From ef90a7ad113d1a68626e3ec2124b4b709becd61b Mon Sep 17 00:00:00 2001 From: lkcl Date: Fri, 2 Sep 2022 23:47:13 +0100 Subject: [PATCH] --- openpower/sv/remap.mdwn | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/openpower/sv/remap.mdwn b/openpower/sv/remap.mdwn index 26f5b945f..e6aea5fc5 100644 --- a/openpower/sv/remap.mdwn +++ b/openpower/sv/remap.mdwn @@ -636,7 +636,18 @@ the SVSTATE SPRs manually. # svshape2 (offset) `svshape2` is an additional convenience instruction that prioritises -setting `SVSHAPE.offset`. It has similar cap +setting `SVSHAPE.offset`. It has identical capabilities to `svindex` and +in terms of both options (skip, etc.) and ability to activate REMAP +(rmm, mask mode) but unlike `svindex` it does not set GPR REMAP, +only a 1D or 2D `svshape`, and +unlike `svshape` it can set an arbirrary `SVSHAPE.offset` immediate. + +One of the limitations of Simple-V is that Vector elements start on the boundary +of the Scalar regfile, which is fine when element-width overrides are not +needed. If the starting point of a Vector with smaller elwidths must begin +in the middle of a register, normally there would be no way to do so except +through LD/ST. `SVSHAPE.offset` caters for this scenario and `svshape2`is +makes it easier. svshape2 offs,inv,yx,rmm,SVd,sk,mm -- 2.30.2