CODEWITHSUNDEEP
androidandroid-ndkmakefilearmneon
fqc0306
fqc0306

Reputation: 19

my android phone can not run when "LOCAL_ARM_NEON := true" in makefile

the appliction abort when i add LOCAL_ARM_NEON := true in android.mk, even without any neon instructions. some words like "-mfpu=neon" alse cause abort.

my phone is motorola android2.2
is my configuration in Android NDK not correct? or my phone arm can not support neon instructions? i need to run neon instructions on my phone.

help me!!!thanks!!!

ps: application.mk:

APP_STL := gnustl_static
APP_ABI := armeabi-v7a
APP_CPPFLAGS += -fexceptions
APP_MODULES := AudioEngine

android.mk:

CC = $(BASE_PATH)/build/prebuilt/linux-x86/arm-eabi-4.4.0/bin/arm-eabi-gcc 
LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

LOCAL_ARM_NEON := true
LOCAL_MODULE    := AudioEngine
LOCAL_SRC_FILES := AudioEngine.cpp Effecter.cpp SoundTouch.cpp TDStretch.cpp RateTransposer.cpp AAFilter.cpp BPMDetect.cpp \
FIFOSampleBuffer.cpp FIRFilter.cpp mmx_optimized.cpp PeakFinder.cpp sse_optimized.cpp cpu_detect_x86.cpp fft.s\
LOCAL_LDLIBS := -L$(SYSROOT)/usr/lib -llog
LOCAL_LDLIBS := -llog

include $(BUILD_SHARED_LIBRARY)

Upvotes: 1

Views: 1281

Answers (2)

Ivo
Ivo

Reputation: 1788

The following approach is used in the the official Hello-Neon-Example:

Android.mk:

# inside a module:

LOCAL_SRC_FILES := helloneon.c

ifeq ($(TARGET_ARCH_ABI),armeabi-v7a)
    LOCAL_CFLAGS := -DHAVE_NEON=1
    LOCAL_SRC_FILES += helloneon-intrinsics.c.neon
endif

#...

Some C/C++ source file:

/* HAVE_NEON is defined in Android.mk */
#ifdef HAVE_NEON
    callNeonFunc();
#else
    callStandardFunc();
#endif

Upvotes: 0

Lyve
Lyve

Reputation: 250

I use a second small .so library that I've written to check if a CPU supports NEON at all. After checking, I decide in java which version of my library I have to load, one built with full NEON support, one without NEON support at all: This is the code, grabbed from the NDK documentation:

JNIEXPORT JNICALL int Java_xypackagename_base_detectCPU_isNeon( JNIEnv* _env, jobject thiz )
{
    uint64_t features;

    if (android_getCpuFamily() != ANDROID_CPU_FAMILY_ARM)
    {
        __android_log_write( ANDROID_LOG_INFO, "detectCPU", "Processor is NOT an ARM processor" );
        return 0;
    }

    __android_log_write( ANDROID_LOG_INFO, "detectCPU", "Processor is an ARM processor" );

    features = android_getCpuFeatures();

    __android_log_print( ANDROID_LOG_INFO, "detectCPU", "Processor features: %u", (unsigned int)features );

    if ((features & ANDROID_CPU_ARM_FEATURE_ARMv7) == 0)
    {
        __android_log_write( ANDROID_LOG_INFO, "detectCPU", "Processor is NOT an ARM v7" );
        return 0;
    }

    __android_log_write( ANDROID_LOG_INFO, "detectCPU", "Processor is an ARM v7" );

    if ((features & ANDROID_CPU_ARM_FEATURE_NEON) == 0)
    {
        __android_log_write( ANDROID_LOG_INFO, "detectCPU", "Processor has NO NEON support" );
        return 0;
    }

    __android_log_write( ANDROID_LOG_INFO, "detectCPU", "Processor has NEON support" );

    return 1;
}

Upvotes: 1

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