From: Adhemerval Zanella via Libc-alpha <libc-alpha@sourceware.org>
To: Naohiro Tamura <naohirot@fujitsu.com>,
Andreas Schwab <schwab@linux-m68k.org>,
libc-alpha@sourceware.org
Subject: Re: [PATCH v3 5/5] config: Rename HAVE_BUILTIN_MEMSET macro
Date: Wed, 11 Aug 2021 17:34:25 -0300 [thread overview]
Message-ID: <32ca6f4b-5bcf-7578-9d01-1529baa9bebf@linaro.org> (raw)
In-Reply-To: <20210805075207.433697-1-naohirot@fujitsu.com>
On 05/08/2021 04:52, Naohiro Tamura via Libc-alpha wrote:
> This patch renames HAVE_BUILTIN_MEMSET macro to
> HAVE_NON_LIB_EXPAND_BUILTIN_MEMSET.
>
> The name "HAVE_BUILTIN_MEMSET" is very confusing.
> This macro cannot be removed even though GCC 6.2, that is minimum
> requirement to compile glibc, already supports __builtin_memset[1].
> It doesn't indicate whether GCC supports __builtin_memset or not.
>
> But it indicates whether GCC supports __builtin_memset which doesn't
> expand to a memset libcall or not.
>
> Therefor HAVE_NON_LIB_EXPAND_BUILTIN_MEMSET is more appropriate to
> increase code readability.
>
> [1] https://gcc.gnu.org/onlinedocs/gcc-6.2.0/gcc/Other-Builtins.html
Sorry, but I don't see much gain in renaming the internal variable. I agree
with the comment improvement.
> ---
> config.h.in | 4 ++--
> configure | 14 +++++++-------
> configure.ac | 10 +++++-----
> elf/rtld.c | 9 +++++----
> 4 files changed, 19 insertions(+), 18 deletions(-)
>
> diff --git a/config.h.in b/config.h.in
> index 8b45a3a61d77..4700dc9eba9b 100644
> --- a/config.h.in
> +++ b/config.h.in
> @@ -40,8 +40,8 @@
> shared between GNU libc and GNU gettext projects. */
> #define HAVE_BUILTIN_EXPECT 1
>
> -/* Define if the compiler supports __builtin_memset. */
> -#undef HAVE_BUILTIN_MEMSET
> +/* Define if the compiler supports non lib expand __builtin_memset. */
> +#undef HAVE_NON_LIB_EXPAND_BUILTIN_MEMSET
>
> /* Define if compiler accepts -ftree-loop-distribute-patterns. */
> #undef HAVE_CC_INHIBIT_LOOP_TO_LIBCALL
Ok.
> diff --git a/configure b/configure
> index 9619c10991d0..224c754cf466 100755
> --- a/configure
> +++ b/configure
> @@ -6263,7 +6263,7 @@ fi
>
> { $as_echo "$as_me:${as_lineno-$LINENO}: checking for __builtin_memset" >&5
> $as_echo_n "checking for __builtin_memset... " >&6; }
> -if ${libc_cv_gcc_builtin_memset+:} false; then :
> +if ${libc_cv_gcc_non_lib_expand_builtin_memset+:} false; then :
> $as_echo_n "(cached) " >&6
> else
> cat > conftest.c <<\EOF
> @@ -6279,16 +6279,16 @@ if { ac_try='${CC-cc} -O3 -S conftest.c -o - | grep -F "memset" > /dev/null'
> $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
> test $ac_status = 0; }; };
> then
> - libc_cv_gcc_builtin_memset=no
> + libc_cv_gcc_non_lib_expand_builtin_memset=no
> else
> - libc_cv_gcc_builtin_memset=yes
> + libc_cv_gcc_non_lib_expand_builtin_memset=yes
> fi
> rm -f conftest*
> fi
> -{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_gcc_builtin_memset" >&5
> -$as_echo "$libc_cv_gcc_builtin_memset" >&6; }
> -if test "$libc_cv_gcc_builtin_memset" = yes ; then
> - $as_echo "#define HAVE_BUILTIN_MEMSET 1" >>confdefs.h
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_gcc_non_lib_expand_builtin_memset" >&5
> +$as_echo "$libc_cv_gcc_non_lib_expand_builtin_memset" >&6; }
> +if test "$libc_cv_gcc_non_lib_expand_builtin_memset" = yes ; then
> + $as_echo "#define HAVE_NON_LIB_EXPAND_BUILTIN_MEMSET 1" >>confdefs.h
>
> fi
>
> diff --git a/configure.ac b/configure.ac
> index 34ecbba54054..451cea7683e6 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -1508,7 +1508,7 @@ if test $libc_cv_have_section_quotes = yes; then
> AC_DEFINE(HAVE_SECTION_QUOTES)
> fi
>
> -AC_CACHE_CHECK(for __builtin_memset, libc_cv_gcc_builtin_memset, [dnl
> +AC_CACHE_CHECK(for __builtin_memset, libc_cv_gcc_non_lib_expand_builtin_memset, [dnl
> cat > conftest.c <<\EOF
> void zero (void *x)
> {
> @@ -1518,13 +1518,13 @@ EOF
> dnl
> if AC_TRY_COMMAND([${CC-cc} -O3 -S conftest.c -o - | grep -F "memset" > /dev/null]);
> then
> - libc_cv_gcc_builtin_memset=no
> + libc_cv_gcc_non_lib_expand_builtin_memset=no
> else
> - libc_cv_gcc_builtin_memset=yes
> + libc_cv_gcc_non_lib_expand_builtin_memset=yes
> fi
> rm -f conftest* ])
> -if test "$libc_cv_gcc_builtin_memset" = yes ; then
> - AC_DEFINE(HAVE_BUILTIN_MEMSET)
> +if test "$libc_cv_gcc_non_lib_expand_builtin_memset" = yes ; then
> + AC_DEFINE(HAVE_NON_LIB_EXPAND_BUILTIN_MEMSET)
> fi
>
> AC_CACHE_CHECK(for redirection of built-in functions, libc_cv_gcc_builtin_redirection, [dnl
I see no point in rename it, a better comment as you are doing is suffice.
