from abc import ABCMeta, abstractmethod
-import builtins
import traceback
+import sys
import warnings
import typing
+import functools
from collections import OrderedDict
from collections.abc import Iterable, MutableMapping, MutableSet, MutableSequence
from enum import Enum
from .. import tracer
-from ..tools import *
+from .._utils import *
+from .._unused import *
__all__ = [
"Value", "Const", "C", "AnyConst", "AnySeq", "Operator", "Mux", "Part", "Slice", "Cat", "Repl",
"Array", "ArrayProxy",
"Signal", "ClockSignal", "ResetSignal",
- "UserValue",
+ "UserValue", "ValueCastable",
"Sample", "Past", "Stable", "Rose", "Fell", "Initial",
- "Statement", "Assign", "Assert", "Assume", "Cover", "Switch", "Delay", "Tick",
- "Passive", "ValueKey", "ValueDict", "ValueSet", "SignalKey", "SignalDict",
- "SignalSet",
+ "Statement", "Switch",
+ "Property", "Assign", "Assert", "Assume", "Cover",
+ "ValueKey", "ValueDict", "ValueSet", "SignalKey", "SignalDict", "SignalSet",
]
DUID.__next_uid += 1
-class Shape(typing.NamedTuple):
+class Shape:
"""Bit width and signedness of a value.
A ``Shape`` can be constructed using:
signed : bool
If ``False``, the value is unsigned. If ``True``, the value is signed two's complement.
"""
- width: int = 1
- signed: bool = False
+ def __init__(self, width=1, signed=False):
+ if not isinstance(width, int) or width < 0:
+ raise TypeError("Width must be a non-negative integer, not {!r}"
+ .format(width))
+ self.width = width
+ self.signed = signed
+
+ def __iter__(self):
+ return iter((self.width, self.signed))
@staticmethod
- def cast(obj):
+ def cast(obj, *, src_loc_at=0):
+ if isinstance(obj, Shape):
+ return obj
if isinstance(obj, int):
return Shape(obj)
if isinstance(obj, tuple):
- return Shape(*obj)
+ width, signed = obj
+ warnings.warn("instead of `{tuple}`, use `{constructor}({width})`"
+ .format(constructor="signed" if signed else "unsigned", width=width,
+ tuple=obj),
+ DeprecationWarning, stacklevel=2 + src_loc_at)
+ return Shape(width, signed)
if isinstance(obj, range):
if len(obj) == 0:
return Shape(0, obj.start < 0)
return Shape(width, signed)
raise TypeError("Object {!r} cannot be used as value shape".format(obj))
+ def __repr__(self):
+ if self.signed:
+ return "signed({})".format(self.width)
+ else:
+ return "unsigned({})".format(self.width)
-# TODO: use dataclasses instead of this hack
-def _Shape___init__(self, width=1, signed=False):
- if not isinstance(width, int) or width < 0:
- raise TypeError("Width must be a non-negative integer, not {!r}"
- .format(width))
-Shape.__init__ = _Shape___init__
+ def __eq__(self, other):
+ if isinstance(other, tuple) and len(other) == 2:
+ width, signed = other
+ if isinstance(width, int) and isinstance(signed, bool):
+ return self.width == width and self.signed == signed
+ else:
+ raise TypeError("Shapes may be compared with other Shapes and (int, bool) tuples, "
+ "not {!r}"
+ .format(other))
+ if not isinstance(other, Shape):
+ raise TypeError("Shapes may be compared with other Shapes and (int, bool) tuples, "
+ "not {!r}"
+ .format(other))
+ return self.width == other.width and self.signed == other.signed
def unsigned(width):
return Const(obj)
if isinstance(obj, Enum):
return Const(obj.value, Shape.cast(type(obj)))
+ if isinstance(obj, ValueCastable):
+ return obj.as_value()
raise TypeError("Object {!r} cannot be converted to an nMigen value".format(obj))
- # TODO(nmigen-0.2): remove this
- @classmethod
- @deprecated("instead of `Value.wrap`, use `Value.cast`")
- def wrap(cls, obj):
- return cls.cast(obj)
-
def __init__(self, *, src_loc_at=0):
super().__init__()
self.src_loc = tracer.get_src_loc(1 + src_loc_at)
def __bool__(self):
- raise TypeError("Attempted to convert nMigen value to boolean")
+ raise TypeError("Attempted to convert nMigen value to Python boolean")
def __invert__(self):
return Operator("~", [self])
self.__check_divisor()
return Operator("//", [other, self])
+ def __check_shamt(self):
+ width, signed = self.shape()
+ if signed:
+ # Neither Python nor HDLs implement shifts by negative values; prohibit any shifts
+ # by a signed value to make sure the shift amount can always be interpreted as
+ # an unsigned value.
