Hi Vineet,

On Thu, Jun 18, 2015 at 8:47 AM, Vineet Gupta
[off-list ref] wrote:

commit a1c48bb160f8368 "Makefile: Fix unrecognized cross-compiler command line
options" moved ARCH specific cc option handling before common -Os/O2 setup.

For ARC this had a subtle effect that we can no longer over-ride generic -O2 with
-O3, hence a performance regression observed going from 3.13 to 3.18 (the above
commit went into 3.16)

I want to understand how to properly fix this. Moving the include of arch makefile
will bring back the old issue. I can introduce another option to set default optim
level, but only arc/m32r care about it anyways.

Can we include $(srctree)/arch/$(SRCARCH)/Makefile twice?

Or perhaps we can not apply the extra -O* if there's already a -O* option?

Alternatively, as we already have CONFIG_CC_OPTIMIZE_FOR_SIZE,
a(nother) Kconfig option may make sense.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds