3d3cd675dae4ea82248cdc4261d6a9cc030ad6ae
1 # SPDX-License-Identifier: LGPL-2.1-or-later
2 # See Notices.txt for copyright information
5 Copyright (C) 2020 Luke Kenneth Casson Leighton <lkcl@lkcl.net>
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*.
11 the basic fundamental idea is: write code once, and if you want a SIMD
12 version of it, use PartitionedSignal in place of Signal. job done.
13 this however requires the code to *not* be designed to use nmigen.If,
14 nmigen.Case, or other constructs: only Mux and other logic.
16 * http://bugs.libre-riscv.org/show_bug.cgi?id=132
19 from ieee754
.part_mul_add
.adder
import PartitionedAdder
20 from ieee754
.part_cmp
.eq_gt_ge
import PartitionedEqGtGe
21 from ieee754
.part_bits
.xor
import PartitionedXOR
22 from ieee754
.part_shift
.part_shift_dynamic
import PartitionedDynamicShift
23 from ieee754
.part_shift
.part_shift_scalar
import PartitionedScalarShift
24 from ieee754
.part_mul_add
.partpoints
import make_partition
, PartitionPoints
25 from operator
import or_
, xor
, and_
, not_
27 from nmigen
import (Signal
, Const
)
31 if isinstance(op1
, PartitionedSignal
):
36 def applyop(op1
, op2
, op
):
37 return op(getsig(op1
), getsig(op2
))
40 class PartitionedSignal
:
41 def __init__(self
, mask
, *args
, **kwargs
):
42 self
.sig
= Signal(*args
, **kwargs
)
43 width
= len(self
.sig
) # get signal width
44 # create partition points
45 if isinstance(mask
, PartitionPoints
):
46 self
.partpoints
= mask
48 self
.partpoints
= make_partition(mask
, width
)
50 for name
in ['add', 'eq', 'gt', 'ge', 'ls', 'xor']:
51 self
.modnames
[name
] = 0
53 def set_module(self
, m
):
56 def get_modname(self
, category
):
57 self
.modnames
[category
] += 1
58 return "%s_%d" % (category
, self
.modnames
[category
])
61 return self
.sig
.eq(getsig(val
))
63 # unary ops that do not require partitioning
68 # unary ops that require partitioning
71 z
= Const(0, len(self
.sig
))
72 result
, _
= self
.sub_op(z
, self
)
75 # binary ops that don't require partitioning
77 def __and__(self
, other
):
78 return applyop(self
, other
, and_
)
80 def __rand__(self
, other
):
81 return applyop(other
, self
, and_
)
83 def __or__(self
, other
):
84 return applyop(self
, other
, or_
)
86 def __ror__(self
, other
):
87 return applyop(other
, self
, or_
)
89 def __xor__(self
, other
):
90 return applyop(self
, other
, xor
)
92 def __rxor__(self
, other
):
93 return applyop(other
, self
, xor
)
95 # binary ops that need partitioning
97 # TODO: detect if the 2nd operand is a Const, a Signal or a
98 # PartitionedSignal. if it's a Const or a Signal, a global shift
99 # can occur. if it's a PartitionedSignal, that's much more interesting.
100 def ls_op(self
, op1
, op2
, carry
, shr_flag
=0):
102 if isinstance(op2
, Const
) or isinstance(op2
, Signal
):
104 pa
= PartitionedScalarShift(len(op1
), self
.partpoints
)
108 pa
= PartitionedDynamicShift(len(op1
), self
.partpoints
)
109 setattr(self
.m
.submodules
, self
.get_modname('ls'), pa
)
112 comb
+= pa
.data
.eq(op1
)
113 comb
+= pa
.shifter
.eq(op2
)
114 comb
+= pa
.shift_right
.eq(shr_flag
)
118 comb
+= pa
.shift_right
.eq(shr_flag
)
119 # XXX TODO: carry-in, carry-out
120 #comb += pa.carry_in.eq(carry)
121 return (pa
.output
, 0)
123 def __lshift__(self
, other
):
124 z
= Const(0, len(self
.partpoints
)+1)
125 result
, _
= self
.ls_op(self
, other
, carry
=z
) # TODO, carry
128 def __rlshift__(self
, other
):
129 raise NotImplementedError
130 return Operator("<<", [other
, self
])
132 def __rshift__(self
, other
):
133 z
= Const(0, len(self
.partpoints
)+1)
134 result
, _
= self
.ls_op(self
, other
, carry
=z
, shr_flag
=1) # TODO, carry
137 def __rrshift__(self
, other
):
138 raise NotImplementedError
139 return Operator(">>", [other
, self
])
141 def add_op(self
, op1
, op2
, carry
):
144 pa
= PartitionedAdder(len(op1
), self
.partpoints
)
145 setattr(self
.m
.submodules
, self
.get_modname('add'), pa
)
149 comb
+= pa
.carry_in
.eq(carry
)
150 return (pa
.output
, pa
.carry_out
)
152 def sub_op(self
, op1
, op2
, carry
=~
0):
155 pa
= PartitionedAdder(len(op1
), self
.partpoints
)
156 setattr(self
.m
.submodules
, self
.get_modname('add'), pa
)
159 comb
+= pa
.b
.eq(~op2
)
160 comb
+= pa
.carry_in
.eq(carry
)
161 return (pa
.output
, pa
.carry_out
)
163 def __add__(self
, other
):
164 result
, _
= self
.add_op(self
, other
, carry
=0)
167 def __radd__(self
, other
):
168 result
, _
= self
.add_op(other
, self
)
171 def __sub__(self
, other
):
172 result
, _
= self
.sub_op(self
, other
)
175 def __rsub__(self
, other
):
176 result
, _
= self
.sub_op(other
, self
)
179 def __mul__(self
, other
):
180 return Operator("*", [self
, other
])
182 def __rmul__(self
, other
):
183 return Operator("*", [other
, self
])
185 def __check_divisor(self
):
186 width
, signed
= self
.shape()
188 # Python's division semantics and Verilog's division semantics
189 # differ for negative divisors (Python uses div/mod, Verilog
190 # uses quo/rem); for now, avoid the issue
191 # completely by prohibiting such division operations.
