sci-misc/stable-diffusion-cpp: cosmetic changes for GGML handling

Add some explicit comments and separations to GGML related variables
to ease synchronization with other projects embedding GGML
such as whisper.cpp, llama.cpp, etc.

Sort CMake variables by order of appearance (mostly) in CMakeList.txt.

Signed-off-by: Gilles Dartiguelongue <gilles.dartiguelongue@esiee.org>

sci-misc/stable-diffusion-cpp/stable-diffusion-cpp-9999.ebuild

@@ -25,16 +25,37 @@ fi
 
 LICENSE="MIT"
 SLOT="0"
-CPU_FLAGS_X86=( avx avx2 f16c )
 
-IUSE="openblas blis rocm cuda opencl vulkan flexiblas webm webp wmma"
+# GGML CPU flags
+X86_CPU_FLAGS=(
+	amx_bf16
+	amx_int8
+	amx_tile
+	avx
+	avx2
+	avx512_bf16
+	avx512_vnni
+	avx512f
+	avx512vbmi
+	avx_vnni
+	bmi2
+	f16c
+	fma3
+	sse4_2
+)
+CPU_FLAGS=( "${X86_CPU_FLAGS[@]/#/cpu_flags_x86_}" )
+GGML_IUSE="${CPU_FLAGS[*]} blis cuda flexiblas openblas opencl rocm vulkan"
+unset X86_CPU_FLAGS CPU_FLAGS
 
+IUSE="${GGML_IUSE} webm webp"
+unset GGML_IUSE
 REQUIRED_USE="
 	?? (
 		openblas
 		blis
 		flexiblas
 	)
+	rocm? ( ${ROCM_REQUIRED_USE} )
 	webm? (
 		webp
 	)
@@ -43,7 +64,7 @@ REQUIRED_USE="
 	)
 "
 
-CDEPEND="
+COMMON_DEPEND="
 	openblas? ( sci-libs/openblas:= )
 	blis? ( sci-libs/blis:= )
 	flexiblas? ( sci-libs/flexiblas:= )
@@ -58,12 +79,14 @@ CDEPEND="
 	webp? ( media-libs/libwebp )
 	webm? ( media-libs/libwebm )
 "
-DEPEND="${CDEPEND}
+DEPEND="${COMMON_DEPEND}
 	opencl? ( dev-util/opencl-headers )
-	vulkan? ( dev-util/vulkan-headers )
+	vulkan? (
+		dev-util/spirv-headers
+		dev-util/vulkan-headers
+	)
 "
-RDEPEND="${CDEPEND}
-	dev-python/numpy
+RDEPEND="${COMMON_DEPEND}
 	opencl? ( dev-libs/opencl-icd-loader )
 	vulkan? ( media-libs/vulkan-loader )
 "
@@ -87,17 +110,20 @@ src_prepare() {
 
 src_configure() {
 	local mycmakeargs=(
-		-DSD_BUILD_SHARED_LIBS=OFF
-		-DSD_SERVER_BUILD_FRONTEND=OFF # requires pnpm and network access
-		-DGGML_NATIVE=0	# don't set march
-		-DGGML_RPC=ON
-		-DSD_CUDA=$(usex cuda)
-		-DSD_OPENCL=$(usex opencl)
+		-DSD_BUILD_EXAMPLES=ON
 		-DSD_WEBP=$(usex webp)
 		-DSD_USE_SYSTEM_WEBP=$(usex webp)
 		-DSD_WEBM=$(usex webm)
 		-DSD_USE_SYSTEM_WEBM=$(usex webm)
+
+		# GGML features controls
+		-DSD_CUDA=$(usex cuda)
 		-DSD_VULKAN=$(usex vulkan)
+		-DSD_OPENCL=$(usex opencl)
+		-DSD_RPC=ON
+
+		-DSD_BUILD_SHARED_LIBS=OFF
+		-DSD_SERVER_BUILD_FRONTEND=OFF # requires pnpm and network access
 
 		# avoid clashing with sci-ml/ggml
 		-DCMAKE_INSTALL_INCLUDEDIR="include/${MY_PN}"
@@ -105,6 +131,27 @@ src_configure() {
 		-DCMAKE_INSTALL_RPATH="\$ORIGIN/../$(get_libdir)/${MY_PN};\$ORIGIN"
 	)
 
+	# GGML backends
+	mycmakeargs+=(
+		-DGGML_NATIVE=OFF	# don't set march
+
+		# CPU Flags
+		-DGGML_SSE42=$(usex cpu_flags_x86_sse4_2)
+		-DGGML_AVX=$(usex cpu_flags_x86_avx)
+		-DGGML_AVX_VNNI=$(usex cpu_flags_x86_avx_vnni)
+		-DGGML_AVX2=$(usex cpu_flags_x86_avx2)
+		-DGGML_BMI2=$(usex cpu_flags_x86_bmi2)
+		-DGGML_AVX512=$(usex cpu_flags_x86_avx512f)
+		-DGGML_AVX512_VBMI=$(usex cpu_flags_x86_avx512vbmi)
+		-DGGML_AVX512_VNNI=$(usex cpu_flags_x86_avx512_vnni)
+		-DGGML_AVX512_BF16=$(usex cpu_flags_x86_avx512_bf16)
+		-DGGML_FMA=$(usex cpu_flags_x86_fma3)
+		-DGGML_F16C=$(usex cpu_flags_x86_f16c)
+		-DGGML_AMX_TILE=$(usex cpu_flags_x86_amx_tile)
+		-DGGML_AMX_INT8=$(usex cpu_flags_x86_amx_int8)
+		-DGGML_AMX_BF16=$(usex cpu_flags_x86_amx_bf16)
+	)
+
 	if use openblas ; then
 		mycmakeargs+=(
 			-DGGML_BLAS=ON -DGGML_BLAS_VENDOR=OpenBLAS