def miter(c0, c1=None, startpoints=None, endpoints=None):
"""
Creates a miter circuit
Parameters
----------
c0 : Circuit
First circuit.
c1 : Circuit
Optional second circuit, if None c0 is mitered with itself.
startpoints : set of str
Nodes to be tied together, must exist in both circuits.
endpoints : set of str
Nodes to be compared, must exist in both circuits.
Returns
-------
Circuit
Miter circuit.
"""
# check for blackboxes
if c0.blackboxes:
raise ValueError(f"{c0.name} contains a blackbox")
if c1 and c1.blackboxes:
raise ValueError(f"{c1.name} contains a blackbox")
# clean inputs
if not c1:
c1 = c0
if not startpoints:
startpoints = c0.startpoints() & c1.startpoints()
if not endpoints:
endpoints = c0.endpoints() & c1.endpoints()
# create miter, relabel
m = Circuit(name=f"miter_{c0.name}_{c1.name}")
m.add_subcircuit(c0, "c0")
m.add_subcircuit(c1, "c1")
# tie inputs
for n in startpoints:
m.add(n, "input", fanout=[f"c0_{n}", f"c1_{n}"])
# compare outputs
m.add("miter", "or")
m.add("sat", "output", fanin="miter")
for n in endpoints:
m.add(f"dif_{n}", "xor", fanin=[f"c0_{n}", f"c1_{n}"], fanout="miter")
return m
def popcount(w):
"""
Create a population count circuit.
Parameters
----------
w : int
Input width of the circuit.
Returns
-------
Circuit
Population count circuit.
"""
c = Circuit(name="popcount")
ps = [[c.add(f"in_{i}", "input")] for i in range(w)]
c.add("tie0", "0")
i = 0
while len(ps) > 1:
# get values
ns = ps.pop(0)
ms = ps.pop(0)
# pad
aw = max(len(ns), len(ms))
while len(ms) < aw:
ms += ["tie0"]
while len(ns) < aw:
ns += ["tie0"]
# instantiate and connect adder
c.add_subcircuit(adder(aw), f"add_{i}")
for j, (n, m) in enumerate(zip(ns, ms)):
c.connect(n, f"add_{i}_a_{j}")
c.connect(m, f"add_{i}_b_{j}")
# add adder outputs
ps.append([f"add_{i}_out_{j}" for j in range(aw + 1)])
i += 1
# connect outputs
for i, o in enumerate(ps[0]):
c.add(f"out_{i}", "output", fanin=o)
if not c.fanout("tie0"):
c.remove("tie0")
return c
def influence_transform(c, n, s):
"""
Creates a circuit to compute sensitivity.
Parameters
----------
c : Circuit
Sequential circuit to unroll.
n : str
Node to compute influence at.
s : str
Startpoint to compute influence for.
Returns
-------
Circuit
Influence circuit.
"""
# check for blackboxes
if c.blackboxes:
raise ValueError(f"{c.name} contains a blackbox")
# check if s is in startpoints
sp = c.startpoints(n)
if s not in sp:
raise ValueError(f"{s} is not in startpoints of {n}")
# get input cone
fi_nodes = c.transitive_fanin(n) | set([n])
sub_c = Circuit("sub_cone", c.graph.subgraph(fi_nodes).copy())
# create two copies of sub circuit, share inputs except s
infl = Circuit(name=f"infl_{s}_on_{n}")
infl.add_subcircuit(sub_c, "c0")
infl.add_subcircuit(sub_c, "c1")
for g in sp:
if g != s:
infl.add(g, "input", fanout=[f"c0_{g}", f"c1_{g}"])
else:
infl.add(f"not_{g}", "not", fanout=f"c1_{s}")
infl.add(g, "input", fanout=[f"c0_{g}", f"not_{g}"])
infl.add("dif", "xor", fanin=[f"c0_{n}", f"c1_{n}"])
infl.add("sat", "output", fanin="dif")
return infl
def sensitivity_transform(c, n):
"""
Creates a circuit to compute sensitivity.
Parameters
----------
c : Circuit
Sequential circuit to unroll.
n : str
Node to compute sensitivity at.
Returns
-------
Circuit
Sensitivity circuit.
