));
+ img_part->decl = NULL_TREE;
+ img_part->alias_set = -1;
+
+ return 2;
+ }
+
+ if (TREE_CODE (type) == ARRAY_TYPE)
+ {
+ tree sz = TYPE_SIZE (type);
+ tree elsz = TYPE_SIZE (TREE_TYPE (type));
+ HOST_WIDE_INT nr;
+ int i;
+
+ if (! sz
+ || ! host_integerp (sz, 1)
+ || TREE_INT_CST_LOW (sz) == 0
+ || ! elsz
+ || ! host_integerp (elsz, 1)
+ || TREE_INT_CST_LOW (elsz) == 0)
+ return 0;
+
+ nr = TREE_INT_CST_LOW (sz) / TREE_INT_CST_LOW (elsz);
+ if (nr > SALIAS_MAX_ARRAY_ELEMENTS)
+ return 0;
+
+ for (i = 0; i < nr; ++i)
+ {
+ bool push = false;
+ int pushed = 0;
+
+ if (has_union
+ && (TREE_CODE (TREE_TYPE (type)) == QUAL_UNION_TYPE
+ || TREE_CODE (TREE_TYPE (type)) == UNION_TYPE))
+ *has_union = true;
+
+ if (!AGGREGATE_TYPE_P (TREE_TYPE (type))) /* var_can_have_subvars */
+ push = true;
+ else if (!(pushed = push_fields_onto_fieldstack
+ (TREE_TYPE (type), fieldstack,
+ offset + i * TREE_INT_CST_LOW (elsz), has_union,
+ TREE_TYPE (type))))
+ /* Empty structures may have actual size, like in C++. So
+ see if we didn't push any subfields and the size is
+ nonzero, push the field onto the stack */
+ push = true;
+
+ if (push)
+ {
+ fieldoff_s *pair;
+
+ pair = VEC_safe_push (fieldoff_s, heap, *fieldstack, NULL);
+ pair->type = TREE_TYPE (type);
+ pair->size = elsz;
+ pair->decl = NULL_TREE;
+ pair->offset = offset + i * TREE_INT_CST_LOW (elsz);
+ pair->alias_set = -1;
+ count++;
+ }
+ else
+ count += pushed;
+ }
+
+ return count;
+ }
+
for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
if (TREE_CODE (field) == FIELD_DECL)
{
bool push = false;
int pushed = 0;
-
- if (has_union
+
+ if (has_union
&& (TREE_CODE (TREE_TYPE (field)) == QUAL_UNION_TYPE
|| TREE_CODE (TREE_TYPE (field)) == UNION_TYPE))
*has_union = true;
-
+
if (!var_can_have_subvars (field))
push = true;
else if (!(pushed = push_fields_onto_fieldstack
(TREE_TYPE (field), fieldstack,
- offset + bitpos_of_field (field), has_union))
+ offset + bitpos_of_field (field), has_union,
+ (DECL_NONADDRESSABLE_P (field)
+ ? addressable_type
+ : TREE_TYPE (field))))
&& DECL_SIZE (field)
&& !integer_zerop (DECL_SIZE (field)))
/* Empty structures may have actual size, like in C++. So
see if we didn't push any subfields and the size is
nonzero, push the field onto the stack */
push = true;
-
+
if (push)
{
fieldoff_s *pair;
pair = VEC_safe_push (fieldoff_s, heap, *fieldstack, NULL);
- pair->field = field;
+ pair->type = TREE_TYPE (field);
+ pair->size = DECL_SIZE (field);
+ pair->decl = field;
pair->offset = offset + bitpos_of_field (field);
+ if (DECL_NONADDRESSABLE_P (field))
+ pair->alias_set = get_alias_set (addressable_type);
+ else
+ pair->alias_set = -1;
count++;
}
else
return count;
}
+/* Create a constraint from ANYTHING variable to VI. */
static void
-make_constraint_to_anything (varinfo_t vi)
+make_constraint_from_anything (varinfo_t vi)
{
struct constraint_expr lhs, rhs;
-
+
lhs.var = vi->id;
lhs.offset = 0;
lhs.type = SCALAR;
-
+
rhs.var = anything_id;
- rhs.offset =0 ;
+ rhs.offset = 0;
rhs.type = ADDRESSOF;
process_constraint (new_constraint (lhs, rhs));
}
+/* Count the number of arguments DECL has, and set IS_VARARGS to true
+ if it is a varargs function. */
+
+static unsigned int
+count_num_arguments (tree decl, bool *is_varargs)
+{
+ unsigned int i = 0;
+ tree t;
+
+ for (t = TYPE_ARG_TYPES (TREE_TYPE (decl));
+ t;
+ t = TREE_CHAIN (t))
+ {
+ if (TREE_VALUE (t) == void_type_node)
+ break;
+ i++;
+ }
+
+ if (!t)
+ *is_varargs = true;
+ return i;
+}
+
+/* Creation function node for DECL, using NAME, and return the index
+ of the variable we've created for the function. */
+
+static unsigned int
+create_function_info_for (tree decl, const char *name)
+{
+ unsigned int index = VEC_length (varinfo_t, varmap);
+ varinfo_t vi;
+ tree arg;
+ unsigned int i;
+ bool is_varargs = false;
+
+ /* Create the variable info. */
+
+ vi = new_var_info (decl, index, name);
+ vi->decl = decl;
+ vi->offset = 0;
+ vi->has_union = 0;
+ vi->size = 1;
+ vi->fullsize = count_num_arguments (decl, &is_varargs) + 1;
+ insert_vi_for_tree (vi->decl, vi);
+ VEC_safe_push (varinfo_t, heap, varmap, vi);
+
+ stats.total_vars++;
+
+ /* If it's varargs, we don't know how many arguments it has, so we
+ can't do much.