192 raise NotImplementedError(
193 "Division by a signed value is not supported")
195 def __mod__(self
, other
):
196 raise NotImplementedError
197 other
= Value
.cast(other
)
198 other
.__check
_divisor
()
199 return Operator("%", [self
, other
])
201 def __rmod__(self
, other
):
202 raise NotImplementedError
203 self
.__check
_divisor
()
204 return Operator("%", [other
, self
])
206 def __floordiv__(self
, other
):
207 raise NotImplementedError
208 other
= Value
.cast(other
)
209 other
.__check
_divisor
()
210 return Operator("//", [self
, other
])
212 def __rfloordiv__(self
, other
):
213 raise NotImplementedError
214 self
.__check
_divisor
()
215 return Operator("//", [other
, self
])
217 # binary comparison ops that need partitioning
219 def _compare(self
, width
, op1
, op2
, opname
, optype
):
220 # print (opname, op1, op2)
221 pa
= PartitionedEqGtGe(width
, self
.partpoints
)
222 setattr(self
.m
.submodules
, self
.get_modname(opname
), pa
)
224 comb
+= pa
.opcode
.eq(optype
) # set opcode
225 if isinstance(op1
, PartitionedSignal
):
226 comb
+= pa
.a
.eq(op1
.sig
)
229 if isinstance(op2
, PartitionedSignal
):
230 comb
+= pa
.b
.eq(op2
.sig
)
235 def __eq__(self
, other
):
236 width
= len(self
.sig
)
237 return self
._compare
(width
, self
, other
, "eq", PartitionedEqGtGe
.EQ
)
239 def __ne__(self
, other
):
240 width
= len(self
.sig
)
241 eq
= self
._compare
(width
, self
, other
, "eq", PartitionedEqGtGe
.EQ
)
242 ne
= Signal(eq
.width
)
243 self
.m
.d
.comb
+= ne
.eq(~eq
)
246 def __gt__(self
, other
):
247 width
= len(self
.sig
)
248 return self
._compare
(width
, self
, other
, "gt", PartitionedEqGtGe
.GT
)
250 def __lt__(self
, other
):
251 width
= len(self
.sig
)
252 # swap operands, use gt to do lt
253 return self
._compare
(width
, other
, self
, "gt", PartitionedEqGtGe
.GT
)
255 def __ge__(self
, other
):
256 width
= len(self
.sig
)
257 return self
._compare
(width
, self
, other
, "ge", PartitionedEqGtGe
.GE
)
259 def __le__(self
, other
):
260 width
= len(self
.sig
)
261 # swap operands, use ge to do le
262 return self
._compare
(width
, other
, self
, "ge", PartitionedEqGtGe
.GE
)
267 """Conversion to boolean.
272 ``1`` if any bits are set, ``0`` otherwise.
274 return self
.any() # have to see how this goes
275 #return Operator("b", [self])
278 """Check if any bits are ``1``.
283 ``1`` if any bits are set, ``0`` otherwise.
285 return self
!= Const(0) # leverage the __ne__ operator here
286 return Operator("r|", [self
])
289 """Check if all bits are ``1``.
294 ``1`` if all bits are set, ``0`` otherwise.
296 return self
== Const(-1) # leverage the __eq__ operator here
299 """Compute pairwise exclusive-or of every bit.
304 ``1`` if an odd number of bits are set, ``0`` if an
305 even number of bits are set.
307 width
= len(self
.sig
)
308 pa
= PartitionedXOR(width
, self
.partpoints
)
309 setattr(self
.m
.submodules
, self
.get_modname("xor"), pa
)
310 self
.m
.d
.comb
+= pa
.a
.eq(self
.sig
)
313 def implies(premise
, conclusion
):
319 ``0`` if ``premise`` is true and ``conclusion`` is not,
322 # amazingly, this should actually work.
323 return ~premise | conclusion