hdl: remove deprecated Sample, Past, Stable, Rose, Fell. (WIP)

Author: whitequark

amaranth/asserts.py

@@ -1,2 +1,4 @@
-from .hdl.ast import AnyConst, AnySeq, Assert, Assume, Cover
-from .hdl.ast import Past, Stable, Rose, Fell, Initial
+from .hdl.ast import AnyConst, AnySeq, Initial, Assert, Assume, Cover
+
+
+__all__ = ["AnyConst", "AnySeq", "Initial", "Assert", "Assume", "Cover"]

amaranth/back/rtlil.py

@@ -337,7 +337,7 @@ def resolve(self, signal, prefix=None):
             wire_name = signal.name
 
         is_sync_driven = signal in self.driven and self.driven[signal]
-        
+
         attrs = dict(signal.attrs)
         if signal._enum_class is not None:
             attrs["enum_base_type"] = signal._enum_class.__name__
@@ -396,12 +396,6 @@ def on_ClockSignal(self, value):
     def on_ResetSignal(self, value):
         raise NotImplementedError # :nocov:
 
-    def on_Sample(self, value):
-        raise NotImplementedError # :nocov:
-
-    def on_Initial(self, value):
-        raise NotImplementedError # :nocov:
-
     def on_Cat(self, value):
         return "{{ {} }}".format(" ".join(reversed([self(o) for o in value.parts])))
 
@@ -496,6 +490,13 @@ def on_AnySeq(self, value):
         self.s.anys[value] = res
         return res
 
+    def on_Initial(self, value):
+        res = self.s.rtlil.wire(width=1, src=_src(value.src_loc))
+        self.s.rtlil.cell("$initstate", ports={
+            "\\Y": res,
+        }, src=_src(value.src_loc))
+        return res
+
     def on_Signal(self, value):
         wire_curr, wire_next = self.s.resolve(value)
         return wire_curr
@@ -644,6 +645,9 @@ def on_AnyConst(self, value):
     def on_AnySeq(self, value):
         raise TypeError # :nocov:
 
+    def on_Initial(self, value):
+        raise TypeError # :nocov:
+
     def on_Operator(self, value):
         if value.operator in ("u", "s"):
             # These operators are transparent on the LHS.
@@ -872,7 +876,7 @@ def _convert_fragment(builder, fragment, name_map, hierarchy):
 
             if sub_type == "$mem_v2" and "MEMID" not in sub_params:
                 sub_params["MEMID"] = builder._make_name(sub_name, local=False)
-            
+
             sub_ports = OrderedDict()
             for port, value in sub_port_map.items():
                 if not isinstance(subfragment, ir.Instance):
@@ -917,7 +921,7 @@ def _convert_fragment(builder, fragment, name_map, hierarchy):
                     stmt_compiler._has_rhs = False
                     stmt_compiler._wrap_assign = False
                     stmt_compiler(group_stmts)
-        
+
         # For every driven signal in the sync domain, create a flop of appropriate type. Which type
         # is appropriate depends on the domain: for domains with sync reset, it is a $dff, for
         # domains with async reset it is an $adff. The latter is directly provided with the reset
@@ -930,7 +934,7 @@ def _convert_fragment(builder, fragment, name_map, hierarchy):
             wire_curr, wire_next = compiler_state.resolve(signal)
 
             if not cd.async_reset:
-                # For sync reset flops, the reset value comes from logic inserted by 
+                # For sync reset flops, the reset value comes from logic inserted by
                 # `hdl.xfrm.DomainLowerer`.
                 module.cell("$dff", ports={
                     "\\CLK": wire_clk,

amaranth/build/plat.py

@@ -9,7 +9,7 @@
 from .. import __version__
 from .._toolchain import *
 from ..hdl import *
-from ..hdl.xfrm import SampleLowerer, DomainLowerer
+from ..hdl.xfrm import DomainLowerer
 from ..lib.cdc import ResetSynchronizer
 from ..back import rtlil, verilog
 from .res import *
@@ -143,7 +143,6 @@ def prepare(self, elaboratable, name="top", **kwargs):
         self._prepared = True
 
