#include "ipa-type-escape.h"
#include "vec.h"
#include "bitmap.h"
+#include "vecprim.h"
/* Obstack used to hold grouping bitmaps and other temporary bitmaps used by
aliasing */
having to keep track of too many V_MAY_DEF expressions at call sites. */
tree global_var;
+/* qsort comparison function to sort type/name tags by DECL_UID. */
+
+static int
+sort_tags_by_id (const void *pa, const void *pb)
+{
+ tree a = *(tree *)pa;
+ tree b = *(tree *)pb;
+
+ return DECL_UID (a) - DECL_UID (b);
+}
+
+/* Initialize WORKLIST to contain those memory tags that are marked call
+ clobbered. Initialized WORKLIST2 to contain the reasons these
+ memory tags escaped. */
+
+static void
+init_transitive_clobber_worklist (VEC (tree, heap) **worklist,
+ VEC (int, heap) **worklist2)
+{
+ referenced_var_iterator rvi;
+ tree curr;
+
+ FOR_EACH_REFERENCED_VAR (curr, rvi)
+ {
+ if (MTAG_P (curr) && is_call_clobbered (curr))
+ {
+ VEC_safe_push (tree, heap, *worklist, curr);
+ VEC_safe_push (int, heap, *worklist2, var_ann (curr)->escape_mask);
+ }
+ }
+}
+
+/* Add ALIAS to WORKLIST (and the reason for escaping REASON to WORKLIST2) if
+ ALIAS is not already marked call clobbered, and is a memory
+ tag. */
+
+static void
+add_to_worklist (tree alias, VEC (tree, heap) **worklist,
+ VEC (int, heap) **worklist2,
+ int reason)
+{
+ if (MTAG_P (alias) && !is_call_clobbered (alias))
+ {
+ VEC_safe_push (tree, heap, *worklist, alias);
+ VEC_safe_push (int, heap, *worklist2, reason);
+ }
+}
+
+/* Mark aliases of TAG as call clobbered, and place any tags on the
+ alias list that were not already call clobbered on WORKLIST. */
+
+static void
+mark_aliases_call_clobbered (tree tag, VEC (tree, heap) **worklist,
+ VEC (int, heap) **worklist2)
+{
+ unsigned int i;
+ VEC (tree, gc) *ma;
+ tree entry;
+ var_ann_t ta = var_ann (tag);
+
+ if (!MTAG_P (tag))
+ return;
+ ma = may_aliases (tag);
+ if (!ma)
+ return;
+
+ for (i = 0; VEC_iterate (tree, ma, i, entry); i++)
+ {
+ if (!unmodifiable_var_p (entry))
+ {
+ add_to_worklist (entry, worklist, worklist2, ta->escape_mask);
+ mark_call_clobbered (entry, ta->escape_mask);
+ }
+ }
+}
+
+/* Tags containing global vars need to be marked as global.
+ Tags containing call clobbered vars need to be marked as call
+ clobbered. */
+
+static void
+compute_tag_properties (void)
+{
+ referenced_var_iterator rvi;
+ tree tag;
+ bool changed = true;
+ VEC (tree, heap) *taglist = NULL;
+
+ FOR_EACH_REFERENCED_VAR (tag, rvi)
+ {
+ if (!MTAG_P (tag) || TREE_CODE (tag) == STRUCT_FIELD_TAG)
+ continue;
+ VEC_safe_push (tree, heap, taglist, tag);
+ }
+
+ /* We sort the taglist by DECL_UID, for two reasons.
+ 1. To get a sequential ordering to make the bitmap accesses
+ faster.
+ 2. Because of the way we compute aliases, it's more likely that
+ an earlier tag is included in a later tag, and this will reduce
+ the number of iterations.
+
+ If we had a real tag graph, we would just topo-order it and be
+ done with it. */
+ qsort (VEC_address (tree, taglist),
+ VEC_length (tree, taglist),
+ sizeof (tree),
+ sort_tags_by_id);
+
+ /* Go through each tag not marked as global, and if it aliases
+ global vars, mark it global.
+
+ If the tag contains call clobbered vars, mark it call
+ clobbered.
+
+ This loop iterates because tags may appear in the may-aliases
+ list of other tags when we group. */
+
+ while (changed)
+ {
+ unsigned int k;
+
+ changed = false;
+ for (k = 0; VEC_iterate (tree, taglist, k, tag); k++)
+ {
+ VEC (tree, gc) *ma;
+ unsigned int i;
+ tree entry;
+ bool tagcc = is_call_clobbered (tag);
+ bool tagglobal = MTAG_GLOBAL (tag);
+
+ if (tagcc && tagglobal)
+ continue;
+
+ ma = may_aliases (tag);
+ if (!ma)
+ continue;
+
+ for (i = 0; VEC_iterate (tree, ma, i, entry); i++)
+ {
+ /* Call clobbered entries cause the tag to be marked
+ call clobbered. */
+ if (!tagcc && is_call_clobbered (entry))
+ {
+ mark_call_clobbered (tag, var_ann (entry)->escape_mask);
+ tagcc = true;
+ changed = true;
+ }
+
+ /* Global vars cause the tag to be marked global. */
+ if (!tagglobal && is_global_var (entry))
+ {
+ MTAG_GLOBAL (tag) = true;
+ changed = true;
+ tagglobal = true;
+ }
+
+ /* Early exit once both global and cc are set, since the
+ loop can't do any more than that. */
+ if (tagcc && tagglobal)
+ break;
+ }
+ }
+ }
+ VEC_free (tree, heap, taglist);
+}
+
+/* Set up the initial variable clobbers and globalness.
+ When this function completes, only tags whose aliases need to be
+ clobbered will be set clobbered. Tags clobbered because they
+ contain call clobbered vars are handled in compute_tag_properties. */
+
+static void
+set_initial_properties (struct alias_info *ai)
+{
+ unsigned int i;
+ referenced_var_iterator rvi;
+ tree var;
+ tree ptr;
+
+ FOR_EACH_REFERENCED_VAR (var, rvi)
+ {
+ if (is_global_var (var)
+ && (!var_can_have_subvars (var)
+ || get_subvars_for_var (var) == NULL))
+ {
+ if (!unmodifiable_var_p (var))
+ mark_call_clobbered (var, ESCAPE_IS_GLOBAL);
+ }
+ else if (TREE_CODE (var) == PARM_DECL
+ && default_def (var)
+ && POINTER_TYPE_P (TREE_TYPE (var)))
+ {
+ tree def = default_def (var);
+ get_ptr_info (def)->value_escapes_p = 1;
+ get_ptr_info (def)->escape_mask |= ESCAPE_IS_PARM;
+ }
+ }
+
+ for (i = 0; VEC_iterate (tree, ai->processed_ptrs, i, ptr); i++)
+ {
+ struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr);
+ var_ann_t v_ann = var_ann (SSA_NAME_VAR (ptr));
+
+ if (pi->value_escapes_p)
+ {
+ /* If PTR escapes then its associated memory tags and
+ pointed-to variables are call-clobbered. */
+ if (pi->name_mem_tag)
+ mark_call_clobbered (pi->name_mem_tag, pi->escape_mask);
+
+ if (v_ann->symbol_mem_tag)
+ mark_call_clobbered (v_ann->symbol_mem_tag, pi->escape_mask);
+
+ if (pi->pt_vars)
+ {
+ bitmap_iterator bi;
+ unsigned int j;
+ EXECUTE_IF_SET_IN_BITMAP (pi->pt_vars, 0, j, bi)
+ if (!unmodifiable_var_p (referenced_var (j)))
+ mark_call_clobbered (referenced_var (j), pi->escape_mask);
+ }
+ }
+
+ /* If the name tag is call clobbered, so is the symbol tag
+ associated with the base VAR_DECL. */
+ if (pi->name_mem_tag
+ && v_ann->symbol_mem_tag
+ && is_call_clobbered (pi->name_mem_tag))
+ mark_call_clobbered (v_ann->symbol_mem_tag, pi->escape_mask);
+
+ /* Name tags and symbol tags that we don't know where they point
+ to, might point to global memory, and thus, are clobbered.
+
+ FIXME: This is not quite right. They should only be
+ clobbered if value_escapes_p is true, regardless of whether
+ they point to global memory or not.
+ So removing this code and fixing all the bugs would be nice.