+ */
+ if (is_varargs)
+ {
+ vi->fullsize = ~0;
+ vi->size = ~0;
+ vi->is_unknown_size_var = true;
+ return index;
+ }
+
+
+ arg = DECL_ARGUMENTS (decl);
+
+ /* Set up variables for each argument. */
+ for (i = 1; i < vi->fullsize; i++)
+ {
+ varinfo_t argvi;
+ const char *newname;
+ char *tempname;
+ unsigned int newindex;
+ tree argdecl = decl;
+
+ if (arg)
+ argdecl = arg;
+
+ newindex = VEC_length (varinfo_t, varmap);
+ asprintf (&tempname, "%s.arg%d", name, i-1);
+ newname = ggc_strdup (tempname);
+ free (tempname);
+
+ argvi = new_var_info (argdecl, newindex, newname);
+ argvi->decl = argdecl;
+ VEC_safe_push (varinfo_t, heap, varmap, argvi);
+ argvi->offset = i;
+ argvi->size = 1;
+ argvi->fullsize = vi->fullsize;
+ argvi->has_union = false;
+ insert_into_field_list_sorted (vi, argvi);
+ stats.total_vars ++;
+ if (arg)
+ {
+ insert_vi_for_tree (arg, argvi);
+ arg = TREE_CHAIN (arg);
+ }
+ }
+
+ /* Create a variable for the return var. */
+ if (DECL_RESULT (decl) != NULL
+ || !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl))))
+ {
+ varinfo_t resultvi;
+ const char *newname;
+ char *tempname;
+ unsigned int newindex;
+ tree resultdecl = decl;
+
+ vi->fullsize ++;
+
+ if (DECL_RESULT (decl))
+ resultdecl = DECL_RESULT (decl);
+
+ newindex = VEC_length (varinfo_t, varmap);
+ asprintf (&tempname, "%s.result", name);
+ newname = ggc_strdup (tempname);
+ free (tempname);
+
+ resultvi = new_var_info (resultdecl, newindex, newname);
+ resultvi->decl = resultdecl;
+ VEC_safe_push (varinfo_t, heap, varmap, resultvi);
+ resultvi->offset = i;
+ resultvi->size = 1;
+ resultvi->fullsize = vi->fullsize;
+ resultvi->has_union = false;
+ insert_into_field_list_sorted (vi, resultvi);
+ stats.total_vars ++;
+ if (DECL_RESULT (decl))
+ insert_vi_for_tree (DECL_RESULT (decl), resultvi);
+ }
+ return index;
+}
+
-/* Return true if FIELDSTACK contains fields that overlap.
+/* Return true if FIELDSTACK contains fields that overlap.
FIELDSTACK is assumed to be sorted by offset. */
static bool
unsigned int index = VEC_length (varinfo_t, varmap);
varinfo_t vi;
tree decltype = TREE_TYPE (decl);
+ tree declsize = DECL_P (decl) ? DECL_SIZE (decl) : TYPE_SIZE (decltype);
bool notokay = false;
bool hasunion;
bool is_global = DECL_P (decl) ? is_global_var (decl) : false;
VEC (fieldoff_s,heap) *fieldstack = NULL;
-
+
+ if (TREE_CODE (decl) == FUNCTION_DECL && in_ipa_mode)
+ return create_function_info_for (decl, name);
hasunion = TREE_CODE (decltype) == UNION_TYPE
- || TREE_CODE (decltype) == QUAL_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);
+ push_fields_onto_fieldstack (decltype, &fieldstack, 0, &hasunion,
+ decltype);
if (hasunion)
{
VEC_free (fieldoff_s, heap, fieldstack);
notokay = true;
- }
+ }
}
-
+
/* If the variable doesn't have subvars, we may end up needing to
sort the field list and create fake variables for all the
fields. */
- vi = new_var_info (decl, index, name, index);
+ vi = new_var_info (decl, index, name);
vi->decl = decl;
vi->offset = 0;
vi->has_union = hasunion;
- if (!TYPE_SIZE (decltype)
- || TREE_CODE (TYPE_SIZE (decltype)) != INTEGER_CST
- || TREE_CODE (decltype) == ARRAY_TYPE
+ if (!declsize
+ || TREE_CODE (declsize) != INTEGER_CST
|| TREE_CODE (decltype) == UNION_TYPE
|| TREE_CODE (decltype) == QUAL_UNION_TYPE)
{
}
else
{
- vi->fullsize = TREE_INT_CST_LOW (TYPE_SIZE (decltype));
+ vi->fullsize = TREE_INT_CST_LOW (declsize);
vi->size = vi->fullsize;
}
-
- insert_id_for_tree (vi->decl, index);
+
+ insert_vi_for_tree (vi->decl, vi);
VEC_safe_push (varinfo_t, heap, varmap, vi);
- if (is_global)
- make_constraint_to_anything (vi);
+ if (is_global && (!flag_whole_program || !in_ipa_mode))
+ make_constraint_from_anything (vi);
stats.total_vars++;
- if (use_field_sensitive
- && !notokay
- && !vi->is_unknown_size_var
- && var_can_have_subvars (decl))
+ if (use_field_sensitive
+ && !notokay
+ && !vi->is_unknown_size_var
+ && var_can_have_subvars (decl)
+ && VEC_length (fieldoff_s, fieldstack) <= MAX_FIELDS_FOR_FIELD_SENSITIVE)
{
unsigned int newindex = VEC_length (varinfo_t, varmap);
fieldoff_s *fo = NULL;
unsigned int i;
- tree field;
for (i = 0; !notokay && VEC_iterate (fieldoff_s, fieldstack, i, fo); i++)
{
- if (!DECL_SIZE (fo->field)
