From: lkcl <lkcl@web>
Date: Mon, 6 Jun 2022 10:31:55 +0000 (+0100)
Subject: (no commit message)
X-Git-Tag: opf_rfc_ls005_v1~1936
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=fa14d3478230d61ca239b3c27fb9904e86e46de2;p=libreriscv.git

---

diff --git a/openpower/sv/remap.mdwn b/openpower/sv/remap.mdwn
index b08ff553f..3294c4954 100644
--- a/openpower/sv/remap.mdwn
+++ b/openpower/sv/remap.mdwn
@@ -138,7 +138,7 @@ Form: SVM-Form SV "Matrix" Form (see [[isatables/fields.text]])
 
 Fields:
 
-* **SVxd** - SV REMAP "xdim" (SVGPR>>1 for Indexed REMAP)
+* **SVxd** - SV REMAP "xdim"
 * **SVyd** - SV REMAP "ydim"
 * **SVzd** - SV REMAP "zdim"
 * **SVRM** - SV REMAP Mode (0b00000 for Matrix, 0b00001 for FFT etc.)
@@ -155,8 +155,8 @@ Fields:
 | 0b0101 | DCT COS table index generation |
 | 0b0110 | DCT half-swap   |
 | 0b0111 | reserved  |
-| 0b1000 | Indexed (XY straight) |
-| 0b1001 | Indexed (YX swapped)  |
+| 0b1000 | reserved |
+| 0b1001 | reserved  |
 | 0b1010 | iDCT Inner butterfly, pre-calculated coefficients |
 | 0b1011 | iDCT Outer butterfly  |
 | 0b1100 | iDCT Inner butterfly, on-the-fly (Vertical-First Mode) |
@@ -178,6 +178,31 @@ to SVSHAPE0-3 with `mtspr`. Circumstances include Matrices with dimensions
 larger than 32, and in-place Transpose.  Potentially a future v3.1 Prefixed
 instruction, `psvshape`, may extend the capability here.
 
+# svindex instruction
+
+`svindex` is a convenience instruction that reduces instruction
+count for Indexed REMAP Mode. It sets up
+(overwrites) all required SVSHAPE SPRs and also modifies SVSTATE
+including VL and MAXVL. Using `svshape` therefore does not also
+require `setvl`.
+
+Form: SVI-Form SV "Indexed" Form (see [[isatables/fields.text]])
+
+    svshape RS,mask,SVd,ew,vf
+
+| 0.5|6.10 |11.15  |16.21 | 22.23 | 25 | 26..31|  name    |
+| -- | --  | ---   | ---- | ----- | -- | ------| -------- |
+|OPCD| RS  | mask  | SVd  | ew    | vf | XO    | svindex |
+
+Fields:
+
+* **SVxd** - SV REMAP "xdim"
+* **SVyd** - SV REMAP "ydim"
+* **SVzd** - SV REMAP "zdim"
+* **SVRM** - SV REMAP Mode (0b00000 for Matrix, 0b00001 for FFT etc.)
+* **vf** - sets "Vertical-First" mode
+* **XO** - standard 5-bit XO field
+
 # REMAP Matrix pseudocode
 
 The algorithm below shows how REMAP works more clearly, and may be