Commit Graph

2 Commits

Author SHA1 Message Date
David Green 824ffd8b12 [ARM] MVE big endian loads/stores
This adds some missing patterns for big endian loads/stores, allowing unaligned
loads/stores to also be selected with an extra VREV, which produces better code
than aligning through a stack. Also moves VLDR_P0 to not be LE only, and
adjusts some of the tests to show all that working.

Differential Revision: https://reviews.llvm.org/D65583

llvm-svn: 368304
2019-08-08 15:15:19 +00:00
David Green 91296295d0 [ARM] MVE big endian bitcasts
This adds big endian MVE patterns for bitcasts. They are defined in llvm as
being the same as a store of the existing type and the load into the new. This
means that they have to become a VREV between the two types, working in the
same way that NEON works in big-endian. This also adds some example tests for
bigendian, showing where code is and isn't different.

The main difference, especially from a testing perspective is that vectors are
passed as v2f64, and so are VREV into and out of call arguments, and the
parameters are passed in a v2f64 format. Same happens for inline assembly where
the register class is used, so it is VREV to a v16i8.

So some of this is probably not correct yet, but it is (mostly) self-consistent
and seems to be consistent with how llvm treats vectors. The rest we can
hopefully fix later. More details about big endian neon can be found in
https://llvm.org/docs/BigEndianNEON.html.

Differential Revision: https://reviews.llvm.org/D65581

llvm-svn: 367780
2019-08-04 10:18:15 +00:00