On Tue, Aug 6, 2024 at 6:19 PM Alexander Monakov <[email protected]> wrote:
>
> Upcoming patches first drop Binutils ISA support from SSE4.2 to SSSE3,
> then bump it to AVX2. Instead of fiddling with detection, just bump
> our configure check to AVX2 immediately: if by some accident somebody
> builds GCC without AVX2 support in the assembler, they will get SSE2
> vectorized lexer, which is not too slow.
OK.
> libcpp/ChangeLog:
>
> * config.in: Regenerate.
> * configure: Regenerate.
> * configure.ac: Check for AVX2 instead of SSE4.2.
> * lex.cc: Adjust for changed config macro.
> ---
> libcpp/config.in | 6 +++---
> libcpp/configure | 4 ++--
> libcpp/configure.ac | 6 +++---
> libcpp/lex.cc | 2 +-
> 4 files changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/libcpp/config.in b/libcpp/config.in
> index 253ef03a3d..a0ca9e4df4 100644
> --- a/libcpp/config.in
> +++ b/libcpp/config.in
> @@ -35,6 +35,9 @@
> */
> #undef HAVE_ALLOCA_H
>
> +/* Define to 1 if you can assemble AVX2 insns. */
> +#undef HAVE_AVX2
> +
> /* Define to 1 if you have the Mac OS X function
> CFLocaleCopyPreferredLanguages in the CoreFoundation framework. */
> #undef HAVE_CFLOCALECOPYPREFERREDLANGUAGES
> @@ -210,9 +213,6 @@
> /* Define to 1 if you have the `putc_unlocked' function. */
> #undef HAVE_PUTC_UNLOCKED
>
> -/* Define to 1 if you can assemble SSE4 insns. */
> -#undef HAVE_SSE4
> -
> /* Define to 1 if you have the <stddef.h> header file. */
> #undef HAVE_STDDEF_H
>
> diff --git a/libcpp/configure b/libcpp/configure
> index 32d6aaa306..74af097620 100755
> --- a/libcpp/configure
> +++ b/libcpp/configure
> @@ -9140,14 +9140,14 @@ case $target in
> int
> main ()
> {
> -asm ("pcmpestri %0, %%xmm0, %%xmm1" : : "i"(0))
> +asm ("vpshufb %ymm0, %ymm1, %ymm2")
> ;
> return 0;
> }
> _ACEOF
> if ac_fn_c_try_compile "$LINENO"; then :
>
> -$as_echo "#define HAVE_SSE4 1" >>confdefs.h
> +$as_echo "#define HAVE_AVX2 1" >>confdefs.h
>
> fi
> rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
> diff --git a/libcpp/configure.ac b/libcpp/configure.ac
> index b883fec776..cfefb63552 100644
> --- a/libcpp/configure.ac
> +++ b/libcpp/configure.ac
> @@ -197,9 +197,9 @@ fi
>
> case $target in
> i?86-* | x86_64-*)
> - AC_TRY_COMPILE([], [asm ("pcmpestri %0, %%xmm0, %%xmm1" : : "i"(0))],
> - [AC_DEFINE([HAVE_SSE4], [1],
> - [Define to 1 if you can assemble SSE4 insns.])])
> + AC_TRY_COMPILE([], [asm ("vpshufb %ymm0, %ymm1, %ymm2")],
> + [AC_DEFINE([HAVE_AVX2], [1],
> + [Define to 1 if you can assemble AVX2 insns.])])
> esac
>
> # Enable --enable-host-shared.
> diff --git a/libcpp/lex.cc b/libcpp/lex.cc
> index 1591dcdf15..fa9c03614c 100644
> --- a/libcpp/lex.cc
> +++ b/libcpp/lex.cc
> @@ -344,7 +344,7 @@ search_line_sse2 (const uchar *s, const uchar *end
> ATTRIBUTE_UNUSED)
> return (const uchar *)p + found;
> }
>
> -#ifdef HAVE_SSE4
> +#ifdef HAVE_AVX2
> /* A version of the fast scanner using SSE 4.2 vectorized string insns. */
>
> static const uchar *
> --
> 2.44.0
>
