litex/migen/fhdl/structure.py

290 lines
6.5 KiB
Python

import math
import inspect
import re
def bits_for(n):
if isinstance(n, Constant):
return n.bv.width
else:
if n == 0:
return 1
else:
return int(math.ceil(math.log(n+1, 2)))
class BV:
def __init__(self, width=1, signed=False):
self.width = width
self.signed = signed
def __repr__(self):
r = str(self.width) + "'"
if self.signed:
r += "s"
r += "d"
return r
def __eq__(self, other):
return self.width == other.width and self.signed == other.signed
class Value:
def __invert__(self):
return _Operator("~", [self])
def __add__(self, other):
return _Operator("+", [self, other])
def __radd__(self, other):
return _Operator("+", [other, self])
def __sub__(self, other):
return _Operator("-", [self, other])
def __rsub__(self, other):
return _Operator("-", [other, self])
def __mul__(self, other):
return _Operator("*", [self, other])
def __rmul__(self, other):
return _Operator("*", [other, self])
def __lshift__(self, other):
return _Operator("<<", [self, other])
def __rlshift__(self, other):
return _Operator("<<", [other, self])
def __rshift__(self, other):
return _Operator(">>", [self, other])
def __rrshift__(self, other):
return _Operator(">>", [other, self])
def __and__(self, other):
return _Operator("&", [self, other])
def __rand__(self, other):
return _Operator("&", [other, self])
def __xor__(self, other):
return _Operator("^", [self, other])
def __rxor__(self, other):
return _Operator("^", [other, self])
def __or__(self, other):
return _Operator("|", [self, other])
def __ror__(self, other):
return _Operator("|", [other, self])
def __lt__(self, other):
return _Operator("<", [self, other])
def __le__(self, other):
return _Operator("<=", [self, other])
def __eq__(self, other):
return _Operator("==", [self, other])
def __ne__(self, other):
return _Operator("!=", [self, other])
def __gt__(self, other):
return _Operator(">", [self, other])
def __ge__(self, other):
return _Operator(">=", [self, other])
def __getitem__(self, key):
if isinstance(key, int):
return _Slice(self, key, key+1)
elif isinstance(key, slice):
start = key.start or 0
stop = key.stop or self.bv.width
if stop > self.bv.width:
stop = self.bv.width
if key.step != None:
raise KeyError
return _Slice(self, start, stop)
else:
raise KeyError
def eq(self, r):
return _Assign(self, r)
class _Operator(Value):
def __init__(self, op, operands):
self.op = op
self.operands = list(map(_cst, operands))
class _Slice(Value):
def __init__(self, value, start, stop):
self.value = value
self.start = start
self.stop = stop
class Cat(Value):
def __init__(self, *args):
self.l = list(map(_cst, args))
class Replicate(Value):
def __init__(self, v, n):
self.v = _cst(v)
self.n = n
class Constant(Value):
def __init__(self, n, bv=None):
self.bv = bv or BV(bits_for(n))
self.n = n
def __repr__(self):
return str(self.bv) + str(self.n)
def __eq__(self, other):
return self.bv == other.bv and self.n == other.n
def _cst(x):
if isinstance(x, int):
return Constant(x)
else:
return x
_forbidden_prefixes = {'inst', 'source', 'sink', 'fsm'}
def _try_class_name(frame):
while frame is not None:
try:
cl = frame.f_locals['self']
prefix = cl.__class__.__name__.lower()
if prefix not in _forbidden_prefixes:
return prefix
except KeyError:
pass
frame = frame.f_back
return None
def _try_module_name(frame):
modules = frame.f_globals["__name__"]
if modules != "__main__":
modules = modules.split('.')
prefix = modules[len(modules)-1]
return prefix
else:
return None
def _make_signal_name(name=None):
frame = inspect.currentframe().f_back.f_back
if name is None:
line = inspect.getframeinfo(frame).code_context[0]
m = re.match('[\t ]*([0-9A-Za-z_\.]+)[\t ]*=', line)
if m is None:
name = "anonymous"
else:
names = m.group(1).split('.')
name = names[len(names)-1]
prefix = _try_class_name(frame)
if prefix is None:
prefix = _try_module_name(frame)
if prefix is None:
prefix = ""
else:
prefix += "_"
return prefix + name
class Signal(Value):
def __init__(self, bv=BV(), name=None, variable=False, reset=0, namer=None):
self.bv = bv
self.variable = variable
self.name = name
if self.name is None:
self.name = _make_signal_name(namer)
self.reset = Constant(reset, bv)
def __hash__(self):
return id(self)
def __repr__(self):
return "<Signal " + self.name + ">"
# statements
class _Assign:
def __init__(self, l, r):
self.l = l
self.r = _cst(r)
class _StatementList:
def __init__(self, l=None):
if l is None: l = []
self.l = l
class If:
def __init__(self, cond, *t):
self.cond = cond
self.t = _StatementList(t)
self.f = _StatementList()
def Else(self, *f):
_insert_else(self, _StatementList(f))
return self
def Elif(self, cond, *t):
_insert_else(self, _StatementList([If(cond, *t)]))
return self
def _insert_else(obj, clause):
o = obj
while o.f.l:
assert(len(o.f.l) == 1)
assert(isinstance(o.f.l[0], If))
o = o.f.l[0]
o.f = clause
def _sl(x):
if isinstance(x, list):
return _StatementList(x)
else:
return x
class Default:
pass
class Case:
def __init__(self, test, *cases):
self.test = test
self.cases = [(c[0], _StatementList(c[1:])) for c in cases if not isinstance(c[0], Default)]
self.default = None
for c in cases:
if isinstance(c[0], Default):
if self.default is not None:
raise ValueError
self.default = _StatementList(c[1:])
if self.default is None:
self.default = _StatementList()
#
class Instance:
def __init__(self, of, outs=[], ins=[], parameters=[], clkport="", rstport="", name=""):
self.of = of
if name:
self.name = name
else:
self.name = of
def process_io(x):
if isinstance(x[1], Signal):
return x # override
elif isinstance(x[1], BV):
return (x[0], Signal(x[1], self.name + "_" + x[0]))
else:
raise TypeError
self.outs = dict(map(process_io, outs))
self.ins = dict(map(process_io, ins))
self.parameters = parameters
self.clkport = clkport
self.rstport = rstport
def __hash__(self):
return id(self)
class Fragment:
def __init__(self, comb=None, sync=None, instances=None, pads=set()):
if comb is None: comb = []
if sync is None: sync = []
if instances is None: instances = []
self.comb = _sl(comb)
self.sync = _sl(sync)
self.instances = instances
self.pads = pads
def __add__(self, other):
return Fragment(self.comb.l + other.comb.l,
self.sync.l + other.sync.l,
self.instances + other.instances,
self.pads | other.pads)