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.equal_ortree import PartitionedEq
21 from ieee754
.part_cmp
.eq_gt_ge
import PartitionedEqGtGe
22 from ieee754
.part_mul_add
.partpoints
import make_partition
23 from operator
import or_
, xor
, and_
, not_
25 from nmigen
import (Signal
,
27 def applyop(op1
, op2
, op
):
28 if isinstance(op1
, PartitionedSignal
):
30 if isinstance(op2
, PartitionedSignal
):
35 class PartitionedSignal
:
36 def __init__(self
, mask
, *args
, **kwargs
):
37 self
.sig
= Signal(*args
, **kwargs
)
38 width
= self
.sig
.shape()[0] # get signal width
39 self
.partpoints
= make_partition(mask
, width
) # create partition points
41 for name
in ['add', 'eq', 'gt', 'ge']:
42 self
.modnames
[name
] = 0
44 def set_module(self
, m
):
47 def get_modname(self
, category
):
48 self
.modnames
[category
] += 1
49 return "%s%d" % (category
, self
.modnames
[category
])
52 if isinstance(val
, PartitionedSignal
):
53 return self
.sig
.eq(val
.sig
)
54 return self
.sig
.eq(val
)
56 # unary ops that require partitioning
59 return Operator("~", [self
])
61 return Operator("-", [self
])
63 # binary ops that don't require partitioning
65 def __and__(self
, other
):
66 return applyop(self
, other
, and_
)
68 def __rand__(self
, other
):
69 return applyop(other
, self
, and_
)
71 def __or__(self
, other
):
72 return applyop(self
, other
, or_
)
74 def __ror__(self
, other
):
75 return applyop(other
, self
, or_
)
77 def __xor__(self
, other
):
78 return applyop(self
, other
, xor
)
80 def __rxor__(self
, other
):
81 return applyop(other
, self
, xor
)
83 # binary ops that need partitioning
85 def __add__(self
, other
):
86 shape
= self
.sig
.shape()
87 pa
= PartitionedAdder(shape
[0], self
.partpoints
)
88 setattr(self
.m
.submodules
, self
.get_modname('add'), pa
)
90 comb
+= pa
.a
.eq(self
.sig
)
91 if isinstance(other
, PartitionedSignal
):
92 comb
+= pa
.b
.eq(other
.sig
)
94 comb
+= pa
.b
.eq(other
)
97 def __radd__(self
, other
):
98 return Operator("+", [other
, self
])
99 def __sub__(self
, other
):
100 return Operator("-", [self
, other
])
101 def __rsub__(self
, other
):
102 return Operator("-", [other
, self
])
104 def __mul__(self
, other
):
105 return Operator("*", [self
, other
])
106 def __rmul__(self
, other
):
107 return Operator("*", [other
, self
])
109 def __check_divisor(self
):
110 width
, signed
= self
.shape()
112 # Python's division semantics and Verilog's division semantics
113 # differ for negative divisors (Python uses div/mod, Verilog
114 # uses quo/rem); for now, avoid the issue
115 # completely by prohibiting such division operations.
116 raise NotImplementedError(
117 "Division by a signed value is not supported")
118 def __mod__(self
, other
):
119 other
= Value
.cast(other
)
120 other
.__check
_divisor
()
121 return Operator("%", [self
, other
])
122 def __rmod__(self
, other
):
123 self
.__check
_divisor
()
124 return Operator("%", [other
, self
])
125 def __floordiv__(self
, other
):
126 other
= Value
.cast(other
)
127 other
.__check
_divisor
()
128 return Operator("//", [self
, other
])
129 def __rfloordiv__(self
, other
):
130 self
.__check
_divisor
()
131 return Operator("//", [other
, self
])
133 def __lshift__(self
, other
):
134 return Operator("<<", [self
, other
])
135 def __rlshift__(self
, other
):
136 return Operator("<<", [other
, self
])
137 def __rshift__(self
, other
):
138 return Operator(">>", [self
, other
])
140 # binary comparison ops that need partitioning
142 def _compare(self
, width
, op1
, op2
, opname
, optype
):
143 #print (opname, op1, op2)
144 pa
= PartitionedEqGtGe(width
, self
.partpoints
)
145 setattr(self
.m
.submodules
, self
.get_modname(opname
), pa
)
147 comb
+= pa
.opcode
.eq(optype
) # set opcode
148 if isinstance(op1
, PartitionedSignal
):
149 comb
+= pa
.a
.eq(op1
.sig
)
152 if isinstance(op2
, PartitionedSignal
):
153 comb
+= pa
.b
.eq(op2
.sig
)
158 def __eq__(self
, other
):
159 width
= self
.sig
.shape()[0]
160 return self
._compare
(width
, self
, other
, "eq", PartitionedEqGtGe
.EQ
)
162 def __ne__(self
, other
):
163 width
= self
.sig
.shape()[0]
164 eq
= self
._compare
(width
, self
, other
, "eq", PartitionedEqGtGe
.EQ
)
165 ne
= Signal(eq
.width
)
166 self
.m
.d
.comb
+= ne
.eq(~eq
)
169 def __gt__(self
, other
):
170 width
= self
.sig
.shape()[0]
171 return self
._compare
(width
, self
, other
, "gt", PartitionedEqGtGe
.GT
)
173 def __lt__(self
, other
):
174 width
= self
.sig
.shape()[0]
175 return self
._compare
(width
, other
, self
, "gt", PartitionedEqGtGe
.GT
)
177 def __ge__(self
, other
):
178 width
= self
.sig
.shape()[0]
179 return self
._compare
(width
, self
, other
, "ge", PartitionedEqGtGe
.GE
)
181 def __le__(self
, other
):
182 width
= self
.sig
.shape()[0]
183 return self
._compare
(width
, other
, self
, "ge", PartitionedEqGtGe
.GE
)
188 """Conversion to boolean.
193 ``1`` if any bits are set, ``0`` otherwise.
195 return Operator("b", [self
])
198 """Check if any bits are ``1``.
203 ``1`` if any bits are set, ``0`` otherwise.
205 return Operator("r|", [self
])
208 """Check if all bits are ``1``.
213 ``1`` if all bits are set, ``0`` otherwise.
215 return Operator("r&", [self
])
218 """Compute pairwise exclusive-or of every bit.
223 ``1`` if an odd number of bits are set, ``0`` if an
224 even number of bits are set.
226 return Operator("r^", [self
])
228 def implies(premise
, conclusion
):
234 ``0`` if ``premise`` is true and ``conclusion`` is not,
237 return ~premise | conclusion