mtl : adapt the MNIST example as starter

examples/mtl/CMakeLists.txt

@@ -2,6 +2,28 @@ set(TARGET mtl-export)
 add_executable(${TARGET} mtl-export.cpp)
 target_link_libraries(${TARGET} PRIVATE common llama ${CMAKE_THREAD_LIBS_INIT})
 target_compile_features(${TARGET} PRIVATE cxx_std_11)
+
 if(TARGET BUILD_INFO)
   add_dependencies(${TARGET} BUILD_INFO)
 endif()
+
+if (APPLE)
+    #
+    # mtl
+
+    find_library(FOUNDATION_LIBRARY Foundation REQUIRED)
+    find_library(METAL_FRAMEWORK    Metal      REQUIRED)
+    find_library(METALKIT_FRAMEWORK MetalKit   REQUIRED)
+    find_library(METALPERFORMANCE_FRAMEWORK MetalPerformanceShaders REQUIRED)
+
+    set(TEST_TARGET mtl)
+    add_executable(${TEST_TARGET} mtl.cpp mtl.h mtl.m)
+    target_link_libraries(${TEST_TARGET} PRIVATE
+        ggml
+        ${FOUNDATION_LIBRARY}
+        ${METAL_FRAMEWORK}
+        ${METALKIT_FRAMEWORK}
+        ${METALPERFORMANCE_FRAMEWORK}
+    )
+endif()
+

examples/mtl/mtl.cpp

@@ -0,0 +1,52 @@
+#include "ggml.h"
+#include "mtl.h"
+
+#include <cstdio>
+#include <cstring>
+#include <cstdlib>
+
+int main(int argc, char ** argv) {
+    ggml_time_init();
+
+    if (argc != 2) {
+        fprintf(stderr, "Usage: %s llama.ggml\n", argv[0]);
+        return -1;
+    }
+
+    const char * fname_cgraph = argv[1];
+
+    // load the compute graph
+    struct ggml_context * ctx_data = NULL;
+    struct ggml_context * ctx_eval = NULL;
+
+    struct ggml_cgraph gf = ggml_graph_import(fname_cgraph, &ctx_data, &ctx_eval);
+    gf.n_threads = 1;
+
+    // allocate eval context
+    // needed during ggml_graph_compute() to allocate a work tensor
+    static size_t buf_size = gf.work_size; // TODO
+    static void * buf = malloc(buf_size);
+
+    struct ggml_init_params params = {
+        /*.mem_size   =*/ buf_size,
+        /*.mem_buffer =*/ buf,
+        /*.no_alloc   =*/ false,
+    };
+
+    struct ggml_context * ctx_work = ggml_init(params);
+
+    // this allocates all Metal resources and memory buffers
+    auto * ctx_mtl = llama_mtl_init(ctx_data, ctx_eval, ctx_work, &gf);
+
+    // the actual inference happens here
+    llama_mtl_eval(ctx_mtl, &gf);
+
+    llama_mtl_free(ctx_mtl);
+
+    ggml_free(ctx_work);
+    ggml_free(ctx_data);
+    ggml_free(ctx_eval);
+
+    return 0;
+}
+

examples/mtl/mtl.h

@@ -0,0 +1,28 @@
+#pragma once
+
+struct ggml_context;
+struct ggml_cgraph;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct ggml_mtl_context;
+
+struct ggml_mtl_context * llama_mtl_init(
+        struct ggml_context * ctx_data,
+        struct ggml_context * ctx_eval,
+        struct ggml_context * ctx_work,
+        struct ggml_cgraph  * gf);
+
+void llama_mtl_free(struct ggml_mtl_context * ctx);
+
+// return 0 on success
+int llama_mtl_eval(
+        struct ggml_mtl_context * ctx,
+        struct ggml_cgraph      * gf);
+
+#ifdef __cplusplus
+}
+#endif
+