+ raise TypeError("Shift amount must be unsigned")
def __lshift__(self, other):
+ other = Value.cast(other)
+ other.__check_shamt()
return Operator("<<", [self, other])
def __rlshift__(self, other):
+ self.__check_shamt()
return Operator("<<", [other, self])
def __rshift__(self, other):
+ other = Value.cast(other)
+ other.__check_shamt()
return Operator(">>", [self, other])
def __rrshift__(self, other):
+ self.__check_shamt()
return Operator(">>", [other, self])
+
def __and__(self, other):
return Operator("&", [self, other])
def __rand__(self, other):
def __ge__(self, other):
return Operator(">=", [self, other])
+ def __abs__(self):
+ width, signed = self.shape()
+ if signed:
+ return Mux(self >= 0, self, -self)
+ else:
+ return self
+
def __len__(self):
return self.shape().width
n = len(self)
if isinstance(key, int):
if key not in range(-n, n):
- raise IndexError("Cannot index {} bits into {}-bit value".format(key, n))
+ raise IndexError(f"Index {key} is out of bounds for a {n}-bit value")
if key < 0:
key += n
return Slice(self, key, key + 1)
else:
raise TypeError("Cannot index value with {}".format(repr(key)))
+ def as_unsigned(self):
+ """Conversion to unsigned.
+
+ Returns
+ -------
+ Value, out
+ This ``Value`` reinterpreted as a unsigned integer.
+ """
+ return Operator("u", [self])
+
+ def as_signed(self):
+ """Conversion to signed.
+
+ Returns
+ -------
+ Value, out
+ This ``Value`` reinterpreted as a signed integer.
+ """
+ return Operator("s", [self])
+
def bool(self):
"""Conversion to boolean.
"""
return ~premise | conclusion
- # TODO(nmigen-0.2): move this to nmigen.compat and make it a deprecated extension
- @deprecated("instead of `.part`, use `.bit_select`")
- def part(self, offset, width):
- return Part(self, offset, width, src_loc_at=1)
-
def bit_select(self, offset, width):
"""Part-select with bit granularity.
Parameters
----------
- offset : Value, in
+ offset : Value, int
Index of first selected bit.
width : int
Number of selected bits.
Part, out
Selected part of the ``Value``
"""
+ offset = Value.cast(offset)
+ if type(offset) is Const and isinstance(width, int):
+ return self[offset.value:offset.value + width]
return Part(self, offset, width, stride=1, src_loc_at=1)
def word_select(self, offset, width):
Parameters
----------
- offset : Value, in
+ offset : Value, int
Index of first selected word.
width : int
Number of selected bits.
