adds a sorting network, unittests and documentation for it.
--
Robert Jordens.
From 7d1ab7420a27df24c41c184712d5e4467020e0d0 Mon Sep 17 00:00:00 2001
From: Robert Jordens <jord...@gmail.com>
Date: Fri, 29 Nov 2013 19:52:42 -0700
Subject: [PATCH 5/5] genlib/sort: add bitonic, combinatorial sorter
complete with with api documentation and unittests
---
doc/api.rst | 7 +++++
migen/genlib/sort.py | 70 +++++++++++++++++++++++++++++++++++++++++++++++++
migen/test/test_sort.py | 28 ++++++++++++++++++++
3 files changed, 105 insertions(+)
create mode 100644 migen/genlib/sort.py
create mode 100644 migen/test/test_sort.py
diff --git a/doc/api.rst b/doc/api.rst
index 958702d..06c8a55 100644
--- a/doc/api.rst
+++ b/doc/api.rst
@@ -28,3 +28,10 @@ migen API Documentation
.. automodule:: migen.genlib.cordic
:members:
:show-inheritance:
+
+:mod:`genlib.sort` Module
+------------------------------
+
+.. automodule:: migen.genlib.sort
+ :members:
+ :show-inheritance:
diff --git a/migen/genlib/sort.py b/migen/genlib/sort.py
new file mode 100644
index 0000000..1bc82ef
--- /dev/null
+++ b/migen/genlib/sort.py
@@ -0,0 +1,70 @@
+from migen.fhdl.std import *
+from migen.fhdl import verilog
+
+class BitonicSort(Module):
+ """Combinatorial sorting network
+
+ The Bitonic sort is implemented as a combinatorial sort using
+ comparators and multiplexers. Its asymptotic complexity (in terms of
+ number of comparators/muxes) is O(n log(n)**2), like mergesort or
+ shellsort.
+
+ http://www.dps.uibk.ac.at/~cosenza/teaching/gpu/sort-batcher.pdf
+
+ http://www.inf.fh-flensburg.de/lang/algorithmen/sortieren/bitonic/bitonicen.htm
+
+ http://www.myhdl.org/doku.php/cookbook:bitonic
+
+ Parameters
+ ----------
+ n : int
+ Number of inputs and output signals.
+ m : int
+ Bit width of inputs and outputs. Or a tuple of `(m, signed)`.
+ ascending : bool
+ Sort direction. `True` if input is to be sorted ascending,
+ `False` for descending. Defaults to ascending.
+
+ Attributes
+ ----------
+ i : list of Signals, in
+ Input values, each `m` wide.
+ o : list of Signals, out
+ Output values, sorted, each `m` bits wide.
+ """
+ def __init__(self, n, m, ascending=True):
+ self.i = [Signal(m) for i in range(n)]
+ self.o = [Signal(m) for i in range(n)]
+ self._sort(self.i, self.o, int(ascending), m)
+
+ def _sort_two(self, i0, i1, o0, o1, dir):
+ self.comb += [
+ o0.eq(i0),
+ o1.eq(i1),
+ If(dir == (i0 > i1),
+ o0.eq(i1),
+ o1.eq(i0),
+ )]
+
+ def _merge(self, i, o, dir, m):
+ n = len(i)
+ k = n//2
+ if n > 1:
+ t = [Signal(m) for j in range(n)]
+ for j in range(k):
+ self._sort_two(i[j], i[j + k], t[j], t[j + k], dir)
+ self._merge(t[:k], o[:k], dir, m)
+ self._merge(t[k:], o[k:], dir, m)
+ else:
+ self.comb += o[0].eq(i[0])
+
+ def _sort(self, i, o, dir, m):
+ n = len(i)
+ k = n//2
+ if n > 1:
+ t = [Signal(m) for j in range(n)]
+ self._sort(i[:k], t[:k], 1, m) # ascending
+ self._sort(i[k:], t[k:], 0, m) # descending
+ self._merge(t, o, dir, m)
+ else:
+ self.comb += o[0].eq(i[0])
diff --git a/migen/test/test_sort.py b/migen/test/test_sort.py
new file mode 100644
index 0000000..99785ab
--- /dev/null
+++ b/migen/test/test_sort.py
@@ -0,0 +1,28 @@
+import unittest
+from random import randrange
+
+from migen.fhdl.std import *
+from migen.genlib.sort import *
+
+from migen.test.support import SimCase, SimBench
+
+class BitonicCase(SimCase, unittest.TestCase):
+ class TestBench(SimBench):
+ def __init__(self):
+ self.submodules.dut = BitonicSort(8, 4, ascending=True)
+
+ def test_sizes(self):
+ self.assertEqual(len(self.tb.dut.i), 8)
+ self.assertEqual(len(self.tb.dut.o), 8)
+ for i in range(8):
+ self.assertEqual(flen(self.tb.dut.i[i]), 4)
+ self.assertEqual(flen(self.tb.dut.o[i]), 4)
+
+ def test_sort(self):
+ def cb(tb, s):
+ for i in tb.dut.i:
+ s.wr(i, randrange(1<<flen(i)))
+ i = [s.rd(i) for i in tb.dut.i]
+ o = [s.rd(o) for o in tb.dut.o]
+ self.assertEqual(sorted(i), o)
+ self.run_with(cb, 20)
--
1.8.3.2
_______________________________________________
Devel mailing list
Devel@lists.milkymist.org
https://ssl.serverraum.org/lists/listinfo/devel
