compiled on RPI3B with 5.4.51-piCore-v8 (beta release)

Compile Flags:
CC="gcc -march=armv8-a+crc -mtune=cortex-a72 -Os -pipe"
CXX="g++ -march=armv8-a+crc -mtune=cortex-a72 -Os -pipe -fno-exceptions -fno-rtti"
LDFLAGS="-Wl,-O1"
export CC CXX LDFLAGS

Dependencies:
compiletc
libXft-dev
libjpeg-turbo-dev
xorg-server-dev

Commands:

tar xf fltk-1.3.5-source.tar.bz2

cd fltk-1.3.5

./configure --prefix=/usr/local --localstatedir=/var --enable-shared --disable-gl --disable-xinerama --disable-xfixes --disable-xcursor --disable-xrender

Configuration Summary
-------------------------------------------------------------------------
    Directories: prefix=/usr/local
                 bindir=${exec_prefix}/bin
                 datadir=${datarootdir}
                 datarootdir=${prefix}/share
                 exec_prefix=${prefix}
                 includedir=${prefix}/include
                 libdir=${exec_prefix}/lib
                 mandir=${datarootdir}/man
       Graphics: X11 + Xft + Xdbe
Image Libraries: JPEG=System
                 PNG=System
                 ZLIB=System
    Large Files: YES
         OpenGL: NO
        Threads: YES



# apply patch to skip unwanted files and reduce compile time

patch Makefile fltk-xft.no-doc.no-test.patch

make -j4  ##comepile time: 12 min##