         fragment = Fragment.get(elaboratable, self)
-        fragment = SampleLowerer()(fragment)
         fragment._propagate_domains(self.create_missing_domain, platform=self)
         fragment = DomainLowerer()(fragment)
 

amaranth/hdl/ast.py

@@ -19,7 +19,7 @@
     "Array", "ArrayProxy",
     "Signal", "ClockSignal", "ResetSignal",
     "ValueCastable",
-    "Sample", "Past", "Stable", "Rose", "Fell", "Initial",
+    "Initial",
     "Statement", "Switch",
     "Property", "Assign", "Assert", "Assume", "Cover",
     "ValueKey", "ValueDict", "ValueSet", "SignalKey", "SignalDict", "SignalSet",
@@ -1443,70 +1443,6 @@ def wrapper_memoized(self, *args, **kwargs):
         return wrapper_memoized
 
 
-# TODO(amaranth-0.5): remove
-@final
-class Sample(Value):
-    """Value from the past.
-
-    A ``Sample`` of an expression is equal to the value of the expression ``clocks`` clock edges
-    of the ``domain`` clock back. If that moment is before the beginning of time, it is equal
-    to the value of the expression calculated as if each signal had its reset value.
-    """
-    @deprecated("instead of using `Sample`, create a register explicitly")
-    def __init__(self, expr, clocks, domain, *, src_loc_at=0):
-        super().__init__(src_loc_at=1 + src_loc_at)
-        self.value  = Value.cast(expr)
-        self.clocks = int(clocks)
-        self.domain = domain
-        if not isinstance(self.value, (Const, Signal, ClockSignal, ResetSignal, Initial)):
-            raise TypeError("Sampled value must be a signal or a constant, not {!r}"
-                            .format(self.value))
-        if self.clocks < 0:
-            raise ValueError("Cannot sample a value {} cycles in the future"
-                             .format(-self.clocks))
-        if not (self.domain is None or isinstance(self.domain, str)):
-            raise TypeError("Domain name must be a string or None, not {!r}"
-                            .format(self.domain))
-
-    def shape(self):
-        return self.value.shape()
-
-    def _rhs_signals(self):
-        return SignalSet((self,))
-
-    def __repr__(self):
-        return "(sample {!r} @ {}[{}])".format(
-            self.value, "<default>" if self.domain is None else self.domain, self.clocks)
-
-
-# TODO(amaranth-0.5): remove
-@deprecated("instead of using `Past`, create a register explicitly")
-def Past(expr, clocks=1, domain=None):
-    with _ignore_deprecated():
-        return Sample(expr, clocks, domain)
-
-
-# TODO(amaranth-0.5): remove
-@deprecated("instead of using `Stable`, create registers and comparisons explicitly")
-def Stable(expr, clocks=0, domain=None):
-    with _ignore_deprecated():
-        return Sample(expr, clocks + 1, domain) == Sample(expr, clocks, domain)
-
-
-# TODO(amaranth-0.5): remove
-@deprecated("instead of using `Rose`, create registers and comparisons explicitly")
-def Rose(expr, clocks=0, domain=None):
-    with _ignore_deprecated():
-        return ~Sample(expr, clocks + 1, domain) & Sample(expr, clocks, domain)
-
-
-# TODO(amaranth-0.5): remove
-@deprecated("instead of using `Fell`, create registers and comparisons explicitly")
-def Fell(expr, clocks=0, domain=None):
-    with _ignore_deprecated():
-        return Sample(expr, clocks + 1, domain) & ~Sample(expr, clocks, domain)
-
-
 @final
 class Initial(Value):
     """Start indicator, for model checking.
@@ -1520,7 +1456,7 @@ def shape(self):
         return Shape(1)
 
