On Thu, Dec 15, 2016 at 01:03:41PM +0100, Hendrik Leppkes wrote: > On Thu, Dec 15, 2016 at 12:57 PM, Diego Biurrun <[email protected]> wrote: > > On Thu, Dec 15, 2016 at 08:43:16AM +0100, Steve Lhomme wrote: > >> On Wed, Dec 14, 2016 at 5:12 PM, Diego Biurrun <[email protected]> wrote: > >> > On Wed, Dec 14, 2016 at 04:46:54PM +0100, Steve Lhomme wrote: > >> >> From: Steve Lhomme <[email protected]> > >> >> > >> >> Without any optimization flags, MSVC does no dead code elimination > >> >> (DCE) at > >> >> all, even for the most trivial cases. DCE is a prerequisite for > >> >> building libav > >> >> correctly, otherwise there are undefined references to functions for > >> >> other > >> >> architectures and disabled components. > >> >> > >> >> -Os -Og is the minimal optimization flags for MSVC that does include > >> >> DCE. It > >> > > >> > -Os -Og are .. that do .. > >> > >> I would say "the setting '-Os -Og' is". One could say "the flags '-Os -Og' > >> are". > > > > Now that you added the quotes it is indeed right ;-p > > > >> >> warns that -Og will be removed but it doesn't work without. -O1 > >> >> includes these > >> >> flags and some other ones not necessary to link properly. > >> > > >> > What does "warn" mean? And is this combination really preferable to > >> > plain -O1? > >> > >> Every C file compiled warns that Og is deprecated and may be removed > >> soon. I prefer it to -O1 because it involves less optimizations, which > >> is the goal of --disable-optimizations. O1 sets "-Og -Os -Oy -Ob2 -Gs > >> -GF -Gy". > > > > Adding a warning for every file is not something we should do lightly. > > Warnings are valuable and they become complete noise when the silly > > warnings drown out the real ones. > > > > If Og is deprecated, what is its replacement? > > Microsoft is discontinuing the fine-grained optimization options and > recommends to just stick to O1 and O2.
Then I suggest we follow that and just use -O1 here, even though a smaller set is normally the more elegant solution. Diego _______________________________________________ libav-devel mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-devel
