1348 lines
60 KiB
Python
1348 lines
60 KiB
Python
from typing import Tuple
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from collections import defaultdict, OrderedDict
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from functools import reduce
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import enum
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import warnings
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from .._utils import flatten, memoize
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from .. import tracer, _unused
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from . import _ast, _cd, _ir, _nir
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__all__ = [
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"UnusedElaboratable", "Elaboratable", "DriverConflict", "Fragment", "Instance",
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"PortDirection", "Design", "build_netlist",
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]
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class UnusedElaboratable(_unused.UnusedMustUse):
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# The warning is initially silenced. If everything that has been constructed remains unused,
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# it means the application likely crashed (with an exception, or in another way that does not
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# call `sys.excepthook`), and it's not necessary to show any warnings.
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# Once elaboration starts, the warning is enabled.
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_MustUse__silence = True
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class Elaboratable(_unused.MustUse):
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_MustUse__warning = UnusedElaboratable
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class DriverConflict(UserWarning):
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pass
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class Fragment:
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@staticmethod
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def get(obj, platform):
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code = None
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origins = []
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while True:
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if isinstance(obj, Fragment):
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if hasattr(obj, "origins"):
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obj.origins = tuple(origins)
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return obj
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elif isinstance(obj, Elaboratable):
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code = obj.elaborate.__code__
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UnusedElaboratable._MustUse__silence = False
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obj._MustUse__used = True
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new_obj = obj.elaborate(platform)
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elif hasattr(obj, "elaborate"):
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warnings.warn(
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message="Class {!r} is an elaboratable that does not explicitly inherit from "
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"Elaboratable; doing so would improve diagnostics"
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.format(type(obj)),
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category=RuntimeWarning,
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stacklevel=2)
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code = obj.elaborate.__code__
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new_obj = obj.elaborate(platform)
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else:
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raise AttributeError(f"Object {obj!r} cannot be elaborated")
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if new_obj is obj:
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raise RecursionError(f"Object {obj!r} elaborates to itself")
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if new_obj is None and code is not None:
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warnings.warn_explicit(
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message=".elaborate() returned None; missing return statement?",
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category=UserWarning,
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filename=code.co_filename,
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lineno=code.co_firstlineno)
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origins.append(obj)
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obj = new_obj
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def __init__(self, *, src_loc=None):
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self.drivers = OrderedDict()
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self.statements = {}
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self.domains = OrderedDict()
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self.subfragments = []
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self.attrs = OrderedDict()
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self.generated = OrderedDict()
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self.flatten = False
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self.src_loc = src_loc
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self.origins = None
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def add_driver(self, signal, domain="comb"):
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assert isinstance(domain, str)
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if domain not in self.drivers:
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self.drivers[domain] = _ast.SignalSet()
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self.drivers[domain].add(signal)
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def iter_drivers(self):
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for domain, signals in self.drivers.items():
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for signal in signals:
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yield domain, signal
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def iter_comb(self):
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if "comb" in self.drivers:
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yield from self.drivers["comb"]
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def iter_sync(self):
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for domain, signals in self.drivers.items():
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if domain == "comb":
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continue
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for signal in signals:
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yield domain, signal
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def add_domains(self, *domains):
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for domain in flatten(domains):
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assert isinstance(domain, _cd.ClockDomain)
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assert domain.name not in self.domains
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self.domains[domain.name] = domain
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def iter_domains(self):
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yield from self.domains
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def add_statements(self, domain, *stmts):
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assert isinstance(domain, str)
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for stmt in _ast.Statement.cast(stmts):
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stmt._MustUse__used = True
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self.statements.setdefault(domain, _ast._StatementList()).append(stmt)
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def add_subfragment(self, subfragment, name=None, *, src_loc=None):
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assert isinstance(subfragment, Fragment)
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self.subfragments.append((subfragment, name, src_loc))
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def find_subfragment(self, name_or_index):
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if isinstance(name_or_index, int):
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if name_or_index < len(self.subfragments):
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subfragment, name, src_loc = self.subfragments[name_or_index]
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return subfragment
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raise NameError(f"No subfragment at index #{name_or_index}")
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else:
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for subfragment, name, src_loc in self.subfragments:
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if name == name_or_index:
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return subfragment
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raise NameError(f"No subfragment with name '{name_or_index}'")
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def find_generated(self, *path):
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if len(path) > 1:
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path_component, *path = path
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return self.find_subfragment(path_component).find_generated(*path)
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else:
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item, = path
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return self.generated[item]
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def elaborate(self, platform):
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return self
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def _merge_subfragment(self, subfragment):
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# Merge subfragment's everything except clock domains into this fragment.
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# Flattening is done after clock domain propagation, so we can assume the domains
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# are already the same in every involved fragment in the first place.
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for domain, signal in subfragment.iter_drivers():
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self.add_driver(signal, domain)
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for domain, statements in subfragment.statements.items():
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self.statements.setdefault(domain, []).extend(statements)
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self.subfragments += subfragment.subfragments
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# Remove the merged subfragment.
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found = False
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for i, (check_subfrag, check_name, check_src_loc) in enumerate(self.subfragments): # :nobr:
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if subfragment == check_subfrag:
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del self.subfragments[i]
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found = True
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break
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assert found
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def _resolve_hierarchy_conflicts(self, hierarchy=("top",), mode="warn"):
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assert mode in ("silent", "warn", "error")
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from ._mem import MemoryInstance
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driver_subfrags = _ast.SignalDict()
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def add_subfrag(registry, entity, entry):
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# Because of missing domain insertion, at the point when this code runs, we have
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# a mixture of bound and unbound {Clock,Reset}Signals. Map the bound ones to
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# the actual signals (because the signal itself can be driven as well); but leave
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# the unbound ones as it is, because there's no concrete signal for it yet anyway.
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if isinstance(entity, _ast.ClockSignal) and entity.domain in self.domains:
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entity = self.domains[entity.domain].clk
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elif isinstance(entity, _ast.ResetSignal) and entity.domain in self.domains:
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entity = self.domains[entity.domain].rst
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if entity not in registry:
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registry[entity] = set()
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registry[entity].add(entry)
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# For each signal driven by this fragment and/or its subfragments, determine which
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# subfragments also drive it.
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for domain, signal in self.iter_drivers():
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add_subfrag(driver_subfrags, signal, (None, hierarchy))
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flatten_subfrags = set()
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for i, (subfrag, name, src_loc) in enumerate(self.subfragments):
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if name is None:
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name = f"<unnamed #{i}>"
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subfrag_hierarchy = hierarchy + (name,)
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if subfrag.flatten:
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# Always flatten subfragments that explicitly request it.
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flatten_subfrags.add((subfrag, subfrag_hierarchy))
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if isinstance(subfrag, (Instance, MemoryInstance)):
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# Never flatten instances.
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continue
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# First, recurse into subfragments and let them detect driver conflicts as well.
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subfrag_drivers = \
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subfrag._resolve_hierarchy_conflicts(subfrag_hierarchy, mode)
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# Second, classify subfragments by signals they drive.
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for signal in subfrag_drivers:
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add_subfrag(driver_subfrags, signal, (subfrag, subfrag_hierarchy))
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# Find out the set of subfragments that needs to be flattened into this fragment
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# to resolve driver-driver conflicts.
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def flatten_subfrags_if_needed(subfrags):
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if len(subfrags) == 1:
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return []
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flatten_subfrags.update((f, h) for f, h in subfrags if f is not None)
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return list(sorted(".".join(h) for f, h in subfrags))
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for signal, subfrags in driver_subfrags.items():
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subfrag_names = flatten_subfrags_if_needed(subfrags)
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if not subfrag_names:
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continue
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# While we're at it, show a message.
