diff --git a/llvm-runtimes/offload/Manifest b/llvm-runtimes/offload/Manifest
index 4abfec7d21eb1..3bdf6b204b033 100644
--- a/llvm-runtimes/offload/Manifest
+++ b/llvm-runtimes/offload/Manifest
@@ -7,5 +7,7 @@ DIST llvm-project-20.1.8.src.tar.xz 147242952 BLAKE2B 7657ac0b26acc5affb1bfc91b9
 DIST llvm-project-20.1.8.src.tar.xz.sig 566 BLAKE2B 85beedfcff1195a974fab2c667b9efd4b715b3480c1b44b1b887fe32c69f72aca0d3b8fb276c03b6cc5a866622f669047aeee5ccb976640b4008ccd31dce77a4 SHA512 d74369bdb4d1b82775161ea53c9c5f3a23ce810f4df5ff617123023f9d8ce720e7d6ecc9e17f8ebd39fd9e7a9de79560abdf2ffe73bcb907a43148d43665d619
 DIST llvm-project-21.1.0-rc2.src.tar.xz 158947868 BLAKE2B 8de20b0bf5219de12240561c3049de09a3253e1ebe33f84533d3f1f2ee9794b09fe2b6aca0b2fb15542b37b901be7bd3e00306cfd266ab59e2703046bcbcaf3d SHA512 0599cbe3d11d9135c355d5c60fdfda98a9689768f41baba0b8981769cc836eba8d226364d601031413c5f43ae1c4dda080ab910d60c983367b438fa32903d173
 DIST llvm-project-21.1.0-rc2.src.tar.xz.sig 438 BLAKE2B 7090c7a98e01e7bf600e4fbb23ad28d2e3bd8e72938863b59c7be8be0de2e1b3e3e2a981955165b833a95992ee086fd525919af7bcd7761073800486b3be3363 SHA512 dbe6cdd544b84d18b51f187e612de8ec05eeb9f1b462b7c4921697aaf6c6b0a00a6f4d3cf320a61cf57a886f11d47049bb5fa817f8bf835991a01b5e4a2d8c0a
+DIST llvm-project-21.1.0-rc3.src.tar.xz 158924056 BLAKE2B 5f3f46a499120c810a944361468cdea64cc29fa41a1c1f4549b1a845e6a36c891cd4af0a9fafda00663f73de61ef2658bf0640b68020cdebb7cb8446ba1cbf09 SHA512 3b84b2c9d8b164983890f797301591b5e20a54adc035b196db9a7f6a19e6ac13fe24d1c7816fe62ac87f853e5b4b9decf177046c43caed8e62ab8e8df574a2ef
+DIST llvm-project-21.1.0-rc3.src.tar.xz.sig 438 BLAKE2B 1a339fe00c27cddc508b369c4007e501266df42fbe0f448df3eecbf853ffa2915a6beef26e69c38169d37c12edcf60ac7c8ca5c0ae671b4c593356ccc6f3e3d5 SHA512 df8b3f747858fbb8c662899e6ea792556405cee2318be125a04e7b94c6dcebbed3ff01890f5e0c52e13b251243cfd1194806cf5ef52b482ae67d68be585574ad
 DIST llvm-project-92164faf17d553359418b9f49c1a41d680d0de49.tar.gz 245033829 BLAKE2B 7bf707e6455259417864a40c53beba4c4a9f6e4cf983671075016b95e537d2c249f97444089734718b5f2c989a2614028bd22142ccadae9c382e66b28758ecab SHA512 bf4105173144e6bb9cdc99ae67b7350228b37eae248c15aae2ce29877a8ee4cb76781a6beff366961fa366d31683b43421d684d019e25f0280735ccd6c22a432
 DIST llvm-project-b075dadbd3e0e928bdeddb3d36af64e8a383e305.tar.gz 244584834 BLAKE2B e6924d5fcc90431bdf859c3d728e44c348fa8ec336967c95fa9d253519c7bf9b3b200048ff8910eea78e5481a11704330ad72960fe753930036f75bca5b163b7 SHA512 80232cd00a2981392cf9fb22daceb164f965d5d5c9edb431226713a5e2f75ba5aaf747329ae5f4b852fd5e7f0be62ad978529080b4dce1bac7af480905b61c3b
diff --git a/llvm-runtimes/offload/offload-21.1.0_rc3.ebuild b/llvm-runtimes/offload/offload-21.1.0_rc3.ebuild
new file mode 100644
index 0000000000000..5f4ab86974966
--- /dev/null
+++ b/llvm-runtimes/offload/offload-21.1.0_rc3.ebuild
@@ -0,0 +1,145 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+PYTHON_COMPAT=( python3_{11..14} )
+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}"
+		-DOFFLOAD_INCLUDE_TESTS=$(usex test)
+		-DLIBOMPTARGET_PLUGINS_TO_BUILD="${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}"
+		# force using shared libffi
+		-DFFI_STATIC_LIBRARIES=NO
+	)
+
+	[[ ! ${LLVM_ALLOW_GPU_TESTING} ]] && mycmakeargs+=(
+		# prevent trying to access the GPU
+		-DLIBOMPTARGET_AMDGPU_ARCH=LIBOMPTARGET_AMDGPU_ARCH-NOTFOUND
+		-DLIBOMPTARGET_NVPTX_ARCH=LIBOMPTARGET_NVPTX_ARCH-NOTFOUND
+	)
+	use test && mycmakeargs+=(
+		# this project does not use standard LLVM cmake macros
+		-DOPENMP_LLVM_LIT_EXECUTABLE="${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
+}