From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Thu, 13 Apr 2023 11:56:20 +0000 (+0100)
Subject: spotted that the Shifted-only group of LD/ST-Post-increment needs to
X-Git-Tag: opf_rfc_ls010_v1~8
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=86aad8c209609e69d6d100255afd06546c71ac1e;p=libreriscv.git

spotted that the Shifted-only group of LD/ST-Post-increment needs to
be in EXT0xx but that Shifted-Post-Increment can be in EXT2xx
i think.
ls011
---

diff --git a/openpower/sv/rfc/ls004.mdwn b/openpower/sv/rfc/ls004.mdwn
index cf687d3a8..6acb74ef2 100644
--- a/openpower/sv/rfc/ls004.mdwn
+++ b/openpower/sv/rfc/ls004.mdwn
@@ -105,14 +105,20 @@ costly.  The totals are
 * 3 Store Indexed Shifted Byte-reverse
 * 6 Floating-Point Load Indexed Shifted (with Update)
 * 6 Floating-Point Store Indexed Shifted (with Update)
+* 6 Load Indexed Shifted Update Post-Increment
+* 4 Store Indexed Shifted Update Post-Increment
+* 2 Floating-Point Load Indexed Shifted Update Post-Increment
+* 2 Floating-Point Store Indexed Shifted Update Post-Increment
 
-Total count: 38 new 9-bit XO instructions, for an approximate total
+Total count: 51 new 9-bit XO instructions, for an approximate total
 XO cost of 3 bits within a single Primary Opcode.  With the savings
 that these instructions represent in hot-loops, as evidenced by their
 inclusion in top-end ISAs such as x86 and ARM, the cost may be considered
-justifiable.  However there is no point in placing these in EXT2xx, they
-need to be in EXT0xx, because if added as 64-bit Encoding the benefit
-reduction in binary size is not achieved.
+justifiable.  However there is no point in placing the 38
+Shifted-only group in EXT2xx, they need to be in EXT0xx, because if added
+as 64-bit Encoding the benefit reduction in binary size is not achieved.
+Post-Increment-Shifted on the other hand could reasonably be proposed
+in EXT2xx.
 
 |  0-5  | 6-10 | 11-15 | 16-20 | 21-22 | 23-31 | Instruction          |
 |-------|------|-------|-------|-------|-------|----------------------|
@@ -153,6 +159,20 @@ reduction in binary size is not achieved.
 |  PO   | FRS  |  RA   |  RB   |  sm   |  XO   | stfdxs FRS,RA,RB,sm  |
 |  PO   | FRS  |  RA   |  RB   |  sm   |  XO   | stfduxs FRS,RA,RB,sm |
 |  PO   | FRS  |  RA   |  RB   |  sm   |  XO   | stfiwxs FRS,RA,RB,sm |
+|  PO   | RT   |  RA   |  RB   |  sm   |  XO   | lbzuspx RT,RA,RB,sm   |
+|  PO   | RT   |  RA   |  RB   |  sm   |  XO   | lhzuspx RT,RA,RB,sm   |
+|  PO   | RT   |  RA   |  RB   |  sm   |  XO   | lhauspx RT,RA,RB,sm   |
+|  PO   | RT   |  RA   |  RB   |  sm   |  XO   | lwzuspx RT,RA,RB,sm   |
+|  PO   | RT   |  RA   |  RB   |  sm   |  XO   | lwauspx RT,RA,RB,sm   |
+|  PO   | RS   |  RA   |  RB   |  sm   |  XO   | stbuspx RS,RA,RB,sm   |
+|  PO   | RS   |  RA   |  RB   |  sm   |  XO   | sthuspx RS,RA,RB,sm   |
+|  PO   | RS   |  RA   |  RB   |  sm   |  XO   | stwuspx RS,RA,RB,sm   |
+|  PO   | RS   |  RA   |  RB   |  sm   |  XO   | stduspx RS,RA,RB,sm   |
+|  PO   | RT   |  RA   |  RB   |  sm   |  XO   | lduspx RT,RA,RB,sm   |
+|  PO   | FRT  |  RA   |  RB   |  sm   |  XO   | lfdupxs FRT,RA,RB,sm  |
+|  PO   | FRT  |  RA   |  RB   |  sm   |  XO   | lfsupxs FRT,RA,RB,sm  |
+|  PO   | FRS  |  RA   |  RB   |  sm   |  XO   | stfdupxs FRS,RA,RB,sm |
+|  PO   | FRS  |  RA   |  RB   |  sm   |  XO   | stfsupxs FRS,RA,RB,sm |
 
 ----------------