--- /dev/null
+# Copyright 1999-2020 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+
+inherit toolchain-funcs
+
+DESCRIPTION="Free UCI chess engine, claimed to be the strongest in the world"
+HOMEPAGE="https://stockfishchess.org/"
+
+SRC_URI="https://github.com/official-stockfish/Stockfish/archive/sf_${PV}.zip -> ${P}.zip"
+LICENSE="GPL-3"
+SLOT="0"
+KEYWORDS="~amd64 ~x86"
+IUSE="cpu_flags_arm_v7 cpu_flags_x86_avx2 cpu_flags_x86_popcnt cpu_flags_x86_sse debug
+ general-32 general-64 +optimize"
+
+DEPEND="|| ( app-arch/unzip app-arch/zip )"
+RDEPEND=""
+
+S="${WORKDIR}/Stockfish-sf_${PV}/src"
+
+src_prepare() {
+ default
+
+ # prevent pre-stripping
+ sed -e 's:-strip $(BINDIR)/$(EXE)::' -i Makefile \
+ || die 'failed to disable stripping in the Makefile'
+}
+
+src_compile() {
+ local my_arch
+
+ # generic unoptimized first
+ use general-32 && my_arch=general-32
+ use general-64 && my_arch=general-64
+
+ # x86
+ use x86 && my_arch=x86-32-old
+ use cpu_flags_x86_sse && my_arch=x86-32
+
+ # amd64
+ use amd64 && my_arch=x86-64
+ use cpu_flags_x86_popcnt && my_arch=x86-64-modern
+
+ # both bmi2 and avx2 are part of hni (haswell new instructions)
+ use cpu_flags_x86_avx2 && my_arch=x86-64-bmi2
+
+ # other architectures
+ use cpu_flags_arm_v7 && my_arch=armv7
+ use ppc && my_arch=ppc
+ use ppc64 && my_arch=ppc64
+
+ # Skip the "build" target and use "all" instead to avoid the config
+ # sanity check (which would throw a fit about our compiler). There's
+ # a nice hack in the Makefile that overrides the value of CXX with
+ # COMPILER to support Travis CI and we abuse it to make sure that we
+ # build with our compiler of choice.
+ emake all ARCH="${my_arch}" \
+ COMP=$(tc-getCXX) \
+ COMPILER=$(tc-getCXX) \
+ debug=$(usex debug "yes" "no") \
+ optimize=$(usex optimize "yes" "no")
+}
+
+src_install() {
+ dobin "${PN}"
+ dodoc ../AUTHORS ../Readme.md
+}