+ It is the cause of a bunch of clobbering. */
+ if ((pi->pt_global_mem || pi->pt_anything)
+ && pi->is_dereferenced && pi->name_mem_tag)
+ {
+ mark_call_clobbered (pi->name_mem_tag, ESCAPE_IS_GLOBAL);
+ MTAG_GLOBAL (pi->name_mem_tag) = true;
+ }
+
+ if ((pi->pt_global_mem || pi->pt_anything)
+ && pi->is_dereferenced
+ && v_ann->symbol_mem_tag)
+ {
+ mark_call_clobbered (v_ann->symbol_mem_tag, ESCAPE_IS_GLOBAL);
+ MTAG_GLOBAL (v_ann->symbol_mem_tag) = true;
+ }
+ }
+}
+
+
+/* This variable is set to true if we are updating the used alone
+ information for SMTs, or are in a pass that is going to break it
+ temporarily. */
+bool updating_used_alone;
+
+/* Compute which variables need to be marked call clobbered because
+ their tag is call clobbered, and which tags need to be marked
+ global because they contain global variables. */
+
+static void
+compute_call_clobbered (struct alias_info *ai)
+{
+ VEC (tree, heap) *worklist = NULL;
+ VEC(int,heap) *worklist2 = NULL;
+
+ set_initial_properties (ai);
+ init_transitive_clobber_worklist (&worklist, &worklist2);
+ while (VEC_length (tree, worklist) != 0)
+ {
+ tree curr = VEC_pop (tree, worklist);
+ int reason = VEC_pop (int, worklist2);
+
+ mark_call_clobbered (curr, reason);
+ mark_aliases_call_clobbered (curr, &worklist, &worklist2);
+ }
+ VEC_free (tree, heap, worklist);
+ VEC_free (int, heap, worklist2);
+ compute_tag_properties ();
+}
+
+
+/* Helper for recalculate_used_alone. Return a conservatively correct
+ answer as to whether STMT may make a store on the LHS to SYM. */
+
+static bool
+lhs_may_store_to (tree stmt, tree sym ATTRIBUTE_UNUSED)
+{
+ tree lhs = TREE_OPERAND (stmt, 0);
+
+ lhs = get_base_address (lhs);
+
+ if (!lhs)
+ return false;
+
+ if (TREE_CODE (lhs) == SSA_NAME)
+ return false;
+ /* We could do better here by looking at the type tag of LHS, but it
+ is unclear whether this is worth it. */
+ return true;
+}
+
+/* Recalculate the used_alone information for SMTs . */
+
+void
+recalculate_used_alone (void)
+{
+ VEC (tree, heap) *calls = NULL;
+ block_stmt_iterator bsi;
+ basic_block bb;
+ tree stmt;
+ size_t i;
+ referenced_var_iterator rvi;
+ tree var;
+
+ /* First, reset all the SMT used alone bits to zero. */
+ updating_used_alone = true;
+ FOR_EACH_REFERENCED_VAR (var, rvi)
+ if (TREE_CODE (var) == SYMBOL_MEMORY_TAG)
+ {
+ SMT_OLD_USED_ALONE (var) = SMT_USED_ALONE (var);
+ SMT_USED_ALONE (var) = 0;
+ }
+
+ /* Walk all the statements.
+ Calls get put into a list of statements to update, since we will
+ need to update operands on them if we make any changes.
+ If we see a bare use of a SMT anywhere in a real virtual use or virtual
+ def, mark the SMT as used alone, and for renaming. */
+ FOR_EACH_BB (bb)
+ {
+ for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
+ {
+ bool iscall = false;
+ ssa_op_iter iter;
+
+ stmt = bsi_stmt (bsi);
+
+ if (TREE_CODE (stmt) == CALL_EXPR
+ || (TREE_CODE (stmt) == MODIFY_EXPR
+ && TREE_CODE (TREE_OPERAND (stmt, 1)) == CALL_EXPR))
+ {
+ iscall = true;
+ VEC_safe_push (tree, heap, calls, stmt);
+ }
+
+ FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter,
+ SSA_OP_VUSE | SSA_OP_VIRTUAL_DEFS)
+ {
+ tree svar = var;
+
+ if (TREE_CODE (var) == SSA_NAME)
+ svar = SSA_NAME_VAR (var);
+
+ if (TREE_CODE (svar) == SYMBOL_MEMORY_TAG)
+ {
+ /* We only care about the LHS on calls. */
+ if (iscall && !lhs_may_store_to (stmt, svar))
+ continue;
+
+ if (!SMT_USED_ALONE (svar))
+ {
+ SMT_USED_ALONE (svar) = true;
+
+ /* Only need to mark for renaming if it wasn't
+ used alone before. */
+ if (!SMT_OLD_USED_ALONE (svar))
+ mark_sym_for_renaming (svar);
+ }
+ }
+ }
+ }
+ }
+
+ /* Update the operands on all the calls we saw. */
+ if (calls)
+ {
+ for (i = 0; VEC_iterate (tree, calls, i, stmt); i++)
+ update_stmt (stmt);
+ }
+ VEC_free (tree, heap, calls);
+ updating_used_alone = false;
+}
/* Compute may-alias information for every variable referenced in function
FNDECL.
We have two classes of memory tags. Memory tags associated with the
pointed-to data type of the pointers in the program. These tags are
- called "type memory tag" (TMT). The other class are those associated
+ called "symbol memory tag" (SMT). The other class are those associated
with SSA_NAMEs, called "name memory tag" (NMT). The basic idea is that
when adding operands for an INDIRECT_REF *P_i, we will first check
whether P_i has a name tag, if it does we use it, because that will have
- more precise aliasing information. Otherwise, we use the standard type
+ more precise aliasing information. Otherwise, we use the standard symbol
tag.
In this phase, we go through all the pointers we found in points-to
3- Compute flow-insensitive aliases
- This pass will compare the alias set of every type memory tag and every
- addressable variable found in the program. Given a type memory tag TMT
- and an addressable variable V. If the alias sets of TMT and V conflict
- (as computed by may_alias_p), then V is marked as an alias tag and added
- to the alias set of TMT.
+ This pass will compare the alias set of every symbol memory tag and
+ every addressable variable found in the program. Given a symbol
+ memory tag SMT and an addressable variable V. If the alias sets of
+ SMT and V conflict (as computed by may_alias_p), then V is marked
+ as an alias tag and added to the alias set of SMT.
For instance, consider the following function:
return *p;
}
- After aliasing analysis has finished, the type memory tag for pointer
+ After aliasing analysis has finished, the symbol memory tag for pointer
'p' will have two aliases, namely variables 'a' and 'b'. Every time
pointer 'p' is dereferenced, we want to mark the operation as a
potential reference to 'a' and 'b'.
max-aliased-vops}), alias sets are grouped to avoid severe
compile-time slow downs and memory consumption. See group_aliases. */
-static void
+static unsigned int
compute_may_aliases (void)
{
struct alias_info *ai;
/* Compute flow-sensitive, points-to based aliasing for all the name
memory tags. Note that this pass needs to be done before flow
insensitive analysis because it uses the points-to information
- gathered before to mark call-clobbered type tags. */
+ gathered before to mark call-clobbered symbol tags. */
compute_flow_sensitive_aliasing (ai);
/* Compute type-based flow-insensitive aliasing for all the type
memory tags. */
compute_flow_insensitive_aliasing (ai);
+ /* Determine if we need to enable alias grouping. */
+ if (ai->total_alias_vops >= MAX_ALIASED_VOPS)
+ group_aliases (ai);
+
+ /* Compute call clobbering information. */
+ compute_call_clobbered (ai);
+
/* If the program has too many call-clobbered variables and/or function
calls, create .GLOBAL_VAR and use it to model call-clobbering
semantics at call sites. This reduces the number of virtual operands
/* Deallocate memory used by aliasing data structures. */
delete_alias_info (ai);
+ updating_used_alone = true;
{
block_stmt_iterator bsi;
basic_block bb;
}
}
}
-
+ recalculate_used_alone ();
+ updating_used_alone = false;
+ return 0;
}
+
struct tree_opt_pass pass_may_alias =
{
"alias", /* name */
(ALIGN/MISALIGNED_)INDIRECT_REF nodes for the pointer passed in DATA. */
static tree
-count_ptr_derefs (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED, void *data)
+count_ptr_derefs (tree *tp, int *walk_subtrees, void *data)
{
struct count_ptr_d *count_p = (struct count_ptr_d *) data;
+ /* Do not walk inside ADDR_EXPR nodes. In the expression &ptr->fld,
+ pointer 'ptr' is *not* dereferenced, it is simply used to compute
+ the address of 'fld' as 'ptr + offsetof(fld)'. */
+ if (TREE_CODE (*tp) == ADDR_EXPR)
+ {
+ *walk_subtrees = 0;
+ return NULL_TREE;
+ }
+
if (INDIRECT_REF_P (*tp) && TREE_OPERAND (*tp, 0) == count_p->ptr)
-/* || (TREE_CODE (*tp) == MEM_REF && MEM_REF_SYMBOL (*tp) == count_p->ptr)) */
count_p->count++;
return NULL_TREE;
tree var;
bitmap_obstack_initialize (&alias_obstack);
- ai = xcalloc (1, sizeof (struct alias_info));
+ ai = XCNEW (struct alias_info);
ai->ssa_names_visited = sbitmap_alloc (num_ssa_names);
sbitmap_zero (ai->ssa_names_visited);
- VARRAY_TREE_INIT (ai->processed_ptrs, 50, "processed_ptrs");
+ ai->processed_ptrs = VEC_alloc (tree, heap, 50);
ai->written_vars = BITMAP_ALLOC (&alias_obstack);
ai->dereferenced_ptrs_store = BITMAP_ALLOC (&alias_obstack);
ai->dereferenced_ptrs_load = BITMAP_ALLOC (&alias_obstack);
{
var_ann_t ann = var_ann (var);
- ann->is_alias_tag = 0;
+ ann->is_aliased = 0;
ann->may_aliases = NULL;
NUM_REFERENCES_CLEAR (ann);
a global variable, so we *don't* clear their call clobberedness
just because they are tags, though we will clear it if they
aren't for global variables. */
- if (ann->mem_tag_kind == NAME_TAG
- || ann->mem_tag_kind == TYPE_TAG
+ if (TREE_CODE (var) == NAME_MEMORY_TAG
+ || TREE_CODE (var) == SYMBOL_MEMORY_TAG
|| !is_global_var (var))
clear_call_clobbered (var);
}
tree var;
sbitmap_free (ai->ssa_names_visited);
- ai->processed_ptrs = NULL;
+ VEC_free (tree, heap, ai->processed_ptrs);
for (i = 0; i < ai->num_addressable_vars; i++)
free (ai->addressable_vars[i]);
delete_points_to_sets ();
}
-
/* Create name tags for all the pointers that have been dereferenced.
