-mfpu=neon-fp-armv8

The "-mfpu=neon-fp-armv8" flag is a compiler option used to specify the floating-point unit (FPU) to be used by the generated code.

In this case, it instructs the compiler to use the NEON FPU, which is a SIMD (Single Instruction Multiple Data) architecture extension for ARM processors. The "-fp-armv8" part specifies that the compiler should generate code for ARMv8 architecture, which is the latest version of the ARM architecture.

Overall, this flag is useful for optimizing code that involves intensive floating-point operations, such as graphics processing, signal processing, and scientific computing.

相关问题

飞腾开发板qt中输入QMAKE_CXXFLAGS += -mfpu=neon报错unrecognized commond lime"-mfpu=neon"

如果你在Qt应用程序的.pro文件中输入"QMAKE_CXXFLAGS += -mfpu=neon"时，遇到了"unrecognized command line option '-mfpu=neon'"的错误，很可能是因为你使用的编译器不支持-mfpu选项。

在这种情况下，你需要使用编译器支持的相应选项来开启NEON指令集。例如，如果你使用的是GCC编译器，可以尝试将选项更改为：

QMAKE_CXXFLAGS += -march=armv7-a -mtune=cortex-a53 -mcpu=native

这个选项会启用ARMv7-A体系结构的NEON指令集。请注意，这个选项只适用于特定的ARM CPU架构，如果你的CPU架构不同，需要相应地进行调整。

如果你使用的是其他编译器，请查阅相应的文档，了解如何开启NEON指令集。

Command line: -prefix /home/liuyh/workspace/qt5.14.2-arm -opensource -confirm-license -release -strip -shared -xplatform linux-arm-gnueabi-g++ -optimized-qmake -c++std c++11 --rpath=no -pch -skip qt3d -skip qtactiveqt -skip qtandroidextras -skip qtcanvas3d -skip qtconnectivity -skip qtdatavis3d -skip qtdoc -skip qtgamepad -skip qtlocation -skip qtmacextras -skip qtnetworkauth -skip qtpurchasing -skip qtremoteobjects -skip qtscript -skip qtscxml -skip qtsensors -skip qtspeech -skip qtsvg -skip qttools -skip qttranslations -skip qtwayland -skip qtwebengine -skip qtwebview -skip qtwinextras -skip qtx11extras -skip qtxmlpatterns -make libs -make examples -nomake tools -nomake tests -gui -widgets -dbus-runtime --glib=no --iconv=no --pcre=qt --zlib=qt -no-openssl --freetype=qt --harfbuzz=qt -no-opengl -linuxfb --xcb=no -tslib --libpng=qt --libjpeg=qt --sqlite=qt -plugin-sql-sqlite -I/opt/tslib/include -L/opt/tslib/lib -recheck-all executing config test machineTuple + arm-linux-gnueabi-g++ -dumpmachine > sh: 1: arm-linux-gnueabi-g++: not found test config.qtbase.tests.machineTuple FAILED executing config test verifyspec + cd /home/liuyh/workspace/QT5.14.2/qt-everywhere-src-5.14.2/config.tests/verifyspec && /home/liuyh/workspace/QT5.14.2/qt-everywhere-src-5.14.2/qtbase/bin/qmake "CONFIG -= qt debug_and_release app_bundle lib_bundle" "CONFIG += shared warn_off console single_arch" 'QMAKE_LIBDIR += /opt/tslib/lib' 'INCLUDEPATH += /opt/tslib/include' -early "CONFIG += cross_compile" /home/liuyh/workspace/QT5.14.2/qt-everywhere-src-5.14.2/qtbase/config.tests/verifyspec + cd /home/liuyh/workspace/QT5.14.2/qt-everywhere-src-5.14.2/config.tests/verifyspec && MAKEFLAGS= /usr/bin/make clean && MAKEFLAGS= /usr/bin/make > rm -f verifyspec.o > rm -f *~ core *.core > arm-linux-gnueabi-g++ -c -O2 -march=armv7-a -mtune=cortex-a7 -mfpu=neon -mfloat-abi=hard -O2 -march=armv7-a -mtune=cortex-a7 -mfpu=neon -mfloat-abi=hard -pipe -O2 -w -fPIC -I/home/liuyh/workspace/QT5.14.2/qt-everywhere-src-5.14.2/qtbase/config.tests/verifyspec -I. -I/opt/tslib/include -I/home/liuyh/workspace/QT5.14.2/qt-everywhere-src-5.14.2/qtbase/mkspecs/linux-arm-gnueabi-g++ -o verifyspec.o /home/liuyh/workspace/QT5.14.2/qt-everywhere-src-5.14.2/qtbase/config.tests/verifyspec/verifyspec.cpp > make：arm-linux-gnueabi-g++：命令未找到 > make: *** [Makefile:172：verifyspec.o] 错误 127

这个错误可能是由于缺少相关的编译器或者库文件，或者是由于目标平台设置不正确导致的。你需要检查你的编译环境和目标平台设置，确保它们都是正确的。另外，根据错误提示，arm-linux-gnueabi-g++命令未找到，可能是缺少相关工具链导致的。你需要安装适合的交叉编译工具链来解决这个问题。同时，你也可以尝试使用其他目标平台进行编译，看是否可以解决这个问题。