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message = ("Signal '{}' is driven from multiple fragments: {}"
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.format(signal, ", ".join(subfrag_names)))
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if mode == "error":
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raise DriverConflict(message)
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elif mode == "warn":
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message += "; hierarchy will be flattened"
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warnings.warn_explicit(message, DriverConflict, *signal.src_loc)
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# Flatten hierarchy.
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for subfrag, subfrag_hierarchy in sorted(flatten_subfrags, key=lambda x: x[1]):
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self._merge_subfragment(subfrag)
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# If we flattened anything, we might be in a situation where we have a driver conflict
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# again, e.g. if we had a tree of fragments like A --- B --- C where only fragments
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# A and C were driving a signal S. In that case, since B is not driving S itself,
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# processing B will not result in any flattening, but since B is transitively driving S,
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# processing A will flatten B into it. Afterwards, we have a tree like AB --- C, which
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# has another conflict.
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if any(flatten_subfrags):
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# Try flattening again.
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return self._resolve_hierarchy_conflicts(hierarchy, mode)
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# Nothing was flattened, we're done!
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return _ast.SignalSet(driver_subfrags.keys())
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def _propagate_domains_up(self, hierarchy=("top",)):
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from ._xfrm import DomainRenamer
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domain_subfrags = defaultdict(set)
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# For each domain defined by a subfragment, determine which subfragments define it.
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for i, (subfrag, name, src_loc) in enumerate(self.subfragments):
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# First, recurse into subfragments and let them propagate domains up as well.
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hier_name = name
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if hier_name is None:
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hier_name = f"<unnamed #{i}>"
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subfrag._propagate_domains_up(hierarchy + (hier_name,))
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# Second, classify subfragments by domains they define.
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for domain_name, domain in subfrag.domains.items():
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if domain.local:
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continue
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domain_subfrags[domain_name].add((subfrag, name, src_loc, i))
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# For each domain defined by more than one subfragment, rename the domain in each
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# of the subfragments such that they no longer conflict.
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for domain_name, subfrags in domain_subfrags.items():
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if len(subfrags) == 1:
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continue
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names = [n for f, n, s, i in subfrags]
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if not all(names):
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names = sorted(f"<unnamed #{i}>" if n is None else f"'{n}'"
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for f, n, s, i in subfrags)
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raise _cd.DomainError(
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"Domain '{}' is defined by subfragments {} of fragment '{}'; it is necessary "
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"to either rename subfragment domains explicitly, or give names to subfragments"
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.format(domain_name, ", ".join(names), ".".join(hierarchy)))
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if len(names) != len(set(names)):
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names = sorted(f"#{i}" for f, n, s, i in subfrags)
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raise _cd.DomainError(
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"Domain '{}' is defined by subfragments {} of fragment '{}', some of which "
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"have identical names; it is necessary to either rename subfragment domains "
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"explicitly, or give distinct names to subfragments"
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.format(domain_name, ", ".join(names), ".".join(hierarchy)))
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for subfrag, name, src_loc, i in subfrags:
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domain_name_map = {domain_name: f"{name}_{domain_name}"}
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self.subfragments[i] = (DomainRenamer(domain_name_map)(subfrag), name, src_loc)
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# Finally, collect the (now unique) subfragment domains, and merge them into our domains.
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for subfrag, name, src_loc in self.subfragments:
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for domain_name, domain in subfrag.domains.items():
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if domain.local:
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continue
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self.add_domains(domain)
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def _propagate_domains_down(self):
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# For each domain defined in this fragment, ensure it also exists in all subfragments.
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for subfrag, name, src_loc in self.subfragments:
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for domain in self.iter_domains():
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if domain in subfrag.domains:
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assert self.domains[domain] is subfrag.domains[domain]
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else:
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subfrag.add_domains(self.domains[domain])
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subfrag._propagate_domains_down()
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def _create_missing_domains(self, missing_domain, *, platform=None):
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from ._xfrm import DomainCollector
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collector = DomainCollector()
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collector(self)
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new_domains = []
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for domain_name in collector.used_domains - collector.defined_domains:
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if domain_name == "comb":
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continue
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value = missing_domain(domain_name)
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if value is None:
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raise _cd.DomainError(f"Domain '{domain_name}' is used but not defined")
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if type(value) is _cd.ClockDomain:
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self.add_domains(value)
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# And expose ports on the newly added clock domain, since it is added directly
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# and there was no chance to add any logic driving it.
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new_domains.append(value)
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else:
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new_fragment = Fragment.get(value, platform=platform)
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if domain_name not in new_fragment.domains:
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defined = new_fragment.domains.keys()
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raise _cd.DomainError(
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"Fragment returned by missing domain callback does not define "
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"requested domain '{}' (defines {})."
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.format(domain_name, ", ".join(f"'{n}'" for n in defined)))
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self.add_subfragment(new_fragment, f"cd_{domain_name}")
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self.add_domains(new_fragment.domains.values())
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return new_domains
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def _propagate_domains(self, missing_domain, *, platform=None):
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self._propagate_domains_up()
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self._propagate_domains_down()
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self._resolve_hierarchy_conflicts()
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new_domains = self._create_missing_domains(missing_domain, platform=platform)
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self._propagate_domains_down()
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return new_domains
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def _prepare_ports(self, ports):
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# Normalize ports to a list.
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new_ports = []
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if isinstance(ports, dict):
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for port_name, (signal, dir) in ports.items():
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new_ports.append((port_name, signal, dir))
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elif isinstance(ports, (list, tuple)):
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for port in ports:
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if isinstance(port, tuple):
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port_name, signal, dir = port
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new_ports.append((port_name, signal, dir))
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else:
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new_ports.append((None, port, None))
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else:
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msg = f"`ports` must be a dict, a list or a tuple, not {ports!r}"
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if isinstance(ports, _ast.Value):
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msg += " (did you mean `ports=(<signal>,)`, rather than `ports=<signal>`?)"
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raise TypeError(msg)
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# Validate ports.
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prenamed_ports = set()
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for (port_name, signal, dir) in new_ports:
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if isinstance(port_name, str):
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if port_name in prenamed_ports:
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raise TypeError(f"Duplicate port name {port_name!r}")
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else:
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prenamed_ports.add(port_name)
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elif port_name is not None:
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raise TypeError(f"Port name must be a string, not {port_name!r}")
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if dir is not None and not isinstance(dir, PortDirection):
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raise TypeError(
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f"Port direction must be a `PortDirection` instance or None, not {dir!r}")
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if not isinstance(signal, (_ast.Signal, _ast.ClockSignal, _ast.ResetSignal)):
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raise TypeError(f"Only signals may be added as ports, not {signal!r}")
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return new_ports
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def prepare(self, ports=(), *, hierarchy=("top",), legalize_assignments=False, missing_domain=lambda name: _cd.ClockDomain(name)):
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from ._xfrm import DomainLowerer
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ports = self._prepare_ports(ports)
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new_domains = self._propagate_domains(missing_domain)
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for domain in new_domains:
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ports.append((None, domain.clk, PortDirection.Input))
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if domain.rst is not None:
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ports.append((None, domain.rst, PortDirection.Input))
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def resolve_signal(signal):
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if isinstance(signal, _ast.ClockSignal):
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domain = self.domains[signal.domain]
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return domain.clk
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elif isinstance(signal, _ast.ResetSignal):
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domain = self.domains[signal.domain]
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if domain.rst is None:
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raise ValueError(f"Using ResetSignal for a reset-less domain {signal.domain}")
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return domain.rst
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else:
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return signal
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ports = [
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(name, resolve_signal(signal), dir)
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for name, signal, dir in ports
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]
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fragment = DomainLowerer()(self)
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if legalize_assignments:
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from ._xfrm import AssignmentLegalizer
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fragment = AssignmentLegalizer()(fragment)
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# Create design and let it do the rest.
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return Design(fragment, ports, hierarchy=hierarchy)
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class Instance(Fragment):
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def __init__(self, type, *args, src_loc=None, src_loc_at=0, **kwargs):
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super().__init__(src_loc=src_loc or tracer.get_src_loc(src_loc_at))
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self.type = type
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self.parameters = OrderedDict()
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self.named_ports = OrderedDict()
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for (kind, name, value) in args:
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if kind == "a":
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self.attrs[name] = value
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elif kind == "p":
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self.parameters[name] = value
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elif kind in ("i", "o", "io"):
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self.named_ports[name] = (_ast.Value.cast(value), kind)
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else:
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raise NameError("Instance argument {!r} should be a tuple (kind, name, value) "
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"where kind is one of \"a\", \"p\", \"i\", \"o\", or \"io\""
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.format((kind, name, value)))
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for kw, arg in kwargs.items():
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if kw.startswith("a_"):
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self.attrs[kw[2:]] = arg
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elif kw.startswith("p_"):
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self.parameters[kw[2:]] = arg
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elif kw.startswith("i_"):
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self.named_ports[kw[2:]] = (_ast.Value.cast(arg), "i")
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elif kw.startswith("o_"):
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self.named_ports[kw[2:]] = (_ast.Value.cast(arg), "o")
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elif kw.startswith("io_"):
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self.named_ports[kw[3:]] = (_ast.Value.cast(arg), "io")
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else:
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raise NameError("Instance keyword argument {}={!r} does not start with one of "
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"\"a_\", \"p_\", \"i_\", \"o_\", or \"io_\""
|
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.format(kw, arg))
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|
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|
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class Design:
|
|
"""Represents a design ready for simulation or netlist building.
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|
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Returned by ``Fragment.prepare``."""
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|
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def __init__(self, fragment, ports, *, hierarchy):
|
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self.fragment = fragment
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self.ports = ports
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self.hierarchy = hierarchy
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|
# dict of Fragment to SignalDict of Signal to name
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|
self.signal_names = {}
|
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self.fragment_names = {}
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|
self._assign_names_to_signals(fragment, ports)
|
|
self._assign_names_to_fragments(fragment, hierarchy)
|
|
# Use just-assigned signal names to name all unnamed ports.
|
|
top_names = self.signal_names[fragment]
|
|
self.ports = [
|
|
(name or top_names[signal], signal, dir)
|
|
for (name, signal, dir) in self.ports
|
|
]
|
|
|
|
def _assign_names_to_signals(self, fragment, ports=None):
|
|
"""Assign names to signals used in a given fragment.
|
|
|
|
The mapping is set in ``self.signal_names``. Because names are deduplicated using local
|
|
information only, the same signal used in a different fragment may get a different name.
|
|
"""
|
|
|
|
signal_names = _ast.SignalDict()
|
|
assigned_names = set()
|
|
|
|
def add_signal_name(signal):
|
|
if signal not in signal_names:
|
|
if signal.name not in assigned_names:
|
|
name = signal.name
|
|
else:
|
|
name = f"{signal.name}${len(assigned_names)}"
|
|
assert name not in assigned_names
|
|
signal_names[signal] = name
|
|
assigned_names.add(name)
|
|
|
|
if ports is not None:
|
|
# First pass: reserve names for pre-named top-level ports. If equal to the signal name, let the signal share it.
|
|
for name, signal, _dir in ports:
|
|
if name is not None:
|
|
assigned_names.add(name)
|
|
if signal.name == name:
|
|
signal_names[signal] = name
|
|
|
|
# Second pass: ensure non-pre-named top-level ports are named first.
|
|
for name, signal, _dir in ports:
|
|
if name is None:
|
|
add_signal_name(signal)
|
|
|
|
for domain_name, domain_signals in fragment.drivers.items():
|
|
if domain_name != "comb":
|
|
domain = fragment.domains[domain_name]
|
|
add_signal_name(domain.clk)
|
|
if domain.rst is not None:
|
|
add_signal_name(domain.rst)
|
|
|
|
for statements in fragment.statements.values():
|
|
for statement in statements:
|
|
for signal in statement._lhs_signals() | statement._rhs_signals():
|
|
if not isinstance(signal, (_ast.ClockSignal, _ast.ResetSignal)):
|
|
add_signal_name(signal)
|
|
|
|
self.signal_names[fragment] = signal_names
|
|
for subfragment, _name, _src_loc in fragment.subfragments:
|
|
self._assign_names_to_signals(subfragment)
|
|
|
|
def _assign_names_to_fragments(self, fragment, hierarchy):
|
|
"""Assign names to this fragment and its subfragments.
|
|
|
|
Subfragments may not necessarily have a name. This method assigns every such subfragment
|
|
a name, ``U$<number>``, where ``<number>`` is based on its location in the hierarchy.
|
|
|
|
Subfragment names may collide with signal names safely in Amaranth, but this may confuse
|
|
backends. This method assigns every such subfragment a name, ``<name>$U$<number>``, where
|
|
``name`` is its original name, and ``<number>`` is based on its location in the hierarchy.
|
|
|
|
Arguments
|
|
---------
|
|
hierarchy : tuple of str
|
|
Name of this fragment.
|
|
|
|
Returns
|
|
-------
|
|
dict of Fragment to tuple of str
|
|
A mapping from this fragment and its subfragments to their full hierarchical names.
|
|
"""
|
|
self.fragment_names[fragment] = hierarchy
|
|
|
|
signal_names = set(self.signal_names[fragment].values())
|
|
for subfragment_index, (subfragment, subfragment_name, subfragment_src_loc) in enumerate(fragment.subfragments):
|
|
if subfragment_name is None:
|
|
subfragment_name = f"U${subfragment_index}"
|
|
elif subfragment_name in signal_names:
|
|
subfragment_name = f"{subfragment_name}$U${subfragment_index}"
|
|
assert subfragment_name not in signal_names
|
|
self._assign_names_to_fragments(subfragment, hierarchy=(*hierarchy, subfragment_name))
|
|
|
|
|
|
############################################################################################### >:3
|
|
|
|
|
|
class PortDirection(enum.Enum):
|
|
Input = "input"
|
|
Output = "output"
|
|
Inout = "inout"
|
|
|
|
|
|
class NetlistDriver:
|
|
def __init__(self, module_idx: int, signal: _ast.Signal,
|
|
domain: '_cd.ClockDomain | None', *, src_loc):
|
|
self.module_idx = module_idx
|
|
self.signal = signal
|
|
self.domain = domain
|
|
self.src_loc = src_loc
|
|
self.assignments = []
|
|
|
|
def emit_value(self, builder):
|
|
if self.domain is None:
|
|
init = _ast.Const(self.signal.init, self.signal.width)
|
|
default, _signed = builder.emit_rhs(self.module_idx, init)
|
|
else:
|
|
default = builder.emit_signal(self.signal)
|
|
if len(self.assignments) == 1:
|
|
assign, = self.assignments
|
|
if assign.cond == 1 and assign.start == 0 and len(assign.value) == len(default):
|
|
return assign.value
|
|
cell = _nir.AssignmentList(self.module_idx, default=default, assignments=self.assignments,
|
|
src_loc=self.signal.src_loc)
|
|
return builder.netlist.add_value_cell(len(default), cell)
|
|
|
|
|
|
class NetlistEmitter:
|
|
def __init__(self, netlist: _nir.Netlist, design):
|
|
self.netlist = netlist
|
|
self.design = design
|
|
self.drivers = _ast.SignalDict()