     def _rhs_signals(self):
-        return SignalSet((self,))
+        return SignalSet()
 
     def __repr__(self):
         return "(initial)"
@@ -1789,8 +1725,6 @@ def __init__(self, value):
         elif isinstance(self.value, ArrayProxy):
             self._hash = hash((ValueKey(self.value.index),
                               tuple(ValueKey(e) for e in self.value._iter_as_values())))
-        elif isinstance(self.value, Sample):
-            self._hash = hash((ValueKey(self.value.value), self.value.clocks, self.value.domain))
         elif isinstance(self.value, Initial):
             self._hash = 0
         else: # :nocov:
@@ -1836,10 +1770,6 @@ def __eq__(self, other):
                     all(ValueKey(a) == ValueKey(b)
                         for a, b in zip(self.value._iter_as_values(),
                                         other.value._iter_as_values())))
-        elif isinstance(self.value, Sample):
-            return (ValueKey(self.value.value) == ValueKey(other.value.value) and
-                    self.value.clocks == other.value.clocks and
-                    self.value.domain == self.value.domain)
         elif isinstance(self.value, Initial):
             return True
         else: # :nocov:

amaranth/hdl/dsl.py

@@ -491,7 +491,6 @@ def domain_name(domain):
                     .format(domain_name(domain)))
 
             stmt._MustUse__used = True
-            stmt = SampleDomainInjector(domain)(stmt)
 
             for signal in stmt._lhs_signals():
                 if signal not in self._driving:
@@ -539,8 +538,7 @@ def elaborate(self, platform):
             fragment.add_subfragment(Fragment.get(self._named_submodules[name], platform), name)
         for submodule in self._anon_submodules:
             fragment.add_subfragment(Fragment.get(submodule, platform), None)
-        statements = SampleDomainInjector("sync")(self._statements)
-        fragment.add_statements(statements)
+        fragment.add_statements(self._statements)
         for signal, domain in self._driving.items():
             fragment.add_driver(signal, domain)
         fragment.add_domains(self._domains.values())

amaranth/hdl/ir.py

@@ -506,11 +506,10 @@ def lca_of(fragu, fragv):
                 self.add_ports(sig, dir="i")
 
     def prepare(self, ports=None, missing_domain=lambda name: ClockDomain(name)):
-        from .xfrm import SampleLowerer, DomainLowerer
+        from .xfrm import DomainLowerer
 
-        fragment = SampleLowerer()(self)
-        new_domains = fragment._propagate_domains(missing_domain)
-        fragment = DomainLowerer()(fragment)
+        new_domains = self._propagate_domains(missing_domain)
+        fragment = DomainLowerer()(self)
         if ports is None:
             fragment._propagate_ports(ports=(), all_undef_as_ports=True)
         else:

amaranth/hdl/xfrm.py

@@ -15,7 +15,6 @@
            "FragmentTransformer",
            "TransformedElaboratable",
            "DomainCollector", "DomainRenamer", "DomainLowerer",
-           "SampleDomainInjector", "SampleLowerer",
            "SwitchCleaner", "LHSGroupAnalyzer", "LHSGroupFilter",
            "ResetInserter", "EnableInserter"]
 
@@ -65,10 +64,6 @@ def on_Cat(self, value):
     def on_ArrayProxy(self, value):
         pass # :nocov:
 
-    @abstractmethod
-    def on_Sample(self, value):
-        pass # :nocov:
-
     @abstractmethod
     def on_Initial(self, value):
         pass # :nocov:
@@ -103,8 +98,6 @@ def on_value(self, value):
             new_value = self.on_Cat(value)
         elif type(value) is ArrayProxy:
             new_value = self.on_ArrayProxy(value)
-        elif type(value) is Sample:
-            new_value = self.on_Sample(value)
         elif type(value) is Initial:
             new_value = self.on_Initial(value)
         else:
@@ -153,9 +146,6 @@ def on_ArrayProxy(self, value):
         return ArrayProxy([self.on_value(elem) for elem in value._iter_as_values()],
                           self.on_value(value.index))
 
