tree 2ddf07aeba640d4c9ee5c144cd6b20eb5f70a20b
parent 3874bb93bcc32f9ed0010c41c237933fc69ee17b
author Fraser Cormack <fraser@codeplay.com> 1613577479 +0000
committer Copybara-Service <copybara-worker@google.com> 1613734039 -0800

[RISCV] Begin to support more subvector inserts/extracts

This patch adds support for INSERT_SUBVECTOR and EXTRACT_SUBVECTOR
(nominally where both operands are scalable vector types) where the
vector, subvector, and index align sufficiently to allow decomposition
to subregister manipulation:

* For extracts, the extracted subvector must correctly align with the
lower elements of a vector register.
* For inserts, the inserted subvector must be at least one full vector
register, and correctly align as above.

This approach should work for fixed-length vector insertion/extraction
too, but that will come later.

Reviewed By: craig.topper, khchen, arcbbb

Differential Revision: https://reviews.llvm.org/D96873

GitOrigin-RevId: d876214990303e07310fb9f7a13b37715f051006