- || TREE_CODE (DECL_SIZE (fo->field)) != INTEGER_CST
- || TREE_CODE (TREE_TYPE (fo->field)) == ARRAY_TYPE
+ if (! fo->size
+ || TREE_CODE (fo->size) != INTEGER_CST
|| fo->offset < 0)
{
notokay = true;
without creating varinfos for the fields anyway, so sorting them is a
waste to boot. */
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,
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);
VEC_free (fieldoff_s, heap, fieldstack);
return index;
}
-
- field = fo->field;
- vi->size = TREE_INT_CST_LOW (DECL_SIZE (field));
+
+ vi->size = TREE_INT_CST_LOW (fo->size);
vi->offset = fo->offset;
- for (i = 1; VEC_iterate (fieldoff_s, fieldstack, i, fo); i++)
+ for (i = VEC_length (fieldoff_s, fieldstack) - 1;
+ i >= 1 && VEC_iterate (fieldoff_s, fieldstack, i, fo);
+ i--)
{
varinfo_t newvi;
- const char *newname;
+ const char *newname = "NULL";
char *tempname;
- field = fo->field;
newindex = VEC_length (varinfo_t, varmap);
- asprintf (&tempname, "%s.%s", vi->name, alias_get_name (field));
- newname = ggc_strdup (tempname);
- free (tempname);
- newvi = new_var_info (decl, newindex, newname, newindex);
+ if (dump_file)
+ {
+ if (fo->decl)
+ asprintf (&tempname, "%s.%s",
+ vi->name, alias_get_name (fo->decl));
+ else
+ asprintf (&tempname, "%s." HOST_WIDE_INT_PRINT_DEC,
+ vi->name, fo->offset);
+ newname = ggc_strdup (tempname);
+ free (tempname);
+ }
+ newvi = new_var_info (decl, newindex, newname);
newvi->offset = fo->offset;
- newvi->size = TREE_INT_CST_LOW (DECL_SIZE (field));
+ newvi->size = TREE_INT_CST_LOW (fo->size);
newvi->fullsize = vi->fullsize;
insert_into_field_list (vi, newvi);
VEC_safe_push (varinfo_t, heap, varmap, newvi);
- if (is_global)
- make_constraint_to_anything (newvi);
+ if (is_global && (!flag_whole_program || !in_ipa_mode))
+ make_constraint_from_anything (newvi);
- stats.total_vars++;
+ stats.total_vars++;
}
VEC_free (fieldoff_s, heap, fieldstack);
}
{
varinfo_t vi = get_varinfo (var);
unsigned int i;
- bitmap_iterator bi;
-
- fprintf (file, "%s = { ", vi->name);
- EXECUTE_IF_SET_IN_BITMAP (get_varinfo (vi->node)->solution, 0, i, bi)
+ bitmap_iterator bi;
+
+ if (find (var) != var)
{
- fprintf (file, "%s ", get_varinfo (i)->name);
+ varinfo_t vipt = get_varinfo (find (var));
+ fprintf (file, "%s = same as %s\n", vi->name, vipt->name);
+ }
+ else
+ {
+ fprintf (file, "%s = { ", vi->name);
+ EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
+ {
+ fprintf (file, "%s ", get_varinfo (i)->name);
+ }
+ fprintf (file, "}");
+ if (vi->no_tbaa_pruning)
+ fprintf (file, " no-tbaa-pruning");
+ fprintf (file, "\n");
}
- fprintf (file, "}\n");
}
/* Print the points-to solution for VAR to stdout. */
dump_solution_for_var (stdout, var);
}
-
/* Create varinfo structures for all of the variables in the
function for intraprocedural mode. */
intra_create_variable_infos (void)
{
tree t;
+ struct constraint_expr lhs, rhs;
- /* For each incoming argument arg, ARG = &ANYTHING */
+ /* For each incoming pointer argument arg, create the constraint ARG
+ = ANYTHING or a dummy variable if flag_argument_noalias is set. */
for (t = DECL_ARGUMENTS (current_function_decl); t; t = TREE_CHAIN (t))
{
- struct constraint_expr lhs;
- struct constraint_expr rhs;
varinfo_t p;
-
- lhs.offset = 0;
- lhs.type = SCALAR;
- lhs.var = create_variable_info_for (t, alias_get_name (t));
-
- rhs.var = anything_id;
- rhs.type = ADDRESSOF;
- rhs.offset = 0;
- for (p = get_varinfo (lhs.var); p; p = p->next)
+ if (!could_have_pointers (t))
+ continue;
+
+ /* If flag_argument_noalias is set, then function pointer
+ arguments are guaranteed not to point to each other. In that
+ case, create an artificial variable PARM_NOALIAS and the
+ constraint ARG = &PARM_NOALIAS. */
+ if (POINTER_TYPE_P (TREE_TYPE (t)) && flag_argument_noalias > 0)
+ {
+ varinfo_t vi;
+ tree heapvar = heapvar_lookup (t);
+
+ lhs.offset = 0;
+ lhs.type = SCALAR;
+ lhs.var = get_vi_for_tree (t)->id;
+
+ if (heapvar == NULL_TREE)
+ {
+ var_ann_t ann;
+ heapvar = create_tmp_var_raw (TREE_TYPE (TREE_TYPE (t)),
+ "PARM_NOALIAS");
+ DECL_EXTERNAL (heapvar) = 1;
+ if (gimple_referenced_vars (cfun))
+ add_referenced_var (heapvar);
+
+ heapvar_insert (t, heapvar);
+
+ ann = get_var_ann (heapvar);
+ if (flag_argument_noalias == 1)