|
|
self.rhs_cache: dict[int, Tuple[_nir.Value, bool, _ast.Value]] = {}
|
|
|
|
# Collected for driver conflict diagnostics only.
|
|
self.late_net_to_signal = {}
|
|
self.connect_src_loc = {}
|
|
|
|
def emit_signal(self, signal) -> _nir.Value:
|
|
if signal in self.netlist.signals:
|
|
return self.netlist.signals[signal]
|
|
value = self.netlist.alloc_late_value(len(signal))
|
|
self.netlist.signals[signal] = value
|
|
for bit, net in enumerate(value):
|
|
self.late_net_to_signal[net] = (signal, bit)
|
|
return value
|
|
|
|
# Used for instance outputs and read port data, not used for actual assignments.
|
|
def emit_lhs(self, value: _ast.Value):
|
|
if isinstance(value, _ast.Signal):
|
|
return self.emit_signal(value)
|
|
elif isinstance(value, _ast.Cat):
|
|
result = []
|
|
for part in value.parts:
|
|
result += self.emit_lhs(part)
|
|
return _nir.Value(result)
|
|
elif isinstance(value, _ast.Slice):
|
|
return self.emit_lhs(value.value)[value.start:value.stop]
|
|
elif isinstance(value, _ast.Operator):
|
|
assert value.operator in ('u', 's')
|
|
return self.emit_lhs(value.operands[0])
|
|
else:
|
|
raise TypeError # :nocov:
|
|
|
|
def extend(self, value: _nir.Value, signed: bool, width: int):
|
|
nets = list(value)
|
|
while len(nets) < width:
|
|
if signed:
|
|
nets.append(nets[-1])
|
|
else:
|
|
nets.append(_nir.Net.from_const(0))
|
|
return _nir.Value(nets)
|
|
|
|
def emit_operator(self, module_idx: int, operator: str, *inputs: _nir.Value, src_loc):
|
|
op = _nir.Operator(module_idx, operator=operator, inputs=inputs, src_loc=src_loc)
|
|
return self.netlist.add_value_cell(op.width, op)
|
|
|
|
def unify_shapes_bitwise(self,
|
|
operand_a: _nir.Value, signed_a: bool, operand_b: _nir.Value, signed_b: bool):
|
|
if signed_a == signed_b:
|
|
width = max(len(operand_a), len(operand_b))
|
|
elif signed_a:
|
|
width = max(len(operand_a), len(operand_b) + 1)
|
|
else: # signed_b
|
|
width = max(len(operand_a) + 1, len(operand_b))
|
|
operand_a = self.extend(operand_a, signed_a, width)
|
|
operand_b = self.extend(operand_b, signed_b, width)
|
|
signed = signed_a or signed_b
|
|
return (operand_a, operand_b, signed)
|
|
|
|
def emit_rhs(self, module_idx: int, value: _ast.Value) -> Tuple[_nir.Value, bool]:
|
|
"""Emits a RHS value, returns a tuple of (value, is_signed)"""
|
|
try:
|
|
result, signed, value = self.rhs_cache[id(value)]
|
|
return result, signed
|
|
except KeyError:
|
|
pass
|
|
if isinstance(value, _ast.Const):
|
|
result = _nir.Value(
|
|
_nir.Net.from_const((value.value >> bit) & 1)
|
|
for bit in range(value.width)
|
|
)
|
|
signed = value.signed
|
|
elif isinstance(value, _ast.Signal):
|
|
result = self.emit_signal(value)
|
|
signed = value.signed
|
|
elif isinstance(value, _ast.Operator):
|
|
if len(value.operands) == 1:
|
|
operand_a, signed_a = self.emit_rhs(module_idx, value.operands[0])
|
|
if value.operator == 's':
|
|
result = operand_a
|
|
signed = True
|
|
elif value.operator == 'u':
|
|
result = operand_a
|
|
signed = False
|
|
elif value.operator == '+':
|
|
result = operand_a
|
|
signed = signed_a
|
|
elif value.operator == '-':
|
|
operand_a = self.extend(operand_a, signed_a, len(operand_a) + 1)
|
|
result = self.emit_operator(module_idx, '-', operand_a,
|
|
src_loc=value.src_loc)
|
|
signed = True
|
|
elif value.operator == '~':
|
|
result = self.emit_operator(module_idx, '~', operand_a,
|
|
src_loc=value.src_loc)
|
|
signed = signed_a
|
|
elif value.operator in ('b', 'r|', 'r&', 'r^'):
|
|
result = self.emit_operator(module_idx, value.operator, operand_a,
|
|
src_loc=value.src_loc)
|
|
signed = False
|
|
else:
|
|
assert False # :nocov:
|
|
elif len(value.operands) == 2:
|
|
operand_a, signed_a = self.emit_rhs(module_idx, value.operands[0])
|
|
operand_b, signed_b = self.emit_rhs(module_idx, value.operands[1])
|
|
if value.operator in ('|', '&', '^'):
|
|
operand_a, operand_b, signed = \
|
|
self.unify_shapes_bitwise(operand_a, signed_a, operand_b, signed_b)
|
|
result = self.emit_operator(module_idx, value.operator, operand_a, operand_b,
|
|
src_loc=value.src_loc)
|
|
elif value.operator in ('+', '-'):
|
|
operand_a, operand_b, signed = \
|
|
self.unify_shapes_bitwise(operand_a, signed_a, operand_b, signed_b)
|
|
width = len(operand_a) + 1
|
|
operand_a = self.extend(operand_a, signed, width)
|
|
operand_b = self.extend(operand_b, signed, width)
|
|
result = self.emit_operator(module_idx, value.operator, operand_a, operand_b,
|
|
src_loc=value.src_loc)
|
|
if value.operator == '-':
|
|
signed = True
|
|
elif value.operator == '*':
|
|
width = len(operand_a) + len(operand_b)
|
|
operand_a = self.extend(operand_a, signed_a, width)
|
|
operand_b = self.extend(operand_b, signed_b, width)
|
|
result = self.emit_operator(module_idx, '*', operand_a, operand_b,