Part, out
Selected part of the ``Value``
"""
+ offset = Value.cast(offset)
+ if type(offset) is Const and isinstance(width, int):
+ return self[offset.value * width:(offset.value + 1) * width]
return Part(self, offset, width, stride=width, src_loc_at=1)
def matches(self, *patterns):
raise SyntaxError("Match pattern must be an integer, a string, or an enumeration, "
"not {!r}"
.format(pattern))
- if isinstance(pattern, str) and any(bit not in "01-" for bit in pattern):
+ if isinstance(pattern, str) and any(bit not in "01- \t" for bit in pattern):
raise SyntaxError("Match pattern '{}' must consist of 0, 1, and - (don't care) "
- "bits"
+ "bits, and may include whitespace"
.format(pattern))
- if isinstance(pattern, str) and len(pattern) != len(self):
+ if (isinstance(pattern, str) and
+ len("".join(pattern.split())) != len(self)):
raise SyntaxError("Match pattern '{}' must have the same width as match value "
"(which is {})"
.format(pattern, len(self)))
SyntaxWarning, stacklevel=3)
continue
if isinstance(pattern, str):
+ pattern = "".join(pattern.split()) # remove whitespace
mask = int(pattern.replace("0", "1").replace("-", "0"), 2)
pattern = int(pattern.replace("-", "0"), 2)
matches.append((self & mask) == pattern)
else:
return Cat(*matches).any()
+ def shift_left(self, amount):
+ """Shift left by constant amount.
+
+ Parameters
+ ----------
+ amount : int
+ Amount to shift by.
+
+ Returns
+ -------
+ Value, out
+ If the amount is positive, the input shifted left. Otherwise, the input shifted right.
+ """
+ if not isinstance(amount, int):
+ raise TypeError("Shift amount must be an integer, not {!r}".format(amount))
+ if amount < 0:
+ return self.shift_right(-amount)
+ if self.shape().signed:
+ return Cat(Const(0, amount), self).as_signed()
+ else:
+ return Cat(Const(0, amount), self) # unsigned
+
+ def shift_right(self, amount):
+ """Shift right by constant amount.
+
+ Parameters
+ ----------
+ amount : int
+ Amount to shift by.
+
+ Returns
+ -------
+ Value, out
+ If the amount is positive, the input shifted right. Otherwise, the input shifted left.
+ """
+ if not isinstance(amount, int):
+ raise TypeError("Shift amount must be an integer, not {!r}".format(amount))
+ if amount < 0:
+ return self.shift_left(-amount)
+ if self.shape().signed:
+ return self[amount:].as_signed()
+ else:
+ return self[amount:] # unsigned
+
+ def rotate_left(self, amount):
+ """Rotate left by constant amount.
+
+ Parameters
+ ----------
+ amount : int
+ Amount to rotate by.
+
+ Returns
+ -------
+ Value, out
+ If the amount is positive, the input rotated left. Otherwise, the input rotated right.
+ """
+ if not isinstance(amount, int):
+ raise TypeError("Rotate amount must be an integer, not {!r}".format(amount))
+ amount %= len(self)
+ return Cat(self[-amount:], self[:-amount]) # meow :3
+
+ def rotate_right(self, amount):
+ """Rotate right by constant amount.
+
+ Parameters
+ ----------
+ amount : int
+ Amount to rotate by.
+
+ Returns
+ -------
+ Value, out
+ If the amount is positive, the input rotated right. Otherwise, the input rotated right.
+ """
+ if not isinstance(amount, int):
+ raise TypeError("Rotate amount must be an integer, not {!r}".format(amount))
+ amount %= len(self)
+ return Cat(self[amount:], self[:amount])
+
def eq(self, value):
"""Assignment.
value |= ~mask
return value
- def __init__(self, value, shape=None):
+ def __init__(self, value, shape=None, *, src_loc_at=0):
# We deliberately do not call Value.__init__ here.
self.value = int(value)
if shape is None:
elif isinstance(shape, int):
shape = Shape(shape, signed=self.value < 0)
else:
- shape = Shape.cast(shape)
+ shape = Shape.cast(shape, src_loc_at=1 + src_loc_at)
self.width, self.signed = shape
self.value = self.normalize(self.value, shape)
- # TODO(nmigen-0.2): move this to nmigen.compat and make it a deprecated extension
- @property
- @deprecated("instead of `const.nbits`, use `const.width`")
- def nbits(self):
- return self.width
-
def shape(self):
return Shape(self.width, self.signed)
def _rhs_signals(self):
- return ValueSet()
+ return SignalSet()
def _as_const(self):
return self.value
class AnyValue(Value, DUID):
def __init__(self, shape, *, src_loc_at=0):
super().__init__(src_loc_at=src_loc_at)
- self.width, self.signed = Shape.cast(shape)
+ self.width, self.signed = Shape.cast(shape, src_loc_at=1 + src_loc_at)
if not isinstance(self.width, int) or self.width < 0:
raise TypeError("Width must be a non-negative integer, not {!r}"
.format(self.width))
return Shape(self.width, self.signed)
def _rhs_signals(self):
- return ValueSet()
+ return SignalSet()
@final
class AnyConst(AnyValue):
def __repr__(self):
- return "(anyconst {}'{})".format(self.nbits, "s" if self.signed else "")
+ return "(anyconst {}'{})".format(self.width, "s" if self.signed else "")
@final
class AnySeq(AnyValue):
def __repr__(self):
- return "(anyseq {}'{})".format(self.nbits, "s" if self.signed else "")
+ return "(anyseq {}'{})".format(self.width, "s" if self.signed else "")
@final
self.operator = operator
self.operands = [Value.cast(op) for op in operands]
- # TODO(nmigen-0.2): move this to nmigen.compat and make it a deprecated extension
- @property
- @deprecated("instead of `.op`, use `.operator`")
- def op(self):
- return self.operator
-
def shape(self):
def _bitwise_binary_shape(a_shape, b_shape):
a_bits, a_sign = a_shape
if self.operator in ("+", "~"):
return Shape(a_width, a_signed)
if self.operator == "-":
- if not a_signed:
- return Shape(a_width + 1, True)
- else:
- return Shape(a_width, a_signed)
+ return Shape(a_width + 1, True)
if self.operator in ("b", "r|", "r&", "r^"):
return Shape(1, False)
+ if self.operator == "u":
+ return Shape(a_width, False)
+ if self.operator == "s":
+ return Shape(a_width, True)
elif len(op_shapes) == 2:
(a_width, a_signed), (b_width, b_signed) = op_shapes
if self.operator in ("+", "-"):
@final
class Slice(Value):
- def __init__(self, value, start, end, *, src_loc_at=0):
+ def __init__(self, value, start, stop, *, src_loc_at=0):
if not isinstance(start, int):
raise TypeError("Slice start must be an integer, not {!r}".format(start))
- if not isinstance(end, int):
- raise TypeError("Slice end must be an integer, not {!r}".format(end))
+ if not isinstance(stop, int):
+ raise TypeError("Slice stop must be an integer, not {!r}".format(stop))
n = len(value)
if start not in range(-(n+1), n+1):
raise IndexError("Cannot start slice {} bits into {}-bit value".format(start, n))
if start < 0:
start += n
- if end not in range(-(n+1), n+1):
- raise IndexError("Cannot end slice {} bits into {}-bit value".format(end, n))
- if end < 0:
- end += n
- if start > end:
- raise IndexError("Slice start {} must be less than slice end {}".format(start, end))
+ if stop not in range(-(n+1), n+1):
+ raise IndexError("Cannot stop slice {} bits into {}-bit value".format(stop, n))
+ if stop < 0:
+ stop += n
+ if start > stop:
+ raise IndexError("Slice start {} must be less than slice stop {}".format(start, stop))
super().__init__(src_loc_at=src_loc_at)
self.value = Value.cast(value)
self.start = start
- self.end = end
+ self.stop = stop
def shape(self):
- return Shape(self.end - self.start)
+ return Shape(self.stop - self.start)
def _lhs_signals(self):
return self.value._lhs_signals()
return self.value._rhs_signals()
def __repr__(self):
- return "(slice {} {}:{})".format(repr(self.value), self.start, self.end)
+ return "(slice {} {}:{})".format(repr(self.value), self.start, self.stop)
@final
return Shape(sum(len(part) for part in self.parts))
def _lhs_signals(self):
- return union((part._lhs_signals() for part in self.parts), start=ValueSet())
+ return union((part._lhs_signals() for part in self.parts), start=SignalSet())
def _rhs_signals(self):
- return union((part._rhs_signals() for part in self.parts), start=ValueSet())
+ return union((part._rhs_signals() for part in self.parts), start=SignalSet())
def _as_const(self):
value = 0
return "(repl {!r} {})".format(self.value, self.count)
-@final
+# @final
class Signal(Value, DUID):
"""A varying integer value.