+ ann->noalias_state = NO_ALIAS;
+ else if (flag_argument_noalias == 2)
+ ann->noalias_state = NO_ALIAS_GLOBAL;
+ else if (flag_argument_noalias == 3)
+ ann->noalias_state = NO_ALIAS_ANYTHING;
+ else
+ gcc_unreachable ();
+ }
+
+ vi = get_vi_for_tree (heapvar);
+ vi->is_artificial_var = 1;
+ vi->is_heap_var = 1;
+ rhs.var = vi->id;
+ rhs.type = ADDRESSOF;
+ rhs.offset = 0;
+ for (p = get_varinfo (lhs.var); p; p = p->next)
+ {
+ struct constraint_expr temp = lhs;
+ temp.var = p->id;
+ process_constraint (new_constraint (temp, rhs));
+ }
+ }
+ else
{
- struct constraint_expr temp = lhs;
- temp.var = p->id;
- process_constraint (new_constraint (temp, rhs));
+ varinfo_t arg_vi = get_vi_for_tree (t);
+
+ for (p = arg_vi; p; p = p->next)
+ make_constraint_from_anything (p);
}
- }
+ }
+}
+
+/* Structure used to put solution bitmaps in a hashtable so they can
+ be shared among variables with the same points-to set. */
+
+typedef struct shared_bitmap_info
+{
+ bitmap pt_vars;
+ hashval_t hashcode;
+} *shared_bitmap_info_t;
+
+static htab_t shared_bitmap_table;
+
+/* Hash function for a shared_bitmap_info_t */
+
+static hashval_t
+shared_bitmap_hash (const void *p)
+{
+ const shared_bitmap_info_t bi = (shared_bitmap_info_t) p;
+ return bi->hashcode;
+}
+
+/* Equality function for two shared_bitmap_info_t's. */
+
+static int
+shared_bitmap_eq (const void *p1, const void *p2)
+{
+ const shared_bitmap_info_t sbi1 = (shared_bitmap_info_t) p1;
+ const shared_bitmap_info_t sbi2 = (shared_bitmap_info_t) p2;
+ return bitmap_equal_p (sbi1->pt_vars, sbi2->pt_vars);
+}
+
+/* Lookup a bitmap in the shared bitmap hashtable, and return an already
+ existing instance if there is one, NULL otherwise. */
+
+static bitmap
+shared_bitmap_lookup (bitmap pt_vars)
+{
+ void **slot;
+ struct shared_bitmap_info sbi;
+
+ sbi.pt_vars = pt_vars;
+ sbi.hashcode = bitmap_hash (pt_vars);
+
+ slot = htab_find_slot_with_hash (shared_bitmap_table, &sbi,
+ sbi.hashcode, NO_INSERT);
+ if (!slot)
+ return NULL;
+ else
+ return ((shared_bitmap_info_t) *slot)->pt_vars;
+}
+
+/* Add a bitmap to the shared bitmap hashtable. */
+
+static void
+shared_bitmap_add (bitmap pt_vars)
+{
+ void **slot;
+ shared_bitmap_info_t sbi = XNEW (struct shared_bitmap_info);
+
+ sbi->pt_vars = pt_vars;
+ sbi->hashcode = bitmap_hash (pt_vars);
+
+ slot = htab_find_slot_with_hash (shared_bitmap_table, sbi,
+ sbi->hashcode, INSERT);
+ gcc_assert (!*slot);
+ *slot = (void *) sbi;
}
+
/* Set bits in INTO corresponding to the variable uids in solution set
- FROM */
+ FROM, which came from variable PTR.
+ For variables that are actually dereferenced, we also use type
+ based alias analysis to prune the points-to sets.
+ IS_DEREFED is true if PTR was directly dereferenced, which we use to
+ help determine whether we are we are allowed to prune using TBAA.
+ If NO_TBAA_PRUNING is true, we do not perform any TBAA pruning of
+ the from set. */
static void
-set_uids_in_ptset (bitmap into, bitmap from)
+set_uids_in_ptset (tree ptr, bitmap into, bitmap from, bool is_derefed,
+ bool no_tbaa_pruning)
{
unsigned int i;
bitmap_iterator bi;
- bool found_anyoffset = false;
subvar_t sv;
+ HOST_WIDE_INT ptr_alias_set = get_alias_set (TREE_TYPE (ptr));
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;
- }
+ unsigned HOST_WIDE_INT var_alias_set;
/* 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;
-
+
if (vi->has_union && get_subvars_for_var (vi->decl) != NULL)
{
/* Variables containing unions may need to be converted to
for (sv = get_subvars_for_var (vi->decl); sv; sv = sv->next)
bitmap_set_bit (into, DECL_UID (sv->var));
}
- else if (TREE_CODE (vi->decl) == VAR_DECL
- || TREE_CODE (vi->decl) == PARM_DECL)
+ else if (TREE_CODE (vi->decl) == VAR_DECL
+ || TREE_CODE (vi->decl) == PARM_DECL
+ || TREE_CODE (vi->decl) == RESULT_DECL)
{
- if (found_anyoffset
- && var_can_have_subvars (vi->decl)
+ if (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));
+ if (sft)
+ {
+ var_alias_set = get_alias_set (sft);
+ if (no_tbaa_pruning
+ || (!is_derefed && !vi->directly_dereferenced)
+ || alias_sets_conflict_p (ptr_alias_set, var_alias_set))
+ 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));
+ /* Otherwise, just add VI->DECL to the alias set.
