diff --git a/llvm-runtimes/offload/Manifest b/llvm-runtimes/offload/Manifest
index e9c79d71cb83b..1e3cae8a4390c 100644
--- a/llvm-runtimes/offload/Manifest
+++ b/llvm-runtimes/offload/Manifest
@@ -7,3 +7,4 @@ DIST llvm-project-20.1.4.src.tar.xz.sig 566 BLAKE2B 1f0f057dedf938190554ca1a51d9
 DIST llvm-project-ac8fc09688e10e983b99224b5dc5cbbeeedb1879.tar.gz 231567089 BLAKE2B f7878f114c908b21d179854bc693716b34b963612c6b5172789a37cd21fa316720d4e9498bc7679058db3e822ed240bfdafd85bfd00154914d747d0c0ed1cb48 SHA512 4c39db8b22fa087ca96c3b4541ec77ba8a826a126b4e93b0650e59b3622b22b329f60fa3780dd4572fdece409fd5833eda473046d7547f6ee3ac8aadb8f2fc34
 DIST llvm-project-b9e32749d273a957e60170d6e7ef205fd1fb1834.tar.gz 232146799 BLAKE2B f7c02bf1e6b9958114f07827ff00264774a7ad54b51c6867d7e66d7c9a94a36fb84f371d7d30c2f094a0d539b565fb651786ed9e0641f2bea8d982073f1a8ac0 SHA512 2d81ead79c606e00549d5205584f1bd272e4d7adf4b376fdba19e7fb719710e80b00b22ee3500ab2b990178fa044ca9fcf45bd2063e62e6a217b11775bb3b163
 DIST llvm-project-d1e38eab95b07b422194427474521623916bbf29.tar.gz 232705423 BLAKE2B bf5200c2223d8cdf7c34c84876d8cfeb9429cb6535ced226b1bf9ab468b6401fe3da8759f0fc1ab3112927304c5f74db29b18be60fa961ce99471caa2c6a1f33 SHA512 8fae137725ad4eb0f5bab73895c65b34d1e36ea039c9fb3978c908ecc6023094d84919b97dc405b86e2dd32f585d87b29cee02293c8156d10a8371b516ca5e7a
+DIST llvm-project-fcb4bda9dcfcdb64d8b069e8416c75d7a1a62e52.tar.gz 233149231 BLAKE2B 95a7a012a1e747afcf83ace3785c8ef6a3e10f6075e59eb1c5b077cc9edae244b648f341bc0ac6a45b2afc8f7ffe130a90a741a04465523f30f8322566386703 SHA512 b46f0c90a1c56750cada24183ca382b267a2d2faa0db7d77a8bdd4e94e6303e57d565cf85447b3c0e0efdd3750efef1e10e8ce6f1fe8f1ae10ee31d25ddf3fb7
diff --git a/llvm-runtimes/offload/offload-21.0.0_pre20250510.ebuild b/llvm-runtimes/offload/offload-21.0.0_pre20250510.ebuild
new file mode 100644
index 0000000000000..57e770784ba80
--- /dev/null
+++ b/llvm-runtimes/offload/offload-21.0.0_pre20250510.ebuild
@@ -0,0 +1,142 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+PYTHON_COMPAT=( python3_{10..13} )
+inherit cmake crossdev flag-o-matic llvm.org python-any-r1
+inherit toolchain-funcs
+
+DESCRIPTION="OpenMP offloading support"
+HOMEPAGE="https://openmp.llvm.org"
+
+LICENSE="Apache-2.0-with-LLVM-exceptions || ( UoI-NCSA MIT )"
+SLOT="0/${LLVM_SOABI}"
+IUSE="+clang +debug ompt test llvm_targets_AMDGPU llvm_targets_NVPTX"
+REQUIRED_USE="
+	llvm_targets_AMDGPU? ( clang )
+	llvm_targets_NVPTX? ( clang )
+"
+RESTRICT="!test? ( test )"
+
+RDEPEND="
+	dev-libs/libffi:=
+	~llvm-core/llvm-${PV}
+	~llvm-runtimes/openmp-${PV}[ompt?]