Parameters
----------
- shape : int or tuple or None
- Either an integer ``width`` or a tuple ``(width, signed)`` specifying the number of bits
- in this ``Signal`` and whether it is signed (can represent negative values).
- ``shape`` defaults to 1-bit and non-signed.
+ shape : ``Shape``-castable object or None
+ Specification for the number of bits in this ``Signal`` and its signedness (whether it
+ can represent negative values). See ``Shape.cast`` for details.
+ If not specified, ``shape`` defaults to 1-bit and non-signed.
name : str
Name hint for this signal. If ``None`` (default) the name is inferred from the variable
- name this ``Signal`` is assigned to. Name collisions are automatically resolved by
- prepending names of objects that contain this ``Signal`` and by appending integer
- sequences.
- reset : int
+ name this ``Signal`` is assigned to.
+ reset : int or integral Enum
Reset (synchronous) or default (combinatorial) value.
When this ``Signal`` is assigned to in synchronous context and the corresponding clock
domain is reset, the ``Signal`` assumes the given value. When this ``Signal`` is unassigned
If ``True``, do not generate reset logic for this ``Signal`` in synchronous statements.
The ``reset`` value is only used as a combinatorial default or as the initial value.
Defaults to ``False``.
- min : int or None
- max : int or None
- If ``shape`` is ``None``, the signal bit width and signedness are
- determined by the integer range given by ``min`` (inclusive,
- defaults to 0) and ``max`` (exclusive, defaults to 2).
attrs : dict
Dictionary of synthesis attributes.
decoder : function or Enum
reset : int
reset_less : bool
attrs : dict
+ decoder : function
"""
- def __init__(self, shape=None, *, name=None, reset=0, reset_less=False, min=None, max=None,
+ def __init__(self, shape=None, *, name=None, reset=0, reset_less=False,
attrs=None, decoder=None, src_loc_at=0):
super().__init__(src_loc_at=src_loc_at)
- # TODO(nmigen-0.2): move this to nmigen.compat and make it a deprecated extension
- if min is not None or max is not None:
- warnings.warn("instead of `Signal(min={min}, max={max})`, "
- "use `Signal(range({min}, {max}))`"
- .format(min=min or 0, max=max or 2),
- DeprecationWarning, stacklevel=2 + src_loc_at)
-
if name is not None and not isinstance(name, str):
raise TypeError("Name must be a string, not {!r}".format(name))
self.name = name or tracer.get_var_name(depth=2 + src_loc_at, default="$signal")
if shape is None:
- if min is None:
- min = 0
- if max is None:
- max = 2
- max -= 1 # make both bounds inclusive
- if min > max:
- raise ValueError("Lower bound {} should be less or equal to higher bound {}"
- .format(min, max + 1))
- self.signed = min < 0 or max < 0
- if min == max:
- self.width = 0
- else:
- self.width = builtins.max(bits_for(min, self.signed),
- bits_for(max, self.signed))
+ shape = unsigned(1)
+ self.width, self.signed = Shape.cast(shape, src_loc_at=1 + src_loc_at)
- else:
- if not (min is None and max is None):
- raise ValueError("Only one of bits/signedness or bounds may be specified")
- self.width, self.signed = Shape.cast(shape)
+ if isinstance(reset, Enum):
+ reset = reset.value
+ if not isinstance(reset, int):
+ raise TypeError("Reset value has to be an int or an integral Enum")
reset_width = bits_for(reset, self.signed)
if reset != 0 and reset_width > self.width:
.format(reset, reset_width, self.width),
SyntaxWarning, stacklevel=2 + src_loc_at)
- self.reset = int(reset)
+ self.reset = reset
self.reset_less = bool(reset_less)
self.attrs = OrderedDict(() if attrs is None else attrs)
except ValueError:
return str(value)
self.decoder = enum_decoder
+ self._enum_class = decoder
else:
self.decoder = decoder
+ self._enum_class = None
- @classmethod
- @deprecated("instead of `Signal.range(...)`, use `Signal(range(...))`")
- def range(cls, *args, src_loc_at=0, **kwargs):
- return cls(range(*args), src_loc_at=2 + src_loc_at, **kwargs)
-
- @classmethod
- @deprecated("instead of `Signal.enum(...)`, use `Signal(...)`")
- def enum(cls, enum_type, *, src_loc_at=0, **kwargs):
- if not issubclass(enum_type, Enum):
- raise TypeError("Type {!r} is not an enumeration")
- return cls(enum_type, src_loc_at=2 + src_loc_at, **kwargs)
-
- @classmethod
- def like(cls, other, *, name=None, name_suffix=None, src_loc_at=0, **kwargs):
+ # Not a @classmethod because nmigen.compat requires it.
