Re: [RFC PATCH] Avoid most of the BUILT_IN_*_CHKP enum values

[Ilya Enkovich <enkovich dot gnu at gmail dot com>]

2015-01-27 17:27 GMT+03:00 Jakub Jelinek <jakub@redhat.com>:
> Hi!
>
> I've grepped for BUILT_IN_.*_CHKP in the sources and we actually need
> far fewer enum values than the 1204 that are being defined.
>
> This patch requires builtins.def to say explicitly (by using
> DEF_*BUILTIN_CHKP macro instead of corresponding DEF_*BUILTIN) which
> ones need that, for all the others only space in the enum is reserved and
> nothing else.
>
> I'd hope this could work around the buggy AIX stabs handling, but even
> on say x86_64-linux it has a benefit of decreasing cc1plus .debug_info
> by about 2.7MB (of course, with dwz that benefit goes to almost nothing,
> just the ~ 7000 bytes or so, plus .debug_str cost (that is merged even
> without dwz between TUs).  The cost without dwz is obviously mainly
> from repeating that in most of the translation units.  But why declare
> BUILT_IN_*_CHKP enums that are never used by anything...

Enum values not mentioned in the code are not fully useless.  When we
have builtin functions defined as 'always_inline' functions, they are
instrumented and enum names may be used in dumps and debugging.
That's not a big value though.  Thanks a lot for taking care of it!

Ilya
>
> 2015-01-27  Jakub Jelinek  <jakub@redhat.com>
>
>         * builtins.def (DEF_BUILTIN_CHKP): Define if not defined.
>         (DEF_LIB_BUILTIN_CHKP, DEF_EXT_LIB_BUILTIN_CHKP): Redefine.
>         (DEF_CHKP_BUILTIN): Define using DEF_BUILTIN_CHKP instead
>         of DEF_BUILTIN.
>         (BUILT_IN_MEMCPY, BUILT_IN_MEMMOVE, BUILT_IN_MEMSET, BUILT_IN_STRCAT,
>         BUILT_IN_STRCHR, BUILT_IN_STRCPY, BUILT_IN_STRLEN): Use
>         DEF_LIB_BUILTIN_CHKP macro instead of DEF_LIB_BUILTIN.
>         (BUILT_IN_MEMCPY_CHK, BUILT_IN_MEMMOVE_CHK, BUILT_IN_MEMPCPY_CHK,
>         BUILT_IN_MEMPCPY, BUILT_IN_MEMSET_CHK, BUILT_IN_STPCPY_CHK,
>         BUILT_IN_STPCPY, BUILT_IN_STRCAT_CHK, BUILT_IN_STRCPY_CHK): Use
>         DEF_EXT_LIB_BUILTIN_CHKP macro instead of DEF_EXT_LIB_BUILTIN.
>         * tree-core.h (enum built_in_function): In between
>         BEGIN_CHKP_BUILTINS and END_CHKP_BUILTINS only define enum values
>         for builtins that use DEF_BUILTIN_CHKP macro.
>
> --- gcc/builtins.def.jj 2015-01-15 23:39:10.000000000 +0100
> +++ gcc/builtins.def    2015-01-27 15:04:44.860924664 +0100
> @@ -63,6 +63,16 @@ along with GCC; see the file COPYING3.
>
>     The builtins is registered only if COND is true.  */
>
> +/* A macro for builtins where the
> +   BUILT_IN_*_CHKP = BUILT_IN_* + BEGIN_CHKP_BUILTINS + 1
> +   enums should be defined too.  */
> +#ifndef DEF_BUILTIN_CHKP
> +#define DEF_BUILTIN_CHKP(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P,     \
> +                        FALLBACK_P, NONANSI_P, ATTRS, IMPLICIT, COND)  \
> +  DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P,    \
> +             NONANSI_P, ATTRS, IMPLICIT, COND)
> +#endif
> +
>  /* A GCC builtin (like __builtin_saveregs) is provided by the
>     compiler, but does not correspond to a function in the standard
>     library.  */
> @@ -87,6 +97,10 @@ along with GCC; see the file COPYING3.
