From ccfbccc044e32492eb8f44c3157a1e1449d9097f Mon Sep 17 00:00:00 2001 From: whitequark Date: Sun, 8 Sep 2019 12:10:31 +0000 Subject: [PATCH] hdl.ast: add Signal.range(...), to replace Signal(min=..., max=...). Fixes #196. --- nmigen/hdl/ast.py | 25 ++++++++++++ nmigen/test/test_hdl_ast.py | 77 ++++++++++++++++++++++++------------- 2 files changed, 75 insertions(+), 27 deletions(-) diff --git a/nmigen/hdl/ast.py b/nmigen/hdl/ast.py index a6839e2..07e00e5 100644 --- a/nmigen/hdl/ast.py +++ b/nmigen/hdl/ast.py @@ -1,6 +1,7 @@ from abc import ABCMeta, abstractmethod import builtins import traceback +import warnings from collections import OrderedDict from collections.abc import Iterable, MutableMapping, MutableSet, MutableSequence from enum import Enum @@ -627,6 +628,13 @@ class Signal(Value, DUID): attrs=None, decoder=None, src_loc_at=0): super().__init__(src_loc_at=src_loc_at) + # TODO(nmigen-0.2): move this to nmigen.compat and make it a deprecated extension + if min is not None or max is not None: + warnings.warn("instead of `Signal(min={min}, max={max})`, " + "use `Signal.range({min}, {max})`" + .format(min=min or 0, max=max or 2), + DeprecationWarning, stacklevel=2 + src_loc_at) + if name is not None and not isinstance(name, str): raise TypeError("Name must be a string, not '{!r}'".format(name)) self.name = name or tracer.get_var_name(depth=2 + src_loc_at, default="$signal") @@ -671,6 +679,23 @@ class Signal(Value, DUID): else: self.decoder = decoder + @classmethod + def range(cls, *args, src_loc_at=0, **kwargs): + """Create Signal that can represent a given range. + + The parameters to ``Signal.range`` are the same as for the built-in ``range`` function. + That is, for any given ``range(*args)``, ``Signal.range(*args)`` can represent any + ``x for x in range(*args)``. + """ + value_range = range(*args) + if len(value_range) > 0: + signed = value_range.start < 0 or (value_range.stop - value_range.step) < 0 + else: + signed = value_range.start < 0 + nbits = max(bits_for(value_range.start, signed), + bits_for(value_range.stop - value_range.step, signed)) + return cls((nbits, signed), src_loc_at=1 + src_loc_at, **kwargs) + @classmethod def like(cls, other, *, name=None, name_suffix=None, src_loc_at=0, **kwargs): """Create Signal based on another. diff --git a/nmigen/test/test_hdl_ast.py b/nmigen/test/test_hdl_ast.py index c9688ee..a5cc22f 100644 --- a/nmigen/test/test_hdl_ast.py +++ b/nmigen/test/test_hdl_ast.py @@ -1,3 +1,4 @@ +import warnings from enum import Enum from ..hdl.ast import * @@ -297,7 +298,7 @@ class SliceTestCase(FHDLTestCase): class BitSelectTestCase(FHDLTestCase): def setUp(self): self.c = Const(0, 8) - self.s = Signal(max=self.c.nbits) + self.s = Signal.range(self.c.nbits) def test_shape(self): s1 = self.c.bit_select(self.s, 2) @@ -321,7 +322,7 @@ class BitSelectTestCase(FHDLTestCase): class WordSelectTestCase(FHDLTestCase): def setUp(self): self.c = Const(0, 8) - self.s = Signal(max=self.c.nbits) + self.s = Signal.range(self.c.nbits) def test_shape(self): s1 = self.c.word_select(self.s, 2) @@ -390,8 +391,8 @@ class ArrayTestCase(FHDLTestCase): def test_becomes_immutable(self): a = Array([1,2,3]) - s1 = Signal(max=len(a)) - s2 = Signal(max=len(a)) + s1 = Signal.range(len(a)) + s2 = Signal.range(len(a)) v1 = a[s1] v2 = a[s2] with self.assertRaisesRegex(ValueError, @@ -407,7 +408,7 @@ class ArrayTestCase(FHDLTestCase): def test_repr(self): a = Array([1,2,3]) self.assertEqual(repr(a), "(array mutable [1, 2, 3])") - s = Signal(max=len(a)) + s = Signal.range(len(a)) v = a[s] self.assertEqual(repr(a), "(array [1, 2, 3])") @@ -415,8 +416,8 @@ class ArrayTestCase(FHDLTestCase): class ArrayProxyTestCase(FHDLTestCase): def test_index_shape(self): m = Array(Array(x * y for y in range(1, 4)) for x in range(1, 4)) - a = Signal(max=3) - b = Signal(max=3) + a = Signal.range(3) + b = Signal.range(3) v = m[a][b] self.assertEqual(v.shape(), (4, False)) @@ -424,14 +425,14 @@ class ArrayProxyTestCase(FHDLTestCase): from collections import namedtuple pair = namedtuple("pair", ("p", "n")) a = Array(pair(i, -i) for i in range(10)) - s = Signal(max=len(a)) + s = Signal.range(len(a)) v = a[s] self.assertEqual(v.p.shape(), (4, False)) self.assertEqual(v.n.shape(), (6, True)) def test_repr(self): a = Array([1, 2, 3]) - s = Signal(max=3) + s = Signal.range(3) v = a[s] self.assertEqual(repr(v), "(proxy (array [1, 2, 3]) (sig s))") @@ -446,30 +447,52 @@ class SignalTestCase(FHDLTestCase): self.assertEqual(s3.shape(), (2, False)) s4 = Signal((2, True)) self.assertEqual(s4.shape(), (2, True)) - s5 = Signal(max=16) - self.assertEqual(s5.shape(), (4, False)) - s6 = Signal(min=4, max=16) + s5 = Signal(0) + self.assertEqual(s5.shape(), (0, False)) + s6 = Signal.range(16) self.assertEqual(s6.shape(), (4, False)) - s7 = Signal(min=-4, max=16) - self.assertEqual(s7.shape(), (5, True)) - s8 = Signal(min=-20, max=16) - self.assertEqual(s8.shape(), (6, True)) - s9 = Signal(0) - self.assertEqual(s9.shape(), (0, False)) - s10 = Signal(max=1) - self.assertEqual(s10.shape(), (0, False)) + s7 = Signal.range(4, 16) + self.assertEqual(s7.shape(), (4, False)) + s8 = Signal.range(-4, 16) + self.assertEqual(s8.shape(), (5, True)) + s9 = Signal.range(-20, 16) + self.assertEqual(s9.shape(), (6, True)) + s10 = Signal.range(0) + self.assertEqual(s10.shape(), (1, False)) + s11 = Signal.range(1) + self.assertEqual(s11.shape(), (1, False)) + # deprecated + with warnings.catch_warnings(): + warnings.filterwarnings(action="ignore", category=DeprecationWarning) + d6 = Signal(max=16) + self.assertEqual(d6.shape(), (4, False)) + d7 = Signal(min=4, max=16) + self.assertEqual(d7.shape(), (4, False)) + d8 = Signal(min=-4, max=16) + self.assertEqual(d8.shape(), (5, True)) + d9 = Signal(min=-20, max=16) + self.assertEqual(d9.shape(), (6, True)) + d10 = Signal(max=1) + self.assertEqual(d10.shape(), (0, False)) def test_shape_bad(self): - with self.assertRaises(ValueError, - msg="Lower bound 10 should be less or equal to higher bound 4"): - Signal(min=10, max=4) - with self.assertRaises(ValueError, - msg="Only one of bits/signedness or bounds may be specified"): - Signal(2, min=10) with self.assertRaises(TypeError, msg="Width must be a non-negative integer, not '-10'"): Signal(-10) + def test_min_max_deprecated(self): + with self.assertWarns(DeprecationWarning, + msg="instead of `Signal(min=0, max=10)`, use `Signal.range(0, 10)`"): + Signal(max=10) + with warnings.catch_warnings(): + warnings.filterwarnings(action="ignore", category=DeprecationWarning) + with self.assertRaises(ValueError, + msg="Lower bound 10 should be less or equal to higher bound 4"): + Signal(min=10, max=4) + with self.assertRaises(ValueError, + msg="Only one of bits/signedness or bounds may be specified"): + Signal(2, min=10) + def test_name(self): s1 = Signal() self.assertEqual(s1.name, "s1") @@ -500,7 +523,7 @@ class SignalTestCase(FHDLTestCase): def test_like(self): s1 = Signal.like(Signal(4)) self.assertEqual(s1.shape(), (4, False)) - s2 = Signal.like(Signal(min=-15)) + s2 = Signal.like(Signal.range(-15, 1)) self.assertEqual(s2.shape(), (5, True)) s3 = Signal.like(Signal(4, reset=0b111, reset_less=True)) self.assertEqual(s3.reset, 0b111) -- 2.30.2