We only create a name tag for a pointer P if P is found to point to
a set of variables (so that we can alias them to *P) or if it is
create_name_tags (void)
{
size_t i;
+ VEC (tree, heap) *with_ptvars = NULL;
+ tree ptr;
+ /* Collect the list of pointers with a non-empty points to set. */
for (i = 1; i < num_ssa_names; i++)
{
tree ptr = ssa_name (i);
continue;
}
- if (pi->pt_vars && !bitmap_empty_p (pi->pt_vars))
+ /* Set pt_anything on the pointers without pt_vars filled in so
+ that they are assigned a symbol tag. */
+ if (pi->pt_vars && !bitmap_empty_p (pi->pt_vars))
+ VEC_safe_push (tree, heap, with_ptvars, ptr);
+ else
+ set_pt_anything (ptr);
+ }
+
+ /* If we didn't find any pointers with pt_vars set, we're done. */
+ if (!with_ptvars)
+ return;
+
+ /* Now go through the pointers with pt_vars, and find a name tag
+ with the same pt_vars as this pointer, or create one if one
+ doesn't exist. */
+ for (i = 0; VEC_iterate (tree, with_ptvars, i, ptr); i++)
+ {
+ struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr);
+ size_t j;
+ tree ptr2;
+ tree old_name_tag = pi->name_mem_tag;
+
+ /* If PTR points to a set of variables, check if we don't
+ have another pointer Q with the same points-to set before
+ creating a tag. If so, use Q's tag instead of creating a
+ new one.
+
+ This is important for not creating unnecessary symbols
+ and also for copy propagation. If we ever need to
+ propagate PTR into Q or vice-versa, we would run into
+ problems if they both had different name tags because
+ they would have different SSA version numbers (which
+ would force us to take the name tags in and out of SSA). */
+ for (j = 0; j < i && VEC_iterate (tree, with_ptvars, j, ptr2); j++)
{
- size_t j;
- tree old_name_tag = pi->name_mem_tag;
-
- /* If PTR points to a set of variables, check if we don't
- have another pointer Q with the same points-to set before
- creating a tag. If so, use Q's tag instead of creating a
- new one.
-
- This is important for not creating unnecessary symbols
- and also for copy propagation. If we ever need to
- propagate PTR into Q or vice-versa, we would run into
- problems if they both had different name tags because
- they would have different SSA version numbers (which
- would force us to take the name tags in and out of SSA). */
- for (j = 1; j < i; j++)
+ struct ptr_info_def *qi = SSA_NAME_PTR_INFO (ptr2);
+
+ if (bitmap_equal_p (pi->pt_vars, qi->pt_vars))
{
- tree q = ssa_name (j);
- struct ptr_info_def *qi;
-
- if (!q || !POINTER_TYPE_P (TREE_TYPE (q)))
- continue;
-
- qi = SSA_NAME_PTR_INFO (q);
-
- if (qi
- && qi->pt_vars
- && qi->name_mem_tag
- && bitmap_equal_p (pi->pt_vars, qi->pt_vars))
- {
- pi->name_mem_tag = qi->name_mem_tag;
- break;
- }
+ pi->name_mem_tag = qi->name_mem_tag;
+ break;
}
-
- /* If we didn't find a pointer with the same points-to set
- as PTR, create a new name tag if needed. */
- if (pi->name_mem_tag == NULL_TREE)
- pi->name_mem_tag = get_nmt_for (ptr);
-
- /* If the new name tag computed for PTR is different than
- the old name tag that it used to have, then the old tag
- needs to be removed from the IL, so we mark it for
- renaming. */
- if (old_name_tag && old_name_tag != pi->name_mem_tag)
- mark_sym_for_renaming (old_name_tag);
}
- else
- {
- /* If the pointer does not point to a known spot, we should
- use type tags. */
- set_pt_anything (ptr);
- continue;
- }
-
+
+ /* If we didn't find a pointer with the same points-to set
+ as PTR, create a new name tag if needed. */
+ if (pi->name_mem_tag == NULL_TREE)
+ pi->name_mem_tag = get_nmt_for (ptr);
+
+ /* If the new name tag computed for PTR is different than
+ the old name tag that it used to have, then the old tag
+ needs to be removed from the IL, so we mark it for
+ renaming. */
+ if (old_name_tag && old_name_tag != pi->name_mem_tag)
+ mark_sym_for_renaming (old_name_tag);
+
TREE_THIS_VOLATILE (pi->name_mem_tag)
- |= TREE_THIS_VOLATILE (TREE_TYPE (TREE_TYPE (ptr)));
-
+ |= TREE_THIS_VOLATILE (TREE_TYPE (TREE_TYPE (ptr)));
+
/* Mark the new name tag for renaming. */
mark_sym_for_renaming (pi->name_mem_tag);
}
+
+ VEC_free (tree, heap, with_ptvars);
}
compute_flow_sensitive_aliasing (struct alias_info *ai)
{
size_t i;
+ tree ptr;
- for (i = 0; i < VARRAY_ACTIVE_SIZE (ai->processed_ptrs); i++)
+ for (i = 0; VEC_iterate (tree, ai->processed_ptrs, i, ptr); i++)
{
- tree ptr = VARRAY_TREE (ai->processed_ptrs, i);
if (!find_what_p_points_to (ptr))
set_pt_anything (ptr);
}
create_name_tags ();
- for (i = 0; i < VARRAY_ACTIVE_SIZE (ai->processed_ptrs); i++)
+ for (i = 0; VEC_iterate (tree, ai->processed_ptrs, i, ptr); i++)
{
unsigned j;
- tree ptr = VARRAY_TREE (ai->processed_ptrs, i);
struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr);
var_ann_t v_ann = var_ann (SSA_NAME_VAR (ptr));
bitmap_iterator bi;
- if (pi->value_escapes_p || pi->pt_anything)
- {
- /* If PTR escapes or may point to anything, then its associated
- memory tags and pointed-to variables are call-clobbered. */
- if (pi->name_mem_tag)
- mark_call_clobbered (pi->name_mem_tag);
-
- if (v_ann->type_mem_tag)
- mark_call_clobbered (v_ann->type_mem_tag);
-
- if (pi->pt_vars)
- EXECUTE_IF_SET_IN_BITMAP (pi->pt_vars, 0, j, bi)
- mark_call_clobbered (referenced_var (j));
- }
/* Set up aliasing information for PTR's name memory tag (if it has
one). Note that only pointers that have been dereferenced will
EXECUTE_IF_SET_IN_BITMAP (pi->pt_vars, 0, j, bi)
{
add_may_alias (pi->name_mem_tag, referenced_var (j));
- add_may_alias (v_ann->type_mem_tag, referenced_var (j));
+ add_may_alias (v_ann->symbol_mem_tag, referenced_var (j));
}
-
- /* If the name tag is call clobbered, so is the type tag
- associated with the base VAR_DECL. */
- if (pi->name_mem_tag
- && v_ann->type_mem_tag
- && is_call_clobbered (pi->name_mem_tag))
- mark_call_clobbered (v_ann->type_mem_tag);
}
}
addressable variables found in setup_pointers_and_addressables.