>  #define DEF_LIB_BUILTIN(ENUM, NAME, TYPE, ATTRS)       \
>    DEF_BUILTIN (ENUM, "__builtin_" NAME, BUILT_IN_NORMAL, TYPE, TYPE,   \
>                true, true, false, ATTRS, true, true)
> +#undef DEF_LIB_BUILTIN_CHKP
> +#define DEF_LIB_BUILTIN_CHKP(ENUM, NAME, TYPE, ATTRS)  \
> +  DEF_BUILTIN_CHKP (ENUM, "__builtin_" NAME, BUILT_IN_NORMAL, TYPE,    \
> +                   TYPE, true, true, false, ATTRS, true, true)
>
>  /* Like DEF_LIB_BUILTIN, except that the function is not one that is
>     specified by ANSI/ISO C.  So, when we're being fully conformant we
> @@ -96,6 +110,10 @@ along with GCC; see the file COPYING3.
>  #define DEF_EXT_LIB_BUILTIN(ENUM, NAME, TYPE, ATTRS)   \
>    DEF_BUILTIN (ENUM, "__builtin_" NAME, BUILT_IN_NORMAL, TYPE, TYPE,   \
>                true, true, true, ATTRS, false, true)
> +#undef DEF_EXT_LIB_BUILTIN_CHKP
> +#define DEF_EXT_LIB_BUILTIN_CHKP(ENUM, NAME, TYPE, ATTRS)      \
> +  DEF_BUILTIN_CHKP (ENUM, "__builtin_" NAME, BUILT_IN_NORMAL, TYPE,    \
> +                   TYPE, true, true, true, ATTRS, false, true)
>
>  /* Like DEF_LIB_BUILTIN, except that the function is only a part of
>     the standard in C94 or above.  */
> @@ -199,8 +217,8 @@ along with GCC; see the file COPYING3.
>  /* Builtin used by the implementation of Pointer Bounds Checker.  */
>  #undef DEF_CHKP_BUILTIN
>  #define DEF_CHKP_BUILTIN(ENUM, NAME, TYPE, ATTRS) \
> -  DEF_BUILTIN (ENUM, "__builtin_" NAME, BUILT_IN_NORMAL, TYPE, TYPE,    \
> -              true, true, false, ATTRS, true, true)
> +  DEF_BUILTIN_CHKP (ENUM, "__builtin_" NAME, BUILT_IN_NORMAL, TYPE,    \
> +                   TYPE, true, true, false, ATTRS, true, true)
>
>  /* Define an attribute list for math functions that are normally
>     "impure" because some of them may write into global memory for
> @@ -595,22 +613,22 @@ DEF_EXT_LIB_BUILTIN    (BUILT_IN_BZERO,
>  DEF_EXT_LIB_BUILTIN    (BUILT_IN_INDEX, "index", BT_FN_STRING_CONST_STRING_INT, ATTR_PURE_NOTHROW_NONNULL_LEAF)
>  DEF_LIB_BUILTIN        (BUILT_IN_MEMCHR, "memchr", BT_FN_PTR_CONST_PTR_INT_SIZE, ATTR_PURE_NOTHROW_NONNULL_LEAF)
>  DEF_LIB_BUILTIN        (BUILT_IN_MEMCMP, "memcmp", BT_FN_INT_CONST_PTR_CONST_PTR_SIZE, ATTR_PURE_NOTHROW_NONNULL_LEAF)
> -DEF_LIB_BUILTIN        (BUILT_IN_MEMCPY, "memcpy", BT_FN_PTR_PTR_CONST_PTR_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
> -DEF_LIB_BUILTIN        (BUILT_IN_MEMMOVE, "memmove", BT_FN_PTR_PTR_CONST_PTR_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
> -DEF_EXT_LIB_BUILTIN    (BUILT_IN_MEMPCPY, "mempcpy", BT_FN_PTR_PTR_CONST_PTR_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
> -DEF_LIB_BUILTIN        (BUILT_IN_MEMSET, "memset", BT_FN_PTR_PTR_INT_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
> +DEF_LIB_BUILTIN_CHKP   (BUILT_IN_MEMCPY, "memcpy", BT_FN_PTR_PTR_CONST_PTR_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
> +DEF_LIB_BUILTIN_CHKP   (BUILT_IN_MEMMOVE, "memmove", BT_FN_PTR_PTR_CONST_PTR_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
