Skip to content
Commit 73dc9964 authored by David Green's avatar David Green
Browse files

[AArch64] Add lane moves to PerfectShuffle tables

This teaches the perfect shuffle tables about lane inserts, that can
help reduce the cost of many entries. Many of the shuffle masks are
one-away from being correct, and a simple lane move can be a lot simpler
than trying to use ext/zip/etc. Because they are not exactly like the
other masks handled in the perfect shuffle tables, they require special
casing to generate them, with a special InsOp Operator.

The lane to insert into is encoded as the RHSID, and the move from is
grabbed from the original mask. This helps reduce the maximum perfect
shuffle entry cost to 3, with many more shuffles being generatable in a
single instruction.

Differential Revision: https://reviews.llvm.org/D123386
parent 7adfa31b
Loading
Loading
Loading
Loading
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Please to comment