On 20/01/2016 10:05, Liang Li wrote:
> Detect if the compiler can support the ifun and avx2, if so, set
> CONFIG_AVX2_OPT which will be used to turn on the avx2 instruction
> optimization.
>
> Signed-off-by: Liang Li <liang.z...@intel.com>
> ---
> configure | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/configure b/configure
> index 44ac9ab..b7f4661 100755
> --- a/configure
> +++ b/configure
> @@ -310,6 +310,7 @@ smartcard=""
> libusb=""
> usb_redir=""
> opengl=""
> +avx2_opt=""
> zlib="yes"
> lzo=""
> snappy=""
> @@ -1827,6 +1828,20 @@ EOF
> fi
>
> ##########################################
> +# avx2 optimization requirement check
> +
> +cat > $TMPC << EOF
> +static void bar(void) {}
Might be nicer to use "void *" and return an actual function name:
static void bar(void) {}
static void *bar_ifunc(void) { return (void *)bar; }
void foo(void) __attribute__((ifunc("bar_ifunc")));
And also you probably should use "readelf --syms ... | grep IFUNC.*foo"
to check that the attribute was not ignored.
Paolo
> +static void foo(void) __attribute__((ifunc("bar")));
> +int main(void) { foo(); return 0; }
> +EOF
> +if compile_prog "" "-mavx2" ; then
> + avx2_opt="yes"
> +else
> + avx2_opt="no"
> +fi
> +
> +#########################################
> # zlib check
>
> if test "$zlib" != "no" ; then
> @@ -4855,6 +4870,7 @@ echo "bzip2 support $bzip2"
> echo "NUMA host support $numa"
> echo "tcmalloc support $tcmalloc"
> echo "jemalloc support $jemalloc"
> +echo "avx2 optimization $avx2_opt"
>
> if test "$sdl_too_old" = "yes"; then
> echo "-> Your SDL version is too old - please upgrade to have SDL support"
> @@ -5236,6 +5252,10 @@ if test "$opengl" = "yes" ; then
> echo "OPENGL_LIBS=$opengl_libs" >> $config_host_mak
> fi
>
> +if test "$avx2_opt" = "yes" ; then
> + echo "CONFIG_AVX2_OPT=y" >> $config_host_mak
> +fi
> +
> if test "$lzo" = "yes" ; then
> echo "CONFIG_LZO=y" >> $config_host_mak
> fi
>
