src/ieee754/part/partsig.py

   1 # SPDX-License-Identifier: LGPL-2.1-or-later
   2 # See Notices.txt for copyright information
   3
   4 """
   5 Copyright (C) 2020 Luke Kenneth Casson Leighton <lkcl@lkcl.net>
   6
   7 dynamic-partitionable class similar to Signal, which, when the partition
   8 is fully open will be identical to Signal.  when partitions are closed,
   9 the class turns into a SIMD variant of Signal.  *this is dynamic*.
  10
  11 http://bugs.libre-riscv.org/show_bug.cgi?id=132
  12 """
  13
  14 from nmigen import (Module, Signal, Elaboratable,
  15                     )
  16 from ieee754.part_mul_add.adder import PartitionedAdder
  17
  18 class PartitionedSignal(Elaboratable):
  19     def __init__(self, partition_points, *args, **kwargs):
  20         self.partpoints = partition_points
  21         self.sig = Signal(*args, **kwargs)
  22         self.modnames = {}
  23         for name in ['add']:
  24             self.modnames[name] = 0
  25         self.m = Module()
  26
  27     def elaborate(self, platform):
  28         return self.m
  29
  30     def get_modname(self, category):
  31         self.modnames[category] += 1
  32         return "%s%d" % (category, self.modnames[category])
  33
  34     def eq(self, val):
  35         return self.sig.eq(val)
  36
  37     def __xor__(self, other):
  38         if isinstance(other, PartitionedSignal):
  39             return self.sig ^ other.sig
  40         return self.sig ^ other
  41
  42     def __add__(self, other):
  43         shape = self.sig.shape()
  44         pa = PartitionedAdder(shape[0], self.partpoints)
  45         setattr(self.m.submodules, self.get_modname('add'), pa)
  46         comb = self.m.d.comb
  47         comb += pa.a.eq(self.sig)
  48         if isinstance(other, PartitionedSignal):
  49             comb += pa.b.eq(other.sig)
  50         else:
  51             comb += pa.b.eq(other)
  52         return pa.output