From: lkcl <lkcl@web>
Date: Fri, 16 Sep 2022 09:49:26 +0000 (+0100)
Subject: (no commit message)
X-Git-Tag: opf_rfc_ls005_v1~407
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=32b4c1471dbc2dd6875affdce511afcee2154a9f;p=libreriscv.git

---

diff --git a/openpower/sv/rfc/ls001.mdwn b/openpower/sv/rfc/ls001.mdwn
index e4ce2014f..d958e41a8 100644
--- a/openpower/sv/rfc/ls001.mdwn
+++ b/openpower/sv/rfc/ls001.mdwn
@@ -407,11 +407,14 @@ into `sv.bc`: it became CISC-like in its complexity and was quickly reverted.
 
 [REMAP](https://libre-soc.org/openpower/sv/remap)
 is extremely advanced but brings features already present in other
-DSPs and Supercomputing ISAs.  Normally (without these features)
-algorithms are are costly or
+DSPs and Supercomputing ISAs. The usual sequential progression
+through elements is pushed through a hardware-defined
+*fully Deterministic*
+"remapping".  Normally (without REMAP)
+algorithms are costly or
 convoluted to implement.  They are typically implemented
 as hard-coded fully loop-unrolled assembler which is often
-auto-generated by specialist dedicated tools, or written
+auto-generated by specialist tools, or written
 entirely by hand.
 All REMAP Schedules *including Indexed*
 are 100% Deterministic from their point of declaration,
@@ -438,6 +441,9 @@ REMAP Schedules, such as Complex Number FFTs.
 * **Parallel Reduction** REMAP, performs an automatic map-reduce using
   *any suitable scalar operation*.
 
+Note that predication is possible on REMAP but is hard to use effectively.
+It is often best to make copies of data (`VCOMPRESS`) then apply REMAP.
+
 \newpage{}
 # Scalar Operations