For every pointer P in AI->POINTERS and addressable variable V in
- AI->ADDRESSABLE_VARS, add V to the may-alias sets of P's type
- memory tag (TMT) if their alias sets conflict. V is then marked as
+ AI->ADDRESSABLE_VARS, add V to the may-alias sets of P's symbol
+ memory tag (SMT) if their alias sets conflict. V is then marked as
an alias tag so that the operand scanner knows that statements
containing V have aliased operands. */
ai->total_alias_vops = 0;
/* For every pointer P, determine which addressable variables may alias
- with P's type memory tag. */
+ with P's symbol memory tag. */
for (i = 0; i < ai->num_pointers; i++)
{
size_t j;
struct alias_map_d *p_map = ai->pointers[i];
- tree tag = var_ann (p_map->var)->type_mem_tag;
+ tree tag = var_ann (p_map->var)->symbol_mem_tag;
var_ann_t tag_ann = var_ann (tag);
p_map->total_alias_vops = 0;
if (may_alias_p (p_map->var, p_map->set, var, v_map->set, false))
{
- subvar_t svars;
size_t num_tag_refs, num_var_refs;
num_tag_refs = NUM_REFERENCES (tag_ann);
/* Add VAR to TAG's may-aliases set. */
- /* If this is an aggregate, we may have subvariables for it
- that need to be pointed to. */
- if (var_can_have_subvars (var)
- && (svars = get_subvars_for_var (var)))
- {
- subvar_t sv;
+ /* We should never have a var with subvars here, because
+ they shouldn't get into the set of addressable vars */
+ gcc_assert (!var_can_have_subvars (var)
+ || get_subvars_for_var (var) == NULL);
- for (sv = svars; sv; sv = sv->next)
- {
- add_may_alias (tag, sv->var);
- /* Update the bitmap used to represent TAG's alias set
- in case we need to group aliases. */
- bitmap_set_bit (p_map->may_aliases, DECL_UID (sv->var));
- }
- }
- else
- {
- add_may_alias (tag, var);
- /* Update the bitmap used to represent TAG's alias set
- in case we need to group aliases. */
- bitmap_set_bit (p_map->may_aliases, DECL_UID (var));
- }
+ add_may_alias (tag, var);
+ /* Update the bitmap used to represent TAG's alias set
+ in case we need to group aliases. */
+ bitmap_set_bit (p_map->may_aliases, DECL_UID (var));
/* Update the total number of virtual operands due to
aliasing. Since we are adding one more alias to TAG's
tags with conflicting alias set numbers but no aliased symbols in
common.
- For example, suppose that we have two memory tags TMT.1 and TMT.2
+ For example, suppose that we have two memory tags SMT.1 and SMT.2
such that
- may-aliases (TMT.1) = { a }
- may-aliases (TMT.2) = { b }
+ may-aliases (SMT.1) = { a }
+ may-aliases (SMT.2) = { b }
- and the alias set number of TMT.1 conflicts with that of TMT.2.
+ and the alias set number of SMT.1 conflicts with that of SMT.2.
Since they don't have symbols in common, loads and stores from
- TMT.1 and TMT.2 will seem independent of each other, which will
+ SMT.1 and SMT.2 will seem independent of each other, which will
lead to the optimizers making invalid transformations (see
testsuite/gcc.c-torture/execute/pr15262-[12].c).
{
size_t j;
struct alias_map_d *p_map1 = ai->pointers[i];
- tree tag1 = var_ann (p_map1->var)->type_mem_tag;
+ tree tag1 = var_ann (p_map1->var)->symbol_mem_tag;
bitmap may_aliases1 = p_map1->may_aliases;
for (j = i + 1; j < ai->num_pointers; j++)
{
struct alias_map_d *p_map2 = ai->pointers[j];
- tree tag2 = var_ann (p_map2->var)->type_mem_tag;
+ tree tag2 = var_ann (p_map2->var)->symbol_mem_tag;
bitmap may_aliases2 = p_map2->may_aliases;
/* If the pointers may not point to each other, do nothing. */
fprintf (dump_file, "\n%s: Total number of aliased vops: %ld\n",
get_name (current_function_decl),
ai->total_alias_vops);
-
- /* Determine if we need to enable alias grouping. */
- if (ai->total_alias_vops >= MAX_ALIASED_VOPS)
- group_aliases (ai);
}
var_ann_t ann = var_ann (var);
/* Make TAG the unique alias of VAR. */
- ann->is_alias_tag = 0;
+ ann->is_aliased = 0;
ann->may_aliases = NULL;
/* Note that VAR and TAG may be the same if the function has no
group_aliases (struct alias_info *ai)
{
size_t i;
+ tree ptr;
/* Sort the POINTERS array in descending order of contributed
virtual operands. */
for (i = 0; i < ai->num_pointers; i++)
{
size_t j;
- tree tag1 = var_ann (ai->pointers[i]->var)->type_mem_tag;
+ tree tag1 = var_ann (ai->pointers[i]->var)->symbol_mem_tag;
bitmap tag1_aliases = ai->pointers[i]->may_aliases;
/* Skip tags that have been grouped already. */
if (ai->pointers[i]->grouped_p)
continue;
- /* See if TAG1 had any aliases in common with other type tags.
+ /* See if TAG1 had any aliases in common with other symbol tags.
If we find a TAG2 with common aliases with TAG1, add TAG2's
aliases into TAG1. */
for (j = i + 1; j < ai->num_pointers; j++)
if (bitmap_intersect_p (tag1_aliases, tag2_aliases))
{
- tree tag2 = var_ann (ai->pointers[j]->var)->type_mem_tag;
+ tree tag2 = var_ann (ai->pointers[j]->var)->symbol_mem_tag;
bitmap_ior_into (tag1_aliases, tag2_aliases);
/* Finally, all the variables that have been grouped cannot be in
the may-alias set of name memory tags. Suppose that we have
- grouped the aliases in this code so that may-aliases(a) = TMT.20
+ grouped the aliases in this code so that may-aliases(a) = SMT.20
p_5 = &a;
...
# a_9 = V_MAY_DEF <a_8>
p_5->field = 0
- ... Several modifications to TMT.20 ...
+ ... Several modifications to SMT.20 ...
# VUSE <a_9>
x_30 = p_5->field
Since p_5 points to 'a', the optimizers will try to propagate 0
into p_5->field, but that is wrong because there have been
- modifications to 'TMT.20' in between. To prevent this we have to
- replace 'a' with 'TMT.20' in the name tag of p_5. */
- for (i = 0; i < VARRAY_ACTIVE_SIZE (ai->processed_ptrs); i++)
+ modifications to 'SMT.20' in between. To prevent this we have to
+ replace 'a' with 'SMT.20' in the name tag of p_5. */
+ for (i = 0; VEC_iterate (tree, ai->processed_ptrs, i, ptr); i++)
{
size_t j;
- tree ptr = VARRAY_TREE (ai->processed_ptrs, i);
tree name_tag = SSA_NAME_PTR_INFO (ptr)->name_mem_tag;
- varray_type aliases;
+ VEC(tree,gc) *aliases;
+ tree alias;
if (name_tag == NULL_TREE)
continue;
aliases = var_ann (name_tag)->may_aliases;
- for (j = 0; aliases && j < VARRAY_ACTIVE_SIZE (aliases); j++)
+ for (j = 0; VEC_iterate (tree, aliases, j, alias); j++)
{
- tree alias = VARRAY_TREE (aliases, j);
var_ann_t ann = var_ann (alias);
- if ((ann->mem_tag_kind == NOT_A_TAG
- || ann->mem_tag_kind == STRUCT_FIELD)
+ if ((!MTAG_P (alias)
+ || TREE_CODE (alias) == STRUCT_FIELD_TAG)
&& ann->may_aliases)
{
tree new_alias;
- gcc_assert (VARRAY_ACTIVE_SIZE (ann->may_aliases) == 1);
+ gcc_assert (VEC_length (tree, ann->may_aliases) == 1);
- new_alias = VARRAY_TREE (ann->may_aliases, 0);
+ new_alias = VEC_index (tree, ann->may_aliases, 0);
replace_may_alias (name_tag, j, new_alias);
}
}
create_alias_map_for (tree var, struct alias_info *ai)
{
struct alias_map_d *alias_map;
- alias_map = xcalloc (1, sizeof (*alias_map));
+ alias_map = XCNEW (struct alias_map_d);
alias_map->var = var;
alias_map->set = get_alias_set (var);
ai->addressable_vars[ai->num_addressable_vars++] = alias_map;
/* Create ADDRESSABLE_VARS and POINTERS. Note that these arrays are
always going to be slightly bigger than we actually need them
because some TREE_ADDRESSABLE variables will be marked
- non-addressable below and only pointers with unique type tags are
+ non-addressable below and only pointers with unique symbol tags are
going to be added to POINTERS. */
- ai->addressable_vars = xcalloc (num_addressable_vars,
- sizeof (struct alias_map_d *));
- ai->pointers = xcalloc (num_pointers, sizeof (struct alias_map_d *));
+ ai->addressable_vars = XCNEWVEC (struct alias_map_d *, num_addressable_vars);
+ ai->pointers = XCNEWVEC (struct alias_map_d *, num_pointers);
ai->num_addressable_vars = 0;
ai->num_pointers = 0;
- /* Since we will be creating type memory tags within this loop, cache the
- value of NUM_REFERENCED_VARS to avoid processing the additional tags
- unnecessarily. */
+ /* Since we will be creating symbol memory tags within this loop,
+ cache the value of NUM_REFERENCED_VARS to avoid processing the
+ additional tags unnecessarily. */
n_vars = num_referenced_vars;
FOR_EACH_REFERENCED_VAR_SAFE (var, varvec, srvi)
/* Name memory tags already have flow-sensitive aliasing
information, so they need not be processed by
- compute_flow_insensitive_aliasing. Similarly, type memory
+ compute_flow_insensitive_aliasing. Similarly, symbol memory
tags are already accounted for when we process their
associated pointer.