+ Don't type prune artificial vars. */
+ if (vi->is_artificial_var)
+ bitmap_set_bit (into, DECL_UID (vi->decl));
+ else
+ {
+ var_alias_set = get_alias_set (vi->decl);
+ if (no_tbaa_pruning
+ || (!is_derefed && !vi->directly_dereferenced)
+ || alias_sets_conflict_p (ptr_alias_set, var_alias_set))
+ bitmap_set_bit (into, DECL_UID (vi->decl));
+ }
}
}
}
static bool have_alias_info = false;
+/* The list of SMT's that are in use by our pointer variables. This
+ is the set of SMT's for all pointers that can point to anything. */
+static bitmap used_smts;
+
+/* Due to the ordering of points-to set calculation and SMT
+ calculation being a bit co-dependent, we can't just calculate SMT
+ used info whenever we want, we have to calculate it around the time
+ that find_what_p_points_to is called. */
+
+/* Mark which SMT's are in use by points-to anything variables. */
+
+void
+set_used_smts (void)
+{
+ int i;
+ varinfo_t vi;
+ used_smts = BITMAP_ALLOC (&pta_obstack);
+
+ for (i = 0; VEC_iterate (varinfo_t, varmap, i, vi); i++)
+ {
+ tree var = vi->decl;
+ tree smt;
+ var_ann_t va;
+ struct ptr_info_def *pi = NULL;
+
+ /* For parm decls, the pointer info may be under the default
+ def. */
+ if (TREE_CODE (vi->decl) == PARM_DECL
+ && gimple_default_def (cfun, var))
+ pi = SSA_NAME_PTR_INFO (gimple_default_def (cfun, var));
+ else if (TREE_CODE (var) == SSA_NAME)
+ pi = SSA_NAME_PTR_INFO (var);
+
+ /* Skip the special variables and those without their own
+ solution set. */
+ if (vi->is_special_var || find (vi->id) != vi->id
+ || !SSA_VAR_P (var)
+ || (pi && !pi->is_dereferenced)
+ || (TREE_CODE (var) == VAR_DECL && !may_be_aliased (var))
+ || !POINTER_TYPE_P (TREE_TYPE (var)))
+ continue;
+
+ if (TREE_CODE (var) == SSA_NAME)
+ var = SSA_NAME_VAR (var);
+
+ va = var_ann (var);
+ if (!va)
+ continue;
+
+ smt = va->symbol_mem_tag;
+ if (smt && bitmap_bit_p (vi->solution, anything_id))
+ bitmap_set_bit (used_smts, DECL_UID (smt));
+ }
+}
+
+/* Merge the necessary SMT's into the bitmap INTO, which is
+ P's varinfo. This involves merging all SMT's that are a subset of
+ the SMT necessary for P. */
+
+static void
+merge_smts_into (tree p, bitmap solution)
+{
+ unsigned int i;
+ bitmap_iterator bi;
+ tree smt;
+ bitmap aliases;
+ tree var = p;
+
+ if (TREE_CODE (p) == SSA_NAME)
+ var = SSA_NAME_VAR (p);
+
+ smt = var_ann (var)->symbol_mem_tag;
+ if (smt)
+ {
+ HOST_WIDE_INT smtset = get_alias_set (TREE_TYPE (smt));
+
+ /* Need to set the SMT subsets first before this
+ will work properly. */
+ bitmap_set_bit (solution, DECL_UID (smt));
+ EXECUTE_IF_SET_IN_BITMAP (used_smts, 0, i, bi)
+ {
+ tree newsmt = referenced_var (i);
+ tree newsmttype = TREE_TYPE (newsmt);
+
+ if (alias_set_subset_of (get_alias_set (newsmttype),
+ smtset))
+ bitmap_set_bit (solution, i);
+ }
+
+ aliases = MTAG_ALIASES (smt);
+ if (aliases)
+ bitmap_ior_into (solution, aliases);
+ }
+}
+
/* Given a pointer variable P, fill in its points-to set, or return
- false if we can't. */
+ false if we can't.
+ Rather than return false for variables that point-to anything, we
+ instead find the corresponding SMT, and merge in it's aliases. In
+ addition to these aliases, we also set the bits for the SMT's
+ themselves and their subsets, as SMT's are still in use by
+ non-SSA_NAME's, and pruning may eliminate every one of their
+ aliases. In such a case, if we did not include the right set of
+ SMT's in the points-to set of the variable, we'd end up with
+ statements that do not conflict but should. */
bool
find_what_p_points_to (tree p)
{
- unsigned int id = 0;
+ tree lookup_p = p;
+ varinfo_t vi;
if (!have_alias_info)
return false;
- if (lookup_id_for_tree (p, &id))
+ /* For parameters, get at the points-to set for the actual parm
+ decl. */
+ if (TREE_CODE (p) == SSA_NAME
+ && TREE_CODE (SSA_NAME_VAR (p)) == PARM_DECL
+ && SSA_NAME_IS_DEFAULT_DEF (p))
+ lookup_p = SSA_NAME_VAR (p);
+
+ vi = lookup_vi_for_tree (lookup_p);
+ if (vi)
{
- varinfo_t vi = get_varinfo (id);
-
if (vi->is_artificial_var)
return false;
if (!var_can_have_subvars (vi->decl)
|| get_subvars_for_var (vi->decl) == NULL)
return false;
- }
+ }
else
{
struct ptr_info_def *pi = get_ptr_info (p);
unsigned int i;
bitmap_iterator bi;
+ bool was_pt_anything = false;
+ bitmap finished_solution;
+ bitmap result;
+
+ if (!pi->is_dereferenced)
+ return false;
/* This variable may have been collapsed, let's get the real
variable. */
- vi = get_varinfo (vi->node);
-
+ vi = get_varinfo (find (vi->id));
+
/* Translate artificial variables into SSA_NAME_PTR_INFO
attributes. */
EXECUTE_IF_SET_IN_BITMAP (vi->solution, 0, i, bi)
if (vi->id == nothing_id)
pi->pt_null = 1;
else if (vi->id == anything_id)
- pi->pt_anything = 1;
+ was_pt_anything = 1;
else if (vi->id == readonly_id)
- pi->pt_anything = 1;
+ was_pt_anything = 1;
else if (vi->id == integer_id)
- pi->pt_anything = 1;
+ was_pt_anything = 1;
else if (vi->is_heap_var)
pi->pt_global_mem = 1;
}
}
- if (pi->pt_anything)
- return false;
+ /* Share the final set of variables when possible. */
+
+ finished_solution = BITMAP_GGC_ALLOC ();
+ stats.points_to_sets_created++;
+
+ /* Instead of using pt_anything, we merge in the SMT aliases
+ for the underlying SMT. In addition, if they could have
+ pointed to anything, they could point to global memory.
