From: whitequark Date: Thu, 13 Dec 2018 11:01:03 +0000 (+0000) Subject: fhdl.ir: implement clock domain propagation. X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=b00aedf1d1a16e9b5b00d4b26086efd342e311e0;p=nmigen.git fhdl.ir: implement clock domain propagation. --- diff --git a/examples/arst.py b/examples/arst.py index d6fcd04..c35640e 100644 --- a/examples/arst.py +++ b/examples/arst.py @@ -14,8 +14,8 @@ class ClockDivisor: return m.lower(platform) -sync = ClockDomain(async_reset=True) ctr = ClockDivisor(factor=16) frag = ctr.get_fragment(platform=None) -# print(rtlil.convert(frag, ports=[sync.clk, sync.reset, ctr.o], clock_domains={"sync": sync})) -print(verilog.convert(frag, ports=[sync.clk, sync.reset, ctr.o], clock_domains={"sync": sync})) +frag.add_domains(ClockDomain("sync", async_reset=True)) +# print(rtlil.convert(frag, ports=[ctr.o])) +print(verilog.convert(frag, ports=[ctr.o])) diff --git a/examples/cdc.py b/examples/cdc.py index caaf679..7e38885 100644 --- a/examples/cdc.py +++ b/examples/cdc.py @@ -3,8 +3,7 @@ from nmigen.back import rtlil, verilog from nmigen.genlib.cdc import * -sys = ClockDomain() i, o = Signal(name="i"), Signal(name="o") frag = MultiReg(i, o).get_fragment(platform=None) -# print(rtlil.convert(frag, ports=[i, o], clock_domains={"sys": sys})) -print(verilog.convert(frag, ports=[i, o], clock_domains={"sys": sys})) +# print(rtlil.convert(frag, ports=[i, o])) +print(verilog.convert(frag, ports=[i, o])) diff --git a/examples/clkdiv.py b/examples/clkdiv.py index 79eec93..6900e1d 100644 --- a/examples/clkdiv.py +++ b/examples/clkdiv.py @@ -14,8 +14,7 @@ class ClockDivisor: return m.lower(platform) -sync = ClockDomain() ctr = ClockDivisor(factor=16) frag = ctr.get_fragment(platform=None) -# print(rtlil.convert(frag, ports=[sync.clk, ctr.o], clock_domains={"sync": sync})) -print(verilog.convert(frag, ports=[sync.clk, ctr.o], clock_domains={"sync": sync})) +# print(rtlil.convert(frag, ports=[ctr.o])) +print(verilog.convert(frag, ports=[ctr.o])) diff --git a/examples/ctrl.py b/examples/ctrl.py index 2d8fcf8..17a9e94 100644 --- a/examples/ctrl.py +++ b/examples/ctrl.py @@ -15,8 +15,7 @@ class ClockDivisor: return CEInserter(self.ce)(m.lower(platform)) -sync = ClockDomain() ctr = ClockDivisor(factor=16) frag = ctr.get_fragment(platform=None) -# print(rtlil.convert(frag, ports=[sync.clk, ctr.o, ctr.ce], clock_domains={"sync": sync})) -print(verilog.convert(frag, ports=[sync.clk, ctr.o, ctr.ce], clock_domains={"sync": sync})) +# print(rtlil.convert(frag, ports=[ctr.o, ctr.ce])) +print(verilog.convert(frag, ports=[ctr.o, ctr.ce])) diff --git a/nmigen/back/rtlil.py b/nmigen/back/rtlil.py index c670e73..93e2d40 100644 --- a/nmigen/back/rtlil.py +++ b/nmigen/back/rtlil.py @@ -396,7 +396,7 @@ class _ValueTransformer(xfrm.ValueTransformer): return "{{ {} }}".format(" ".join(self(node.value) for _ in range(node.count))) -def convert_fragment(builder, fragment, name, top, clock_domains): +def convert_fragment(builder, fragment, name, top): with builder.module(name, attrs={"top": 1} if top else {}) as module: xformer = _ValueTransformer(module) @@ -413,7 +413,7 @@ def convert_fragment(builder, fragment, name, top, clock_domains): # Transform all clocks clocks and resets eagerly and outside of any hierarchy, to make # sure they get sensible (non-prefixed) names. This does not affect semantics. for domain, _ in fragment.iter_sync(): - cd = clock_domains[domain] + cd = fragment.domains[domain] xformer(cd.clk) xformer(cd.rst) @@ -422,8 +422,7 @@ def convert_fragment(builder, fragment, name, top, clock_domains): # name) names. for subfragment, sub_name in fragment.subfragments: sub_name, sub_port_map = \ - convert_fragment(builder, subfragment, top=False, name=sub_name, - clock_domains=clock_domains) + convert_fragment(builder, subfragment, top=False, name=sub_name) with xformer.hierarchy(sub_name): module.cell(sub_name, name=sub_name, ports={ p: xformer(s) for p, s in sub_port_map.items() @@ -484,13 +483,11 @@ def convert_fragment(builder, fragment, name, top, clock_domains): triggers = [] if domain is None: triggers.append(("always",)) - elif domain in clock_domains: - cd = clock_domains[domain] + else: + cd = fragment.domains[domain] triggers.append(("posedge", xformer(cd.clk))) if cd.async_reset: triggers.append(("posedge", xformer(cd.rst))) - else: - raise ValueError("Clock domain {} not found in design".format(domain)) for trigger in triggers: with process.sync(*trigger) as sync: @@ -509,15 +506,17 @@ def convert_fragment(builder, fragment, name, top, clock_domains): return module.name, port_map -def convert(fragment, ports=[], clock_domains={}): +def convert(fragment, ports=[]): + fragment._propagate_domains(ensure_sync_exists=True) + # Clock domain reset always takes priority over all other logic. To ensure this, insert # decision trees for clock domain reset as the very last step before synthesis. fragment = xfrm.ResetInserter({ - cd.name: cd.rst for cd in clock_domains.values() if cd.rst is not None + cd.name: cd.rst for cd in fragment.domains.values() if cd.rst is not None })(fragment) - ins, outs = fragment._propagate_ports(ports, clock_domains) + ins, outs = fragment._propagate_ports(ports) builder = _Builder() - convert_fragment(builder, fragment, name="top", top=True, clock_domains=clock_domains) + convert_fragment(builder, fragment, name="top", top=True) return str(builder) diff --git a/nmigen/fhdl/ir.py b/nmigen/fhdl/ir.py index 8b838c9..0945fcb 100644 --- a/nmigen/fhdl/ir.py +++ b/nmigen/fhdl/ir.py @@ -2,9 +2,14 @@ from collections import defaultdict, OrderedDict from ..tools import * from .ast import * +from .cd import * -__all__ = ["Fragment"] +__all__ = ["Fragment", "DomainError"] + + +class DomainError(Exception): + pass class Fragment: @@ -12,6 +17,7 @@ class Fragment: self.ports = ValueSet() self.drivers = OrderedDict() self.statements = [] + self.domains = OrderedDict() self.subfragments = [] def add_ports(self, *ports): @@ -40,6 +46,15 @@ class Fragment: for signal in signals: yield domain, signal + def add_domains(self, *domains): + for domain in domains: + assert isinstance(domain, ClockDomain) + assert domain.name not in self.domains + self.domains[domain.name] = domain + + def iter_domains(self): + yield from self.domains + def add_statements(self, *stmts): self.statements += Statement.wrap(stmts) @@ -47,13 +62,79 @@ class Fragment: assert isinstance(subfragment, Fragment) self.subfragments.append((subfragment, name)) - def _propagate_ports(self, ports, clock_domains={}): + def _propagate_domains_up(self, hierarchy=("top",)): + from .xfrm import DomainRenamer + + domain_subfrags = defaultdict(lambda: set()) + + # For each domain defined by a subfragment, determine which subfragments define it. + for i, (subfrag, name) in enumerate(self.subfragments): + # First, recurse into subfragments and let them propagate domains up as well. + hier_name = name + if hier_name is None: + hier_name = "".format(i) + subfrag._propagate_domains_up(hierarchy + (hier_name,)) + + # Second, classify subfragments by domains they define. + for domain in subfrag.iter_domains(): + domain_subfrags[domain].add((subfrag, name, i)) + + # For each domain defined by more than one subfragment, rename the domain in each + # of the subfragments such that they no longer conflict. + for domain, subfrags in domain_subfrags.items(): + if len(subfrags) == 1: + continue + + names = [n for f, n, i in subfrags] + if not all(names): + names = sorted("".format(i) if n is None else "'{}'".format(n) + for f, n, i in subfrags) + raise DomainError("Domain '{}' is defined by subfragments {} of fragment '{}'; " + "it is necessary to either rename subfragment domains " + "explicitly, or give names to subfragments" + .format(domain, ", ".join(names), ".".join(hierarchy))) + + if len(names) != len(set(names)): + names = sorted("#{}".format(i) for f, n, i in subfrags) + raise DomainError("Domain '{}' is defined by subfragments {} of fragment '{}', " + "some of which have identical names; it is necessary to either " + "rename subfragment domains explicitly, or give distinct names " + "to subfragments" + .format(domain, ", ".join(names), ".".join(hierarchy))) + + for subfrag, name, i in subfrags: + self.subfragments[i] = \ + (DomainRenamer({domain: "{}_{}".format(name, domain)})(subfrag), name) + + # Finally, collect the (now unique) subfragment domains, and merge them into our domains. + for subfrag, name in self.subfragments: + for domain in subfrag.iter_domains(): + self.add_domains(subfrag.domains[domain]) + + def _propagate_domains_down(self): + # For each domain defined in this fragment, ensure it also exists in all subfragments. + for subfrag, name in self.subfragments: + for domain in self.iter_domains(): + if domain in subfrag.domains: + assert self.domains[domain] is subfrag.domains[domain] + else: + subfrag.add_domains(self.domains[domain]) + + subfrag._propagate_domains_down() + + def _propagate_domains(self, ensure_sync_exists=False): + self._propagate_domains_up() + if ensure_sync_exists and not self.domains: + self.add_domains(ClockDomain("sync")) + self._propagate_domains_down() + + def _propagate_ports(self, ports): # Collect all signals we're driving (on LHS of statements), and signals we're using # (on RHS of statements, or in clock domains). self_driven = union(s._lhs_signals() for s in self.statements) self_used = union(s._rhs_signals() for s in self.statements) for domain, _ in self.iter_sync(): - cd = clock_domains[domain] + cd = self.domains[domain] self_used.add(cd.clk) if cd.rst is not None: self_used.add(cd.rst) @@ -69,8 +150,7 @@ class Fragment: for subfrag, name in self.subfragments: # Always ask subfragments to provide all signals we're using and signals we're asked # to provide. If the subfragment is not driving it, it will silently ignore it. - sub_ins, sub_outs = subfrag._propagate_ports(ports=self_used | ports, - clock_domains=clock_domains) + sub_ins, sub_outs = subfrag._propagate_ports(ports=self_used | ports) # Refine the input port approximation: if a subfragment is driving a signal, # it is definitely not our input. ins -= sub_outs diff --git a/nmigen/fhdl/xfrm.py b/nmigen/fhdl/xfrm.py index 07c454d..86268f6 100644 --- a/nmigen/fhdl/xfrm.py +++ b/nmigen/fhdl/xfrm.py @@ -56,7 +56,7 @@ class ValueTransformer: elif isinstance(value, Repl): return self.on_Repl(value) else: - raise TypeError("Cannot transform value {!r}".format(value)) + raise