|
|
src_loc=value.src_loc)
|
|
signed = signed_a or signed_b
|
|
elif value.operator == '//':
|
|
width = len(operand_a) + signed_b
|
|
operand_a, operand_b, signed = \
|
|
self.unify_shapes_bitwise(operand_a, signed_a, operand_b, signed_b)
|
|
if len(operand_a) < width:
|
|
operand_a = self.extend(operand_a, signed, width)
|
|
operand_b = self.extend(operand_b, signed, width)
|
|
operator = 's//' if signed else 'u//'
|
|
result = _nir.Value(
|
|
self.emit_operator(module_idx, operator, operand_a, operand_b,
|
|
src_loc=value.src_loc)[:width]
|
|
)
|
|
elif value.operator == '%':
|
|
width = len(operand_b)
|
|
operand_a, operand_b, signed = \
|
|
self.unify_shapes_bitwise(operand_a, signed_a, operand_b, signed_b)
|
|
operator = 's%' if signed else 'u%'
|
|
result = _nir.Value(
|
|
self.emit_operator(module_idx, operator, operand_a, operand_b,
|
|
src_loc=value.src_loc)[:width]
|
|
)
|
|
signed = signed_b
|
|
elif value.operator == '<<':
|
|
operand_a = self.extend(operand_a, signed_a,
|
|
len(operand_a) + 2 ** len(operand_b) - 1)
|
|
result = self.emit_operator(module_idx, '<<', operand_a, operand_b,
|
|
src_loc=value.src_loc)
|
|
signed = signed_a
|
|
elif value.operator == '>>':
|
|
operator = 's>>' if signed_a else 'u>>'
|
|
result = self.emit_operator(module_idx, operator, operand_a, operand_b,
|
|
src_loc=value.src_loc)
|
|
signed = signed_a
|
|
elif value.operator in ('==', '!='):
|
|
operand_a, operand_b, signed = \
|
|
self.unify_shapes_bitwise(operand_a, signed_a, operand_b, signed_b)
|
|
result = self.emit_operator(module_idx, value.operator, operand_a, operand_b,
|
|
src_loc=value.src_loc)
|
|
signed = False
|
|
elif value.operator in ('<', '>', '<=', '>='):
|
|
operand_a, operand_b, signed = \
|
|
self.unify_shapes_bitwise(operand_a, signed_a, operand_b, signed_b)
|
|
operator = ('s' if signed else 'u') + value.operator
|
|
result = self.emit_operator(module_idx, operator, operand_a, operand_b,
|
|
src_loc=value.src_loc)
|
|
signed = False
|
|
else:
|
|
assert False # :nocov:
|
|
elif len(value.operands) == 3:
|
|
assert value.operator == 'm'
|
|
operand_s, signed_s = self.emit_rhs(module_idx, value.operands[0])
|
|
operand_a, signed_a = self.emit_rhs(module_idx, value.operands[1])
|
|
operand_b, signed_b = self.emit_rhs(module_idx, value.operands[2])
|
|
if len(operand_s) != 1:
|
|
operand_s = self.emit_operator(module_idx, 'b', operand_s,
|
|
src_loc=value.src_loc)
|
|
operand_a, operand_b, signed = \
|
|
self.unify_shapes_bitwise(operand_a, signed_a, operand_b, signed_b)
|
|
result = self.emit_operator(module_idx, 'm', operand_s, operand_a, operand_b,
|
|
src_loc=value.src_loc)
|
|
else:
|
|
assert False # :nocov:
|
|
elif isinstance(value, _ast.Slice):
|
|
inner, _signed = self.emit_rhs(module_idx, value.value)
|
|
result = _nir.Value(inner[value.start:value.stop])
|
|
signed = False
|
|
elif isinstance(value, _ast.Part):
|
|
inner, signed = self.emit_rhs(module_idx, value.value)
|
|
offset, _signed = self.emit_rhs(module_idx, value.offset)
|
|
cell = _nir.Part(module_idx, value=inner, value_signed=signed, width=value.width,
|
|
stride=value.stride, offset=offset, src_loc=value.src_loc)
|
|
result = self.netlist.add_value_cell(value.width, cell)
|
|
signed = False
|
|
elif isinstance(value, _ast.ArrayProxy):
|
|
elems = [self.emit_rhs(module_idx, elem) for elem in value.elems]
|
|
width = 0
|
|
signed = False
|
|
for elem, elem_signed in elems:
|
|
if elem_signed:
|
|
if not signed:
|
|
width += 1
|
|
signed = True
|
|
width = max(width, len(elem))
|
|
elif signed:
|
|
width = max(width, len(elem) + 1)
|
|
else:
|
|
width = max(width, len(elem))
|
|
elems = tuple(self.extend(elem, elem_signed, width) for elem, elem_signed in elems)
|
|
index, _signed = self.emit_rhs(module_idx, value.index)
|
|
cell = _nir.ArrayMux(module_idx, width=width, elems=elems, index=index,
|
|
src_loc=value.src_loc)
|
|
result = self.netlist.add_value_cell(width, cell)
|
|
elif isinstance(value, _ast.Cat):
|
|
nets = []
|
|
for val in value.parts:
|
|
inner, _signed = self.emit_rhs(module_idx, val)
|
|
for net in inner:
|
|
nets.append(net)
|
|
result = _nir.Value(nets)
|
|
signed = False
|
|
elif isinstance(value, _ast.AnyValue):
|
|
result = self.netlist.add_value_cell(value.width,
|
|
_nir.AnyValue(module_idx, kind=value.kind.value, width=value.width,
|
|
src_loc=value.src_loc))
|
|
signed = value.signed
|
|
elif isinstance(value, _ast.Initial):
|
|
result = self.netlist.add_value_cell(1, _nir.Initial(module_idx, src_loc=value.src_loc))
|
|
signed = False
|
|
else:
|
|
assert False # :nocov:
|
|
assert value.shape().width == len(result), \
|
|
f"Value {value!r} with shape {value.shape()!r} does not match " \
|
|
f"result with width {len(result)}"
