Commit Graph

3 Commits

Author SHA1 Message Date
Fraser Cormack e80ca3af82 [RISCV] Fix INSERT/EXTRACT_SUBVECTOR on fractional LMUL types
This patch fixes a bug where the lowering for INSERT_SUBVECTOR and
EXTRACT_SUBVECTOR would insist on first extracting a register-aligned
LMUL1 vector type before perfoming the slide up/down. This was even if
the vector was a fractional LMUL type, in which case the aligned
EXTRACT_SUBVECTOR was invalid.

This issue only occurred for scalable vector types, but a variety of
tests for both scalable and fixed-length vectors have been added to
ensure this does not regress in the future.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D97556
2021-03-01 11:51:05 +00:00
Fraser Cormack bd4d421688 [RISCV] Support EXTRACT_SUBVECTOR on vector masks
This patch adds support for extracting subvectors from vector masks.
This can be either extracting a scalable vector from another, or a fixed-length
vector from a fixed-length or scalable vector.

Since RVV lacks a way to slide vector masks down on an element-wise
basis and we don't know the true length of the vector registers, in many
cases we must resort to using equivalently-sized i8 vectors to perform
the operation. When this is not possible we fall back and extend to a
suitable i8 vector.

Support was also added for fixed-length truncation to mask types.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D97475
2021-03-01 11:20:09 +00:00
Fraser Cormack 821f8bb29a [RISCV] Unify scalable- and fixed-vector EXTRACT_SUBVECTOR lowering
This patch unifies the two disparate paths for lowering
EXTRACT_SUBVECTOR operations under one roof. Consequently, with this
patch it is possible to support any fixed-length subvector extraction,
not just "cast-like" ones.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D97192
2021-02-25 11:46:57 +00:00