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; }