Structure fields, on the other hand, have to have some of this
information processed for them, but it's pointless to mark them
non-addressable (since they are fake variables anyway). */
- if (v_ann->mem_tag_kind != NOT_A_TAG
- && v_ann->mem_tag_kind != STRUCT_FIELD)
+ if (MTAG_P (var) && TREE_CODE (var) != STRUCT_FIELD_TAG)
continue;
/* Remove the ADDRESSABLE flag from every addressable variable whose
/* Global variables and addressable locals may be aliased. Create an
entry in ADDRESSABLE_VARS for VAR. */
- if (may_be_aliased (var))
+ if (may_be_aliased (var)
+ && (!var_can_have_subvars (var)
+ || get_subvars_for_var (var) == NULL))
{
create_alias_map_for (var, ai);
mark_sym_for_renaming (var);
}
/* Add pointer variables that have been dereferenced to the POINTERS
- array and create a type memory tag for them. */
+ array and create a symbol memory tag for them. */
if (POINTER_TYPE_P (TREE_TYPE (var)))
{
if ((bitmap_bit_p (ai->dereferenced_ptrs_store, DECL_UID (var))
tag = get_tmt_for (var, ai);
t_ann = var_ann (tag);
- /* The type tag will need to be renamed into SSA
+ /* The symbol tag will need to be renamed into SSA
afterwards. Note that we cannot do this inside
get_tmt_for because aliasing may run multiple times
- and we only create type tags the first time. */
+ and we only create symbol tags the first time. */
mark_sym_for_renaming (tag);
/* Similarly, if pointer VAR used to have another type
tag, we will need to process it in the renamer to
remove the stale virtual operands. */
- if (v_ann->type_mem_tag)
- mark_sym_for_renaming (v_ann->type_mem_tag);
+ if (v_ann->symbol_mem_tag)
+ mark_sym_for_renaming (v_ann->symbol_mem_tag);
/* Associate the tag with pointer VAR. */
- v_ann->type_mem_tag = tag;
+ v_ann->symbol_mem_tag = tag;
/* If pointer VAR has been used in a store operation,
then its memory tag must be marked as written-to. */
if (bitmap_bit_p (ai->dereferenced_ptrs_store, DECL_UID (var)))
bitmap_set_bit (ai->written_vars, DECL_UID (tag));
- /* If pointer VAR is a global variable or a PARM_DECL,
- then its memory tag should be considered a global
- variable. */
- if (TREE_CODE (var) == PARM_DECL || is_global_var (var))
- mark_call_clobbered (tag);
-
/* All the dereferences of pointer VAR count as
references of TAG. Since TAG can be associated with
several pointers, add the dereferences of VAR to the
else
{
/* The pointer has not been dereferenced. If it had a
- type memory tag, remove it and mark the old tag for
+ symbol memory tag, remove it and mark the old tag for
renaming to remove it out of the IL. */
var_ann_t ann = var_ann (var);
- tree tag = ann->type_mem_tag;
+ tree tag = ann->symbol_mem_tag;
if (tag)
{
mark_sym_for_renaming (tag);
- ann->type_mem_tag = NULL_TREE;
+ ann->symbol_mem_tag = NULL_TREE;
}
}
}
call-clobbered variables. */
if (global_var && var != global_var)
{
- subvar_t svars;
add_may_alias (var, global_var);
- if (var_can_have_subvars (var)
- && (svars = get_subvars_for_var (var)))
- {
- subvar_t sv;
- for (sv = svars; sv; sv = sv->next)
- mark_sym_for_renaming (sv->var);
- }
+ gcc_assert (!get_subvars_for_var (var));
}
mark_sym_for_renaming (var);
bool alias_set_only)
{
tree mem;
- var_ann_t m_ann;
alias_stats.alias_queries++;
alias_stats.simple_queries++;
/* By convention, a variable cannot alias itself. */
- mem = var_ann (ptr)->type_mem_tag;
+ mem = var_ann (ptr)->symbol_mem_tag;
if (mem == var)
{
alias_stats.alias_noalias++;
alias_stats.simple_resolved++;
return false;
}
-
- /* If -fargument-noalias-global is >1, pointer arguments may
+
+ /* If -fargument-noalias-global is > 2, pointer arguments may
+ not point to anything else. */
+ if (flag_argument_noalias > 2 && TREE_CODE (ptr) == PARM_DECL)
+ {
+ alias_stats.alias_noalias++;
+ alias_stats.simple_resolved++;
+ return false;
+ }
+
+ /* If -fargument-noalias-global is > 1, pointer arguments may
not point to global variables. */
if (flag_argument_noalias > 1 && is_global_var (var)
&& TREE_CODE (ptr) == PARM_DECL)
return false;
}
- m_ann = var_ann (mem);
-
- gcc_assert (m_ann->mem_tag_kind == TYPE_TAG);
+ gcc_assert (TREE_CODE (mem) == SYMBOL_MEMORY_TAG);
alias_stats.tbaa_queries++;
- /* If VAR is a pointer with the same alias set as PTR, then dereferencing
- PTR can't possibly affect VAR. Note, that we are specifically testing
- for PTR's alias set here, not its pointed-to type. We also can't
- do this check with relaxed aliasing enabled. */
- if (POINTER_TYPE_P (TREE_TYPE (var))
- && var_alias_set != 0
- && mem_alias_set != 0)
- {
- HOST_WIDE_INT ptr_alias_set = get_alias_set (ptr);
- if (ptr_alias_set == var_alias_set)
- {
- alias_stats.alias_noalias++;
- alias_stats.tbaa_resolved++;
- return false;
- }
- }
-
/* If the alias sets don't conflict then MEM cannot alias VAR. */
if (!alias_sets_conflict_p (mem_alias_set, var_alias_set))
{
size_t i;
var_ann_t v_ann = get_var_ann (var);
var_ann_t a_ann = get_var_ann (alias);
+ tree al;
/* Don't allow self-referential aliases. */
gcc_assert (var != alias);
#endif
if (v_ann->may_aliases == NULL)
- VARRAY_TREE_INIT (v_ann->may_aliases, 2, "aliases");
+ v_ann->may_aliases = VEC_alloc (tree, gc, 2);
/* Avoid adding duplicates. */
- for (i = 0; i < VARRAY_ACTIVE_SIZE (v_ann->may_aliases); i++)
- if (alias == VARRAY_TREE (v_ann->may_aliases, i))
+ for (i = 0; VEC_iterate (tree, v_ann->may_aliases, i, al); i++)
+ if (alias == al)
return;
- /* If VAR is a call-clobbered variable, so is its new ALIAS.
- FIXME, call-clobbering should only depend on whether an address
- escapes. It should be independent of aliasing. */
- if (is_call_clobbered (var))
- mark_call_clobbered (alias);
-
- /* Likewise. If ALIAS is call-clobbered, so is VAR. */
- else if (is_call_clobbered (alias))
- mark_call_clobbered (var);
-
- VARRAY_PUSH_TREE (v_ann->may_aliases, alias);
- a_ann->is_alias_tag = 1;
+ VEC_safe_push (tree, gc, v_ann->may_aliases, alias);
+ a_ann->is_aliased = 1;
}
replace_may_alias (tree var, size_t i, tree new_alias)
{
var_ann_t v_ann = var_ann (var);
- VARRAY_TREE (v_ann->may_aliases, i) = new_alias;
-
- /* If VAR is a call-clobbered variable, so is NEW_ALIAS.
- FIXME, call-clobbering should only depend on whether an address
- escapes. It should be independent of aliasing. */
- if (is_call_clobbered (var))
- mark_call_clobbered (new_alias);
-
- /* Likewise. If NEW_ALIAS is call-clobbered, so is VAR. */
- else if (is_call_clobbered (new_alias))
- mark_call_clobbered (var);
+ VEC_replace (tree, v_ann->may_aliases, i, new_alias);
}
3- STMT is an assignment to a non-local variable, or
4- STMT is a return statement.
- AI points to the alias information collected so far. */
+ AI points to the alias information collected so far.
