From c9f6e5fd35852dc1499f2306aeb1ada2273f90ab Mon Sep 17 00:00:00 2001
From: PatStiles <pdstiles78@gmail.com>
Date: Wed, 30 Oct 2024 00:32:22 -0300
Subject: [PATCH] create metal backend lib + add interface

---
 icicle/backend/metal/CMakeLists.txt       |  44 +++++++++
 icicle/backend/metal/metal_device_api.cpp | 107 ++++++++++++++++++++++
 2 files changed, 151 insertions(+)
 create mode 100644 icicle/backend/metal/CMakeLists.txt
 create mode 100644 icicle/backend/metal/metal_device_api.cpp

diff --git a/icicle/backend/metal/CMakeLists.txt b/icicle/backend/metal/CMakeLists.txt
new file mode 100644
index 000000000..985aba7b3
--- /dev/null
+++ b/icicle/backend/metal/CMakeLists.txt
@@ -0,0 +1,44 @@
+cmake_minimum_required(VERSION 3.18)
+
+# CPU backend is built directly into icicle library
+
+target_sources(icicle_device PRIVATE src/cpu_device_api.cpp)
+
+# field API library
+if (FIELD)
+    target_sources(icicle_field PRIVATE
+        src/field/cpu_vec_ops.cpp
+    )
+    if (NTT)
+        target_sources(icicle_field PRIVATE src/field/cpu_ntt.cpp src/polynomials/cpu_polynomial_backend.cpp)
+    endif()
+    if (POSEIDON)
+        target_sources(icicle_field PRIVATE src/hash/cpu_poseidon.cpp)
+    endif()
+    target_include_directories(icicle_field PRIVATE include)
+endif() # FIELD
+
+# curve API library
+if (CURVE)
+    target_sources(icicle_curve PRIVATE
+        src/curve/cpu_mont_conversion.cpp
+    )
+    if (MSM)
+        target_sources(icicle_curve PRIVATE src/curve/cpu_msm.cpp)
+    endif()
+    if (ECNTT)
+        target_sources(icicle_curve PRIVATE src/curve/cpu_ecntt.cpp)
+    endif()
+    # incdir is PUBLIC because config-extension headers are exposed to app
+    target_include_directories(icicle_curve PUBLIC include)
+endif()
+
+if (HASH)
+    target_sources(icicle_hash PRIVATE
+        src/hash/cpu_keccak.cpp
+        src/hash/cpu_blake2s.cpp
+        src/hash/cpu_merkle_tree.cpp
+    )
+    target_include_directories(icicle_hash PUBLIC include)
+endif()
+
diff --git a/icicle/backend/metal/metal_device_api.cpp b/icicle/backend/metal/metal_device_api.cpp
new file mode 100644
index 000000000..0641a3410
--- /dev/null
+++ b/icicle/backend/metal/metal_device_api.cpp
@@ -0,0 +1,107 @@
+
+#include <iostream>
+#include <cstring>
+#include "icicle/device_api.h"
+#include "icicle/errors.h"
+#include "icicle/utils/log.h"
+
+using namespace icicle;
+
+class MetalDeviceAPI : public DeviceAPI
+{
+public:
+  eIcicleError set_device(const Device& device) override
+  {
+    return (device.id == 0) ? eIcicleError::SUCCESS : eIcicleError::INVALID_DEVICE;
+  }
+
+  eIcicleError get_device_count(int& device_count) const override
+  {
+    device_count = 1;
+    return eIcicleError::SUCCESS;
+  }
+
+  // Memory management
+  eIcicleError allocate_memory(void** ptr, size_t size) const override
+  {
+    //TODO
+    return (*ptr == nullptr) ? eIcicleError::ALLOCATION_FAILED : eIcicleError::SUCCESS;
+  }
+
+  eIcicleError allocate_memory_async(void** ptr, size_t size, icicleStreamHandle stream) const override
+  {
+    return MetalDeviceAPI::allocate_memory(ptr, size);
+  }
+
+  eIcicleError free_memory(void* ptr) const override
+  {
+    //TODO
+    return eIcicleError::SUCCESS;
+  }
+
+  eIcicleError free_memory_async(void* ptr, icicleStreamHandle stream) const override
+  {
+    return MetalDeviceAPI::free_memory(ptr);
+  }
+
+  eIcicleError get_available_memory(size_t& total /*OUT*/, size_t& free /*OUT*/) const override
+  {
+    //TODO
+    return eIcicleError::API_NOT_IMPLEMENTED;
+  }
+
+  eIcicleError memset(void* ptr, int value, size_t size) const override
+  {
+    //TODO
+    return eIcicleError::SUCCESS;
+  }
+
+  eIcicleError memset_async(void* ptr, int value, size_t size, icicleStreamHandle stream) const override
+  {
+    //TODO
+    return eIcicleError::SUCCESS;
+  }
+
+  eIcicleError memCopy(void* dst, const void* src, size_t size) const
+  {
+    //TODO:
+    return eIcicleError::SUCCESS;
+  }
+
+  // Data transfer
+  eIcicleError copy(void* dst, const void* src, size_t size, eCopyDirection direction) const override
+  {
+    return memCopy(dst, src, size);
+  }
+
+  eIcicleError copy_async(
+    void* dst, const void* src, size_t size, eCopyDirection direction, icicleStreamHandle stream) const override
+  {
+    return memCopy(dst, src, size);
+  }
+
+  // Synchronization
+  eIcicleError synchronize(icicleStreamHandle stream = nullptr) const override { return eIcicleError::SUCCESS; }
+
+  // Stream management
+  eIcicleError create_stream(icicleStreamHandle* stream) const override
+  {
+    *stream = nullptr; // no streams for CPU
+    return eIcicleError::SUCCESS;
+  }
+
+  eIcicleError destroy_stream(icicleStreamHandle stream) const override
+  {
+    return (nullptr == stream) ? eIcicleError::SUCCESS : eIcicleError::STREAM_DESTRUCTION_FAILED;
+  }
+
+  eIcicleError get_device_properties(DeviceProperties& properties) const override
+  {
+    properties.using_host_memory = true;
+    properties.num_memory_regions = 0;
+    properties.supports_pinned_memory = false;
+    return eIcicleError::SUCCESS;
+  }
+};
+
+REGISTER_DEVICE_API("METAL", MetalDeviceAPI);