Why march=haswell on a AMD FX-8370 processor

While reviewing my build of Qt6.3.1 I noticed this piece of code is being compiled with march=haswell (Intel processor) which seems strange as my processor is a AMD FX-8370 Vishera processor. Could someone explain please ?

/usr/bin/g++ -DENABLE_PIXMAN_DRAWHELPERS -DGui_EXPORTS -DQT_ASCII_CAST_WARNINGS -DQT_BUILDING_QT -DQT_BUILD_GUI_LIB -DQT_CORE_LIB -DQT_DBUS_LIB -DQT_DEPRECATED_WARNINGS -DQT_DEPRECATED_WARNINGS_SINCE=0x060000 -DQT_DISABLE_DEPRECATED_BEFORE=0x050000 -DQT_MOC_COMPAT -DQT_NO_CAST_TO_ASCII -DQT_NO_DEBUG -DQT_NO_EXCEPTIONS -DQT_NO_FOREACH -DQT_NO_JAVA_STYLE_ITERATORS -DQT_NO_NARROWING_CONVERSIONS_IN_CONNECT -DQT_NO_USING_NAMESPACE -DQT_QPA_DEFAULT_PLATFORM_NAME=\"xcb\" -DQT_USE_QSTRINGBUILDER -D_LARGEFILE64_SOURCE -D_LARGEFILE_SOURCE -I/misc/work/Qt6/qt-6.3/build-qt6/qtbase/src/gui/Gui_autogen/include -I/misc/work/Qt6/qt-6.3/build-qt6/qtbase/include -I/misc/work/Qt6/qt-6.3/build-qt6/qtbase/include/QtGui -I/misc/work/Qt6/qt-6.3/qtbase/src/gui -I/misc/work/Qt6/qt-6.3/build-qt6/qtbase/src/gui -I/misc/work/Qt6/qt-6.3/qtbase/src/gui/../3rdparty/VulkanMemoryAllocator -I/misc/work/Qt6/qt-6.3/build-qt6/qtbase/include/QtGui/6.3.1 -I/misc/work/Qt6/qt-6.3/build-qt6/qtbase/include/QtGui/6.3.1/QtGui -I/usr/include/at-spi-2.0 -I/usr/include/dbus-1.0 -I/usr/lib/dbus-1.0/include -I/misc/work/Qt6/qt-6.3/build-qt6/qtbase/include/QtCore -I/misc/work/Qt6/qt-6.3/qtbase/mkspecs/linux-g++ -I/misc/work/Qt6/qt-6.3/build-qt6/qtbase/src/corelib -I/misc/work/Qt6/qt-6.3/build-qt6/qtbase/include/QtCore/6.3.1 -I/misc/work/Qt6/qt-6.3/build-qt6/qtbase/include/QtCore/6.3.1/QtCore -I/misc/work/Qt6/qt-6.3/build-qt6/qtbase/include/QtDBus -isystem /usr/include/glib-2.0 -isystem /usr/lib/glib-2.0/include -isystem /usr/include/harfbuzz -isystem /usr/include/freetype2 -m64 -mfpmath=sse -O3 -march=native -fomit-frame-pointer -pipe -w -DQT_NO_VERSION_TAGGING -mno-tbm -mno-xop -DNDEBUG -O3 -fPIC -fvisibility=hidden -fvisibility-inlines-hidden -Wall -Wextra -fno-exceptions -fPIC -Wsuggest-override -std=c++17 -march=haswell -MD -MT qtbase/src/gui/CMakeFiles/Gui.dir/painting/qdrawhelper_avx2.cpp.o -MF qtbase/src/gui/CMakeFiles/Gui.dir/painting/qdrawhelper_avx2.cpp.o.d -o qtbase/src/gui/CMakeFiles/Gui.dir/painting/qdrawhelper_avx2.cpp.o -c /misc/work/Qt6/qt-6.3/qtbase/src/gui/painting/qdrawhelper_avx2.cpp