|
|
# Add the value itself to the cache to make sure `id(value)` remains allocated and pointing
|
|
# at `value`. This would be a weakref.WeakKeyDictionary if `value` was hashable.
|
|
self.rhs_cache[id(value)] = result, signed, value
|
|
return (result, signed)
|
|
|
|
def connect(self, lhs: _nir.Value, rhs: _nir.Value, *, src_loc):
|
|
assert len(lhs) == len(rhs)
|
|
for left, right in zip(lhs, rhs):
|
|
if left in self.netlist.connections:
|
|
signal, bit = self.late_net_to_signal[left]
|
|
other_src_loc = self.connect_src_loc[left]
|
|
raise _ir.DriverConflict(f"Bit {bit} of signal {signal!r} has multiple drivers: "
|
|
f"{other_src_loc} and {src_loc}")
|
|
self.netlist.connections[left] = right
|
|
self.connect_src_loc[left] = src_loc
|
|
|
|
def emit_stmt(self, module_idx: int, fragment: _ir.Fragment, domain: str,
|
|
stmt: _ast.Statement, cond: _nir.Net):
|
|
if domain == "comb":
|
|
cd: _cd.ClockDomain | None = None
|
|
else:
|
|
cd = fragment.domains[domain]
|
|
if isinstance(stmt, _ast.Assign):
|
|
if isinstance(stmt.lhs, _ast.Signal):
|
|
signal = stmt.lhs
|
|
start = 0
|
|
width = signal.width
|
|
elif isinstance(stmt.lhs, _ast.Slice):
|
|
signal = stmt.lhs.value
|
|
start = stmt.lhs.start
|
|
width = stmt.lhs.stop - stmt.lhs.start
|
|
else:
|
|
assert False # :nocov:
|
|
assert isinstance(signal, _ast.Signal)
|
|
if signal in self.drivers:
|
|
driver = self.drivers[signal]
|
|
if driver.domain is not cd:
|
|
domain_name = cd.name if cd is not None else "comb"
|
|
other_domain_name = driver.domain.name if driver.domain is not None else "comb"
|
|
raise _ir.DriverConflict(
|
|
f"Signal {signal} driven from domain {domain_name} at {stmt.src_loc} and domain "
|
|
f"{other_domain_name} at {driver.src_loc}")
|
|
if driver.module_idx != module_idx:
|
|
mod_name = ".".join(self.netlist.modules[module_idx].name or ("<toplevel>",))
|
|
other_mod_name = \
|
|
".".join(self.netlist.modules[driver.module_idx].name or ("<toplevel>",))
|
|
raise _ir.DriverConflict(
|
|
f"Signal {signal} driven from module {mod_name} at {stmt.src_loc} and "
|
|
f"module {other_mod_name} at {driver.src_loc}")
|
|
else:
|
|
driver = NetlistDriver(module_idx, signal, domain=cd, src_loc=stmt.src_loc)
|
|
self.drivers[signal] = driver
|
|
rhs, signed = self.emit_rhs(module_idx, stmt.rhs)
|
|
if len(rhs) > width:
|
|
rhs = _nir.Value(rhs[:width])
|
|
if len(rhs) < width:
|
|
rhs = self.extend(rhs, signed, width)
|
|
driver.assignments.append(_nir.Assignment(cond=cond, start=start, value=rhs,
|
|
src_loc=stmt.src_loc))
|
|
elif isinstance(stmt, _ast.Property):
|
|
test, _signed = self.emit_rhs(module_idx, stmt.test)
|
|
if len(test) != 1:
|
|
test = self.emit_operator(module_idx, 'b', test, src_loc=stmt.src_loc)
|
|
test, = test
|
|
en_cell = _nir.AssignmentList(module_idx,
|
|
default=_nir.Value.zeros(),
|
|
assignments=[
|
|
_nir.Assignment(cond=cond, start=0, value=_nir.Value.ones(),
|
|
src_loc=stmt.src_loc)
|
|
],
|
|
src_loc=stmt.src_loc)
|
|
cond, = self.netlist.add_value_cell(1, en_cell)
|
|
if cd is None:
|
|
cell = _nir.AsyncProperty(module_idx, kind=stmt.kind.value, test=test, en=cond,
|
|
name=stmt.name, src_loc=stmt.src_loc)
|
|
else:
|
|
clk, = self.emit_signal(cd.clk)
|
|
cell = _nir.SyncProperty(module_idx, kind=stmt.kind.value, test=test, en=cond,
|
|
clk=clk, clk_edge=cd.clk_edge, name=stmt.name,
|
|
src_loc=stmt.src_loc)
|
|
self.netlist.add_cell(cell)
|
|
elif isinstance(stmt, _ast.Switch):
|
|
test, _signed = self.emit_rhs(module_idx, stmt.test)
|
|
conds = []
|
|
for patterns in stmt.cases:
|
|
if patterns:
|
|
for pattern in patterns:
|
|
assert len(pattern) == len(test)
|
|
cell = _nir.Matches(module_idx, value=test, patterns=patterns,
|
|
src_loc=stmt.case_src_locs.get(patterns))
|
|
net, = self.netlist.add_value_cell(1, cell)
|
|
conds.append(net)
|
|
else:
|
|
conds.append(_nir.Net.from_const(1))
|
|
cell = _nir.PriorityMatch(module_idx, en=cond, inputs=_nir.Value(conds),
|
|
src_loc=stmt.src_loc)
|
|
conds = self.netlist.add_value_cell(len(conds), cell)
|
|
for subcond, substmts in zip(conds, stmt.cases.values()):
|
|
for substmt in substmts:
|
|
self.emit_stmt(module_idx, fragment, domain, substmt, subcond)
|
|
else:
|
|
assert False # :nocov:
|
|
|
|
def emit_tribuf(self, module_idx: int, instance: _ir.Instance):
|
|
pad = self.emit_lhs(instance.named_ports["Y"][0])
|
|
o, _signed = self.emit_rhs(module_idx, instance.named_ports["A"][0])
|
|
(oe,), _signed = self.emit_rhs(module_idx, instance.named_ports["EN"][0])
|
|
assert len(pad) == len(o)
|
|
cell = _nir.IOBuffer(module_idx, pad=pad, o=o, oe=oe, src_loc=instance.src_loc)
|
|
self.netlist.add_cell(cell)
|
|
|
|
def emit_memory(self, module_idx: int, fragment: '_mem.MemoryInstance', name: str):
|
|
cell = _nir.Memory(module_idx,
|
|
width=fragment._width,
|
|
depth=fragment._depth,
|
|
init=fragment._init,
|
|
name=name,
|
|
attributes=fragment._attrs,
|
|
src_loc=fragment.src_loc,
|
|
)
|
|
return self.netlist.add_cell(cell)
|
|
|
|
def emit_write_port(self, module_idx: int, fragment: '_mem.MemoryInstance',
|
|
port: '_mem.MemoryInstance._WritePort', memory: int):
|
|
data, _signed = self.emit_rhs(module_idx, port._data)
|
|
addr, _signed = self.emit_rhs(module_idx, port._addr)
|
|
en, _signed = self.emit_rhs(module_idx, port._en)
|
|
en = _nir.Value([en[bit // port._granularity] for bit in range(len(port._data))])
|
|
cd = fragment.domains[port._domain]
|
|
clk, = self.emit_signal(cd.clk)
|
|
cell = _nir.SyncWritePort(module_idx,
|
|
memory=memory,
|
|
data=data,
|
|
addr=addr,
|
|
en=en,
|
|
clk=clk,
|
|
clk_edge=cd.clk_edge,
|
|
src_loc=port._data.src_loc,
|
|
)
|
|
return self.netlist.add_cell(cell)
|
|
|
|
def emit_read_port(self, module_idx: int, fragment: '_mem.MemoryInstance',
|
|
port: '_mem.MemoryInstance._ReadPort', memory: int,
|
|
write_ports: 'list[int]'):
|
|
addr, _signed = self.emit_rhs(module_idx, port._addr)
|
|
if port._domain == "comb":
|
|
cell = _nir.AsyncReadPort(module_idx,
|
|
memory=memory,
|
|
width=len(port._data),
|
|
addr=addr,
|
|
src_loc=port._data.src_loc,
|
|
)
|
|
else:
|
|
(en,), _signed = self.emit_rhs(module_idx, port._en)
|
|
cd = fragment.domains[port._domain]
|
|
clk, = self.emit_signal(cd.clk)
|
|
cell = _nir.SyncReadPort(module_idx,
