* invoke.texi (-fstrict-aliasing): Document.
* rtl.texi (MEM_ALIAS_SET): Document.
* flags.h (flag_strict_aliasing): Declare.
* toplev.c (flag_strict_aliasing): Define.
(f_options): Add -strict-aliasing.
(main): Set flag_strict_aliasing if -O2 or higher.
* tree.h (tree_type): Add alias_set field.
(TYPE_ALIAS_SET): New macro.
(TYPE_ALIAS_SET_KNOWN_P): Likewise.
(get_alias_set): Declare.
* tree.c (lang_get_alias_set): Define.
(make_node): Initialize TYPE_ALIAS_SET.
(get_alias_set): New function.
* print-tree.c (print_node): Dump the alias set for a type.
* c-tree.h (c_get_alias_set): Declare.
* c-common.c (c_get_alias_set): New function.
* c-decl.c (init_decl_processing): Set lang_get_alias_set.
* expr.c (protect_from_queue): Propogage alias sets.
(expand_assignment): Calculate alias set for new MEMs.
(expand_expr): Likewise.
* function.c (put_var_into_stack): Likewise.
(put_reg_into_stack): Likewise.
(gen_mem_addressof): Likewise.
(assign_parms): Likewise.
* stmt.c (expand_decl): Likewise.
* varasm.c (make_decl_rtl): Eliminate redundant clearing of
DECL_RTL. Calculate alias set for new MEMs.
* rtl.def (REG): Add dummy operand.
(MEM): Add extra operand to store the MEM_ALIAS_SET.
* rtl.h (MEM_ALIAS_SET): New macro.
(gen_rtx_MEM): Declare.
* emit-rtl.c (gen_rtx_MEM): New function.
* gengenrtl.c (sepcial_rtx): Make MEMs special.
* alias.c (CHECK_ALIAS_SETS_FOR_CONSISTENCY): New macro.
(DIFFERENT_ALIAS_SETS_P): Likewise.
(canon_rtx): Propogate the alias set to the new MEM.
(true_dependence): Check the alias sets.
(anti_dependence): Likewise.
(output_dependence): Likewise.
* explow.c (stabilize): Progoate alias sets.
* integrate.c (copy_rtx_and_substitute): Likewise.
* final.c (alter_subreg): Make sure not to leave MEM_IN_STRUCT_P
in an unpredictable state. Propogate alias sets.
* reload1.c (reload): Clear MEM_ALIAS_SET for new MEMs about which
we have no alias information.
From-SVN: r20719