+ @staticmethod
+ def like(other, *, name=None, name_suffix=None, src_loc_at=0, **kwargs):
"""Create Signal based on another.
Parameters
new_name = other.name + str(name_suffix)
else:
new_name = tracer.get_var_name(depth=2 + src_loc_at, default="$like")
- kw = dict(shape=cls.cast(other).shape(), name=new_name)
- if isinstance(other, cls):
+ kw = dict(shape=Value.cast(other).shape(), name=new_name)
+ if isinstance(other, Signal):
kw.update(reset=other.reset, reset_less=other.reset_less,
attrs=other.attrs, decoder=other.decoder)
kw.update(kwargs)
- return cls(**kw, src_loc_at=1 + src_loc_at)
-
- # TODO(nmigen-0.2): move this to nmigen.compat and make it a deprecated extension
- @property
- @deprecated("instead of `signal.nbits`, use `signal.width`")
- def nbits(self):
- return self.width
-
- @nbits.setter
- @deprecated("instead of `signal.nbits = x`, use `signal.width = x`")
- def nbits(self, value):
- self.width = value
+ return Signal(**kw, src_loc_at=1 + src_loc_at)
def shape(self):
return Shape(self.width, self.signed)
def _lhs_signals(self):
- return ValueSet((self,))
+ return SignalSet((self,))
def _rhs_signals(self):
- return ValueSet((self,))
+ return SignalSet((self,))
def __repr__(self):
return "(sig {})".format(self.name)
return Shape(1)
def _lhs_signals(self):
- return ValueSet((self,))
+ return SignalSet((self,))
def _rhs_signals(self):
raise NotImplementedError("ClockSignal must be lowered to a concrete signal") # :nocov:
return Shape(1)
def _lhs_signals(self):
- return ValueSet((self,))
+ return SignalSet((self,))
def _rhs_signals(self):
raise NotImplementedError("ResetSignal must be lowered to a concrete signal") # :nocov:
return (Value.cast(elem) for elem in self.elems)
def shape(self):
- width, signed = 0, False
+ unsigned_width = signed_width = 0
+ has_unsigned = has_signed = False
for elem_width, elem_signed in (elem.shape() for elem in self._iter_as_values()):
- width = max(width, elem_width + elem_signed)
- signed = max(signed, elem_signed)
- return Shape(width, signed)
+ if elem_signed:
+ has_signed = True
+ signed_width = max(signed_width, elem_width)
+ else:
+ has_unsigned = True
+ unsigned_width = max(unsigned_width, elem_width)
+ # The shape of the proxy must be such that it preserves the mathematical value of the array
+ # elements. I.e., shape-wise, an array proxy must be identical to an equivalent mux tree.
+ # To ensure this holds, if the array contains both signed and unsigned values, make sure
+ # that every unsigned value is zero-extended by at least one bit.
+ if has_signed and has_unsigned and unsigned_width >= signed_width:
+ # Array contains both signed and unsigned values, and at least one of the unsigned
+ # values won't be zero-extended otherwise.
+ return signed(unsigned_width + 1)
+ else:
+ # Array contains values of the same signedness, or else all of the unsigned values
+ # are zero-extended.
