From 14f428d6b7ba3586895a186d70649a1cd510ad2e Mon Sep 17 00:00:00 2001 From: lkcl Date: Mon, 5 Sep 2022 11:55:31 +0100 Subject: [PATCH] --- openpower/sv.mdwn | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/openpower/sv.mdwn b/openpower/sv.mdwn index de6ef8824..0769fbe1e 100644 --- a/openpower/sv.mdwn +++ b/openpower/sv.mdwn @@ -340,8 +340,7 @@ v3.1 EXT01 usage, and because SVP64 is already 64-bit Prefixed, Prefixed-Prefixed-instructions (SVP64 Prefixed v3.1 Prefixed) would become a whopping 96-bit long instruction. Avoiding this situation is a high priority which in turn by necessity puts pressure -on the 32-bit Major Opcode space. Alternative locations for SVP64 -Prefixing include EXT006 and EXT017, with EXT006 being most favourable. +on the 32-bit Major Opcode space. SVP64 itself is already under pressure, being only 24 bits. If it is not permitted to take up 25% of EXT001 then it would have to be proposed @@ -351,6 +350,9 @@ However when combined with the bitmanip scalar instructions requiring two Major opcodes this would come to a grand total of 3 precious Major opcodes. On balance, then, sacrificing 25% of EXT001 is the "least difficult" choice. +Alternative locations for SVP64 +Prefixing include EXT006 and EXT017, with EXT006 being most favourable +as there is room for future expansion. Note also that EXT022, the Official Architectural Sandbox area available for "Custom non-approved purposes" according to the Power -- 2.30.2