diff options
Diffstat (limited to 'gcc/tree-ssa-alias.c')
| -rw-r--r-- | gcc/tree-ssa-alias.c | 79 |
1 files changed, 73 insertions, 6 deletions
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c index 75dbbb4..387a696 100644 --- a/gcc/tree-ssa-alias.c +++ b/gcc/tree-ssa-alias.c @@ -43,6 +43,7 @@ Boston, MA 02110-1301, USA. */ #include "tree-ssa-structalias.h" #include "convert.h" #include "params.h" +#include "ipa-type-escape.h" #include "vec.h" #include "bitmap.h" @@ -86,6 +87,8 @@ struct alias_stats_d unsigned int simple_resolved; unsigned int tbaa_queries; unsigned int tbaa_resolved; + unsigned int structnoaddress_queries; + unsigned int structnoaddress_resolved; }; @@ -95,7 +98,7 @@ static struct alias_stats_d alias_stats; /* Local functions. */ static void compute_flow_insensitive_aliasing (struct alias_info *); static void dump_alias_stats (FILE *); -static bool may_alias_p (tree, HOST_WIDE_INT, tree, HOST_WIDE_INT); +static bool may_alias_p (tree, HOST_WIDE_INT, tree, HOST_WIDE_INT, bool); static tree create_memory_tag (tree type, bool is_type_tag); static tree get_tmt_for (tree, struct alias_info *); static tree get_nmt_for (tree); @@ -346,6 +349,7 @@ count_ptr_derefs (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED, void *data) struct count_ptr_d *count_p = (struct count_ptr_d *) data; 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; @@ -433,7 +437,6 @@ count_uses_and_derefs (tree ptr, tree stmt, unsigned *num_uses_p, gcc_assert (*num_uses_p >= *num_derefs_p); } - /* Initialize the data structures used for alias analysis. */ static struct alias_info * @@ -780,8 +783,8 @@ compute_flow_insensitive_aliasing (struct alias_info *ai) || bitmap_bit_p (ai->written_vars, DECL_UID (var)); if (!tag_stored_p && !var_stored_p) continue; - - if (may_alias_p (p_map->var, p_map->set, var, v_map->set)) + + 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; @@ -862,7 +865,7 @@ compute_flow_insensitive_aliasing (struct alias_info *ai) bitmap may_aliases2 = p_map2->may_aliases; /* If the pointers may not point to each other, do nothing. */ - if (!may_alias_p (p_map1->var, p_map1->set, tag2, p_map2->set)) + if (!may_alias_p (p_map1->var, p_map1->set, tag2, p_map2->set, true)) continue; /* The two pointers may alias each other. If they already have @@ -1453,7 +1456,8 @@ maybe_create_global_var (struct alias_info *ai) static bool may_alias_p (tree ptr, HOST_WIDE_INT mem_alias_set, - tree var, HOST_WIDE_INT var_alias_set) + tree var, HOST_WIDE_INT var_alias_set, + bool alias_set_only) { tree mem; var_ann_t m_ann; @@ -1520,6 +1524,65 @@ may_alias_p (tree ptr, HOST_WIDE_INT mem_alias_set, alias_stats.tbaa_resolved++; return false; } + + /* If var is a record or union type, ptr cannot point into var + unless there is some operation explicit address operation in the + program that can reference a field of the ptr's dereferenced + type. This also assumes that the types of both var and ptr are + contained within the compilation unit, and that there is no fancy + addressing arithmetic associated with any of the types + involved. */ + + if ((mem_alias_set != 0) && (var_alias_set != 0)) + { + tree ptr_type = TREE_TYPE (ptr); + tree var_type = TREE_TYPE (var); + + /* The star count is -1 if the type at the end of the pointer_to + chain is not a record or union type. */ + if ((!alias_set_only) && + ipa_type_escape_star_count_of_interesting_type (var_type) >= 0) + { + int ptr_star_count = 0; + + /* Ipa_type_escape_star_count_of_interesting_type is a little to + restrictive for the pointer type, need to allow pointers to + primitive types as long as those types cannot be pointers + to everything. */ + while (POINTER_TYPE_P (ptr_type)) + /* Strip the *'s off. */ + { + ptr_type = TREE_TYPE (ptr_type); + ptr_star_count++; + } + + /* There does not appear to be a better test to see if the + pointer type was one of the pointer to everything + types. */ + + if (ptr_star_count > 0) + { + alias_stats.structnoaddress_queries++; + if (ipa_type_escape_field_does_not_clobber_p (var_type, + TREE_TYPE (ptr))) + { + alias_stats.structnoaddress_resolved++; + alias_stats.alias_noalias++; + return false; + } + } + else if (ptr_star_count == 0) + { + /* If ptr_type was not really a pointer to type, it cannot + alias. */ + alias_stats.structnoaddress_queries++; + alias_stats.structnoaddress_resolved++; + alias_stats.alias_noalias++; + return false; + } + } + } + alias_stats.alias_mayalias++; return true; } @@ -1851,6 +1914,10 @@ dump_alias_stats (FILE *file) alias_stats.tbaa_queries); fprintf (file, "Total TBAA resolved:\t%u\n", alias_stats.tbaa_resolved); + fprintf (file, "Total non-addressable structure type queries:\t%u\n", + alias_stats.structnoaddress_queries); + fprintf (file, "Total non-addressable structure type resolved:\t%u\n", + alias_stats.structnoaddress_resolved); } |