feat: extend ggml_backend_reg_layla to support Metal backend

Author: l3utterfly

ggml/include/ggml-backend.h

@@ -202,7 +202,7 @@ extern "C" {
     //
     // Backend registry
     //
-    GGML_API void               ggml_backend_reg_layla(bool useVulkan, bool useOpenCL, bool useHexagon);
+    GGML_API void               ggml_backend_reg_layla(bool useVulkan, bool useOpenCL, bool useHexagon, bool useMetal);
 
     GGML_API void ggml_backend_device_register(ggml_backend_dev_t device);
 

ggml/src/ggml-backend-reg.cpp

@@ -159,6 +159,8 @@ struct ggml_backend_reg_entry {
     dl_handle_ptr handle;
 };
 
+static bool _useMetal = false;
+
 struct ggml_backend_registry {
     std::vector<ggml_backend_reg_entry> backends;
     std::vector<ggml_backend_dev_t> devices;
@@ -168,7 +170,8 @@ struct ggml_backend_registry {
         register_backend(ggml_backend_cuda_reg());
 #endif
 #ifdef GGML_USE_METAL
-        register_backend(ggml_backend_metal_reg());
+        if(_useMetal)
+            register_backend(ggml_backend_metal_reg());
 #endif
 #ifdef GGML_USE_SYCL
         register_backend(ggml_backend_sycl_reg());
@@ -334,7 +337,7 @@ int is_i8mm_supported()
 #endif
 }
 
-void ggml_backend_reg_layla(bool useVulkan, bool useOpenCL, bool useHexagon) {
+void ggml_backend_reg_layla(bool useVulkan, bool useOpenCL, bool useHexagon, bool useMetal) {
     if(useVulkan) {
         get_reg().load_backend("libggml-vulkan.so", false);
     }
@@ -347,6 +350,8 @@ void ggml_backend_reg_layla(bool useVulkan, bool useOpenCL, bool useHexagon) {
         get_reg().load_backend("libggml-hexagon.so", false);
     }
 
+    _useMetal = useMetal;
+
     // load cpu backend depending on feature detection
     if(is_i8mm_supported()) {
         get_reg().load_backend("libggml-blas.so", false);