Hi,
this patch removes second char array from tree_def union and makes it
!TYPELESS_STORAGE. Now all accesses to anything in tree no longer have alias
set 0, but they all have alias set 1 :)
This is because the way we handle unions. However it still increases TBAA
effectivity by about 12%. From:
Alias oracle query stats:
refs_may_alias_p: 65066258 disambiguations, 74846942 queries
ref_maybe_used_by_call_p: 152444 disambiguations, 65966862 queries
call_may_clobber_ref_p: 22546 disambiguations, 28559 queries
nonoverlapping_component_refs_p: 0 disambiguations, 36816 queries
nonoverlapping_refs_since_match_p: 27230 disambiguations, 58300 must
overlaps, 86300 queries
aliasing_component_refs_p: 66090 disambiguations, 2048800 queries
TBAA oracle: 25578632 disambiguations 59483650 queries
12219919 are in alias set 0
10534575 queries asked about the same object
125 queries asked about the same alias set
0 access volatile
9491563 are dependent in the DAG
1658836 are aritificially in conflict with void *
Modref stats:
modref use: 14421 disambiguations, 48129 queries
modref clobber: 1528229 disambiguations, 1926907 queries
3881547 tbaa queries (2.014392 per modref query)
565057 base compares (0.293246 per modref query)
PTA query stats:
pt_solution_includes: 947491 disambiguations, 13119151 queries
pt_solutions_intersect: 1043695 disambiguations, 13221495 queries
To:
Alias oracle query stats:
refs_may_alias_p: 66455561 disambiguations, 75202803 queries
ref_maybe_used_by_call_p: 155301 disambiguations, 67370278 queries
call_may_clobber_ref_p: 22550 disambiguations, 28587 queries
nonoverlapping_component_refs_p: 0 disambiguations, 37058 queries
nonoverlapping_refs_since_match_p: 28126 disambiguations, 59906 must
overlaps, 88990 queries
aliasing_component_refs_p: 66375 disambiguations, 2440039 queries
TBAA oracle: 28800751 disambiguations 64328055 queries
8053661 are in alias set 0
11181983 queries asked about the same object
125 queries asked about the same alias set
0 access volatile
13905691 are dependent in the DAG
2385844 are aritificially in conflict with void *
Modref stats:
modref use: 16781 disambiguations, 52031 queries
modref clobber: 1745589 disambiguations, 2149518 queries
4192266 tbaa queries (1.950328 per modref query)
559148 base compares (0.260127 per modref query)
PTA query stats:
pt_solution_includes: 906487 disambiguations, 13105994 queries
pt_solutions_intersect: 1041144 disambiguations, 13659726 queries
Bootstrapped/regtested x86_64-linux, OK?
* tree.c (build_string): Update.
* tree-core.h (tree_fixed_cst): Avoid typeless storage.
diff --git a/gcc/tree-core.h b/gcc/tree-core.h
index c9280a8d3b1..63dbb5b8eab 100644
--- a/gcc/tree-core.h
+++ b/gcc/tree-core.h
@@ -1401,7 +1401,8 @@ struct GTY(()) tree_fixed_cst {
struct GTY(()) tree_string {
struct tree_typed typed;
int length;
- char str[1];
+ /* Avoid char array that would make whole type to be typeless storage. */
+ struct {char c;} str[1];
};
struct GTY(()) tree_complex {
diff --git a/gcc/tree.c b/gcc/tree.c
index 81f867ddded..84115630184 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -2273,7 +2273,7 @@ build_string (unsigned len, const char *str /*= NULL */)
memcpy (s->string.str, str, len);
else
memset (s->string.str, 0, len);
- s->string.str[len] = '\0';
+ s->string.str[len].c = '\0';
return s;
}
