1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
// SPDX-License-Identifier: Apache-2.0
package chisel3.util.experimental.decode
import chisel3.util.BitPat
sealed class TruthTable private (val table: Seq[(BitPat, BitPat)], val default: BitPat, val sort: Boolean) {
def inputWidth = table.head._1.getWidth
def outputWidth = table.head._2.getWidth
override def toString: String = {
def writeRow(map: (BitPat, BitPat)): String =
s"${map._1.rawString}->${map._2.rawString}"
(table.map(writeRow) ++ Seq(s"${" " * (inputWidth + 2)}${default.rawString}")).mkString("\n")
}
def copy(table: Seq[(BitPat, BitPat)] = this.table, default: BitPat = this.default, sort: Boolean = this.sort) =
TruthTable(table, default, sort)
override def equals(y: Any): Boolean = {
y match {
case y: TruthTable => toString == y.toString
case _ => false
}
}
}
object TruthTable {
/** Convert a table and default output into a [[TruthTable]]. */
def apply(table: Iterable[(BitPat, BitPat)], default: BitPat, sort: Boolean = true): TruthTable = {
val inputWidth = table.map(_._1.getWidth).max
require(table.map(_._2.getWidth).toSet.size == 1, "output width not equal.")
val outputWidth = table.map(_._2.getWidth).head
val mergedTable = table.map {
// pad input signals if necessary
case (in, out) if inputWidth > in.width =>
(BitPat.N(inputWidth - in.width) ## in, out)
case (in, out) => (in, out)
}
.groupBy(_._1.toString)
.map {
case (key, values) =>
// merge same input inputs.
values.head._1 -> BitPat(s"b${Seq
.tabulate(outputWidth) { i =>
val outputSet = values
.map(_._2)
.map(_.rawString)
.map(_(i))
.toSet
.filterNot(_ == '?')
require(
outputSet.size != 2,
s"TruthTable conflict in :\n${values.map { case (i, o) => s"${i.rawString}->${o.rawString}" }.mkString("\n")}"
)
outputSet.headOption.getOrElse('?')
}
.mkString}")
}
.toSeq
import BitPat.bitPatOrder
new TruthTable(if (sort) mergedTable.sorted else mergedTable, default, sort)
}
/** Parse TruthTable from its string representation. */
def fromString(tableString: String): TruthTable = {
TruthTable(
tableString
.split("\n")
.filter(_.contains("->"))
.map(_.split("->").map(str => BitPat(s"b$str")))
.map(bps => bps(0) -> bps(1))
.toSeq,
BitPat(s"b${tableString.split("\n").filterNot(_.contains("->")).head.replace(" ", "")}")
)
}
/** consume 1 table, split it into up to 3 tables with the same default bits.
*
* @return table and its indexes from original bits.
* @note
* Since most of minimizer(like espresso) cannot handle a multiple default table.
* It is useful to split a table into 3 tables based on the default type.
*/
private[decode] def split(
table: TruthTable
): Seq[(TruthTable, Seq[Int])] = {
def bpFilter(bitPat: BitPat, indexes: Seq[Int]): BitPat =
BitPat(s"b${bitPat.rawString.zipWithIndex.filter(b => indexes.contains(b._2)).map(_._1).mkString}")
def tableFilter(indexes: Seq[Int]): Option[(TruthTable, Seq[Int])] = {
if (indexes.nonEmpty)
Some(
(
TruthTable(
table.table.map { case (in, out) => in -> bpFilter(out, indexes) },
bpFilter(table.default, indexes)
),
indexes
)
)
else None
}
def index(bitPat: BitPat, bpType: Char): Seq[Int] =
bitPat.rawString.zipWithIndex.filter(_._1 == bpType).map(_._2)
Seq('1', '0', '?').flatMap(t => tableFilter(index(table.default, t)))
}
/** consume tables, merge it into single table with different default bits.
*
* @note
* Since most of minimizer(like espresso) cannot handle a multiple default table.
* It is useful to split a table into 3 tables based on the default type.
*/
private[decode] def merge(
tables: Seq[(TruthTable, Seq[Int])]
): TruthTable = {
def reIndex(bitPat: BitPat, table: TruthTable, indexes: Seq[Int]): Seq[(Char, Int)] =
table.table
.map(a => a._1.toString -> a._2)
.collectFirst { case (k, v) if k == bitPat.toString => v }
.getOrElse(BitPat.dontCare(indexes.size))
.rawString
.zip(indexes)
def bitPat(indexedChar: Seq[(Char, Int)]) = BitPat(s"b${indexedChar
.sortBy(_._2)
.map(_._1)
.mkString}")
TruthTable(
tables
.flatMap(_._1.table.map(_._1))
.map { key =>
key -> bitPat(tables.flatMap { case (table, indexes) => reIndex(key, table, indexes) })
},
bitPat(tables.flatMap { case (table, indexes) => table.default.rawString.zip(indexes) })
)
}
}
|