+ return Shape(max(unsigned_width, signed_width), has_signed)
def _lhs_signals(self):
- signals = union((elem._lhs_signals() for elem in self._iter_as_values()), start=ValueSet())
+ signals = union((elem._lhs_signals() for elem in self._iter_as_values()),
+ start=SignalSet())
return signals
def _rhs_signals(self):
- signals = union((elem._rhs_signals() for elem in self._iter_as_values()), start=ValueSet())
+ signals = union((elem._rhs_signals() for elem in self._iter_as_values()),
+ start=SignalSet())
return self.index._rhs_signals() | signals
def __repr__(self):
def _lazy_lower(self):
if self.__lowered is None:
- self.__lowered = Value.cast(self.lower())
+ lowered = self.lower()
+ if isinstance(lowered, UserValue):
+ lowered = lowered._lazy_lower()
+ self.__lowered = Value.cast(lowered)
return self.__lowered
def shape(self):
return self._lazy_lower()._rhs_signals()
+class ValueCastable:
+ """Base class for classes which can be cast to Values.
+
+ A ``ValueCastable`` can be cast to ``Value``, meaning its precise representation does not have
+ to be immediately known. This is useful in certain metaprogramming scenarios. Instead of
+ providing fixed semantics upfront, it is kept abstract for as long as possible, only being
+ cast to a concrete nMigen value when required.
+
+ Note that it is necessary to ensure that nMigen's view of representation of all values stays
+ internally consistent. The class deriving from ``ValueCastable`` must decorate the ``as_value``
+ method with the ``lowermethod`` decorator, which ensures that all calls to ``as_value``return the
+ same ``Value`` representation. If the class deriving from ``ValueCastable`` is mutable, it is
+ up to the user to ensure that it is not mutated in a way that changes its representation after
+ the first call to ``as_value``.
+ """
+ def __new__(cls, *args, **kwargs):
+ self = super().__new__(cls)
+ if not hasattr(self, "as_value"):
+ raise TypeError(f"Class '{cls.__name__}' deriving from `ValueCastable` must override the `as_value` method")
+
+ if not hasattr(self.as_value, "_ValueCastable__memoized"):
+ raise TypeError(f"Class '{cls.__name__}' deriving from `ValueCastable` must decorate the `as_value` "
+ "method with the `ValueCastable.lowermethod` decorator")
+ return self
+
+ @staticmethod
+ def lowermethod(func):
+ """Decorator to memoize lowering methods.
+
+ Ensures the decorated method is called only once, with subsequent method calls returning the
+ object returned by the first first method call.
+
+ This decorator is required to decorate the ``as_value`` method of ``ValueCastable`` subclasses.
+ This is to ensure that nMigen's view of representation of all values stays internally
+ consistent.
+ """
+ @functools.wraps(func)
+ def wrapper_memoized(self, *args, **kwargs):
+ if not hasattr(self, "_ValueCastable__lowered_to"):
+ self.__lowered_to = func(self, *args, **kwargs)
+ return self.__lowered_to
+ wrapper_memoized.__memoized = True
+ return wrapper_memoized
+
+
@final
class Sample(Value):
"""Value from the past.
return self.value.shape()
def _rhs_signals(self):
- return ValueSet((self,))
+ return SignalSet((self,))
def __repr__(self):
return "(sample {!r} @ {}[{}])".format(
An ``Initial`` signal is ``1`` at the first cycle of model checking, and ``0`` at any other.