+ But we cannot do that for ref-all pointers because these
+ aliases have not been computed yet. */
+ if (was_pt_anything)
+ {
+ if (PTR_IS_REF_ALL (p))
+ {
+ pi->pt_anything = 1;
+ return false;
+ }
- if (!pi->pt_vars)
- pi->pt_vars = BITMAP_GGC_ALLOC ();
+ merge_smts_into (p, finished_solution);
+ pi->pt_global_mem = 1;
+ }
+
+ set_uids_in_ptset (vi->decl, finished_solution, vi->solution,
+ vi->directly_dereferenced,
+ vi->no_tbaa_pruning);
+ result = shared_bitmap_lookup (finished_solution);
- set_uids_in_ptset (pi->pt_vars, vi->solution);
+ if (!result)
+ {
+ shared_bitmap_add (finished_solution);
+ pi->pt_vars = finished_solution;
+ }
+ else
+ {
+ pi->pt_vars = result;
+ bitmap_clear (finished_solution);
+ }
if (bitmap_empty_p (pi->pt_vars))
pi->pt_vars = NULL;
}
-/* Initialize things necessary to perform PTA */
-
-static void
-init_alias_vars (void)
-{
- bitmap_obstack_initialize (&ptabitmap_obstack);
-}
-
/* Dump points-to information to OUTFILE. */
{
fprintf (outfile, "Stats:\n");
fprintf (outfile, "Total vars: %d\n", stats.total_vars);
+ fprintf (outfile, "Non-pointer vars: %d\n",
+ stats.nonpointer_vars);
fprintf (outfile, "Statically unified vars: %d\n",
stats.unified_vars_static);
- fprintf (outfile, "Collapsed vars: %d\n", stats.collapsed_vars);
fprintf (outfile, "Dynamically unified vars: %d\n",
stats.unified_vars_dynamic);
fprintf (outfile, "Iterations: %d\n", stats.iterations);
+ fprintf (outfile, "Number of edges: %d\n", stats.num_edges);
+ fprintf (outfile, "Number of implicit edges: %d\n",
+ stats.num_implicit_edges);
}
for (i = 0; i < VEC_length (varinfo_t, varmap); i++)
/* Create the NULL variable, used to represent that a variable points
to NULL. */
nothing_tree = create_tmp_var_raw (void_type_node, "NULL");
- var_nothing = new_var_info (nothing_tree, 0, "NULL", 0);
- insert_id_for_tree (nothing_tree, 0);
+ var_nothing = new_var_info (nothing_tree, 0, "NULL");
+ insert_vi_for_tree (nothing_tree, var_nothing);
var_nothing->is_artificial_var = 1;
var_nothing->offset = 0;
var_nothing->size = ~0;
/* Create the ANYTHING variable, used to represent that a variable
points to some unknown piece of memory. */
anything_tree = create_tmp_var_raw (void_type_node, "ANYTHING");
- var_anything = new_var_info (anything_tree, 1, "ANYTHING", 1);
- insert_id_for_tree (anything_tree, 1);
+ var_anything = new_var_info (anything_tree, 1, "ANYTHING");
+ insert_vi_for_tree (anything_tree, var_anything);
var_anything->is_artificial_var = 1;
var_anything->size = ~0;
var_anything->offset = 0;
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,
+ work in the presence of linked list and other p = *p type loops,
by saying that *ANYTHING = ANYTHING. */
VEC_safe_push (varinfo_t, heap, varmap, var_anything);
lhs.type = SCALAR;
rhs.type = ADDRESSOF;
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, heap, constraints, new_constraint (lhs, rhs));
-
+
/* Create the READONLY variable, used to represent that a variable
points to readonly memory. */
readonly_tree = create_tmp_var_raw (void_type_node, "READONLY");
- var_readonly = new_var_info (readonly_tree, 2, "READONLY", 2);
+ var_readonly = new_var_info (readonly_tree, 2, "READONLY");
var_readonly->is_artificial_var = 1;
var_readonly->offset = 0;
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);
+ insert_vi_for_tree (readonly_tree, var_readonly);
readonly_id = 2;
VEC_safe_push (varinfo_t, heap, varmap, var_readonly);
rhs.type = ADDRESSOF;
rhs.var = anything_id;
rhs.offset = 0;
-
+
process_constraint (new_constraint (lhs, rhs));
-
+
/* Create the INTEGER variable, used to represent that a variable points
to an INTEGER. */
integer_tree = create_tmp_var_raw (void_type_node, "INTEGER");
- var_integer = new_var_info (integer_tree, 3, "INTEGER", 3);
- insert_id_for_tree (integer_tree, 3);
+ var_integer = new_var_info (integer_tree, 3, "INTEGER");
+ insert_vi_for_tree (integer_tree, var_integer);
var_integer->is_artificial_var = 1;
var_integer->size = ~0;
var_integer->fullsize = ~0;
integer_id = 3;
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. */
+ /* INTEGER = ANYTHING, because we don't know where a dereference of
+ a random integer will point to. */
lhs.type = SCALAR;
lhs.var = integer_id;
lhs.offset = 0;
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));
-}
+/* Initialize things necessary to perform PTA */
-/* 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 void
+init_alias_vars (void)
+{
+ bitmap_obstack_initialize (&pta_obstack);
+ bitmap_obstack_initialize (&oldpta_obstack);
+ bitmap_obstack_initialize (&predbitmap_obstack);
-static bool
-need_to_solve (void)
+ constraint_pool = create_alloc_pool ("Constraint pool",
+ sizeof (struct constraint), 30);
+ variable_info_pool = create_alloc_pool ("Variable info pool",
+ sizeof (struct variable_info), 30);
+ constraints = VEC_alloc (constraint_t, heap, 8);
+ varmap = VEC_alloc (varinfo_t, heap, 8);
+ vi_for_tree = pointer_map_create ();
+
+ memset (&stats, 0, sizeof (stats));
+ shared_bitmap_table = htab_create (511, shared_bitmap_hash,
+ shared_bitmap_eq, free);
+ init_base_vars ();
+}
+
+/* Remove the REF and ADDRESS edges from GRAPH, as well as all the
+ predecessor edges. */
+
+static void
+remove_preds_and_fake_succs (constraint_graph_t graph)
{
- int i;
- varinfo_t v;
- bool found_address_taken = false;
- bool found_non_anything = false;
+ unsigned int i;
- for (i = 0; VEC_iterate (varinfo_t, varmap, i, v); i++)
+ /* Clear the implicit ref and address nodes from the successor
+ lists. */
+ for (i = 0; i < FIRST_REF_NODE; i++)
{
- if (v->is_special_var)
- continue;
+ if (graph->succs[i])
+ bitmap_clear_range (graph->succs[i], FIRST_REF_NODE,
+ FIRST_REF_NODE * 2);
+ }
- if (v->address_taken)
- found_address_taken = true;
+ /* Free the successor list for the non-ref nodes. */
+ for (i = FIRST_REF_NODE; i < graph->size; i++)
+ {
+ if (graph->succs[i])
+ BITMAP_FREE (graph->succs[i]);
+ }
- 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;
+ /* Now reallocate the size of the successor list as, and blow away
+ the predecessor bitmaps. */
+ graph->size = VEC_length (varinfo_t, varmap);
+ graph->succs = XRESIZEVEC (bitmap, graph->succs, graph->size);
- if (found_address_taken && found_non_anything)
- return true;
+ free (graph->implicit_preds);
+ graph->implicit_preds = NULL;
+ free (graph->preds);
+ graph->preds = NULL;
+ bitmap_obstack_release (&predbitmap_obstack);
+}
+
+/* Compute the set of variables we can't TBAA prune. */
+
+static void
+compute_tbaa_pruning (void)
+{
+ unsigned int size = VEC_length (varinfo_t, varmap);
+ unsigned int i;
+ bool any;
+
+ changed_count = 0;
+ changed = sbitmap_alloc (size);
+ sbitmap_zero (changed);
+
+ /* Mark all initial no_tbaa_pruning nodes as changed. */
+ any = false;
+ for (i = 0; i < size; ++i)
+ {
+ varinfo_t ivi = get_varinfo (i);
+
+ if (find (i) == i && ivi->no_tbaa_pruning)
+ {
+ any = true;
+ if ((graph->succs[i] && !bitmap_empty_p (graph->succs[i]))
+ || VEC_length (constraint_t, graph->complex[i]) > 0)
+ {
+ SET_BIT (changed, i);
+ ++changed_count;
+ }
+ }
}
- return false;
+ while (changed_count > 0)
+ {
+ struct topo_info *ti = init_topo_info ();
+ ++stats.iterations;
+
+ bitmap_obstack_initialize (&iteration_obstack);
+
+ compute_topo_order (graph, ti);
+
+ while (VEC_length (unsigned, ti->topo_order) != 0)
+ {
+ bitmap_iterator bi;
+
+ i = VEC_pop (unsigned, ti->topo_order);
+
+ /* If this variable is not a representative, skip it. */
+ if (find (i) != i)
+ continue;
+
+ /* If the node has changed, we need to process the complex
+ constraints and outgoing edges again. */
+ if (TEST_BIT (changed, i))
+ {
+ unsigned int j;
+ constraint_t c;
+ VEC(constraint_t,heap) *complex = graph->complex[i];
+
+ RESET_BIT (changed, i);
+ --changed_count;
+
+ /* Process the complex copy constraints. */
+ for (j = 0; VEC_iterate (constraint_t, complex, j, c); ++j)
+ {
+ if (c->lhs.type == SCALAR && c->rhs.type == SCALAR)
+ {
+ varinfo_t lhsvi = get_varinfo (find (c->lhs.var));
+
+ if (!lhsvi->no_tbaa_pruning)
+ {
+ lhsvi->no_tbaa_pruning = true;
+ if (!TEST_BIT (changed, lhsvi->id))
+ {
+ SET_BIT (changed, lhsvi->id);
+ ++changed_count;
+ }
+ }
+ }
+ }
+
+ /* Propagate to all successors. */
+ EXECUTE_IF_IN_NONNULL_BITMAP (graph->succs[i], 0, j, bi)
+ {
+ unsigned int to = find (j);
+ varinfo_t tovi = get_varinfo (to);
+
+ /* Don't propagate to ourselves. */
+ if (to == i)
+ continue;
+
+ if (!tovi->no_tbaa_pruning)
+ {
+ tovi->no_tbaa_pruning = true;
+ if (!TEST_BIT (changed, to))
+ {
+ SET_BIT (changed, to);
+ ++changed_count;
+ }
+ }
+ }
+ }
+ }
+
+ free_topo_info (ti);
+ bitmap_obstack_release (&iteration_obstack);
+ }
+
+ sbitmap_free (changed);
+
+ if (any)
+ {
+ for (i = 0; i < size; ++i)
+ {
+ varinfo_t ivi = get_varinfo (i);
+ varinfo_t ivip = get_varinfo (find (i));
+
+ if (ivip->no_tbaa_pruning)
+ {
+ tree var = ivi->decl;
+
+ if (TREE_CODE (var) == SSA_NAME)
+ var = SSA_NAME_VAR (var);
+
+ if (POINTER_TYPE_P (TREE_TYPE (var)))
+ {
+ DECL_NO_TBAA_P (var) = 1;
+
+ /* Tell the RTL layer that this pointer can alias
+ anything. */
+ DECL_POINTER_ALIAS_SET (var) = 0;
+ }
+ }
+ }
+ }
}
/* Create points-to sets for the current function. See the comments
void
compute_points_to_sets (struct alias_info *ai)
{
+ struct scc_info *si;
basic_block bb;
timevar_push (TV_TREE_PTA);
init_alias_vars ();
-
- constraint_pool = create_alloc_pool ("Constraint pool",
- sizeof (struct constraint), 30);
- variable_info_pool = create_alloc_pool ("Variable info pool",
- sizeof (struct variable_info), 30);
- constraint_edge_pool = create_alloc_pool ("Constraint edges",
- sizeof (struct constraint_edge), 30);
-
- 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 ();
+ init_alias_heapvars ();
intra_create_variable_infos ();
/* Now walk all statements and derive aliases. */
FOR_EACH_BB (bb)
{
- block_stmt_iterator bsi;
+ block_stmt_iterator bsi;
tree phi;
- for (phi = phi_nodes (bb); phi; phi = TREE_CHAIN (phi))
- if (is_gimple_reg (PHI_RESULT (phi)))
- find_func_aliases (phi, ai);
+ for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
+ {
+ if (is_gimple_reg (PHI_RESULT (phi)))
+ {
+ find_func_aliases (phi);
+
+ /* 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 (phi, ai);
+ }
+ }
+
+ for (bsi = bsi_start (bb); !bsi_end_p (bsi); )
+ {
