The LIT test cases were migrated with the script provided by
Nikita Popov. Due to the size of the change it is split into
several parts.
Reviewed By: nemanja, nikic
Differential Revision: https://reviews.llvm.org/D135474
VSX introduced some permute instructions that are direct
replacements for Altivec ones except they can target all
the VSX registers. We have added code generation for most
of these but somehow missed the low/hi word merges (XXMRG[LH]W).
This caused some additional spills on some large
computationally intensive code.
This patch simply adds the missed patterns.
There are some patterns involving the permuted scalar to vector node
for which we don't have patterns without direct moves on little endian
subtargets. This causes selection errors. While we can of course add
the missing patterns, any additional effort to make this work is not
useful since there is no support for any CPU that can run in
little endian mode and does not support direct moves.
We will emit these permuted nodes on all VSX little endian subtargets
but don't have the patterns available to match them on subtargets
that don't have direct moves.
Fixes: https://bugs.llvm.org/show_bug.cgi?id=47916
