From 15b3a177f3ff6ea32287324509e7a891caf5f300 Mon Sep 17 00:00:00 2001 From: lkcl Date: Sat, 28 Aug 2021 17:09:05 +0100 Subject: [PATCH] --- openpower/sv/svp64/appendix.mdwn | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/openpower/sv/svp64/appendix.mdwn b/openpower/sv/svp64/appendix.mdwn index e1177b25e..1eee04bfb 100644 --- a/openpower/sv/svp64/appendix.mdwn +++ b/openpower/sv/svp64/appendix.mdwn @@ -441,9 +441,20 @@ ffirst LD/ST operations on an aligned boundary. Likewise, to reduce workloads or balance resources. CR-based data-dependent first on the other hand MUST not truncate VL -arbitrarily. This because it is a precise test on which algorithms +arbitrarily to a length decided by the hardware: VL MUST only be +truncated based explicitly on whether a test fails. +This because it is a precise test on which algorithms will rely. +## Data-dependent fail-first on CR operations (crand etc) + +Operations that actually produce or alter CR Field as a result +do not also in turn have an Rc=1 mode. However it makes no +sense to try to test the 4 bits of a CR Field for being equal +or not equal to zero. + +TODO + # pred-result mode This mode merges common CR testing with predication, saving on instruction -- 2.30.2