From 911573bb071225cefe792f83c772ecd8de4c7a61 Mon Sep 17 00:00:00 2001 From: lkcl Date: Mon, 8 Aug 2022 12:49:49 +0100 Subject: [PATCH] --- openpower/sv/svp64/appendix.mdwn | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/openpower/sv/svp64/appendix.mdwn b/openpower/sv/svp64/appendix.mdwn index 4e3182144..dd0dbf8ef 100644 --- a/openpower/sv/svp64/appendix.mdwn +++ b/openpower/sv/svp64/appendix.mdwn @@ -661,8 +661,11 @@ The CR-based data-driven fail-on-first is new and not found in ARM SVE or RVV. At the same time it is also "old" because it is a generalisation of the Z80 [Block compare](https://rvbelzen.tripod.com/z80prgtemp/z80prg04.htm) -instructions, especially - It is extremely useful for reducing instruction count, +instructions, especially +[CPIR](http://z80-heaven.wikidot.com/instructions-set:cpir) +which is based on CP (compare) as the ultimate "element" (suffix) +operation to which the repeat (prefix) is applied. +It is extremely useful for reducing instruction count, however requires speculative execution involving modifications of VL to get high performance implementations. An additional mode (RC1=1) effectively turns what would otherwise be an arithmetic operation -- 2.30.2