"""
def __init__(self, *, src_loc_at=0):
- super().__init__(src_loc_at=1 + src_loc_at)
+ super().__init__(src_loc_at=src_loc_at)
def shape(self):
return Shape(1)
def _rhs_signals(self):
- return ValueSet((self,))
+ return SignalSet((self,))
def __repr__(self):
return "(initial)"
self.src_loc = tracer.get_src_loc(1 + src_loc_at)
@staticmethod
- def wrap(obj):
+ def cast(obj):
if isinstance(obj, Iterable):
- return _StatementList(sum((Statement.wrap(e) for e in obj), []))
+ return _StatementList(sum((Statement.cast(e) for e in obj), []))
else:
if isinstance(obj, Statement):
return _StatementList([obj])
return "(eq {!r} {!r})".format(self.lhs, self.rhs)
-class Property(Statement):
+class UnusedProperty(UnusedMustUse):
+ pass
+
+
+class Property(Statement, MustUse):
+ _MustUse__warning = UnusedProperty
+
def __init__(self, test, *, _check=None, _en=None, src_loc_at=0):
super().__init__(src_loc_at=src_loc_at)
self.test = Value.cast(test)
self._en.src_loc = self.src_loc
def _lhs_signals(self):
- return ValueSet((self._en, self._check))
+ return SignalSet((self._en, self._check))
def _rhs_signals(self):
return self.test._rhs_signals()
new_keys = ()
for key in keys:
if isinstance(key, str):
- pass
+ key = "".join(key.split()) # remove whitespace
elif isinstance(key, int):
key = format(key, "b").rjust(len(self.test), "0")
elif isinstance(key, Enum):
new_keys = (*new_keys, key)
if not isinstance(stmts, Iterable):
stmts = [stmts]
- self.cases[new_keys] = Statement.wrap(stmts)
+ self.cases[new_keys] = Statement.cast(stmts)
if orig_keys in case_src_locs:
self.case_src_locs[new_keys] = case_src_locs[orig_keys]
def _lhs_signals(self):
signals = union((s._lhs_signals() for ss in self.cases.values() for s in ss),
- start=ValueSet())
+ start=SignalSet())
return signals
def _rhs_signals(self):
signals = union((s._rhs_signals() for ss in self.cases.values() for s in ss),
- start=ValueSet())
+ start=SignalSet())
return self.test._rhs_signals() | signals
def __repr__(self):
return "(switch {!r} {})".format(self.test, " ".join(case_reprs))
-@final
-class Delay(Statement):
- def __init__(self, interval=None, *, src_loc_at=0):
- super().__init__(src_loc_at=src_loc_at)
- self.interval = None if interval is None else float(interval)
-
- def _rhs_signals(self):
- return ValueSet()
-
- def __repr__(self):
- if self.interval is None:
- return "(delay ε)"
- else:
- return "(delay {:.3}us)".format(self.interval * 1e6)
-
-
-@final
-class Tick(Statement):
- def __init__(self, domain="sync", *, src_loc_at=0):
- super().__init__(src_loc_at=src_loc_at)
- self.domain = str(domain)
-
- def _rhs_signals(self):
- return ValueSet()
-
- def __repr__(self):
- return "(tick {})".format(self.domain)
-
-
-@final
-class Passive(Statement):
- def __init__(self, *, src_loc_at=0):
- super().__init__(src_loc_at=src_loc_at)
-
- def _rhs_signals(self):
- return ValueSet()
-
- def __repr__(self):
- return "(passive)"
-
-
class _MappedKeyCollection(metaclass=ABCMeta):
@abstractmethod
def _map_key(self, key):
self._hash = hash((self.value.operator,
tuple(ValueKey(o) for o in self.value.operands)))
elif isinstance(self.value, Slice):
- self._hash = hash((ValueKey(self.value.value), self.value.start, self.value.end))
+ self._hash = hash((ValueKey(self.value.value), self.value.start, self.value.stop))
elif isinstance(self.value, Part):
self._hash = hash((ValueKey(self.value.value), ValueKey(self.value.offset),
self.value.width, self.value.stride))
elif isinstance(self.value, Slice):
return (ValueKey(self.value.value) == ValueKey(other.value.value) and
self.value.start == other.value.start and
- self.value.end == other.value.end)
+ self.value.stop == other.value.stop)
elif isinstance(self.value, Part):
return (ValueKey(self.value.value) == ValueKey(other.value.value) and
ValueKey(self.value.offset) == ValueKey(other.value.offset) and
class SignalKey:
def __init__(self, signal):
self.signal = signal
- if type(signal) is Signal:
+ if isinstance(signal, Signal):
self._intern = (0, signal.duid)
elif type(signal) is ClockSignal:
self._intern = (1, signal.domain)
projects / nmigen.git / blobdiff