--- /usr/portage/media-libs/mesa/mesa-18.3.0_rc2.ebuild	2018-11-12 22:09:34.000000000 +0300
+++ mesa-18.3.0_rc2.ebuild	2018-11-14 21:01:51.247243610 +0300
@@ -5,7 +5,7 @@ EAPI=6
 
 PYTHON_COMPAT=( python3_4 python3_5 python3_6 python3_7 )
 
-inherit llvm meson multilib-minimal pax-utils python-any-r1
+inherit llvm meson multilib-minimal pax-utils python-any-r1 toolchain-funcs
 
 OPENGL_DIR="xorg-x11"
 
@@ -38,7 +38,8 @@ done
 IUSE="${IUSE_VIDEO_CARDS}
 	+classic d3d9 debug +dri3 +egl +gallium +gbm gles1 gles2 +llvm lm_sensors
 	opencl osmesa pax_kernel pic selinux test unwind vaapi valgrind vdpau
-	vulkan wayland xa xvmc"
+	vulkan wayland xa xvmc cpu_flags_x86_avx cpu_flags_x86_avx2
+	cpu_flags_x86_avx512f cpu_flags_x86_avx512er cpu_flags_x86_avx512bw"
 
 REQUIRED_USE="
 	d3d9?   ( dri3 || ( video_cards_r300 video_cards_r600 video_cards_radeonsi video_cards_nouveau video_cards_vmware ) )
@@ -313,6 +314,12 @@ pkg_setup() {
 	python-any-r1_pkg_setup
 }
 
+src_prepare(){
+	default
+	# must be regenerated
+	rm -f "src/gallium/drivers/swr/rasterizer/jitter/gen_builder.hpp"
+}
+
 multilib_src_configure() {
 	local emesonargs=()
 
@@ -437,6 +444,36 @@ multilib_src_configure() {
 	fi
 
 	if use gallium; then
+		local swr=
+		# build swr feature modules from CFLAGS to useflags cpu_flags_x86_*
+		# less then CFLAGS - never be used, more - can (upgrade or bindist)
+		if [[ ${ABI} == amd64 ]] && use llvm; then
+			local i test='#if defined(__AVX512F__) && defined(__AVX512ER__)
+#error knl
+#elif defined(__AVX512F__) && defined(__AVX512BW__)
+#error skx
+#elif defined(__AVX2__)
+#error avx2
+#elif defined(__AVX__)
+#error avx
+#endif'
+			test=$(echo "$test"|$(tc-getCPP) - -o /dev/null ${CFLAGS} 2>&1|head -n 1)
+			test=${test##* }
+			for i in knl skx avx2 avx; do
+				case $i in
+				knl)use cpu_flags_x86_avx512f && use cpu_flags_x86_avx512er || continue;;
+				skx)use cpu_flags_x86_avx512f && use cpu_flags_x86_avx512bw || continue;;
+				*)use cpu_flags_x86_$i || continue;;
+				esac
+				swr+=,$i
+				[[ "$test" == $i ]] && break
+			done
+			swr=${swr#,}
+		fi
+		if [[ -n "$swr" ]]; then
+			gallium_enable -- swr
+			emesonargs+=( -Dswr-arches=$swr )
+		fi
 		gallium_enable -- swrast
 		emesonargs+=( -Dosmesa=$(usex osmesa gallium none) )
 	else