+	llvm_targets_AMDGPU? ( dev-libs/rocr-runtime:= )
+"
+DEPEND="
+	${RDEPEND}
+"
+# tests:
+# - dev-python/lit provides the test runner
+# - llvm-core/llvm provide test utils (e.g. FileCheck)
+# - llvm-core/clang provides the compiler to run tests
+BDEPEND="
+	dev-lang/perl
+	virtual/pkgconfig
+	clang? ( llvm-core/clang )
+	llvm_targets_AMDGPU? ( llvm-core/clang[llvm_targets_AMDGPU] )
+	llvm_targets_NVPTX? ( llvm-core/clang[llvm_targets_NVPTX] )
+	test? (
+		$(python_gen_any_dep '
+			dev-python/lit[${PYTHON_USEDEP}]
+		')
+		llvm-core/clang
+	)
+"
+
+LLVM_COMPONENTS=( offload cmake runtimes/cmake libc )
+LLVM_TEST_COMPONENTS=( openmp/cmake )
+llvm.org_set_globals
+
+pkg_pretend() {
+	if [[ ${LLVM_ALLOW_GPU_TESTING} ]]; then
+		ewarn "LLVM_ALLOW_GPU_TESTING set.  This package will run tests against your"
+		ewarn "GPU if it is supported.  Note that these tests may be flaky, fail or"
+		ewarn "hang, or even cause your GPU to crash (requiring a reboot)."
+	fi
+}
+
+python_check_deps() {
+	python_has_version "dev-python/lit[${PYTHON_USEDEP}]"
+}
+
+pkg_setup() {
+	if use test; then
+		python-any-r1_pkg_setup
+	fi
+}
+
+src_configure() {
+	if use clang && ! is_crosspkg; then
+		# Only do this conditionally to allow overriding with
+		# e.g. CC=clang-13 in case of breakage
+		if ! tc-is-clang ; then
+			local -x CC=${CHOST}-clang
+			local -x CXX=${CHOST}-clang++
+		fi
+
+		strip-unsupported-flags
+	fi
+
+	# LLVM_ENABLE_ASSERTIONS=NO does not guarantee this for us, #614844
+	use debug || local -x CPPFLAGS="${CPPFLAGS} -DNDEBUG"
+
+	local libdir="$(get_libdir)"
+	local ffi_cflags=$($(tc-getPKG_CONFIG) --cflags-only-I libffi)
+	local ffi_ldflags=$($(tc-getPKG_CONFIG) --libs-only-L libffi)
+	local plugins="host"
+	local build_devicertl=FALSE
+
+	if has "${CHOST%%-*}" aarch64 powerpc64le x86_64; then
+		if use llvm_targets_AMDGPU; then
+			plugins+=";amdgpu"
+			build_devicertl=TRUE
+		fi
+		if use llvm_targets_NVPTX; then
+			plugins+=";cuda"
+			build_devicertl=TRUE
+		fi
+	fi
+
+	local mycmakeargs=(
+		-DLLVM_ROOT="${ESYSROOT}/usr/lib/llvm/${LLVM_MAJOR}"
+
+		-DOFFLOAD_LIBDIR_SUFFIX="${libdir#lib}"
+		-DLIBOMPTARGET_PLUGINS_TO_BUILD="${plugins}"
+		-DLIBOMPTARGET_OMPT_SUPPORT="$(usex ompt)"
+		-DLIBOMPTARGET_BUILD_DEVICERTL_BCLIB="${build_devicertl}"
+
+		# this breaks building static target libs
+		-DBUILD_SHARED_LIBS=OFF
+
+		-DFFI_INCLUDE_DIR="${ffi_cflags#-I}"
+		-DFFI_LIBRARY_DIR="${ffi_ldflags#-L}"
+	)
+
+	[[ ! ${LLVM_ALLOW_GPU_TESTING} ]] && mycmakeargs+=(
+		# prevent trying to access the GPU
+		-DLIBOMPTARGET_AMDGPU_ARCH=LIBOMPTARGET_AMDGPU_ARCH-NOTFOUND
+		-DLIBOMPTARGET_NVPTX_ARCH=LIBOMPTARGET_NVPTX_ARCH-NOTFOUND
+	)
+	use test && mycmakeargs+=(
+		# this project does not use standard LLVM cmake macros
+		-DOPENMP_LLVM_LIT_EXECUTABLE="${EPREFIX}/usr/bin/lit"
+		-DOPENMP_LIT_ARGS="$(get_lit_flags)"
+
+		-DOPENMP_TEST_C_COMPILER="$(type -P "${CHOST}-clang")"
+		-DOPENMP_TEST_CXX_COMPILER="$(type -P "${CHOST}-clang++")"
+		# requires flang
+		-DOPENMP_TEST_Fortran_COMPILER=
+	)
+
+	cmake_src_configure
+}
+
+src_test() {
+	# respect TMPDIR!
+	local -x LIT_PRESERVES_TMP=1
+
+	cmake_build check-offload
+}