New patch: [AArch64] [BE] [1/2] Make large opaque integer modes endianness-safe.

[David Sherwood]

Hi Christophe,

Sorry to bother you again. After my clarification email below are you now
happy for these patches to go in?

Kind Regards,
David Sherwood.

> -----Original Message-----
> From: David Sherwood [mailto:david.sherwood@arm.com]
> Sent: 27 November 2014 14:53
> To: 'Christophe Lyon'
> Cc: gcc-patches@gcc.gnu.org; Marcus Shawcroft; Alan Hayward; 'Tejas Belagod'; Richard Sandiford
> Subject: RE: New patch: [AArch64] [BE] [1/2] Make large opaque integer modes endianness-safe.
> 
> > On 18 November 2014 10:14, David Sherwood <david.sherwood@arm.com> wrote:
> > > Hi Christophe,
> > >
> > > Ah sorry. My mistake - it fixes this in bugzilla:
> > >
> > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59810
> >
> > I did look at that PR, but since it has no testcase attached, I was unsure.
> > And I am still not :-)
> > PR 59810 is "[AArch64] LDn/STn implementations are not ABI-conformant
> > for bigendian."
> > but the advsimd-intrinsics/vldX.c and vldX_lane.c now PASS with Alan's
> > patches on aarch64_be, so I thought Alan's patches solve PR59810.
> >
> > What am I missing?
> 
> Hi Christophe,
> 
> I think probably this is our fault for making our lives way too difficult and
> artificially splitting all these patches up. :)
> 
> Alan's patch:
> 
> https://gcc.gnu.org/ml/gcc-patches/2014-10/msg00952.html
> 
> fixes some issues on aarch64_be, but also causes regressions. For example,
> 
> ====
> Tests that now fail, but worked before:
> 
> aarch64_be-elf-aem: gcc.dg/vect/slp-perm-8.c -flto -ffat-lto-objects execution test
> aarch64_be-elf-aem: gcc.dg/vect/slp-perm-8.c execution test
> aarch64_be-elf-aem: gcc.dg/vect/vect-over-widen-1-big-array.c -flto -ffat-lto-objects execution test
> ...
> 
> Tests that now work, but didn't before:
> 
> aarch64_be-elf-aem: gcc.dg/vect/fast-math-vect-complex-3.c execution test
> aarch64_be-elf-aem: gcc.dg/vect/if-cvt-stores-vect-ifcvt-18.c execution test
> aarch64_be-elf-aem: gcc.dg/vect/no-scevccp-outer-10a.c execution test
> ...
> ====
> 
> His patch is only half of the story and must be applied at the same time as the
> "[AArch64] [BE] [1/2] Make large opaque integer modes endianness-safe."
> patch. With both patches applied the result looks much healthier:
> 
> ====
> # Comparing 1 common sum files
> ## /bin/sh ./src/gcc/contrib/compare_tests  /tmp/gxx-sum1.10051 /tmp/gxx-sum2.10051
> Tests that now work, but didn't before:
> 
> aarch64_be-elf-aem: gcc.dg/torture/pr52028.c   -O3 -fomit-frame-pointer  execution test
> aarch64_be-elf-aem: gcc.dg/torture/pr52028.c   -O3 -fomit-frame-pointer -funroll-all-loops -finline-
> functions  execution test
> aarch64_be-elf-aem: gcc.dg/torture/pr52028.c   -O3 -fomit-frame-pointer -funroll-loops  execution test
> ...
> ====
> 
> with no new regressions. After applying both patches the aarch64_be gcc testsuite is
> on a parity with the aarch64 testsuite. Furthermore, after applying both of these patches:
> 
> "[AArch64] [BE] [1/2] Make large opaque integer modes endianness-safe"
> "[AArch64] [BE] Fix vector load/stores to not use ld1/st1"
> 
> it then becomes safe for us to remove the CCMC macro, which is the cause of
> unnecessary spills to the stack for certain auto-vectorised code. So really I
> suppose when I posted my second patch
> 
> "[AArch64] [BE] [2/2] Make large opaque integer modes endianness-safe"
> 
> I should have really just called this
> 
> "[AArch64] [BE] Remove CCMC for aarch64"
> 
> in order to make it clear exactly what the purpose of these patches is.
> 
> Kind Regards,
> David Sherwood.