On Mon, 2014-12-08 at 22:08 -0800, Matt Turner wrote: > On Mon, Dec 8, 2014 at 9:43 PM, Timothy Arceri <t_arc...@yahoo.com.au> wrote: > > Nowadays GCC assumes stack pointer is 16-byte aligned even on 32-bits, but > > that is an assumption OpenGL drivers (or any dynamic library for that > > matter) > > can't afford to make as there are many closed- and open- source application > > binaries out there that only assume 4-byte stack alignment. > > > > V3: move all sse4.1 build flag config to the same location > > and add comment as to why we need to do the realign > > > > V2: use $target_cpu rather than $host_cpu > > and setup build flags in config rather than makefile > > > > https://bugs.freedesktop.org/show_bug.cgi?id=86788 > > Signed-off-by: Timothy Arceri <t_arc...@yahoo.com.au> > > Reviewed-by: Matt Turner <matts...@gmail.com> > > CC: "10.4" <mesa-sta...@lists.freedesktop.org> > > --- > > If there are no other comments I'll commit it to master > > tomorrow. > > > > The last hunk should be dropped when applying to 10.4. > > > > configure.ac | 11 ++++++++++- > > src/mesa/Makefile.am | 2 +- > > src/mesa/main/sse_minmax.c | 3 --- > > 3 files changed, 11 insertions(+), 5 deletions(-) > > > > diff --git a/configure.ac b/configure.ac > > index b0df1bb..e510bcf 100644 > > --- a/configure.ac > > +++ b/configure.ac > > @@ -253,8 +253,16 @@ AC_SUBST([VISIBILITY_CXXFLAGS]) > > dnl > > dnl Optional flags, check for compiler support > > dnl > > +SSE41_CFLAGS="-msse4.1" > > +dnl 32-bit Mesa is 4-byte aligned to allow support for old applications > > +dnl therefore we need to realign the stack when using SSE > > I don't think this comment is right. It doesn't have anything to do > with Mesa. The 32-bit ABI just doesn't require the stack to be >4 byte > aligned.
Thanks for the clarification I was wondering where the 4-byte align config switch was but it was just me misreading Jose's comments on the bug report. > > Søren's pixman patch has this comment, which I think is fine: > > Code compiled by GCC with -msse2 and -mssse3 assumes a 16 byte aligned > stack, but on x86-32 such alignment is not guaranteed. > > (Just replace "-msse2 and -mssse3" with "-msse*") > > > +case "$target_cpu" in > > + i?86) > > + SSE41_CFLAGS="$SSE41_CFLAGS -mstackrealign" > > + ;; > > Okay, starting to wonder if you're trolling me with this. :-| uh sorry I did indent it, but not to the right place. The i?86) shouldn't be indented either. All fixed in the next version, thanks for all the feedback. > > Look at the other instances of ;; -- they're either on the same line > as the previous statement or they're aligned with it. > _______________________________________________ > mesa-stable mailing list > mesa-sta...@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/mesa-stable _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