|
|
memory=memory,
|
|
width=len(port._data),
|
|
addr=addr,
|
|
en=en,
|
|
clk=clk,
|
|
clk_edge=cd.clk_edge,
|
|
transparent_for=tuple(write_ports[idx] for idx in port._transparent_for),
|
|
src_loc=port._data.src_loc,
|
|
)
|
|
data = self.netlist.add_value_cell(len(port._data), cell)
|
|
self.connect(self.emit_lhs(port._data), data, src_loc=port._data.src_loc)
|
|
|
|
def emit_instance(self, module_idx: int, instance: _ir.Instance, name: str):
|
|
ports_i = {}
|
|
ports_o = {}
|
|
ports_io = {}
|
|
outputs = []
|
|
next_output_bit = 0
|
|
for port_name, (port_conn, dir) in instance.named_ports.items():
|
|
if dir == 'i':
|
|
ports_i[port_name], _signed = self.emit_rhs(module_idx, port_conn)
|
|
elif dir == 'o':
|
|
port_conn = self.emit_lhs(port_conn)
|
|
ports_o[port_name] = (next_output_bit, len(port_conn))
|
|
outputs.append((next_output_bit, port_conn))
|
|
next_output_bit += len(port_conn)
|
|
elif dir == 'io':
|
|
ports_io[port_name] = self.emit_lhs(port_conn)
|
|
else:
|
|
assert False # :nocov:
|
|
cell = _nir.Instance(module_idx,
|
|
type=instance.type,
|
|
name=name,
|
|
parameters=instance.parameters,
|
|
attributes=instance.attrs,
|
|
ports_i=ports_i,
|
|
ports_o=ports_o,
|
|
ports_io=ports_io,
|
|
src_loc=instance.src_loc,
|
|
)
|
|
output_nets = self.netlist.add_value_cell(width=next_output_bit, cell=cell)
|
|
for start_bit, port_conn in outputs:
|
|
self.connect(port_conn, _nir.Value(output_nets[start_bit:start_bit + len(port_conn)]),
|
|
src_loc=instance.src_loc)
|
|
|
|
def emit_top_ports(self, fragment: _ir.Fragment):
|
|
inouts = set()
|
|
for cell in self.netlist.cells:
|
|
if isinstance(cell, _nir.IOBuffer):
|
|
inouts.update(cell.pad)
|
|
if isinstance(cell, _nir.Instance):
|
|
for value in cell.ports_io.values():
|
|
inouts.update(value)
|
|
|
|
next_input_bit = 2 # 0 and 1 are reserved for constants
|
|
top = self.netlist.top
|
|
|
|
for name, signal, dir in self.design.ports:
|
|
signal_value = self.emit_signal(signal)
|
|
if dir is None:
|
|
is_driven = False
|
|
is_inout = False
|
|
for net in signal_value:
|
|
if net in self.netlist.connections:
|
|
is_driven = True
|
|
if net in inouts:
|
|
is_inout = True
|
|
if is_driven:
|
|
dir = PortDirection.Output
|
|
elif is_inout:
|
|
dir = PortDirection.Inout
|
|
else:
|
|
dir = PortDirection.Input
|
|
if dir == PortDirection.Input:
|
|
top.ports_i[name] = (next_input_bit, signal.width)
|
|
value = _nir.Value(
|
|
_nir.Net.from_cell(0, bit)
|
|
for bit in range(next_input_bit, next_input_bit + signal.width)
|
|
)
|
|
next_input_bit += signal.width
|
|
self.connect(signal_value, value, src_loc=signal.src_loc)
|
|
elif dir == PortDirection.Output:
|
|
top.ports_o[name] = signal_value
|
|
elif dir == PortDirection.Inout:
|
|
top.ports_io[name] = (next_input_bit, signal.width)
|
|
value = _nir.Value(
|
|
_nir.Net.from_cell(0, bit)
|
|
for bit in range(next_input_bit, next_input_bit + signal.width)
|
|
)
|
|
next_input_bit += signal.width
|
|
self.connect(signal_value, value, src_loc=signal.src_loc)
|
|
else:
|
|
raise ValueError(f"Invalid port direction {dir!r}")
|
|
|
|
def emit_drivers(self):
|
|
for driver in self.drivers.values():
|
|
value = driver.emit_value(self)
|
|
if driver.domain is not None:
|
|
clk, = self.emit_signal(driver.domain.clk)
|
|
if driver.domain.rst is not None and driver.domain.async_reset:
|
|
arst, = self.emit_signal(driver.domain.rst)
|
|
else:
|
|
arst = _nir.Net.from_const(0)
|
|
cell = _nir.FlipFlop(driver.module_idx,
|
|
data=value,
|
|
init=driver.signal.init,
|
|
clk=clk,
|
|
clk_edge=driver.domain.clk_edge,
|
|
arst=arst,
|
|
attributes=driver.signal.attrs,
|
|
src_loc=driver.signal.src_loc,
|
|
)
|
|
value = self.netlist.add_value_cell(len(value), cell)
|
|
if driver.assignments:
|
|
src_loc = driver.assignments[0].src_loc
|
|
else:
|
|
src_loc = driver.signal.src_loc
|
|
self.connect(self.emit_signal(driver.signal), value, src_loc=src_loc)
|
|
|
|
def emit_undriven(self):
|
|
# Connect all undriven signal bits to their initial values. This can only happen for entirely
|
|
# undriven signals, or signals that are partially driven by instances.
|
|
for signal, value in self.netlist.signals.items():
|
|
for bit, net in enumerate(value):
|
|
if net.is_late and net not in self.netlist.connections:
|
|
self.netlist.connections[net] = _nir.Net.from_const((signal.init >> bit) & 1)
|
|
|
|
def emit_fragment(self, fragment: _ir.Fragment, parent_module_idx: 'int | None', *, cell_src_loc=None):
|
|
from . import _mem
|
|
|
|
fragment_name = self.design.fragment_names[fragment]
|
|
if isinstance(fragment, _ir.Instance):
|
|
assert parent_module_idx is not None
|
|
if fragment.type == "$tribuf":
|
|
self.emit_tribuf(parent_module_idx, fragment)
|
|
else:
|
|
self.emit_instance(parent_module_idx, fragment, name=fragment_name[-1])
|
|
elif isinstance(fragment, _mem.MemoryInstance):
|
|
assert parent_module_idx is not None
|
|
memory = self.emit_memory(parent_module_idx, fragment, name=fragment_name[-1])
|
|
write_ports = []
|
|
for port in fragment._write_ports:
|
|
write_ports.append(self.emit_write_port(parent_module_idx, fragment, port, memory))
|
|
for port in fragment._read_ports:
|
|
self.emit_read_port(parent_module_idx, fragment, port, memory, write_ports)
|
|
elif type(fragment) is _ir.Fragment:
|
|
module_idx = self.netlist.add_module(parent_module_idx, fragment_name, src_loc=fragment.src_loc, cell_src_loc=cell_src_loc)
|
|
signal_names = self.design.signal_names[fragment]
|
|
self.netlist.modules[module_idx].signal_names = signal_names
|
|
for signal in signal_names:
|
|
self.emit_signal(signal)
|
|
for domain, stmts in fragment.statements.items():
|
|
for stmt in stmts:
|
|
self.emit_stmt(module_idx, fragment, domain, stmt, _nir.Net.from_const(1))
|
|
for subfragment, _name, sub_src_loc in fragment.subfragments:
|
|
self.emit_fragment(subfragment, module_idx, cell_src_loc=sub_src_loc)
|
|
if parent_module_idx is None:
|
|
self.emit_drivers()
|
|
self.emit_top_ports(fragment)
|
|
self.emit_undriven()
|
|
else:
|
|
assert False # :nocov:
|
|
|
|
|
|
def _emit_netlist(netlist: _nir.Netlist, design):
|
|
NetlistEmitter(netlist, design).emit_fragment(design.fragment, None)
|
|
|
|
|
|
def _compute_net_flows(netlist: _nir.Netlist):
