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hdl.ast: Value.{wrap→cast}

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Preparation for #225.
This commit is contained in:
whitequark 2019-10-11 10:49:34 +00:00
parent 9fe27a15ad
commit d72d4a55fd
5 changed files with 51 additions and 42 deletions
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53
nmigen/hdl/ast.py
View file

@ -47,9 +47,12 @@ def _enum_to_bits(enum_value):
class Value(metaclass=ABCMeta):
@staticmethod
def wrap(obj):
"""Ensures that the passed object is an nMigen value. Booleans and integers
are automatically wrapped into ``Const``."""
def cast(obj):
"""Converts ``obj`` to an nMigen value.
Booleans and integers are wrapped into a :class:`Const`. Enumerations whose members are
all integers are converted to a :class:`Const` with a shape that fits every member.
"""
if isinstance(obj, Value):
return obj
elif isinstance(obj, (bool, int)):
@ -57,7 +60,13 @@ class Value(metaclass=ABCMeta):
elif isinstance(obj, Enum):
return Const(obj.value, _enum_shape(type(obj)))
else:
raise TypeError("Object '{!r}' is not an nMigen value".format(obj))
raise TypeError("Object {!r} is not 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__()
@ -93,14 +102,14 @@ class Value(metaclass=ABCMeta):
# completely by prohibiting such division operations.
raise NotImplementedError("Division by a signed value is not supported")
def __mod__(self, other):
other = Value.wrap(other)
other = Value.cast(other)
other.__check_divisor()
return Operator("%", [self, other])
def __rmod__(self, other):
self.__check_divisor()
return Operator("%", [other, self])
def __floordiv__(self, other):
other = Value.wrap(other)
other = Value.cast(other)
other.__check_divisor()
return Operator("//", [self, other])
def __rfloordiv__(self, other):
@ -452,7 +461,7 @@ class Operator(Value):
def __init__(self, op, operands, *, src_loc_at=0):
super().__init__(src_loc_at=1 + src_loc_at)
self.op = op
self.operands = [Value.wrap(o) for o in operands]
self.operands = [Value.cast(o) for o in operands]
@staticmethod
def _bitwise_binary_shape(a_shape, b_shape):
@ -540,7 +549,7 @@ def Mux(sel, val1, val0):
Value, out
Output ``Value``. If ``sel`` is asserted, the Mux returns ``val1``, else ``val0``.
"""
sel = Value.wrap(sel)
sel = Value.cast(sel)
if len(sel) != 1:
sel = sel.bool()
return Operator("m", [sel, val1, val0])
@ -567,7 +576,7 @@ class Slice(Value):
raise IndexError("Slice start {} must be less than slice end {}".format(start, end))
super().__init__(src_loc_at=src_loc_at)
self.value = Value.wrap(value)
self.value = Value.cast(value)
self.start = start
self.end = end
@ -594,7 +603,7 @@ class Part(Value):
super().__init__(src_loc_at=src_loc_at)
self.value = value
self.offset = Value.wrap(offset)
self.offset = Value.cast(offset)
self.width = width
self.stride = stride
@ -639,7 +648,7 @@ class Cat(Value):
"""
def __init__(self, *args, src_loc_at=0):
super().__init__(src_loc_at=src_loc_at)
self.parts = [Value.wrap(v) for v in flatten(args)]
self.parts = [Value.cast(v) for v in flatten(args)]
def shape(self):
return sum(len(part) for part in self.parts), False
@ -688,7 +697,7 @@ class Repl(Value):
.format(count))
super().__init__(src_loc_at=src_loc_at)
self.value = Value.wrap(value)
self.value = Value.cast(value)
self.count = count
def shape(self):
@ -857,7 +866,7 @@ class Signal(Value, DUID):
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.wrap(other).shape(), name=new_name)
kw = dict(shape=cls.cast(other).shape(), name=new_name)