-bool
+ Return the type of escape site found, if we found one, or NO_ESCAPE
+ if none. */
+
+enum escape_type
is_escape_site (tree stmt, struct alias_info *ai)
{
tree call = get_call_expr_in (stmt);
ai->num_calls_found++;
if (!TREE_SIDE_EFFECTS (call))
- ai->num_pure_const_calls_found++;
+ {
+ ai->num_pure_const_calls_found++;
+ return ESCAPE_TO_PURE_CONST;
+ }
- return true;
+ return ESCAPE_TO_CALL;
}
else if (TREE_CODE (stmt) == ASM_EXPR)
- return true;
+ return ESCAPE_TO_ASM;
else if (TREE_CODE (stmt) == MODIFY_EXPR)
{
tree lhs = TREE_OPERAND (stmt, 0);
/* If we couldn't recognize the LHS of the assignment, assume that it
is a non-local store. */
if (lhs == NULL_TREE)
- return true;
+ return ESCAPE_UNKNOWN;
/* If the RHS is a conversion between a pointer and an integer, the
pointer escapes since we can't track the integer. */
&& POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND
(TREE_OPERAND (stmt, 1), 0)))
&& !POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (stmt, 1))))
- return true;
+ return ESCAPE_BAD_CAST;
/* If the LHS is an SSA name, it can't possibly represent a non-local
memory store. */
if (TREE_CODE (lhs) == SSA_NAME)
- return false;
+ return NO_ESCAPE;
/* FIXME: LHS is not an SSA_NAME. Even if it's an assignment to a
local variables we cannot be sure if it will escape, because we
Midkiff, ``Escape analysis for java,'' in Proceedings of the
Conference on Object-Oriented Programming Systems, Languages, and
Applications (OOPSLA), pp. 1-19, 1999. */
- return true;
+ return ESCAPE_STORED_IN_GLOBAL;
}
else if (TREE_CODE (stmt) == RETURN_EXPR)
- return true;
+ return ESCAPE_TO_RETURN;
- return false;
+ return NO_ESCAPE;
}
+/* Create a new memory tag of type TYPE.
+ Does NOT push it into the current binding. */
+
+static tree
+create_tag_raw (enum tree_code code, tree type, const char *prefix)
+{
+ tree tmp_var;
+ tree new_type;
+
+ /* Make the type of the variable writable. */
+ new_type = build_type_variant (type, 0, 0);
+ TYPE_ATTRIBUTES (new_type) = TYPE_ATTRIBUTES (type);
+
+ tmp_var = build_decl (code, create_tmp_var_name (prefix),
+ type);
+ /* Make the variable writable. */
+ TREE_READONLY (tmp_var) = 0;
+
+ /* It doesn't start out global. */
+ MTAG_GLOBAL (tmp_var) = 0;
+ TREE_STATIC (tmp_var) = 0;
+ TREE_USED (tmp_var) = 1;
+
+ return tmp_var;
+}
/* Create a new memory tag of type TYPE. If IS_TYPE_TAG is true, the tag
is considered to represent all the pointers whose pointed-to types are
create_memory_tag (tree type, bool is_type_tag)
{
var_ann_t ann;
- tree tag = create_tmp_var_raw (type, (is_type_tag) ? "TMT" : "NMT");
+ tree tag = create_tag_raw (is_type_tag ? SYMBOL_MEMORY_TAG : NAME_MEMORY_TAG,
+ type, (is_type_tag) ? "SMT" : "NMT");
/* By default, memory tags are local variables. Alias analysis will
determine whether they should be considered globals. */
TREE_ADDRESSABLE (tag) = 1;
ann = get_var_ann (tag);
- ann->mem_tag_kind = (is_type_tag) ? TYPE_TAG : NAME_TAG;
- ann->type_mem_tag = NULL_TREE;
+ ann->symbol_mem_tag = NULL_TREE;
/* Add the tag to the symbol table. */
add_referenced_tmp_var (tag);
if (tag == NULL_TREE)
tag = create_memory_tag (TREE_TYPE (TREE_TYPE (ptr)), false);
-
- /* If PTR is a PARM_DECL, it points to a global variable or malloc,
- then its name tag should be considered a global variable. */
- if (TREE_CODE (SSA_NAME_VAR (ptr)) == PARM_DECL
- || pi->pt_global_mem)
- mark_call_clobbered (tag);
-
return tag;
}
-/* Return the type memory tag associated to pointer PTR. A memory tag is an
- artificial variable that represents the memory location pointed-to by
- PTR. It is used to model the effects of pointer de-references on
- addressable variables.
+/* Return the symbol memory tag associated to pointer PTR. A memory
+ tag is an artificial variable that represents the memory location
+ pointed-to by PTR. It is used to model the effects of pointer
+ de-references on addressable variables.
- AI points to the data gathered during alias analysis. This function
- populates the array AI->POINTERS. */
+ AI points to the data gathered during alias analysis. This
+ function populates the array AI->POINTERS. */
static tree
get_tmt_for (tree ptr, struct alias_info *ai)
for (i = 0, tag = NULL_TREE; i < ai->num_pointers; i++)
{
struct alias_map_d *curr = ai->pointers[i];
- tree curr_tag = var_ann (curr->var)->type_mem_tag;
- if (tag_set == curr->set
- && TYPE_READONLY (tag_type) == TYPE_READONLY (TREE_TYPE (curr_tag)))
+ tree curr_tag = var_ann (curr->var)->symbol_mem_tag;
+ if (tag_set == curr->set)
{
tag = curr_tag;
break;
{
struct alias_map_d *alias_map;
- /* If PTR did not have a type tag already, create a new TMT.*
+ /* If PTR did not have a symbol tag already, create a new SMT.*
artificial variable representing the memory location
pointed-to by PTR. */
- if (var_ann (ptr)->type_mem_tag == NULL_TREE)
+ if (var_ann (ptr)->symbol_mem_tag == NULL_TREE)
tag = create_memory_tag (tag_type, true);
else
- tag = var_ann (ptr)->type_mem_tag;
+ tag = var_ann (ptr)->symbol_mem_tag;
/* Add PTR to the POINTERS array. Note that we are not interested in
PTR's alias set. Instead, we cache the alias set for the memory that
PTR points to. */
- alias_map = xcalloc (1, sizeof (*alias_map));
+ alias_map = XCNEW (struct alias_map_d);
alias_map->var = ptr;
alias_map->set = tag_set;
ai->pointers[ai->num_pointers++] = alias_map;
/* If the pointed-to type is volatile, so is the tag. */
TREE_THIS_VOLATILE (tag) |= TREE_THIS_VOLATILE (tag_type);
- /* Make sure that the type tag has the same alias set as the
+ /* Make sure that the symbol tag has the same alias set as the
pointed-to type. */
gcc_assert (tag_set == get_alias_set (tag));
- /* If PTR's pointed-to type is read-only, then TAG's type must also
- be read-only. */
- gcc_assert (TYPE_READONLY (tag_type) == TYPE_READONLY (TREE_TYPE (tag)));
-
return tag;
}
TREE_THIS_VOLATILE (global_var) = 0;
TREE_ADDRESSABLE (global_var) = 0;
+ create_var_ann (global_var);
+ mark_call_clobbered (global_var, ESCAPE_UNKNOWN);
add_referenced_tmp_var (global_var);
mark_sym_for_renaming (global_var);
}
FOR_EACH_REFERENCED_VAR (var, rvi)
{
var_ann_t ann = var_ann (var);
- if (ann->type_mem_tag)
+ if (ann->symbol_mem_tag)
dump_variable (file, var);
}
- fprintf (file, "\nType memory tags\n\n");
+ fprintf (file, "\nSymbol memory tags\n\n");
FOR_EACH_REFERENCED_VAR (var, rvi)
{
- var_ann_t ann = var_ann (var);
- if (ann->mem_tag_kind == TYPE_TAG)
+ if (TREE_CODE (var) == SYMBOL_MEMORY_TAG)
dump_variable (file, var);
}
FOR_EACH_REFERENCED_VAR (var, rvi)
{
- var_ann_t ann = var_ann (var);
- if (ann->mem_tag_kind == NAME_TAG)
+ if (TREE_CODE (var) == NAME_MEMORY_TAG)
dump_variable (file, var);
}
pi = SSA_NAME_PTR_INFO (t);
if (pi == NULL)
{
- pi = ggc_alloc (sizeof (*pi));
+ pi = GGC_NEW (struct ptr_info_def);
memset ((void *)pi, 0, sizeof (*pi));
SSA_NAME_PTR_INFO (t) = pi;
}
}
-/* Dump points-to info pointed by PTO into STDERR. */
+/* Dump points-to info pointed to by PTO into STDERR. */
void
debug_points_to_info (void)
void
dump_may_aliases_for (FILE *file, tree var)
{
- varray_type aliases;
+ VEC(tree, gc) *aliases;
if (TREE_CODE (var) == SSA_NAME)
var = SSA_NAME_VAR (var);
if (aliases)
{
size_t i;
+ tree al;
fprintf (file, "{ ");
- for (i = 0; i < VARRAY_ACTIVE_SIZE (aliases); i++)
+ for (i = 0; VEC_iterate (tree, aliases, i, al); i++)
{
- print_generic_expr (file, VARRAY_TREE (aliases, i), dump_flags);
+ print_generic_expr (file, al, dump_flags);
fprintf (file, " ");
}
fprintf (file, "}");
/* Globally visible variables can have their addresses taken by other
translation units. */
- if (DECL_EXTERNAL (var) || TREE_PUBLIC (var))
+
+ if (MTAG_P (var)
+ && (MTAG_GLOBAL (var) || TREE_PUBLIC (var)))
+ return true;
+ else if (!MTAG_P (var)
+ && (DECL_EXTERNAL (var) || TREE_PUBLIC (var)))
return true;
/* Automatic variables can't have their addresses escape any other way.
}
-/* Add VAR to the list of may-aliases of PTR's type tag. If PTR
- doesn't already have a type tag, create one. */
+/* Given two symbols return TRUE if one is in the alias set of the other. */
+bool
+is_aliased_with (tree tag, tree sym)
+{
+ size_t i;
+ VEC(tree,gc) *aliases;
+ tree al;
+
+ if (var_ann (sym)->is_aliased)
+ {
+ aliases = var_ann (tag)->may_aliases;
+
+ if (aliases == NULL)
+ return false;
+
+ for (i = 0; VEC_iterate (tree, aliases, i, al); i++)
+ if (al == sym)
+ return true;
+ }
+ else
+ {
+ aliases = var_ann (sym)->may_aliases;
+
+ if (aliases == NULL)
+ return false;
+
+ for (i = 0; VEC_iterate (tree, aliases, i, al); i++)
+ if (al == tag)
+ return true;
+ }
+
+ return false;
+}
+
+
+/* Add VAR to the list of may-aliases of PTR's symbol tag. If PTR
+ doesn't already have a symbol tag, create one. */
void
add_type_alias (tree ptr, tree var)
{
- varray_type aliases;
- tree tag;
+ VEC(tree, gc) *aliases;
+ tree tag, al;
var_ann_t ann = var_ann (ptr);
subvar_t svars;
VEC (tree, heap) *varvec = NULL;
+ unsigned i;
- if (ann->type_mem_tag == NULL_TREE)
+ if (ann->symbol_mem_tag == NULL_TREE)
{
tree q = NULL_TREE;
tree tag_type = TREE_TYPE (TREE_TYPE (ptr));
HOST_WIDE_INT tag_set = get_alias_set (tag_type);
safe_referenced_var_iterator rvi;
- /* PTR doesn't have a type tag, create a new one and add VAR to
+ /* PTR doesn't have a symbol tag, create a new one and add VAR to
the new tag's alias set.
FIXME, This is slower than necessary. We need to determine
whether there is another pointer Q with the same alias set as
- PTR. This could be sped up by having type tags associated
+ PTR. This could be sped up by having symbol tags associated
with types. */
FOR_EACH_REFERENCED_VAR_SAFE (q, varvec, rvi)
{
&& tag_set == get_alias_set (TREE_TYPE (TREE_TYPE (q))))
{
/* Found another pointer Q with the same alias set as
- the PTR's pointed-to type. If Q has a type tag, use
+ the PTR's pointed-to type. If Q has a symbol tag, use
it. Otherwise, create a new memory tag for PTR. */
var_ann_t ann1 = var_ann (q);
- if (ann1->type_mem_tag)
- ann->type_mem_tag = ann1->type_mem_tag;
+ if (ann1->symbol_mem_tag)
+ ann->symbol_mem_tag = ann1->symbol_mem_tag;
else
- ann->type_mem_tag = create_memory_tag (tag_type, true);
+ ann->symbol_mem_tag = create_memory_tag (tag_type, true);
goto found_tag;
}
}
- /* Couldn't find any other pointer with a type tag we could use.
+ /* Couldn't find any other pointer with a symbol tag we could use.
Create a new memory tag for PTR. */
- ann->type_mem_tag = create_memory_tag (tag_type, true);
+ ann->symbol_mem_tag = create_memory_tag (tag_type, true);
}
found_tag:
- /* If VAR is not already PTR's type tag, add it to the may-alias set
- for PTR's type tag. */
- gcc_assert (var_ann (var)->type_mem_tag == NOT_A_TAG);
- tag = ann->type_mem_tag;
+ /* If VAR is not already PTR's symbol tag, add it to the may-alias set
+ for PTR's symbol tag. */
+ gcc_assert (!MTAG_P (var));
+ tag = ann->symbol_mem_tag;
/* If VAR has subvars, add the subvars to the tag instead of the
actual var. */
mark_sym_for_renaming (tag);
if ((aliases = var_ann (tag)->may_aliases) != NULL)
{
- size_t i;
- for (i = 0; i < VARRAY_ACTIVE_SIZE (aliases); i++)
- mark_sym_for_renaming (VARRAY_TREE (aliases, i));
+ for (i = 0; VEC_iterate (tree, aliases, i, al); i++)
+ mark_sym_for_renaming (al);
}
/* If we had grouped aliases, VAR may have aliases of its own. Mark
aliases of VAR will need to be updated. */
if ((aliases = var_ann (var)->may_aliases) != NULL)
{
- size_t i;
- for (i = 0; i < VARRAY_ACTIVE_SIZE (aliases); i++)
- mark_sym_for_renaming (VARRAY_TREE (aliases, i));
+ for (i = 0; VEC_iterate (tree, aliases, i, al); i++)
+ mark_sym_for_renaming (al);
}
VEC_free (tree, heap, varvec);
}
-/* Create a new type tag for PTR. Construct the may-alias list of this type
+/* Create a new symbol tag for PTR. Construct the may-alias list of this type
tag so that it has the aliasing of VAR.
- Note, the set of aliases represented by the new type tag are not marked
+ Note, the set of aliases represented by the new symbol tag are not marked
for renaming. */
void
tree tag;
subvar_t svars;
- gcc_assert (p_ann->type_mem_tag == NULL_TREE);
- gcc_assert (v_ann->mem_tag_kind == NOT_A_TAG);
+ gcc_assert (p_ann->symbol_mem_tag == NULL_TREE);
+ gcc_assert (!MTAG_P (var));
- /* Add VAR to the may-alias set of PTR's new type tag. If VAR has
+ /* Add VAR to the may-alias set of PTR's new symbol tag. If VAR has
subvars, add the subvars to the tag instead of the actual var. */
if (var_can_have_subvars (var)
&& (svars = get_subvars_for_var (var)))
subvar_t sv;
tag = create_memory_tag (tag_type, true);
- p_ann->type_mem_tag = tag;
+ p_ann->symbol_mem_tag = tag;
for (sv = svars; sv; sv = sv->next)
add_may_alias (tag, sv->var);
same defs/uses/vdefs/vuses will be found after replacing a reference
to var (or ARRAY_REF to var) with an INDIRECT_REF to ptr whose value
is the address of var. */
- varray_type aliases = v_ann->may_aliases;
+ VEC(tree, gc) *aliases = v_ann->may_aliases;
if ((aliases != NULL)
- && (VARRAY_ACTIVE_SIZE (aliases) == 1))
+ && (VEC_length (tree, aliases) == 1))
{
- tree ali = VARRAY_TREE (aliases, 0);
+ tree ali = VEC_index (tree, aliases, 0);
- if (get_var_ann (ali)->mem_tag_kind == TYPE_TAG)
+ if (TREE_CODE (ali) == SYMBOL_MEMORY_TAG)
{
- p_ann->type_mem_tag = ali;
+ p_ann->symbol_mem_tag = ali;
return;
}
}
tag = create_memory_tag (tag_type, true);
- p_ann->type_mem_tag = tag;
+ p_ann->symbol_mem_tag = tag;
if (aliases == NULL)
add_may_alias (tag, var);
else
{
- size_t i;
+ unsigned i;
+ tree al;
- for (i = 0; i < VARRAY_ACTIVE_SIZE (aliases); i++)
- add_may_alias (tag, VARRAY_TREE (aliases, i));
+ for (i = 0; VEC_iterate (tree, aliases, i, al); i++)
+ add_may_alias (tag, al);
}
}
+
+ TREE_READONLY (tag) = TREE_READONLY (var);
+ MTAG_GLOBAL (tag) = is_global_var (var);
}
variable. Implicit uses occur when we can't tell what part we
are referencing, and have to make conservative assumptions. */
bool implicit_uses;
+ /* True if the structure is only written to or taken its address. */
+ bool write_only;
} *used_part_t;
/* An array of used_part structures, indexed by variable uid. */
static int
used_part_map_eq (const void *va, const void *vb)
{
- const struct used_part_map *a = va, *b = vb;
+ const struct used_part_map *a = (const struct used_part_map *) va;
+ const struct used_part_map *b = (const struct used_part_map *) vb;
return (a->uid == b->uid);
}
{
struct used_part_map *h, in;
in.uid = uid;
- h = htab_find_with_hash (used_portions, &in, uid);
+ h = (struct used_part_map *) htab_find_with_hash (used_portions, &in, uid);
if (!h)
return NULL;
return h->to;
struct used_part_map *h;
