From: lkcl <lkcl@web>
Date: Wed, 16 Dec 2020 01:22:09 +0000 (+0000)
Subject: (no commit message)
X-Git-Tag: convert-csv-opcode-to-binary~1306^2~1
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=b165f6b3d1f912fd5df86a6907e5e590994bda91;p=libreriscv.git

---

diff --git a/openpower/sv/svp_rewrite/svp64.mdwn b/openpower/sv/svp_rewrite/svp64.mdwn
index 760970f30..dda30fd4f 100644
--- a/openpower/sv/svp_rewrite/svp64.mdwn
+++ b/openpower/sv/svp_rewrite/svp64.mdwn
@@ -25,12 +25,25 @@ defined in the Prefix Fields section.
 
 ## Remapped Encoding Fields
 
+There are two different encodings: single-predication (typically arithmetic operations i.e. with more than one source register) and twin-predication (one source, one destination).  They require different encodings
+
+Single Predication (2+ src ops):
+
 | Remapped Encoding Field Name | Field bits | Description    |
 |------------------------------|------------|----------------|
 | MASKMODE                     | `0`        | Predicate Mode |
 | MASK                         | `1:3`      | Execution Mask |
 | TBD                          | `4:23`     | TBD            |
 
+Twin Predication (1 src, 1 dest):
+
+| Remapped Encoding Field Name | Field bits | Description    |
+|------------------------------|------------|----------------|
+| MASKMODE                     | `0`        | Predicate Mode |
+| SRCMASK                      | `1:3`      | Source    Mask |
+| DSTMASK                      | `4:6`      | Dest      Mask |
+| TBD                          | `7:23`     | TBD            |
+
 ## Predicate MASK Encoding
 
 One bit indicates the mode: CR or Int predication.   The two types may not be mixed.