> +DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_MEMPCPY, "mempcpy", BT_FN_PTR_PTR_CONST_PTR_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
> +DEF_LIB_BUILTIN_CHKP   (BUILT_IN_MEMSET, "memset", BT_FN_PTR_PTR_INT_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
>  DEF_EXT_LIB_BUILTIN    (BUILT_IN_RINDEX, "rindex", BT_FN_STRING_CONST_STRING_INT, ATTR_PURE_NOTHROW_NONNULL_LEAF)
> -DEF_EXT_LIB_BUILTIN    (BUILT_IN_STPCPY, "stpcpy", BT_FN_STRING_STRING_CONST_STRING, ATTR_NOTHROW_NONNULL_LEAF)
> +DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_STPCPY, "stpcpy", BT_FN_STRING_STRING_CONST_STRING, ATTR_NOTHROW_NONNULL_LEAF)
>  DEF_EXT_LIB_BUILTIN    (BUILT_IN_STPNCPY, "stpncpy", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
>  DEF_EXT_LIB_BUILTIN    (BUILT_IN_STRCASECMP, "strcasecmp", BT_FN_INT_CONST_STRING_CONST_STRING, ATTR_PURE_NOTHROW_NONNULL_LEAF)
> -DEF_LIB_BUILTIN        (BUILT_IN_STRCAT, "strcat", BT_FN_STRING_STRING_CONST_STRING, ATTR_NOTHROW_NONNULL_LEAF)
> -DEF_LIB_BUILTIN        (BUILT_IN_STRCHR, "strchr", BT_FN_STRING_CONST_STRING_INT, ATTR_PURE_NOTHROW_NONNULL_LEAF)
> +DEF_LIB_BUILTIN_CHKP   (BUILT_IN_STRCAT, "strcat", BT_FN_STRING_STRING_CONST_STRING, ATTR_NOTHROW_NONNULL_LEAF)
> +DEF_LIB_BUILTIN_CHKP   (BUILT_IN_STRCHR, "strchr", BT_FN_STRING_CONST_STRING_INT, ATTR_PURE_NOTHROW_NONNULL_LEAF)
>  DEF_LIB_BUILTIN        (BUILT_IN_STRCMP, "strcmp", BT_FN_INT_CONST_STRING_CONST_STRING, ATTR_PURE_NOTHROW_NONNULL_LEAF)
> -DEF_LIB_BUILTIN        (BUILT_IN_STRCPY, "strcpy", BT_FN_STRING_STRING_CONST_STRING, ATTR_RET1_NOTHROW_NONNULL_LEAF)
> +DEF_LIB_BUILTIN_CHKP   (BUILT_IN_STRCPY, "strcpy", BT_FN_STRING_STRING_CONST_STRING, ATTR_RET1_NOTHROW_NONNULL_LEAF)
>  DEF_LIB_BUILTIN        (BUILT_IN_STRCSPN, "strcspn", BT_FN_SIZE_CONST_STRING_CONST_STRING, ATTR_PURE_NOTHROW_NONNULL_LEAF)
>  DEF_EXT_LIB_BUILTIN    (BUILT_IN_STRDUP, "strdup", BT_FN_STRING_CONST_STRING, ATTR_MALLOC_NOTHROW_NONNULL_LEAF)
>  DEF_EXT_LIB_BUILTIN    (BUILT_IN_STRNDUP, "strndup", BT_FN_STRING_CONST_STRING_SIZE, ATTR_MALLOC_NOTHROW_NONNULL_LEAF)
> -DEF_LIB_BUILTIN        (BUILT_IN_STRLEN, "strlen", BT_FN_SIZE_CONST_STRING, ATTR_PURE_NOTHROW_NONNULL_LEAF)
> +DEF_LIB_BUILTIN_CHKP   (BUILT_IN_STRLEN, "strlen", BT_FN_SIZE_CONST_STRING, ATTR_PURE_NOTHROW_NONNULL_LEAF)
>  DEF_EXT_LIB_BUILTIN    (BUILT_IN_STRNCASECMP, "strncasecmp", BT_FN_INT_CONST_STRING_CONST_STRING_SIZE, ATTR_PURE_NOTHROW_NONNULL_LEAF)
>  DEF_LIB_BUILTIN        (BUILT_IN_STRNCAT, "strncat", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
>  DEF_LIB_BUILTIN        (BUILT_IN_STRNCMP, "strncmp", BT_FN_INT_CONST_STRING_CONST_STRING_SIZE, ATTR_PURE_NOTHROW_NONNULL_LEAF)
> @@ -844,14 +862,14 @@ DEF_BUILTIN_STUB (BUILT_IN_ALLOCA_WITH_A
>
>  /* Object size checking builtins.  */
>  DEF_GCC_BUILTIN               (BUILT_IN_OBJECT_SIZE, "object_size", BT_FN_SIZE_CONST_PTR_INT, ATTR_PURE_NOTHROW_LEAF_LIST)
> -DEF_EXT_LIB_BUILTIN    (BUILT_IN_MEMCPY_CHK, "__memcpy_chk", BT_FN_PTR_PTR_CONST_PTR_SIZE_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
