src/openpower/sv/svp64.py

   1 # SPDX-License-Identifier: LGPLv3+
   2 # Copyright (C) 2021 Luke Kenneth Casson Leighton <lkcl@lkcl.net>
   3 # Funded by NLnet http://nlnet.nl
   4 """SVP64 Data Structures
   5
   6 For full spec see https://libre-soc.org/openpower/sv/
   7 """
   8
   9 from nmigen import Record
  10
  11
  12 # in nMigen, Record begins at the LSB and fills upwards
  13 # however in OpenPOWER, numbering is MSB0.  sigh.
  14 class SVP64Rec(Record):
  15     """SVP64 RM (Remap) Record.
  16
  17     https://libre-soc.org/openpower/sv/svp64/
  18
  19     | Field Name  | Field bits | Description                            |
  20     |-------------|------------|----------------------------------------|
  21     | MASKMODE    | `0`        | Execution (predication) Mask Kind      |
  22     | MASK        | `1:3`      | Execution Mask                         |
  23     | ELWIDTH     | `4:5`      | Element Width                          |
  24     | ELWIDTH_SRC | `6:7`      | Element Width for Source               |
  25     | SUBVL       | `8:9`      | Sub-vector length                      |
  26     | EXTRA       | `10:18`    | context-dependent extra                |
  27     | MODE        | `19:23`    | changes Vector behaviour               |
  28     """
  29     def __init__(self, name=None):
  30         Record.__init__(self, layout=[("mode"    , 5),
  31                                       ("extra"   , 9),
  32                                       ("subvl"   , 2),
  33                                       ("ewsrc"   , 2),
  34                                       ("elwidth" , 2),
  35                                       ("mask"    , 3),
  36                                       ("mmode"   , 1)], name=name)
  37
  38     def ports(self):
  39         return [self.mmode, self.mask, self.elwidth, self.ewsrc,
  40                 self.subvl, self.extra, self.mode]
  41
  42
  43 # in nMigen, Record begins at the LSB and fills upwards
  44 # however in OpenPOWER, numbering is MSB0.  sigh.
  45 class SVP64REMAP(Record):
  46     """SVP64 SHAPE (REMAP) Record.
  47
  48     https://libre-soc.org/openpower/sv/remap/
  49
  50     | Field Name  | Field bits | Description                            |
  51     |-------------|------------|----------------------------------------|
  52     | XDIMSZ      | `0:5`      | X Dimension size                       |
  53     | YDIMSZ      | `6:11`     | Y Dimension size                       |
  54     | ZDIMSZ      | `12:17`    | Z Dimension size                       |
  55     | PERMUTE     | `18:20`    | Permutation order (XYZ, XZY, YXZ...)   |
  56     | INVXYZ      | `21:23`    | Invert order of X or Y or Z            |
  57     | OFFSET      | `24:29`    | Adds to index before modulo            |
  58     | APPLYDIM    | `30:31`    | how many dimensions in use             |
  59     """
  60     def __init__(self, name=None):
  61         Record.__init__(self, layout=[("applydim" , 2),
  62                                       ("offset"   , 6),
  63                                       ("invxyz"   , 3),
  64                                       ("permute"  , 3),
  65                                       ("zdimsz"   , 6),
  66                                       ("ydimsz"   , 6),
  67                                       ("xdimsz"   , 6)], name=name)
  68
  69     def ports(self):
  70         return [self.applydim, self.offset, self.invxyz, self.permute,
  71                 self.zdimsz, self.ydimsz, self.xdimsz]
  72