diff --git a/dev-lang/ispc/ispc-1.22.0-r1.ebuild b/dev-lang/ispc/ispc-1.22.0-r1.ebuild
index 7b18a7303e8a2..d05fa1f7195e3 100644
--- a/dev-lang/ispc/ispc-1.22.0-r1.ebuild
+++ b/dev-lang/ispc/ispc-1.22.0-r1.ebuild
@@ -21,12 +21,13 @@ SRC_URI="
 LICENSE="BSD BSD-2 UoI-NCSA"
 SLOT="0"
 KEYWORDS="~amd64 ~arm ~arm64 ~ppc64 ~x86"
-IUSE="examples openmp test"
+IUSE="examples gpu openmp test"
 RESTRICT="!test? ( test )"
 
 DEPEND="
 	<sys-devel/clang-$((${LLVM_MAX_SLOT} + 1)):=
 	sys-libs/ncurses:=
+	gpu? ( dev-libs/level-zero:= )
 	!openmp? ( dev-cpp/tbb:= )
 "
 RDEPEND="
@@ -57,6 +58,14 @@ src_prepare() {
 		sed -i -e 's:set(target_arch "i686"):return():' cmake/GenerateBuiltins.cmake || die
 	fi
 
+	# do not require bundled gtest
+	mkdir -p ispcrt/tests/vendor/google/googletest || die
+	cat > ispcrt/tests/vendor/google/googletest/CMakeLists.txt <<-EOF || die
+		find_package(GTest)
+	EOF
+	# remove hacks that break unbundling
+	sed -i -e '/gmock/d' -e '/install/,$d' ispcrt/tests/CMakeLists.txt || die
+
 	cmake_src_prepare
 }
 
@@ -67,6 +76,7 @@ src_configure() {
 		-DISPC_INCLUDE_EXAMPLES=OFF
 		-DISPC_INCLUDE_TESTS=$(usex test)
 		-DISPC_INCLUDE_UTILS=OFF
+		-DISPCRT_BUILD_GPU=$(usex gpu)
 		-DISPCRT_BUILD_TASK_MODEL=$(usex openmp OpenMP TBB)
 	)
 	cmake_src_configure
diff --git a/dev-lang/ispc/metadata.xml b/dev-lang/ispc/metadata.xml
index eb96ff15c20ad..1ac64e1abb824 100644
--- a/dev-lang/ispc/metadata.xml
+++ b/dev-lang/ispc/metadata.xml
@@ -9,6 +9,9 @@
 		<remote-id type="github">ispc/ispc</remote-id>
 	</upstream>
 	<use>
+		<flag name="gpu">
+			Enable Level0 GPU support in ispcrt.
+		</flag>
 		<flag name="openmp">
 			Build with OpenMP task model (otherwise, TBB task model is used).
 		</flag>
diff --git a/profiles/arch/amd64/package.use.mask b/profiles/arch/amd64/package.use.mask
index 9d39b1452131d..1a2f77a0990a6 100644
--- a/profiles/arch/amd64/package.use.mask
+++ b/profiles/arch/amd64/package.use.mask
@@ -17,6 +17,10 @@
 
 #--- END OF EXAMPLES ---
 
+# Michał Górny <mgorny@gentoo.org> (2023-12-31)
+# Requires dev-libs/level-zero.
+dev-lang/ispc -gpu
+
 # Andrew Ammerlaan <andrewammerlaan@gentoo.org> (2023-12-18)
 # Experimental and only available on a subset of architectures
 sys-kernel/gentoo-kernel -generic-uki
diff --git a/profiles/arch/base/package.use.mask b/profiles/arch/base/package.use.mask
index bf44291817272..65c07619a41af 100644
--- a/profiles/arch/base/package.use.mask
+++ b/profiles/arch/base/package.use.mask
@@ -1,6 +1,10 @@
 # Copyright 1999-2023 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
+# Michał Górny <mgorny@gentoo.org> (2023-12-31)
+# Requires dev-libs/level-zero.
+dev-lang/ispc gpu
+
 # Andrew Ammerlaan <andrewammerlaan@gentoo.org> (2023-12-18)
 # Experimental and only available on a subset of architectures
 sys-kernel/gentoo-kernel generic-uki
diff --git a/profiles/features/musl/package.use.mask b/profiles/features/musl/package.use.mask
index 7e616368e8226..c9b7d23aaca60 100644
--- a/profiles/features/musl/package.use.mask
+++ b/profiles/features/musl/package.use.mask
@@ -1,6 +1,10 @@
 # Copyright 1999-2023 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
+# Michał Górny <mgorny@gentoo.org> (2023-12-31)
+# Requires dev-libs/level-zero.
+dev-lang/ispc gpu
+
 # Andrew Ammerlaan <andrewammerlaan@gentoo.org> (2023-12-18)
 # Requires systemd
 sys-kernel/gentoo-kernel generic-uki