[PATCH] [AArch64 - BE] BUILD_VECTOR lane order is reversed in big-endian mode

Asiri Rathnayake asiri.rathnayake at arm.com
Thu Aug 28 03:51:40 PDT 2014

Hi t.p.northover,

Hi Tim,

This is a revamp of [1].

That patch was rejected mainly because it lacked enough testing. I've added tests to cover all ModImmTypes and addressed the other minor points you mentioned there.

  - The need to use rev64 instructions with big-endian vectors is documented at [2]
  - Most ModImmTypes have a symmetric counter-part, and the lane reversal causes them to be encoded in that opposite pattern. A few ModImmTypes (7,8, 11, 12) do not have that property and gets pushed into memory. But this is irrelevant as far as correctness is concerned.


- Asiri

[1] http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20140714/226398.html
[2] http://llvm.org/docs/BigEndianNEON.html


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