Re: [PATCH v2 1/6] config: Added HAVE_AARCH64_SVE_ASM for aarch64

[Szabolcs Nagy via Libc-alpha <libc-alpha@sourceware.org>]

The 05/12/2021 09:26, Naohiro Tamura wrote:
> From: Naohiro Tamura <naohirot@jp.fujitsu.com>
> 
> This patch checks if assembler supports '-march=armv8.2-a+sve' to
> generate SVE code or not, and then define HAVE_AARCH64_SVE_ASM macro.

this is ok for master.

i will commit it for you.

> ---
>  config.h.in                  |  5 +++++
>  sysdeps/aarch64/configure    | 28 ++++++++++++++++++++++++++++
>  sysdeps/aarch64/configure.ac | 15 +++++++++++++++
>  3 files changed, 48 insertions(+)
> 
> diff --git a/config.h.in b/config.h.in
> index 99036b887f..13fba9bb8d 100644
> --- a/config.h.in
> +++ b/config.h.in
> @@ -121,6 +121,11 @@
>  /* AArch64 PAC-RET code generation is enabled.  */
>  #define HAVE_AARCH64_PAC_RET 0
>  
> +/* Assembler support ARMv8.2-A SVE.
> +   This macro becomes obsolete when glibc increased the minimum
> +   required version of GNU 'binutils' to 2.28 or later. */
> +#define HAVE_AARCH64_SVE_ASM 0
> +
>  /* ARC big endian ABI */
>  #undef HAVE_ARC_BE
>  
> diff --git a/sysdeps/aarch64/configure b/sysdeps/aarch64/configure
> index 83c3a23e44..4c1fac49f3 100644
> --- a/sysdeps/aarch64/configure
> +++ b/sysdeps/aarch64/configure
> @@ -304,3 +304,31 @@ fi
>  $as_echo "$libc_cv_aarch64_variant_pcs" >&6; }
>  config_vars="$config_vars
>  aarch64-variant-pcs = $libc_cv_aarch64_variant_pcs"
> +
> +# Check if asm support armv8.2-a+sve
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for SVE support in assembler" >&5
> +$as_echo_n "checking for SVE support in assembler... " >&6; }
> +if ${libc_cv_asm_sve+:} false; then :
> +  $as_echo_n "(cached) " >&6
> +else
> +  cat > conftest.s <<\EOF
> +        ptrue p0.b
> +EOF
> +if { ac_try='${CC-cc} -c -march=armv8.2-a+sve conftest.s 1>&5'
> +  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
> +  (eval $ac_try) 2>&5
> +  ac_status=$?
> +  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
> +  test $ac_status = 0; }; }; then
> +  libc_cv_aarch64_sve_asm=yes
> +else
> +  libc_cv_aarch64_sve_asm=no
> +fi
> +rm -f conftest*
> +fi
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_asm_sve" >&5
> +$as_echo "$libc_cv_asm_sve" >&6; }
> +if test $libc_cv_aarch64_sve_asm = yes; then
> +  $as_echo "#define HAVE_AARCH64_SVE_ASM 1" >>confdefs.h
> +
> +fi
> diff --git a/sysdeps/aarch64/configure.ac b/sysdeps/aarch64/configure.ac
> index 66f755078a..3347c13fa1 100644
> --- a/sysdeps/aarch64/configure.ac
> +++ b/sysdeps/aarch64/configure.ac
> @@ -90,3 +90,18 @@ EOF
>    fi
>    rm -rf conftest.*])
>  LIBC_CONFIG_VAR([aarch64-variant-pcs], [$libc_cv_aarch64_variant_pcs])
> +
> +# Check if asm support armv8.2-a+sve
> +AC_CACHE_CHECK(for SVE support in assembler, libc_cv_asm_sve, [dnl
> +cat > conftest.s <<\EOF
> +        ptrue p0.b
> +EOF
> +if AC_TRY_COMMAND(${CC-cc} -c -march=armv8.2-a+sve conftest.s 1>&AS_MESSAGE_LOG_FD); then
> +  libc_cv_aarch64_sve_asm=yes
> +else
> +  libc_cv_aarch64_sve_asm=no
> +fi
> +rm -f conftest*])
> +if test $libc_cv_aarch64_sve_asm = yes; then
> +  AC_DEFINE(HAVE_AARCH64_SVE_ASM)
> +fi
> -- 
> 2.17.1
>