> -DEF_EXT_LIB_BUILTIN    (BUILT_IN_MEMMOVE_CHK, "__memmove_chk", BT_FN_PTR_PTR_CONST_PTR_SIZE_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
> -DEF_EXT_LIB_BUILTIN    (BUILT_IN_MEMPCPY_CHK, "__mempcpy_chk", BT_FN_PTR_PTR_CONST_PTR_SIZE_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
> -DEF_EXT_LIB_BUILTIN    (BUILT_IN_MEMSET_CHK, "__memset_chk", BT_FN_PTR_PTR_INT_SIZE_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
> -DEF_EXT_LIB_BUILTIN    (BUILT_IN_STPCPY_CHK, "__stpcpy_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
> +DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_MEMCPY_CHK, "__memcpy_chk", BT_FN_PTR_PTR_CONST_PTR_SIZE_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
> +DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_MEMMOVE_CHK, "__memmove_chk", BT_FN_PTR_PTR_CONST_PTR_SIZE_SIZE, ATTR_RET1_NOTHROW_NONNULL_LEAF)
> +DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_MEMPCPY_CHK, "__mempcpy_chk", BT_FN_PTR_PTR_CONST_PTR_SIZE_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
> +DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_MEMSET_CHK, "__memset_chk", BT_FN_PTR_PTR_INT_SIZE_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
> +DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_STPCPY_CHK, "__stpcpy_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
>  DEF_EXT_LIB_BUILTIN    (BUILT_IN_STPNCPY_CHK, "__stpncpy_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
> -DEF_EXT_LIB_BUILTIN    (BUILT_IN_STRCAT_CHK, "__strcat_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
> -DEF_EXT_LIB_BUILTIN    (BUILT_IN_STRCPY_CHK, "__strcpy_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
> +DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_STRCAT_CHK, "__strcat_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
> +DEF_EXT_LIB_BUILTIN_CHKP (BUILT_IN_STRCPY_CHK, "__strcpy_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
>  DEF_EXT_LIB_BUILTIN    (BUILT_IN_STRNCAT_CHK, "__strncat_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
>  DEF_EXT_LIB_BUILTIN    (BUILT_IN_STRNCPY_CHK, "__strncpy_chk", BT_FN_STRING_STRING_CONST_STRING_SIZE_SIZE, ATTR_NOTHROW_NONNULL_LEAF)
>  DEF_EXT_LIB_BUILTIN    (BUILT_IN_SNPRINTF_CHK, "__snprintf_chk", BT_FN_INT_STRING_SIZE_INT_SIZE_CONST_STRING_VAR, ATTR_FORMAT_PRINTF_NOTHROW_5_6)
> --- gcc/tree-core.h.jj  2015-01-21 10:29:52.000000000 +0100
> +++ gcc/tree-core.h     2015-01-27 15:03:14.519485758 +0100
> @@ -158,10 +158,14 @@ enum built_in_function {
>    BEGIN_CHKP_BUILTINS,
>
>  #undef DEF_BUILTIN
> -#define DEF_BUILTIN(ENUM, N, C, T, LT, B, F, NA, AT, IM, COND) ENUM##_CHKP,
> +#define DEF_BUILTIN(ENUM, N, C, T, LT, B, F, NA, AT, IM, COND)
> +#undef DEF_BUILTIN_CHKP
> +#define DEF_BUILTIN_CHKP(ENUM, N, C, T, LT, B, F, NA, AT, IM, COND) \
> +  ENUM##_CHKP = ENUM + BEGIN_CHKP_BUILTINS + 1,
>  #include "builtins.def"
> +#undef DEF_BUILTIN_CHKP
>
> -  END_CHKP_BUILTINS,
> +  END_CHKP_BUILTINS = BEGIN_CHKP_BUILTINS * 2 + 1,
>
>    /* Complex division routines in libgcc.  These are done via builtins
>       because emit_library_call_value can't handle complex values.  */
>
>         Jakub