TypeError("Cannot transform value {!r}".format(value)) # :nocov: def __call__(self, value): return self.on_value(value) @@ -84,7 +84,7 @@ class StatementTransformer: elif isinstance(stmt, (list, tuple)): return self.on_statements(stmt) else: - raise TypeError("Cannot transform statement {!r}".format(stmt)) + raise TypeError("Cannot transform statement {!r}".format(stmt)) # :nocov: def __call__(self, value): return self.on_statement(value) @@ -95,6 +95,10 @@ class FragmentTransformer: for subfragment, name in fragment.subfragments: new_fragment.add_subfragment(self(subfragment), name) + def map_domains(self, fragment, new_fragment): + for domain in fragment.iter_domains(): + new_fragment.add_domains(fragment.domains[domain]) + def map_statements(self, fragment, new_fragment): if hasattr(self, "on_statement"): new_fragment.add_statements(map(self.on_statement, fragment.statements)) @@ -108,6 +112,7 @@ class FragmentTransformer: def on_fragment(self, fragment): new_fragment = Fragment() self.map_subfragments(fragment, new_fragment) + self.map_domains(fragment, new_fragment) self.map_statements(fragment, new_fragment) self.map_drivers(fragment, new_fragment) return new_fragment @@ -117,25 +122,36 @@ class FragmentTransformer: class DomainRenamer(FragmentTransformer, ValueTransformer, StatementTransformer): - def __init__(self, domains): - if isinstance(domains, str): - domains = {"sync": domains} - self.domains = OrderedDict(domains) + def __init__(self, domain_map): + if isinstance(domain_map, str): + domain_map = {"sync": domain_map} + self.domain_map = OrderedDict(domain_map) def on_ClockSignal(self, value): - if value.domain in self.domains: - return ClockSignal(self.domains[value.domain]) + if value.domain in self.domain_map: + return ClockSignal(self.domain_map[value.domain]) return value def on_ResetSignal(self, value): - if value.domain in self.domains: - return ResetSignal(self.domains[value.domain]) + if value.domain in self.domain_map: + return ResetSignal(self.domain_map[value.domain]) return value + def map_domains(self, fragment, new_fragment): + for domain in fragment.iter_domains(): + cd = fragment.domains[domain] + if domain in self.domain_map: + if cd.name == domain: + # Rename the actual ClockDomain object. + cd.name = self.domain_map[domain] + else: + assert cd.name == self.domain_map[domain] + new_fragment.add_domains(cd) + def map_drivers(self, fragment, new_fragment): for domain, signals in fragment.drivers.items(): - if domain in self.domains: - domain = self.domains[domain] + if domain in self.domain_map: + domain = self.domain_map[domain] for signal in signals: new_fragment.drive(signal, domain) diff --git a/nmigen/genlib/cdc.py b/nmigen/genlib/cdc.py index 411296e..396e45a 100644 --- a/nmigen/genlib/cdc.py +++ b/nmigen/genlib/cdc.py @@ -5,13 +5,13 @@ __all__ = ["MultiReg"] class MultiReg: - def __init__(self, i, o, odomain="sys", n=2, reset=0): + def __init__(self, i, o, odomain="sync", n=2, reset=0): self.i = i self.o = o self.odomain = odomain - self._regs = [Signal(self.i.shape(), name="cdc{}".format(i), reset=reset, reset_less=True, - attrs={"no_retiming": True}) + self._regs = [Signal(self.i.shape(), name="cdc{}".format(i), + reset=reset, reset_less=True, attrs={"no_retiming": True}) for i in range(n)] def get_fragment(self, platform): diff --git a/nmigen/test/test_fhdl_dsl.py b/nmigen/test/test_fhdl_dsl.py index b4ad259..c0acaed 100644 --- a/nmigen/test/test_fhdl_dsl.py +++ b/nmigen/test/test_fhdl_dsl.py @@ -1,5 +1,3 @@ -from contextlib import contextmanager - from ..fhdl.ast import * from ..fhdl.dsl import * from .tools import * diff --git a/nmigen/test/test_fhdl_ir.py b/nmigen/test/test_fhdl_ir.py index 708acec..86cd55a 100644 --- a/nmigen/test/test_fhdl_ir.py +++ b/nmigen/test/test_fhdl_ir.py @@ -1,4 +1,5 @@ from ..fhdl.ast import * +from ..fhdl.cd import * from ..fhdl.ir import * from .tools import * @@ -18,6 +19,7 @@ class FragmentPortsTestCase(FHDLTestCase): self.c1.eq(self.s1), self.s1.eq(self.c1) ) + ins, outs = f._propagate_ports(ports=()) self.assertEqual(ins, ValueSet()) self.assertEqual(outs, ValueSet()) @@ -28,6 +30,7 @@ class FragmentPortsTestCase(FHDLTestCase): f.add_statements( self.c1.eq(self.s1) ) + ins, outs = f._propagate_ports(ports=()) self.assertEqual(ins, ValueSet((self.s1,))) self.assertEqual(outs, ValueSet()) @@ -38,6 +41,7 @@ class FragmentPortsTestCase(FHDLTestCase): f.add_statements( self.c1.eq(self.s1) ) + ins, outs = f._propagate_ports(ports=(self.c1,)) self.assertEqual(ins, ValueSet((self.s1,))) self.assertEqual(outs, ValueSet((self.c1,))) @@ -69,8 +73,150 @@ class FragmentPortsTestCase(FHDLTestCase): self.c2.eq(1) ) f1.add_subfragment(f2) + ins, outs = f1._propagate_ports(ports=(self.c2,)) self.assertEqual(ins, ValueSet()) self.assertEqual(outs, ValueSet((self.c2,))) self.assertEqual(f1.ports, ValueSet((self.c2,))) self.assertEqual(f2.ports, ValueSet((self.c2,))) + + def test_input_cd(self): + sync = ClockDomain() + f = Fragment() + f.add_statements( + self.c1.eq(self.s1) + ) + f.add_domains(sync) + f.drive(self.c1, "sync") + + ins, outs = f._propagate_ports(ports=()) + self.assertEqual(ins, ValueSet((self.s1, sync.clk, sync.rst))) + self.assertEqual(outs, ValueSet(())) + self.assertEqual(f.ports, ValueSet((self.s1, sync.clk, sync.rst))) + + def test_input_cd_reset_less(self): + sync = ClockDomain(reset_less=True) + f = Fragment() + f.add_statements( + self.c1.eq(self.s1) + ) + f.add_domains(sync) + f.drive(self.c1, "sync") + + ins, outs = f._propagate_ports(ports=()) + self.assertEqual(ins, ValueSet((self.s1, sync.clk))) + self.assertEqual(outs, ValueSet(())) + self.assertEqual(f.ports, ValueSet((self.s1, sync.clk))) + + +class FragmentDomainsTestCase(FHDLTestCase): + def test_propagate_up(self): + cd = ClockDomain() + + f1 = Fragment() + f2 = Fragment() + f1.add_subfragment(f2) + f2.add_domains(cd) + + f1._propagate_domains_up() + self.assertEqual(f1.domains, {"cd": cd}) + + def test_domain_conflict(self): + cda = ClockDomain("sync") + cdb = ClockDomain("sync") + + fa = Fragment() + fa.add_domains(cda) + fb = Fragment() + fb.add_domains(cdb) + f = Fragment() + f.add_subfragment(fa, "a") + f.add_subfragment(fb, "b") + + f._propagate_domains_up() + self.assertEqual(f.domains, {"a_sync": cda, "b_sync": cdb}) + (fa, _), (fb, _) = f.subfragments + self.assertEqual(fa.domains, {"a_sync": cda}) + self.assertEqual(fb.domains, {"b_sync": cdb}) + + def test_domain_conflict_anon(self): + cda = ClockDomain("sync") + cdb = ClockDomain("sync") + + fa = Fragment() + fa.add_domains(cda) + fb = Fragment() + fb.add_domains(cdb) + f = Fragment() + f.add_subfragment(fa, "a") + f.add_subfragment(fb) + + with self.assertRaises(DomainError, + msg="Domain 'sync' is defined by subfragments 'a', of fragment " + "'top'; it is necessary to either rename subfragment domains explicitly, " + "or give names to subfragments"): + f._propagate_domains_up() + + def test_domain_conflict_name(self): + cda = ClockDomain("sync") + cdb = ClockDomain("sync") + + fa = Fragment() + fa.add_domains(cda) + fb = Fragment() + fb.add_domains(cdb) + f = Fragment() + f.add_subfragment(fa, "x") + f.add_subfragment(fb, "x") + + with self.assertRaises(DomainError, + msg="Domain 'sync' is defined by subfragments #0, #1 of fragment 'top', some " + "of which have identical names; it is necessary to either rename subfragment " + "domains explicitly, or give distinct names to subfragments"): + f._propagate_domains_up() + + def test_propagate_down(self): + cd = ClockDomain() + + f1 = Fragment() + f2 = Fragment() + f1.add_domains(cd) + f1.add_subfragment(f2) + + f1._propagate_domains_down() + self.assertEqual(f2.domains, {"cd": cd}) + + def test_propagate_down_idempotent(self): + cd = ClockDomain() + + f1 = Fragment() + f1.add_domains(cd) + f2 = Fragment() + f2.add_domains(cd) + f1.add_subfragment(f2) + + f1._propagate_domains_down() + self.assertEqual(f1.domains, {"cd": cd}) + self.assertEqual(f2.domains, {"cd": cd}) + + def test_propagate(self): + cd = ClockDomain() + + f1 = Fragment() + f2 = Fragment() + f1.add_domains(cd) + f1.add_subfragment(f2) + + f1._propagate_domains() + self.assertEqual(f1.domains, {"cd": cd}) + self.assertEqual(f2.domains, {"cd": cd}) + + def test_propagate_default(self): + f1 = Fragment() + f2 = Fragment() + f1.add_subfragment(f2) + + f1._propagate_domains(ensure_sync_exists=True) + self.assertEqual(f1.domains.keys(), {"sync"}) + self.assertEqual(f2.domains.keys(), {"sync"}) + self.assertEqual(f1.domains["sync"], f2.domains["sync"]) diff --git a/nmigen/test/test_fhdl_xfrm.py b/nmigen/test/test_fhdl_xfrm.py index 0e1d3fa..78346d8 100644 --- a/nmigen/test/test_fhdl_xfrm.py +++ b/nmigen/test/test_fhdl_xfrm.py @@ -1,4 +1,5 @@ from ..fhdl.ast import * +from ..fhdl.cd import * from ..fhdl.ir import * from ..fhdl.xfrm import * from .tools import * @@ -56,6 +57,37 @@ class DomainRenamerTestCase(FHDLTestCase): ) """) + def test_rename_cd(self): + cd_sync = ClockDomain() + cd_pix = ClockDomain() + + f = Fragment() + f.add_domains(cd_sync, cd_pix) + + f = DomainRenamer("ext")(f) + self.assertEqual(cd_sync.name, "ext") + self.assertEqual(f.domains, { + "ext": cd_sync, + "pix": cd_pix, + }) + + def test_rename_cd_subfragment(self): + cd_sync = ClockDomain() + cd_pix = ClockDomain() + + f1 = Fragment() + f1.add_domains(cd_sync, cd_pix) + f2 = Fragment() + f2.add_domains(cd_sync) + f1.add_subfragment(f2) + + f1 = DomainRenamer("ext")(f1) + self.assertEqual(cd_sync.name, "ext") + self.assertEqual(f1.domains, { + "ext": cd_sync, + "pix": cd_pix, + }) + class ResetInserterTestCase(FHDLTestCase): def setUp(self): @@ -87,6 +119,7 @@ class ResetInserterTestCase(FHDLTestCase): self.s1.eq(1), self.s2.eq(0), ) + f.add_domains(ClockDomain("sync")) f.drive(self.s1, "sync") f.drive(self.s2, "pix") diff --git a/nmigen/test/tools.py b/nmigen/test/tools.py index 9e3a8f0..65cf0ff 100644 --- a/nmigen/test/tools.py +++ b/nmigen/test/tools.py @@ -1,5 +1,6 @@ import re import unittest +from contextlib import contextmanager from ..fhdl.ast import * @@ -14,3 +15,11 @@ class FHDLTestCase(unittest.TestCase): repr_str = re.sub(r"\( (?=\()", "(", repr_str) repr_str = re.sub(r"\) (?=\))", ")", repr_str) self.assertEqual(repr(obj), repr_str.strip()) + + @contextmanager + def assertRaises(self, exception, msg=None): + with super().assertRaises(exception) as cm: + yield + if msg is not None: + # WTF? unittest.assertRaises is completely broken. + self.assertEqual(str(cm.exception), msg)