> diff --git a/elf/rtld.c b/elf/rtld.c
> index d733359eaf80..a18494fcd38e 100644
> --- a/elf/rtld.c
> +++ b/elf/rtld.c
> @@ -527,11 +527,12 @@ _dl_start (void *arg)
> /* Partly clean the `bootstrap_map' structure up. Don't use
> `memset' since it might not be built in or inlined and we cannot
> make function calls at this point. Use '__builtin_memset' if we
> - know it is available. We do not have to clear the memory if we
> - do not have to use the temporary bootstrap_map. Global variables
> - are initialized to zero by default. */
> + know it is available and does not expand to a memset libcall.
> + We do not have to clear the memory if we do not have to use the
> + temporary bootstrap_map. Global variables are initialized to
> + zero by default. */
> #ifndef DONT_USE_BOOTSTRAP_MAP
> -# ifdef HAVE_BUILTIN_MEMSET
> +# ifdef HAVE_NON_LIB_EXPAND_BUILTIN_MEMSET
> __builtin_memset (bootstrap_map.l_info, '\0', sizeof (bootstrap_map.l_info));
> # else
> for (size_t cnt = 0;
>
Ok.
next prev parent reply other threads:[~2021-08-11 20:34 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-13 8:22 [PATCH] benchtests: Add memset zero fill benchmark tests Naohiro Tamura via Libc-alpha
2021-07-13 13:50 ` Lucas A. M. Magalhaes via Libc-alpha
2021-07-20 6:31 ` [PATCH v2 0/5] " Naohiro Tamura via Libc-alpha
2021-08-05 7:47 ` [PATCH v3 0/5] benchtests: Add memset zero fill benchmark test Naohiro Tamura via Libc-alpha
2021-08-05 7:49 ` [PATCH v3 1/5] benchtests: Enable scripts/plot_strings.py to read stdin Naohiro Tamura via Libc-alpha
2021-08-05 7:56 ` Siddhesh Poyarekar
2021-09-08 1:46 ` naohirot--- via Libc-alpha
2021-09-08 12:56 ` Siddhesh Poyarekar
2021-09-09 0:22 ` naohirot--- via Libc-alpha
2021-09-13 3:45 ` Siddhesh Poyarekar
2021-08-05 7:50 ` [PATCH v3 2/5] benchtests: Add memset zero fill benchtest Naohiro Tamura via Libc-alpha
2021-09-08 2:03 ` naohirot--- via Libc-alpha
2021-09-10 20:40 ` Lucas A. M. Magalhaes via Libc-alpha
2021-09-13 0:53 ` naohirot--- via Libc-alpha
2021-09-13 14:05 ` Lucas A. M. Magalhaes via Libc-alpha
2021-09-14 0:38 ` [PATCH v4] " Naohiro Tamura via Libc-alpha
2021-09-14 0:44 ` [PATCH v3 2/5] " naohirot--- via Libc-alpha
2021-09-14 14:02 ` Wilco Dijkstra via Libc-alpha
2021-09-15 8:24 ` naohirot--- via Libc-alpha
2021-09-21 1:27 ` naohirot--- via Libc-alpha
2021-09-21 11:09 ` Wilco Dijkstra via Libc-alpha
2021-09-22 1:05 ` [PATCH v5] " Naohiro Tamura via Libc-alpha
2023-02-09 17:23 ` Carlos O'Donell via Libc-alpha
2023-02-10 1:26 ` Siddhesh Poyarekar via Libc-alpha
2021-09-22 1:07 ` [PATCH v3 2/5] " naohirot--- via Libc-alpha
2021-09-28 1:40 ` naohirot--- via Libc-alpha
2021-09-30 0:55 ` Tamura, Naohiro/田村 直� via Libc-alpha
2021-10-18 12:57 ` Lucas A. M. Magalhaes via Libc-alpha
2021-10-20 13:44 ` Wilco Dijkstra via Libc-alpha
2021-10-20 15:35 ` Lucas A. M. Magalhaes via Libc-alpha
2021-10-20 17:47 ` Wilco Dijkstra via Libc-alpha
2021-10-22 13:08 ` Lucas A. M. Magalhaes via Libc-alpha
2021-08-05 7:51 ` [PATCH v3 3/5] benchtests: Remove redundant assert.h Naohiro Tamura via Libc-alpha
2021-09-08 1:59 ` naohirot--- via Libc-alpha