void **loc;
- h = xmalloc (sizeof (struct used_part_map));
+ h = XNEW (struct used_part_map);
h->uid = uid;
h->to = to;
loc = htab_find_slot_with_hash (used_portions, h,
used_part_t up;
if ((up = up_lookup (uid)) == NULL)
{
- up = xcalloc (1, sizeof (struct used_part));
+ up = XCNEW (struct used_part);
up->minused = INT_MAX;
up->maxused = 0;
up->explicit_uses = false;
up->implicit_uses = false;
+ up->write_only = true;
}
return up;
}
-/* Create and return a structure sub-variable for field FIELD of
- variable VAR. */
+/* Create and return a structure sub-variable for field type FIELD at
+ offset OFFSET, with size SIZE, of variable VAR. */
static tree
-create_sft (tree var, tree field)
+create_sft (tree var, tree field, unsigned HOST_WIDE_INT offset,
+ unsigned HOST_WIDE_INT size)
{
var_ann_t ann;
- tree subvar = create_tmp_var_raw (TREE_TYPE (field), "SFT");
+ tree subvar = create_tag_raw (STRUCT_FIELD_TAG, field, "SFT");
/* We need to copy the various flags from VAR to SUBVAR, so that
they are is_global_var iff the original variable was. */
DECL_CONTEXT (subvar) = DECL_CONTEXT (var);
- DECL_EXTERNAL (subvar) = DECL_EXTERNAL (var);
+ MTAG_GLOBAL (subvar) = DECL_EXTERNAL (var);
TREE_PUBLIC (subvar) = TREE_PUBLIC (var);
TREE_STATIC (subvar) = TREE_STATIC (var);
TREE_READONLY (subvar) = TREE_READONLY (var);
+ TREE_ADDRESSABLE (subvar) = TREE_ADDRESSABLE (var);
/* Add the new variable to REFERENCED_VARS. */
ann = get_var_ann (subvar);
- ann->mem_tag_kind = STRUCT_FIELD;
- ann->type_mem_tag = NULL;
+ ann->symbol_mem_tag = NULL;
add_referenced_tmp_var (subvar);
-
+ SFT_PARENT_VAR (subvar) = var;
+ SFT_OFFSET (subvar) = offset;
+ SFT_SIZE (subvar) = size;
return subvar;
}
used_part_t up;
size_t uid = DECL_UID (var);
- if (!up_lookup (uid))
+ up = up_lookup (uid);
+ if (!up
+ || up->write_only)
return;
- up = up_lookup (uid);
push_fields_onto_fieldstack (TREE_TYPE (var), &fieldstack, 0, NULL);
if (VEC_length (fieldoff_s, fieldstack) != 0)
{
for (i = 0; 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;
HOST_WIDE_INT fosize;
tree currfotype;
- fosize = TREE_INT_CST_LOW (DECL_SIZE (fo->field));
- currfotype = TREE_TYPE (fo->field);
+ fosize = TREE_INT_CST_LOW (fo->size);
+ currfotype = fo->type;
/* If this field isn't in the used portion,
or it has the exact same offset and size as the last
&& fosize == lastfosize
&& currfotype == lastfotype))
continue;
- sv = ggc_alloc (sizeof (struct subvar));
- sv->offset = fo->offset;
- sv->size = fosize;
+ sv = GGC_NEW (struct subvar);
sv->next = *subvars;
- sv->var = create_sft (var, fo->field);
+ sv->var = create_sft (var, fo->type, fo->offset, fosize);
if (dump_file)
{
fprintf (dump_file, "structure field tag %s created for var %s",
get_name (sv->var), get_name (var));
fprintf (dump_file, " offset " HOST_WIDE_INT_PRINT_DEC,
- sv->offset);
+ SFT_OFFSET (sv->var));
fprintf (dump_file, " size " HOST_WIDE_INT_PRINT_DEC,
- sv->size);
+ SFT_SIZE (sv->var));
fprintf (dump_file, "\n");
}
entire structure. */
static tree
-find_used_portions (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
+find_used_portions (tree *tp, int *walk_subtrees, void *lhs_p)
{
switch (TREE_CODE (*tp))
{
+ case MODIFY_EXPR:
+ /* Recurse manually here to track whether the use is in the
+ LHS of an assignment. */
+ find_used_portions (&TREE_OPERAND (*tp, 0), walk_subtrees, tp);
+ return find_used_portions (&TREE_OPERAND (*tp, 1), walk_subtrees, NULL);
+ case REALPART_EXPR:
+ case IMAGPART_EXPR:
case COMPONENT_REF:
+ case ARRAY_REF:
{
HOST_WIDE_INT bitsize;
+ HOST_WIDE_INT bitmaxsize;
HOST_WIDE_INT bitpos;
- tree offset;
- enum machine_mode mode;
- int unsignedp;
- int volatilep;
tree ref;
- ref = get_inner_reference (*tp, &bitsize, &bitpos, &offset, &mode,
- &unsignedp, &volatilep, false);
- if (DECL_P (ref) && offset == NULL && bitsize != -1)
- {
+ ref = get_ref_base_and_extent (*tp, &bitpos, &bitsize, &bitmaxsize);
+ if (DECL_P (ref)
+ && var_can_have_subvars (ref)
+ && bitmaxsize != -1)
+ {
size_t uid = DECL_UID (ref);
used_part_t up;
if (bitpos <= up->minused)
up->minused = bitpos;
- if ((bitpos + bitsize >= up->maxused))
- up->maxused = bitpos + bitsize;
-
- up->explicit_uses = true;
+ if ((bitpos + bitmaxsize >= up->maxused))
+ up->maxused = bitpos + bitmaxsize;
+
+ if (bitsize == bitmaxsize)
+ up->explicit_uses = true;
+ else
+ up->implicit_uses = true;
+ if (!lhs_p)
+ up->write_only = false;
up_insert (uid, up);
*walk_subtrees = 0;
return NULL_TREE;
}
- else if (DECL_P (ref))
- {
- if (DECL_SIZE (ref)
- && var_can_have_subvars (ref)
- && TREE_CODE (DECL_SIZE (ref)) == INTEGER_CST)
- {
- used_part_t up;
- size_t uid = DECL_UID (ref);
-
- up = get_or_create_used_part_for (uid);
-
- up->minused = 0;
- up->maxused = TREE_INT_CST_LOW (DECL_SIZE (ref));
-
- up->implicit_uses = true;
-
- up_insert (uid, up);
-
- *walk_subtrees = 0;
- return NULL_TREE;
- }
- }
}
break;
/* This is here to make sure we mark the entire base variable as used
up->minused = 0;
up->maxused = TREE_INT_CST_LOW (DECL_SIZE (var));
up->implicit_uses = true;
+ if (!lhs_p)
+ up->write_only = false;
up_insert (uid, up);
*walk_subtrees = 0;
}
}
break;
+ case CALL_EXPR:
+ {
+ tree *arg;
+ for (arg = &TREE_OPERAND (*tp, 1); *arg; arg = &TREE_CHAIN (*arg))
+ {
+ if (TREE_CODE (TREE_VALUE (*arg)) != ADDR_EXPR)
+ find_used_portions (&TREE_VALUE (*arg), walk_subtrees, NULL);
+ }
+ *walk_subtrees = 0;
+ return NULL_TREE;
+ }
case VAR_DECL:
case PARM_DECL:
+ case RESULT_DECL:
{
tree var = *tp;
if (DECL_SIZE (var)
/* Create structure field variables for structures used in this function. */
-static void
+static unsigned int
create_structure_vars (void)
{
basic_block bb;
if (var
&& DECL_SIZE (var)
&& var_can_have_subvars (var)
- && var_ann (var)->mem_tag_kind == NOT_A_TAG
+ && !MTAG_P (var)
&& TREE_CODE (DECL_SIZE (var)) == INTEGER_CST)
create_overlap_variables_for (var);
}
htab_delete (used_portions);
VEC_free (tree, heap, varvec);
-
+ return 0;
}
static bool
TODO_dump_func, /* todo_flags_finish */
0 /* letter */
};
+
+/* Reset the DECL_CALL_CLOBBERED flags on our referenced vars. In
+ theory, this only needs to be done for globals. */
+
+static unsigned int
+reset_cc_flags (void)
+{
+ tree var;
+ referenced_var_iterator rvi;
+
+ FOR_EACH_REFERENCED_VAR (var, rvi)
+ DECL_CALL_CLOBBERED (var) = false;
+ return 0;
+}
+
+struct tree_opt_pass pass_reset_cc_flags =
+{
+ NULL, /* name */
+ NULL, /* gate */
+ reset_cc_flags, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ 0, /* tv_id */
+ PROP_referenced_vars |PROP_cfg, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ 0, /* todo_flags_finish */
+ 0 /* letter */
+};
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