On March 18, 2019 2:56:05 PM PDT, Matthias Kaehlcke <mka@xxxxxxxxxxxx> wrote: >On Mon, Mar 18, 2019 at 02:47:13PM -0700, 'Nick Desaulniers' via Clang >Built Linux wrote: >> On Mon, Mar 18, 2019 at 2:10 PM Matthias Kaehlcke <mka@xxxxxxxxxxxx> >wrote: >> > >> > The clang option -Oz enables *aggressive* optimization for size, >> > which doesn't necessarily result in smaller images, but can have >> > negative impact on performance. Switch back to the less aggressive >> > -Os. >> > >> > This reverts commit 6748cb3c299de1ffbe56733647b01dbcc398c419. >> >> Does scripts/checkpatch.pl complain about this format (full sha, no >> title)? > >Nope, for reverts checkpatch is happy with it, I suppose because by >default the subject of the reverted patch is part of the revert's >subject. > >> Not sure that necessitates a v2, but if so would be good to >> mention that Clang generates excessive calls into libgcc/compiler-rt >> at -Oz. Thanks for the patch and the discussion/sanity check. > >I can send a v2 if 'needed'. > >> Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > >Thanks! > >Matthias > >> > >> > Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> >> > Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx> >> > --- >> > Makefile | 2 +- >> > 1 file changed, 1 insertion(+), 1 deletion(-) >> > >> > diff --git a/Makefile b/Makefile >> > index 9ef547fc7ffe..191f3ce3cb5e 100644 >> > --- a/Makefile >> > +++ b/Makefile >> > @@ -667,7 +667,7 @@ KBUILD_CFLAGS += $(call >cc-disable-warning, format-overflow) >> > KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context) >> > >> > ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE >> > -KBUILD_CFLAGS += $(call cc-option,-Oz,-Os) >> > +KBUILD_CFLAGS += -Os >> > else >> > KBUILD_CFLAGS += -O2 >> > endif >> >> >> Would be nice, still, to have -Ok. -- Sent from my Android device with K-9 Mail. Please excuse my brevity.