2021-09-13 3:36 ` Siddhesh Poyarekar
2021-08-05 7:51 ` [PATCH v3 4/5] benchtests: Fix validate_benchout.py exceptions Naohiro Tamura via Libc-alpha
2021-09-08 1:55 ` naohirot--- via Libc-alpha
2021-09-13 3:42 ` Siddhesh Poyarekar
2021-09-13 3:50 ` Siddhesh Poyarekar
2021-09-13 13:44 ` [PATCH v4] " Naohiro Tamura via Libc-alpha
2021-09-15 3:23 ` Siddhesh Poyarekar
2021-09-16 1:12 ` naohirot--- via Libc-alpha
2021-09-16 1:41 ` Siddhesh Poyarekar
2021-09-16 2:23 ` [PATCH v5] " Naohiro Tamura via Libc-alpha
2021-09-16 3:48 ` Siddhesh Poyarekar
2021-09-16 5:23 ` naohirot--- via Libc-alpha
2021-09-16 2:26 ` [PATCH v4] " naohirot--- via Libc-alpha
2021-09-13 13:46 ` [PATCH v3 4/5] " naohirot--- via Libc-alpha
2021-08-05 7:52 ` [PATCH v3 5/5] config: Rename HAVE_BUILTIN_MEMSET macro Naohiro Tamura via Libc-alpha
2021-08-11 20:34 ` Adhemerval Zanella via Libc-alpha [this message]
2021-07-20 6:34 ` [PATCH v2 1/5] benchtests: Enable scripts/plot_strings.py to read stdin Naohiro Tamura via Libc-alpha
2021-07-20 6:35 ` [PATCH v2 2/5] benchtests: Add memset zero fill benchtest Naohiro Tamura via Libc-alpha
2021-07-20 16:48 ` Noah Goldstein via Libc-alpha
2021-07-21 12:56 ` naohirot--- via Libc-alpha
2021-07-21 13:07 ` naohirot--- via Libc-alpha
2021-07-21 18:14 ` Noah Goldstein via Libc-alpha
2021-07-21 19:17 ` Wilco Dijkstra via Libc-alpha
2021-07-26 8:42 ` naohirot--- via Libc-alpha
2021-07-26 11:15 ` Wilco Dijkstra via Libc-alpha
2021-07-27 2:24 ` naohirot--- via Libc-alpha
2021-07-27 17:26 ` Wilco Dijkstra via Libc-alpha
2021-07-28 7:27 ` naohirot--- via Libc-alpha
2021-08-04 9:11 ` naohirot--- via Libc-alpha
2021-07-26 8:39 ` naohirot--- via Libc-alpha
2021-07-26 17:22 ` Noah Goldstein via Libc-alpha
2021-07-20 6:35 ` [PATCH v2 3/5] benchtests: Add a script to convert benchout string JSON to CSV Naohiro Tamura via Libc-alpha
2021-07-21 2:41 ` naohirot--- via Libc-alpha
2021-07-27 20:17 ` Joseph Myers
2021-07-29 1:56 ` naohirot--- via Libc-alpha
2021-07-29 4:42 ` Siddhesh Poyarekar
2021-07-30 7:05 ` naohirot--- via Libc-alpha
2021-07-31 10:47 ` Siddhesh Poyarekar
2021-07-20 6:36 ` [PATCH v2 4/5] benchtests: Remove redundant assert.h Naohiro Tamura via Libc-alpha
2021-07-20 6:37 ` [PATCH v2 5/5] benchtests: Fix validate_benchout.py exceptions Naohiro Tamura via Libc-alpha
2021-07-26 8:34 ` [PATCH] config: Remove HAVE_BUILTIN_MEMSET macro Naohiro Tamura via Libc-alpha
2021-07-26 8:48 ` naohirot--- via Libc-alpha
2021-07-26 8:49 ` Andreas Schwab
2021-07-26 9:42 ` naohirot--- via Libc-alpha
2021-07-26 9:51 ` Andreas Schwab
2021-07-26 13:16 ` naohirot--- via Libc-alpha
2021-07-26 8:35 ` [PATCH] benchtests: Add a script to merge two benchout string files Naohiro Tamura via Libc-alpha
2021-07-27 20:51 ` Joseph Myers
2021-07-30 7:04 ` naohirot--- via Libc-alpha
-- strict thread matches above, loose matches on Subject: below --
2021-08-11 21:01 [PATCH v3 5/5] config: Rename HAVE_BUILTIN_MEMSET macro Wilco Dijkstra via Libc-alpha
2021-08-11 21:17 ` Andreas Schwab
2021-08-11 23:02 ` Wilco Dijkstra via Libc-alpha
2021-08-12 7:46 ` Andreas Schwab
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