From: lkcl Date: Sat, 19 Dec 2020 19:18:39 +0000 (+0000) Subject: (no commit message) X-Git-Tag: convert-csv-opcode-to-binary~1169 X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=c153e114ce00d56000cfa6a0f16e5742672bed21;p=libreriscv.git --- diff --git a/openpower/sv/svp_rewrite/svp64.mdwn b/openpower/sv/svp_rewrite/svp64.mdwn index f6d1bf166..746e1a4bf 100644 --- a/openpower/sv/svp_rewrite/svp64.mdwn +++ b/openpower/sv/svp_rewrite/svp64.mdwn @@ -18,7 +18,9 @@ suffix. The prefix always comes before the suffix in PC order. SVP64 is designed so that when the prefix is all zeros, no effect or influence occurs (no augmentation) such that all standard OpenPOWER -v3.0/1B instructions are "unaltered". This is termed `scalar identity behaviour` (based on the mathematical definition for "identity", as in, "identity matrix" or better "identity transformation") +v3.0/1B instructions are "unaltered". This is termed `scalar identity behaviour` (based on the mathematical definition for "identity", as in, "identity matrix" or better "identity transformation"). + +Note that this is completely different from when VL=0. VL=0 turns all operations under its influence into `nops`, whereas when VL=1 and the SV prefix is all zeros, the operation simply acts as if SV had not been applied at all (an "identity operation"). # Definition of Reserved in this spec.