|
|
# Computes the net flows for all modules of the netlist.
|
|
#
|
|
# The rules for net flows are as follows:
|
|
#
|
|
# - the modules that have a given net in their net_flow form a subtree of the hierarchy
|
|
# - Internal is used in the root of the subtree and nowhere else
|
|
# - Output is used for modules that contain the definition of the net, or are on the
|
|
# path from the definition to the root
|
|
# - remaining modules have a flow of Input (unless the net is a top-level inout port,
|
|
# in which case it is Inout)
|
|
#
|
|
# In other words, the tree looks something like this:
|
|
#
|
|
# - [no flow] <<< top
|
|
# - [no flow]
|
|
# - Internal
|
|
# - Input << use
|
|
# - [no flow]
|
|
# - Input
|
|
# - Input << use
|
|
# - Output
|
|
# - Input << use
|
|
# - [no flow]
|
|
# - Output << def
|
|
# - Input
|
|
# - Input
|
|
# - [no flow]
|
|
# - [no flow]
|
|
# - [no flow]
|
|
#
|
|
# This function doesn't assign the Inout flow — that is corrected later, in compute_ports.
|
|
lca = {}
|
|
|
|
# Initialize by marking the definition point of every net.
|
|
for cell_idx, cell in enumerate(netlist.cells):
|
|
for net in cell.output_nets(cell_idx):
|
|
lca[net] = cell.module_idx
|
|
netlist.modules[cell.module_idx].net_flow[net] = _nir.ModuleNetFlow.Internal
|
|
|
|
# Marks a use of a net within a given module, and adjusts its netflows in all modules
|
|
# as required.
|
|
def use_net(net, use_module):
|
|
if net.is_const:
|
|
return
|
|
# If the net is already present in the current module, we're done.
|
|
if net in netlist.modules[use_module].net_flow:
|
|
return
|
|
modules = netlist.modules
|
|
# Otherwise, we need to route the net through the hierarchy from def_module
|
|
# to use_module. We do that by treating use_module and def_module as pointers
|
|
# and moving them up the hierarchy until they meet at the new LCA.
|
|
def_module = lca[net]
|
|
# While def_module deeper than use_module, go up with def_module.
|
|
while len(modules[def_module].name) > len(modules[use_module].name):
|
|
modules[def_module].net_flow[net] = _nir.ModuleNetFlow.Output
|
|
def_module = modules[def_module].parent
|
|
# While use_module deeper than def_module, go up with use_module.
|
|
# If use_module is below def_module in the hierarchy, we may hit
|
|
# another module which already uses this net before hitting def_module,
|
|
# so check for this case.
|
|
while len(modules[def_module].name) < len(modules[use_module].name):
|
|
if net in modules[use_module].net_flow:
|
|
return
|
|
modules[use_module].net_flow[net] = _nir.ModuleNetFlow.Input
|
|
use_module = modules[use_module].parent
|
|
# Now both pointers should be at the same depth within the hierarchy.
|
|
assert len(modules[def_module].name) == len(modules[use_module].name)
|
|
# Move both pointers up until they meet.
|
|
while def_module != use_module:
|
|
modules[def_module].net_flow[net] = _nir.ModuleNetFlow.Output
|
|
def_module = modules[def_module].parent
|
|
modules[use_module].net_flow[net] = _nir.ModuleNetFlow.Input
|
|
use_module = modules[use_module].parent
|
|
assert len(modules[def_module].name) == len(modules[use_module].name)
|
|
# And mark the new LCA.
|
|
modules[def_module].net_flow[net] = _nir.ModuleNetFlow.Internal
|
|
lca[net] = def_module
|
|
|
|
# Now mark all uses and flesh out the structure.
|
|
for cell in netlist.cells:
|
|
for net in cell.input_nets():
|
|
use_net(net, cell.module_idx)
|
|
# TODO: ?
|
|
for module_idx, module in enumerate(netlist.modules):
|
|
for signal in module.signal_names:
|
|
for net in netlist.signals[signal]:
|
|
use_net(net, module_idx)
|
|
|
|
|
|
def _compute_ports(netlist: _nir.Netlist):
|
|
# Compute the indexes at which the outputs of a cell should be split to create a distinct port.
|
|
# These indexes are stored here as nets.
|
|
port_starts = set()
|
|
for start, _ in netlist.top.ports_i.values():
|
|
port_starts.add(_nir.Net.from_cell(0, start))
|
|
for start, width in netlist.top.ports_io.values():
|
|
port_starts.add(_nir.Net.from_cell(0, start))
|
|
for cell_idx, cell in enumerate(netlist.cells):
|
|
if isinstance(cell, _nir.Instance):
|
|
for start, _ in cell.ports_o.values():
|
|
port_starts.add(_nir.Net.from_cell(cell_idx, start))
|
|
|
|
# Compute the set of all inout nets. Currently, a net has inout flow iff it is connected to
|
|
# a toplevel inout port.
|
|
inouts = set()
|
|
for start, width in netlist.top.ports_io.values():
|
|
for idx in range(start, start + width):
|
|
inouts.add(_nir.Net.from_cell(0, idx))
|
|
|
|
for module in netlist.modules:
|
|
# Collect preferred names for ports. If a port exactly matches a signal, we reuse
|
|
# the signal name for the port. Otherwise, we synthesize a private name.
|
|
name_table = {}
|
|
for signal, name in module.signal_names.items():
|
|
value = netlist.signals[signal]
|
|
if value not in name_table and not name.startswith('$'):
|
|
name_table[value] = name
|
|
|
|
# Adjust any input flows to inout as necessary.
|
|
for (net, flow) in module.net_flow.items():
|
|
if flow == _nir.ModuleNetFlow.Input and net in inouts:
|
|
module.net_flow[net] = _nir.ModuleNetFlow.Inout
|
|
|
|
# Gather together "adjacent" nets with the same flow into ports.
|
|
visited = set()
|
|
for net in sorted(module.net_flow):
|
|
flow = module.net_flow[net]
|
|
if flow == _nir.ModuleNetFlow.Internal:
|
|
continue
|
|
if net in visited:
|
|
continue
|
|
# We found a net that needs a port. Keep joining the next nets output by the same
|
|
# cell into the same port, if applicable, but stop at instance/top port boundaries.
|
|
nets = [net]
|
|
while True:
|
|
succ = _nir.Net.from_cell(net.cell, net.bit + 1)
|
|
if succ in port_starts:
|
|
break
|
|
if succ not in module.net_flow:
|
|
break
|
|
if module.net_flow[succ] != module.net_flow[net]:
|
|
break
|
|
net = succ
|
|
nets.append(net)
|
|
value = _nir.Value(nets)
|
|
# Joined as many nets as we could, now name and add the port.
|
|
if value in name_table:
|
|
name = name_table[value]
|
|
else:
|
|
name = f"port${value[0].cell}${value[0].bit}"
|
|
module.ports[name] = (value, flow)
|
|
visited.update(value)
|
|
|
|
# The 0th cell and the 0th module correspond to the toplevel. Transfer the net flows from
|
|
# the toplevel cell (used for data flow) to the toplevel module (used to split netlist into
|
|
# modules in the backends).
|
|
top_module = netlist.modules[0]
|
|
for name, (start, width) in netlist.top.ports_i.items():
|
|
top_module.ports[name] = (
|
|
_nir.Value(_nir.Net.from_cell(0, start + bit) for bit in range(width)),
|
|
_nir.ModuleNetFlow.Input
|
|
)
|
|
for name, (start, width) in netlist.top.ports_io.items():
|
|
top_module.ports[name] = (
|
|
_nir.Value(_nir.Net.from_cell(0, start + bit) for bit in range(width)),
|
|
_nir.ModuleNetFlow.Inout
|
|
)
|
|
for name, value in netlist.top.ports_o.items():
|
|
top_module.ports[name] = (value, _nir.ModuleNetFlow.Output)
|
|
|
|
|
|
def build_netlist(fragment, ports, *, name="top", **kwargs):
|
|
design = fragment.prepare(ports=ports, hierarchy=(name,), legalize_assignments=True, **kwargs)
|
|
netlist = _nir.Netlist()
|
|
_emit_netlist(netlist, design)
|
|
netlist.resolve_all_nets()
|
|
_compute_net_flows(netlist)
|
|
_compute_ports(netlist)
|
|
return netlist
|