if isinstance(other, cls):
kw.update(reset=other.reset, reset_less=other.reset_less,
attrs=other.attrs, decoder=other.decoder)
@ -1052,7 +1061,7 @@ class ArrayProxy(Value):
def __init__(self, elems, index, *, src_loc_at=0):
super().__init__(src_loc_at=1 + src_loc_at)
self.elems = elems
self.index = Value.wrap(index)
self.index = Value.cast(index)
def __getattr__(self, attr):
return ArrayProxy([getattr(elem, attr) for elem in self.elems], self.index)
@ -1061,7 +1070,7 @@ class ArrayProxy(Value):
return ArrayProxy([ elem[index] for elem in self.elems], self.index)
def _iter_as_values(self):
return (Value.wrap(elem) for elem in self.elems)
return (Value.cast(elem) for elem in self.elems)
def shape(self):
width, signed = 0, False
@ -1113,7 +1122,7 @@ class UserValue(Value):
def _lazy_lower(self):
if self.__lowered is None:
self.__lowered = Value.wrap(self.lower())
self.__lowered = Value.cast(self.lower())
return self.__lowered
def shape(self):
@ -1136,7 +1145,7 @@ class Sample(Value):
"""
def __init__(self, expr, clocks, domain, *, src_loc_at=0):
super().__init__(src_loc_at=1 + src_loc_at)
self.value = Value.wrap(expr)
self.value = Value.cast(expr)
self.clocks = int(clocks)
self.domain = domain
if not isinstance(self.value, (Const, Signal, ClockSignal, ResetSignal, Initial)):
@ -1219,8 +1228,8 @@ class Statement:
class Assign(Statement):
def __init__(self, lhs, rhs, *, src_loc_at=0):
super().__init__(src_loc_at=src_loc_at)
self.lhs = Value.wrap(lhs)
self.rhs = Value.wrap(rhs)
self.lhs = Value.cast(lhs)
self.rhs = Value.cast(rhs)
def _lhs_signals(self):
return self.lhs._lhs_signals()
@ -1235,7 +1244,7 @@ class Assign(Statement):
class Property(Statement):
def __init__(self, test, *, _check=None, _en=None, src_loc_at=0):
super().__init__(src_loc_at=src_loc_at)
self.test = Value.wrap(test)
self.test = Value.cast(test)
self._check = _check
self._en = _en
if self._check is None:
@ -1283,7 +1292,7 @@ class Switch(Statement):
# be automatically traced, so whatever constructs a Switch may optionally provide it.
self.case_src_locs = {}
self.test = Value.wrap(test)
self.test = Value.cast(test)
self.cases = OrderedDict()
for orig_keys, stmts in cases.items():
# Map: None -> (); key -> (key,); (key...) -> (key...)
@ -1466,7 +1475,7 @@ class _MappedKeySet(MutableSet, _MappedKeyCollection):
class ValueKey:
def __init__(self, value):
self.value = Value.wrap(value)
self.value = Value.cast(value)
if isinstance(self.value, Const):
self._hash = hash(self.value.value)
elif isinstance(self.value, (Signal, AnyValue)):

6
nmigen/hdl/dsl.py
View file

@ -172,7 +172,7 @@ class Module(_ModuleBuilderRoot, Elaboratable):
return data
def _check_signed_cond(self, cond):
cond = Value.wrap(cond)
cond = Value.cast(cond)
width, signed = cond.shape()
if signed:
warnings.warn("Signed values in If/Elif conditions usually result from inverting "
@ -249,7 +249,7 @@ class Module(_ModuleBuilderRoot, Elaboratable):
def Switch(self, test):
self._check_context("Switch", context=None)
switch_data = self._set_ctrl("Switch", {
"test": Value.wrap(test),
"test": Value.cast(test),
"cases": OrderedDict(),
"src_loc": tracer.get_src_loc(src_loc_at=1),
"case_src_locs": {},
@ -383,7 +383,7 @@ class Module(_ModuleBuilderRoot, Elaboratable):
tests, cases = [], OrderedDict()
for if_test, if_case in zip(if_tests + [None], if_bodies):
if if_test is not None:
if_test = Value.wrap(if_test)
if_test = Value.cast(if_test)
if len(if_test) != 1:
if_test = if_test.bool()
tests.append(if_test)