configure: detect ifunc and avx2 attribute

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.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Liang Li <liang.z.li@intel.com>
Message-Id: <1457416397-26671-2-git-send-email-liang.z.li@intel.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
This commit is contained in:
Liang Li 2016-03-08 13:53:16 +08:00 committed by Amit Shah
parent 614e8018ed
commit 99f2dbd343

21
configure vendored
View File

@ -280,6 +280,7 @@ libusb=""
usb_redir=""
opengl=""
opengl_dmabuf="no"
avx2_opt="no"
zlib="yes"
lzo=""
snappy=""
@ -1773,6 +1774,21 @@ EOF
fi
##########################################
# avx2 optimization requirement check
cat > $TMPC << EOF
static void bar(void) {}
static void *bar_ifunc(void) {return (void*) bar;}
static void foo(void) __attribute__((ifunc("bar_ifunc")));
int main(void) { foo(); return 0; }
EOF
if compile_prog "-mavx2" "" ; then
if readelf --syms $TMPE |grep "IFUNC.*foo" >/dev/null 2>&1; then
avx2_opt="yes"
fi
fi
#########################################
# zlib check
if test "$zlib" != "no" ; then
@ -4790,6 +4806,7 @@ 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"
@ -5178,6 +5195,10 @@ if test "$opengl" = "yes" ; then
fi
fi
if test "$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