Busybox uses FAST_FUNC macro to tweak with IA-32 calling conventions in
order to make the function call slightly smaller or slightly faster.
However, when I experiment with GCC's LTO (Link Time Optimization), I
discovered that FAST_FUNC could hinder LTO's optimization so that the
resulting executable become a few bytes larger (than what is compiled
without FAST_FUNC).
This change allows to specify e.g.
CONFIG_EXTRA_CFLAGS="-DFAST_FUNC= -flto"
and compile with LTO without a source code hack.
Signed-off-by: Kang-Che Sung <explorer09@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
f10f7a21d4