sci-ml/ollama: 9999 refactor blas handling

Use code for potential `blas-utils.eclass`.
Correctly forwarding the flexiblas dep to virtual/blas should fix failing
`BLAS=Generic` case.

Closes: https://bugs.gentoo.org/969379
Signed-off-by: Paul Zander <negril.nx+gentoo@gmail.com>

sci-ml/ollama/metadata.xml

@@ -6,8 +6,11 @@
 		<name>Paul Zander</name>
 	</maintainer>
 	<use>
+		<flag name="blis">Use <pkg>sci-libs/blis</pkg> as blas provider</flag>
 		<flag name="cuda">Enable NVIDIA CUDA support</flag>
+		<flag name="flexiblas">Use <pkg>sci-libs/flexiblas</pkg> as blas provider</flag>
 		<flag name="mkl">Use <pkg>sci-libs/mkl</pkg> for blas, lapack and sparse blas routines</flag>
+		<flag name="openblas">Use <pkg>sci-libs/openblas</pkg> as blas provider</flag>
 		<flag name="rocm">Enable ROCm gpu computing support</flag>
 	</use>
 	<upstream>

sci-ml/ollama/ollama-9999.ebuild

@@ -26,9 +26,15 @@ fi
 LICENSE="MIT"
 SLOT="0"
 
-IUSE="blas cuda rocm mkl vulkan"
+IUSE="cuda rocm vulkan"
 # IUSE+=" opencl"
 
+BLAS_BACKENDS="blis mkl openblas"
+BLAS_REQUIRED_USE="blas? ( ?? ( ${BLAS_BACKENDS} ) )"
+
+IUSE+=" blas flexiblas ${BLAS_BACKENDS}"
+REQUIRED_USE+=" ${BLAS_REQUIRED_USE}"
+
 declare -rgA CPU_FEATURES=(
 	[AVX2]="x86"
 	[AVX512F]="x86"
@@ -51,14 +57,24 @@ add_cpu_features_use
 
 RESTRICT="mirror test"
 
+# FindBLAS.cmake
+# If Fortran is an enabled compiler it sets BLAS_mkl_THREADING to gnu. -> sci-libs/mkl[gnu-openmp]
+# If Fortran is not an enabled compiler it sets BLAS_mkl_THREADING to intel. -> sci-libs/mkl[llvm-openmp]
 COMMON_DEPEND="
 	blas? (
-		!mkl? (
+		blis? (
-			virtual/blas
+			sci-libs/blis:=
+		)
+		flexiblas? (
+			sci-libs/flexiblas[blis?,mkl?,openblas?]
 		)
 		mkl? (
 			sci-libs/mkl[llvm-openmp]
 		)
+		openblas? (
+			sci-libs/openblas
+		)
+		virtual/blas[flexiblas=]
 	)
 	cuda? (
 		dev-util/nvidia-cuda-toolkit:=
@@ -264,10 +280,26 @@ src_configure() {
 	)
 
 	if use blas; then
-		if use mkl; then
+		if use flexiblas ; then
+			mycmakeargs+=(
+				-DGGML_BLAS_VENDOR="FlexiBLAS"
+			)
+		elif use blis ; then
+			mycmakeargs+=(
+				-DGGML_BLAS_VENDOR="FLAME"
+			)
+		elif use mkl ; then
 			mycmakeargs+=(
 				-DGGML_BLAS_VENDOR="Intel10_64lp"
 			)
+		# elif use nvhpc ; then
+		# 	mycmakeargs+=(
+		# 		-DGGML_BLAS_VENDOR="NVHPC"
+		# 	)
+		elif use openblas ; then
+			mycmakeargs+=(
+				-DGGML_BLAS_VENDOR="OpenBLAS"
+			)
 		else
 			mycmakeargs+=(
 				-DGGML_BLAS_VENDOR="Generic"