"""
# check for blackboxes
if c.blackboxes:
raise ValueError(f"{c.name} contains a blackbox")
# check for startpoints
startpoints = c.startpoints(n)
if len(startpoints) < 1:
raise ValueError(f"{n} has no startpoints")
# get input cone
fi_nodes = c.transitive_fanin(n) | set([n])
sub_c = Circuit(graph=c.graph.subgraph(fi_nodes).copy())
# create sensitivity circuit
sen = Circuit()
sen.add_subcircuit(sub_c, "orig")
for s in startpoints:
sen.add(s, "input", fanout=f"orig_{s}")
# add popcount
sen.add_subcircuit(popcount(len(startpoints)), "pc")
# add inverted input copies
for i, s0 in enumerate(startpoints):
sen.add_subcircuit(sub_c, f"inv_{s0}")
# connect inputs
for s1 in startpoints:
if s0 != s1:
sen.connect(s1, f"inv_{s0}_{s1}")
else:
# connect inverted input
sen.set_type(f"inv_{s0}_{s1}", "not")
sen.connect(s0, f"inv_{s0}_{s1}")
# compare to orig
sen.add(
f"dif_{s0}",
"xor",
fanin=[f"orig_{n}", f"inv_{s0}_{n}"],
fanout=f"pc_in_{i}",
)
sen.add(f"dif_out_{s0}", "output", fanin=f"dif_{s0}")
# instantiate population count
for o in range(clog2(len(startpoints) + 1)):
sen.add(f"sen_out_{o}", "output", fanin=f"pc_out_{o}")
return sen
def banyan(bw):
"""
Create a Banyan switching network
Parameters
----------
bw : int
Input/output width of the network.
Returns
-------
Circuit
Network circuit.
"""
b = Circuit()
# generate switch
m = mux(2)
s = Circuit(name="switch")
s.add_subcircuit(m, f"m0")
s.add_subcircuit(m, f"m1")
s.add("in_0", "buf", fanout=["m0_in_0", "m1_in_1"])
s.add("in_1", "buf", fanout=["m0_in_1", "m1_in_0"])
s.add("out_0", "buf", fanin="m0_out")
s.add("out_1", "buf", fanin="m1_out")
s.add("sel", "input", fanout=["m0_sel_0", "m1_sel_0"])
# generate banyan
I = int(2 * clog2(bw) - 2)
J = int(bw / 2)
# add switches
for i in range(I * J):
b.add_subcircuit(s, f"swb_{i}")
# make connections
swb_ins = [f"swb_{i//2}_in_{i%2}" for i in range(I * J * 2)]
swb_outs = [f"swb_{i//2}_out_{i%2}" for i in range(I * J * 2)]
# connect switches
for i in range(clog2(J)):
r = J / (2**i)
for j in range(J):
t = (j % r) >= (r / 2)
# straight
out_i = int((i * bw) + (2 * j) + t)
in_i = int((i * bw + bw) + (2 * j) + t)
b.connect(swb_outs[out_i], swb_ins[in_i])
# cross
out_i = int((i * bw) + (2 * j) + (1 - t) + ((r - 1) *
((1 - t) * 2 - 1)))
in_i = int((i * bw + bw) + (2 * j) + (1 - t))
b.connect(swb_outs[out_i], swb_ins[in_i])
if r > 2:
# straight
out_i = int(((I * J * 2) - ((2 + i) * bw)) + (2 * j) + t)
in_i = int(((I * J * 2) - ((1 + i) * bw)) + (2 * j) + t)
b.connect(swb_outs[out_i], swb_ins[in_i])
# cross
out_i = int(((I * J * 2) - ((2 + i) * bw)) + (2 * j) +
(1 - t) + ((r - 1) * ((1 - t) * 2 - 1)))
in_i = int(((I * J * 2) - ((1 + i) * bw)) + (2 * j) + (1 - t))
b.connect(swb_outs[out_i], swb_ins[in_i])
# create banyan io
net_ins = swb_ins[:bw]
net_outs = swb_outs[-bw:]
for i, net_in in enumerate(net_ins):
b.add(f"in_{i}", "input", fanout=net_in)
for i, net_out in enumerate(net_outs):
b.add(f"out_{i}", "output", fanin=net_out)
for i in range(I * J):
b.add(f"sel_{i}", "input", fanout=f"swb_{i}_sel")
return b