+ tree stmt = bsi_stmt (bsi);
+
+ find_func_aliases (stmt);
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
- find_func_aliases (bsi_stmt (bsi), ai);
+ /* 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 (stmt, ai);
+
+ /* The information in CHANGE_DYNAMIC_TYPE_EXPR nodes has now
+ been captured, and we can remove them. */
+ if (TREE_CODE (stmt) == CHANGE_DYNAMIC_TYPE_EXPR)
+ bsi_remove (&bsi, true);
+ else
+ bsi_next (&bsi);
+ }
}
- build_constraint_graph ();
if (dump_file)
{
fprintf (dump_file, "Points-to analysis\n\nConstraints:\n\n");
dump_constraints (dump_file);
}
-
- 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)
+ fprintf (dump_file,
+ "\nCollapsing static cycles and doing variable "
+ "substitution:\n");
+ build_pred_graph ();
+ si = perform_var_substitution (graph);
+ move_complex_constraints (graph, si);
+ free_var_substitution_info (si);
+
+ build_succ_graph ();
+ find_indirect_cycles (graph);
+
+ /* Implicit nodes and predecessors are no longer necessary at this
+ point. */
+ remove_preds_and_fake_succs (graph);
+
+ if (dump_file)
+ fprintf (dump_file, "\nSolving graph:\n");
+
+ solve_graph (graph);
+
+ compute_tbaa_pruning ();
+
if (dump_file)
dump_sa_points_to_info (dump_file);
-
+
have_alias_info = true;
timevar_pop (TV_TREE_PTA);
varinfo_t v;
int i;
- htab_delete (id_for_tree);
- bitmap_obstack_release (&ptabitmap_obstack);
+ htab_delete (shared_bitmap_table);
+ if (dump_file && (dump_flags & TDF_STATS))
+ fprintf (dump_file, "Points to sets created:%d\n",
+ stats.points_to_sets_created);
+
+ pointer_map_destroy (vi_for_tree);
+ bitmap_obstack_release (&pta_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);
- }
+ VEC_free (constraint_t, heap, graph->complex[i]);
+ free (graph->complex);
+
+ free (graph->rep);
free (graph->succs);
- free (graph->preds);
+ free (graph->indirect_cycles);
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);
-
+ free_alloc_pool (constraint_pool);
have_alias_info = false;
}
+
+/* Return true if we should execute IPA PTA. */
+static bool
+gate_ipa_pta (void)
+{
+ return (flag_unit_at_a_time != 0
+ && flag_ipa_pta
+ /* Don't bother doing anything if the program has errors. */
+ && !(errorcount || sorrycount));
+}
+
+/* Execute the driver for IPA PTA. */
+static unsigned int
+ipa_pta_execute (void)
+{
+ struct cgraph_node *node;
+ struct scc_info *si;
+
+ in_ipa_mode = 1;
+ init_alias_heapvars ();
+ init_alias_vars ();
+
+ for (node = cgraph_nodes; node; node = node->next)
+ {
+ if (!node->analyzed || cgraph_is_master_clone (node))
+ {
+ unsigned int varid;
+
+ varid = create_function_info_for (node->decl,
+ cgraph_node_name (node));
+ if (node->local.externally_visible)
+ {
+ varinfo_t fi = get_varinfo (varid);
+ for (; fi; fi = fi->next)
+ make_constraint_from_anything (fi);
+ }
+ }
+ }
+ for (node = cgraph_nodes; node; node = node->next)
+ {
+ if (node->analyzed && cgraph_is_master_clone (node))
+ {
+ struct function *cfun = DECL_STRUCT_FUNCTION (node->decl);
+ basic_block bb;
+ tree old_func_decl = current_function_decl;
+ if (dump_file)
+ fprintf (dump_file,
+ "Generating constraints for %s\n",
+ cgraph_node_name (node));
+ push_cfun (cfun);
+ current_function_decl = node->decl;
+
+ FOR_EACH_BB_FN (bb, cfun)
+ {
+ block_stmt_iterator bsi;
+ tree phi;
+
+ for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
+ {
+ if (is_gimple_reg (PHI_RESULT (phi)))
+ {
+ find_func_aliases (phi);
+ }
+ }
+
+ for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
+ {
+ tree stmt = bsi_stmt (bsi);
+ find_func_aliases (stmt);
+ }
+ }
+ current_function_decl = old_func_decl;
+ pop_cfun ();
+ }
+ else
+ {
+ /* Make point to anything. */
+ }
+ }
+
+
+
+ if (dump_file)
+ {
+ fprintf (dump_file, "Points-to analysis\n\nConstraints:\n\n");
+ dump_constraints (dump_file);
+ }
+
+ if (dump_file)
+ fprintf (dump_file,
+ "\nCollapsing static cycles and doing variable "
+ "substitution:\n");
+
+ build_pred_graph ();
+ si = perform_var_substitution (graph);
+ move_complex_constraints (graph, si);
+ free_var_substitution_info (si);
+
+ build_succ_graph ();
+ find_indirect_cycles (graph);
+
+ /* Implicit nodes and predecessors are no longer necessary at this
+ point. */
+ remove_preds_and_fake_succs (graph);
+
+ if (dump_file)
+ fprintf (dump_file, "\nSolving graph:\n");
+
+ solve_graph (graph);
+
+ if (dump_file)
+ dump_sa_points_to_info (dump_file);
+
+ in_ipa_mode = 0;
+ delete_alias_heapvars ();
+ delete_points_to_sets ();
+ return 0;
+}
+
+struct tree_opt_pass pass_ipa_pta =
+{
+ "pta", /* name */
+ gate_ipa_pta, /* gate */
+ ipa_pta_execute, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_IPA_PTA, /* tv_id */
+ 0, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ 0, /* todo_flags_finish */
+ 0 /* letter */
+};
+
+/* Initialize the heapvar for statement mapping. */
+void
+init_alias_heapvars (void)
+{
+ if (!heapvar_for_stmt)
+ heapvar_for_stmt = htab_create_ggc (11, tree_map_hash, tree_map_eq,
+ NULL);
+}
+
+void
+delete_alias_heapvars (void)
+{
+ htab_delete (heapvar_for_stmt);
+ heapvar_for_stmt = NULL;
+}
+
+
+#include "gt-tree-ssa-structalias.h"
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