Refactor Makefile build of TFLite

- Enable Ruy for ARM64 Makefile build
- Remove build_generic_aarch64_lib.sh which is obsolete by build_aarch64_lib.sh
- BUILD_WITH_NNAPI is disabled by default
- Use aarch64 instead of armv8-a for ARM64 TARGET_ARCH to make
  compatible with "uname -m" result
- Generate ARM64 outputs under make/gen/linux_aarch64

PiperOrigin-RevId: 294362807
Change-Id: I8b5fecce28bf3e16bc318497f498970b6dea07cc

tensorflow/lite/g3doc/guide/build_arm64.md

@@ -46,7 +46,7 @@ Then compile:
 ```
 
 This should compile a static library in:
-`tensorflow/lite/tools/make/gen/aarch64_armv8-a/lib/libtensorflow-lite.a`.
+`tensorflow/lite/tools/make/gen/linux_aarch64/lib/libtensorflow-lite.a`.
 
 ## Compile natively on ARM64
 
@@ -75,4 +75,4 @@ Then compile:
 ```
 
 This should compile a static library in:
-`tensorflow/lite/tools/make/gen/aarch64_armv8-a/lib/libtensorflow-lite.a`.
+`tensorflow/lite/tools/make/gen/linux_aarch64/lib/libtensorflow-lite.a`.

tensorflow/lite/tools/make/Makefile

@@ -146,22 +146,15 @@ else
 	CORE_CC_EXCLUDE_SRCS += tensorflow/lite/mmap_allocation_disabled.cc
 endif
 
-BUILD_WITH_NNAPI ?= true
-ifeq ($(BUILD_TYPE),micro)
-	BUILD_WITH_NNAPI=false
+BUILD_WITH_RUY ?= false
+ifeq ($(TARGET_ARCH),aarch64)
+	BUILD_WITH_RUY=true
 endif
-ifeq ($(TARGET),windows)
-	BUILD_WITH_NNAPI=false
-endif
-ifeq ($(TARGET),ios)
-	BUILD_WITH_NNAPI=false
-endif
-ifeq ($(TARGET),rpi)
-	BUILD_WITH_NNAPI=false
-endif
-ifeq ($(TARGET),generic-aarch64)
-	BUILD_WITH_NNAPI=false
+ifeq ($(BUILD_WITH_RUY),true)
+  CXXFLAGS += -DTFLITE_WITH_RUY
 endif
+
+BUILD_WITH_NNAPI ?= false
 ifeq ($(BUILD_WITH_NNAPI),true)
 	CORE_CC_ALL_SRCS += tensorflow/lite/delegates/nnapi/nnapi_delegate.cc
 	CORE_CC_ALL_SRCS += tensorflow/lite/delegates/nnapi/quant_lstm_sup.cc
@@ -219,7 +212,8 @@ ALL_SRCS := \
 	$(CMD_LINE_TOOLS_SRCS)
 
 # Where compiled objects are stored.
-GENDIR := $(MAKEFILE_DIR)/gen/$(TARGET)_$(TARGET_ARCH)/
+TARGET_OUT_DIR ?= $(TARGET)_$(TARGET_ARCH)
+GENDIR := $(MAKEFILE_DIR)/gen/$(TARGET_OUT_DIR)/
 OBJDIR := $(GENDIR)obj/
 BINDIR := $(GENDIR)bin/
 LIBDIR := $(GENDIR)lib/

tensorflow/lite/tools/make/build_generic_aarch64_lib.sh

@@ -1,22 +0,0 @@
-#!/bin/bash -x
-# Copyright 2017 The TensorFlow Authors. All Rights Reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-# ==============================================================================
-
-set -e
-
-SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-cd "$SCRIPT_DIR/../../../.."
-
-CC_PREFIX=aarch64-linux-gnu- make -j 3 -f tensorflow/lite/tools/make/Makefile TARGET=generic-aarch64 TARGET_ARCH=armv8-a

tensorflow/lite/tools/make/build_lib.sh

@@ -20,5 +20,5 @@ set -e
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 TENSORFLOW_DIR="${SCRIPT_DIR}/../../../.."
 
-make -j 4 BUILD_WITH_NNAPI=false -C "${TENSORFLOW_DIR}" -f tensorflow/lite/tools/make/Makefile
+make -j 4 -C "${TENSORFLOW_DIR}" -f tensorflow/lite/tools/make/Makefile
 

tensorflow/lite/tools/make/targets/aarch64_makefile.inc

@@ -2,8 +2,9 @@
 ifeq ($(TARGET),aarch64)
   # The aarch64 architecture covers all 64-bit ARM chips. This arch mandates
   # NEON, so FPU flags are not needed below.
-  TARGET_ARCH := armv8-a
+  TARGET_ARCH := aarch64
   TARGET_TOOLCHAIN_PREFIX := aarch64-linux-gnu-
+  TARGET_OUT_DIR := linux_aarch64
 
   CXXFLAGS += \
     -march=armv8-a \
@@ -24,7 +25,6 @@ ifeq ($(TARGET),aarch64)
     -Wl,--as-needed \
     -lrt
 
-       
   LIBS := \
     -lstdc++ \
     -lpthread \

tensorflow/lite/tools/make/targets/generic_aarch64_makefile.inc

@@ -1,33 +0,0 @@
-# Settings for generic aarch64 boards such as Odroid C2 or Pine64.
-ifeq ($(TARGET),generic-aarch64)
-  # The aarch64 architecture covers all 64-bit ARM chips. This arch mandates
-  # NEON, so FPU flags are not needed below.
-  TARGET_ARCH := armv8-a
-  TARGET_TOOLCHAIN_PREFIX := aarch64-linux-gnu-
-
-  CXXFLAGS += \
-    -march=armv8-a \
-    -funsafe-math-optimizations \
-    -ftree-vectorize \
-    -fPIC
-
-  CCFLAGS += \
-    -march=armv8-a \
-    -funsafe-math-optimizations \
-    -ftree-vectorize \
-    -fPIC
-
-  LDFLAGS := \
-    -Wl,--no-export-dynamic \
-    -Wl,--exclude-libs,ALL \
-    -Wl,--gc-sections \
-    -Wl,--as-needed
-
-       
-  LIBS := \
-    -lstdc++ \
-    -lpthread \
-    -lm \
-    -ldl
-
-endif

tensorflow/lite/tools/make/targets/rpi_makefile.inc

@@ -7,7 +7,7 @@ ifeq ($(TARGET),rpi)
 
   ifeq ($(TARGET_ARCH), armv7l)
     CXXFLAGS += \
-			-march=armv7-a \
+      -march=armv7-a \
       -mfpu=neon-vfpv4 \
       -funsafe-math-optimizations \
       -ftree-vectorize \
@@ -25,6 +25,8 @@ ifeq ($(TARGET),rpi)
       -Wl,--exclude-libs,ALL \
       -Wl,--gc-sections \
       -Wl,--as-needed
+
+    BUILD_WITH_RUY := true
   endif
 
   # TODO(petewarden) In the future, we'll want to use OpenBLAS as a faster
@@ -50,7 +52,7 @@ ifeq ($(TARGET),rpi)
       -Wl,--gc-sections \
       -Wl,--as-needed
   endif
-       
+
   LIBS := \
     -lstdc++ \
     -lpthread \