[kernel][mobile] add mobile-optimized CPU backend

aphrodite_kernels/CMakeLists.txt

@@ -100,7 +100,8 @@ endif()
 #
 if (NOT APHRODITE_TARGET_DEVICE STREQUAL "cuda" AND
     NOT APHRODITE_TARGET_DEVICE STREQUAL "rocm")
-    if (APHRODITE_TARGET_DEVICE STREQUAL "cpu")
+    if (APHRODITE_TARGET_DEVICE STREQUAL "cpu" OR
+        APHRODITE_TARGET_DEVICE STREQUAL "android")
         include(${CMAKE_CURRENT_LIST_DIR}/cmake/cpu_extension.cmake)
     else()
         return()

aphrodite_kernels/cmake/cpu_extension.cmake

@@ -337,6 +337,32 @@ if(USE_ONEDNN)
         ${APHRODITE_EXT_SRC})
 endif()
 
+# Mobile-optimized kernels (ARM NEON) for Android
+if(APHRODITE_TARGET_DEVICE STREQUAL "android")
+    message(STATUS "Building mobile-optimized kernels for Android")
+    set(APHRODITE_MOBILE_SRC
+        "csrc/cpu/mobile/quant.cpp"
+        "csrc/cpu/mobile/blas.cpp"
+        "csrc/cpu/mobile/gemm.cpp"
+        "csrc/cpu/mobile/reduce.cpp"
+        "csrc/cpu/mobile/scalar.cpp"
+        "csrc/cpu/mobile/nn.cpp"
+        "csrc/cpu/mobile/attention.cpp"
+        "csrc/cpu/mobile/torch_bindings.cpp")
+    set(APHRODITE_EXT_SRC
+        ${APHRODITE_EXT_SRC}
+        ${APHRODITE_MOBILE_SRC})
+    # Add ARM NEON compile flags for mobile kernels
+    # Note: These flags may already be set by ASIMD_FOUND detection above
+    # but we ensure they're present for Android builds
+    if(NOT ASIMD_FOUND)
+        list(APPEND CXX_COMPILE_FLAGS
+            "-march=armv8-a+neon"
+            "-mfpu=neon-fp-armv8")
+    endif()
+    message(STATUS "Mobile kernel source files: ${APHRODITE_MOBILE_SRC}")
+endif()
+
 message(STATUS "CPU extension source files: ${APHRODITE_EXT_SRC}")
 
 #

aphrodite_kernels/csrc/cpu/mobile/README.md

@@ -0,0 +1 @@
+Mobile-optimized compute kernels, based on [cactus](https://github.com/cactus-compute/cactus).