-    def on_Sample(self, value):
-        return Sample(self.on_value(value.value), value.clocks, value.domain)
-
     def on_Initial(self, value):
         return value
 
@@ -369,9 +359,6 @@ def on_ArrayProxy(self, value):
             self.on_value(elem)
         self.on_value(value.index)
 
-    def on_Sample(self, value):
-        self.on_value(value.value)
-
     def on_Initial(self, value):
         pass
 
@@ -509,81 +496,6 @@ def on_fragment(self, fragment):
         return new_fragment
 
 
-class SampleDomainInjector(ValueTransformer, StatementTransformer):
-    def __init__(self, domain):
-        self.domain = domain
-
-    @_ignore_deprecated
-    def on_Sample(self, value):
-        if value.domain is not None:
-            return value
-        return Sample(value.value, value.clocks, self.domain)
-
-    def __call__(self, stmts):
-        return self.on_statement(stmts)
-
-
-class SampleLowerer(FragmentTransformer, ValueTransformer, StatementTransformer):
-    def __init__(self):
-        self.initial = None
-        self.sample_cache = None
-        self.sample_stmts = None
-
-    def _name_reset(self, value):
-        if isinstance(value, Const):
-            return f"c${value.value}", value.value
-        elif isinstance(value, Signal):
-            return f"s${value.name}", value.reset
-        elif isinstance(value, ClockSignal):
-            return "clk", 0
-        elif isinstance(value, ResetSignal):
-            return "rst", 1
-        elif isinstance(value, Initial):
-            return "init", 0 # Past(Initial()) produces 0, 1, 0, 0, ...
-        else:
-            raise NotImplementedError # :nocov:
-
-    @_ignore_deprecated
-    def on_Sample(self, value):
-        if value in self.sample_cache:
-            return self.sample_cache[value]
-
-        sampled_value = self.on_value(value.value)
-        if value.clocks == 0:
-            sample = sampled_value
-        else:
-            assert value.domain is not None
-            sampled_name, sampled_reset = self._name_reset(value.value)
-            name = f"$sample${sampled_name}${value.domain}${value.clocks}"
-            sample = Signal.like(value.value, name=name, reset_less=True, reset=sampled_reset)
-            sample.attrs["amaranth.sample_reg"] = True
-
-            prev_sample = self.on_Sample(Sample(sampled_value, value.clocks - 1, value.domain))
-            if value.domain not in self.sample_stmts:
-                self.sample_stmts[value.domain] = []
-            self.sample_stmts[value.domain].append(sample.eq(prev_sample))
-
-        self.sample_cache[value] = sample
-        return sample
-
-    def on_Initial(self, value):
-        if self.initial is None:
-            self.initial = Signal(name="init")
-        return self.initial
-
-    def map_statements(self, fragment, new_fragment):
-        self.initial = None
-        self.sample_cache = ValueDict()
-        self.sample_stmts = OrderedDict()
-        new_fragment.add_statements(map(self.on_statement, fragment.statements))
-        for domain, stmts in self.sample_stmts.items():
-            new_fragment.add_statements(stmts)
-            for stmt in stmts:
-                new_fragment.add_driver(stmt.lhs, domain)
-        if self.initial is not None:
-            new_fragment.add_subfragment(Instance("$initstate", o_Y=self.initial))
-
-
 class SwitchCleaner(StatementVisitor):
     def on_ignore(self, stmt):
         return stmt

amaranth/sim/_pyrtl.py

@@ -101,9 +101,6 @@ def on_AnyConst(self, value):
     def on_AnySeq(self, value):
         raise NotImplementedError # :nocov:
 
-    def on_Sample(self, value):
-        raise NotImplementedError # :nocov:
-
     def on_Initial(self, value):
         raise NotImplementedError # :nocov: