src/soc/fu/div/experiment/test/test_goldschmidt_div_sqrt.py

   1 # SPDX-License-Identifier: LGPL-3-or-later
   2 # Copyright 2022 Jacob Lifshay programmerjake@gmail.com
   3
   4 # Funded by NLnet Assure Programme 2021-02-052, https://nlnet.nl/assure part
   5 # of Horizon 2020 EU Programme 957073.
   6
   7 from dataclasses import fields, replace
   8 import math
   9 import unittest
  10 from nmutil.formaltest import FHDLTestCase
  11 from nmutil.sim_util import do_sim, hash_256
  12 from nmigen.sim import Tick, Delay
  13 from nmigen.hdl.ast import Signal
  14 from nmigen.hdl.dsl import Module
  15 from soc.fu.div.experiment.goldschmidt_div_sqrt import (
  16     GoldschmidtDivHDL, GoldschmidtDivHDLState, GoldschmidtDivOp, GoldschmidtDivParams,
  17     GoldschmidtDivState, ParamsNotAccurateEnough, goldschmidt_div,
  18     FixedPoint, RoundDir, goldschmidt_sqrt_rsqrt)
  19
  20
  21 class TestFixedPoint(FHDLTestCase):
  22     def test_str_roundtrip(self):
  23         for frac_wid in range(8):
  24             for bits in range(-1 << 9, 1 << 9):
  25                 with self.subTest(bits=hex(bits), frac_wid=frac_wid):
  26                     value = FixedPoint(bits, frac_wid)
  27                     round_trip_value = FixedPoint.cast(str(value))
  28                     self.assertEqual(value, round_trip_value)
  29
  30     @staticmethod
  31     def trap(f):
  32         try:
  33             return f(), None
  34         except (ValueError, ZeroDivisionError) as e:
  35             return None, e.__class__.__name__
  36
  37     def test_sqrt(self):
  38         for frac_wid in range(8):
  39             for bits in range(1 << 9):
  40                 for round_dir in RoundDir:
  41                     radicand = FixedPoint(bits, frac_wid)
  42                     expected_f = math.sqrt(float(radicand))
  43                     expected = self.trap(lambda: FixedPoint.with_frac_wid(
  44                         expected_f, frac_wid, round_dir))
  45                     with self.subTest(radicand=repr(radicand),
  46                                       round_dir=str(round_dir),
  47                                       expected=repr(expected)):
  48                         result = self.trap(lambda: radicand.sqrt(round_dir))
  49                         self.assertEqual(result, expected)
  50
  51     def test_rsqrt(self):
  52         for frac_wid in range(8):
  53             for bits in range(1, 1 << 9):
  54                 for round_dir in RoundDir:
  55                     radicand = FixedPoint(bits, frac_wid)
  56                     expected_f = 1 / math.sqrt(float(radicand))
  57                     expected = self.trap(lambda: FixedPoint.with_frac_wid(
  58                         expected_f, frac_wid, round_dir))
  59                     with self.subTest(radicand=repr(radicand),
  60                                       round_dir=str(round_dir),
  61                                       expected=repr(expected)):
  62                         result = self.trap(lambda: radicand.rsqrt(round_dir))
  63                         self.assertEqual(result, expected)
  64
  65
  66 class TestGoldschmidtDiv(FHDLTestCase):
  67     def test_case1(self):
  68         with self.assertRaises(ParamsNotAccurateEnough):
  69             GoldschmidtDivParams(io_width=3, extra_precision=2,
  70                                  table_addr_bits=3, table_data_bits=5,
  71                                  iter_count=2)
  72
  73     def test_case2(self):
  74         with self.assertRaises(ParamsNotAccurateEnough):
  75             GoldschmidtDivParams(io_width=4, extra_precision=1,
  76                                  table_addr_bits=1, table_data_bits=5,
  77                                  iter_count=1)
  78
  79     @staticmethod
  80     def cases(io_width, cases=None):
  81         assert isinstance(io_width, int) and io_width >= 1
  82         if cases is not None:
  83             for n, d in cases:
  84                 assert isinstance(d, int) \
  85                     and 0 < d < (1 << io_width), "invalid case"
  86                 assert isinstance(n, int) \
  87                     and 0 <= n < (d << io_width), "invalid case"
  88                 yield (n, d)
  89         elif io_width > 6:
  90             assert io_width * 2 <= 256, \
  91                 "can't generate big enough numbers for test cases"
  92             for i in range(10000):
  93                 d = hash_256(f'd {i}') % (1 << io_width)
  94                 if d == 0:
  95                     d = 1
  96                 n = hash_256(f'n {i}') % (d << io_width)
  97                 yield (n, d)
  98         else:
  99             for d in range(1, 1 << io_width):
 100                 for n in range(d << io_width):
 101                     yield (n, d)
 102
 103     def tst(self, io_width, cases=None):
 104         assert isinstance(io_width, int)
 105         params = GoldschmidtDivParams.get(io_width)
 106         with self.subTest(params=str(params)):
 107             for n, d in self.cases(io_width, cases):
 108                 expected_q, expected_r = divmod(n, d)
 109                 with self.subTest(n=hex(n), d=hex(d),
 110                                   expected_q=hex(expected_q),
 111                                   expected_r=hex(expected_r)):
 112                     trace = []
 113
 114                     def trace_fn(state):
 115                         assert isinstance(state, GoldschmidtDivState)
 116                         trace.append((replace(state)))
 117                     q, r = goldschmidt_div(n, d, params, trace=trace_fn)
 118                     with self.subTest(q=hex(q), r=hex(r), trace=repr(trace)):
 119                         self.assertEqual((q, r), (expected_q, expected_r))
 120
 121     def tst_sim(self, io_width, cases=None, pipe_reg_indexes=(),
 122                 sync_rom=False):
 123         assert isinstance(io_width, int)
 124         params = GoldschmidtDivParams.get(io_width)
 125         m = Module()
 126         dut = GoldschmidtDivHDL(params, pipe_reg_indexes=pipe_reg_indexes,
 127                                 sync_rom=sync_rom)
 128         m.submodules.dut = dut
 129         # make sync domain get added
 130         m.d.sync += Signal().eq(0)
 131
 132         def inputs_proc():
 133             yield Tick()
 134             for n, d in self.cases(io_width, cases):
 135                 yield dut.n.eq(n)
 136                 yield dut.d.eq(d)
 137                 yield Tick()
 138
 139         def check_interals(n, d):
 140             # check internals only if dut is completely combinatorial
 141             # so we don't have to figure out how to read values in
 142             # previous clock cycles
 143             if dut.total_pipeline_registers != 0:
 144                 return
 145             ref_trace = []
 146
 147             def ref_trace_fn(state):
 148                 assert isinstance(state, GoldschmidtDivState)
 149                 ref_trace.append((replace(state)))
 150             goldschmidt_div(n=n, d=d, params=params, trace=ref_trace_fn)
 151             self.assertEqual(len(dut.trace), len(ref_trace))
 152             for index, state in enumerate(dut.trace):
 153                 ref_state = ref_trace[index]
 154                 last_op = None if index == 0 else params.ops[index - 1]
 155                 with self.subTest(index=index, state=repr(state),
 156                                   ref_state=repr(ref_state),
 157                                   last_op=str(last_op)):
 158                     for field in fields(GoldschmidtDivHDLState):
 159                         sig = getattr(state, field.name)
 160                         if not isinstance(sig, Signal):
 161                             continue
 162                         ref_value = getattr(ref_state, field.name)
 163                         ref_value_str = repr(ref_value)
 164                         if isinstance(ref_value, int):
 165                             ref_value_str = hex(ref_value)
 166                         value = yield sig
 167                         with self.subTest(field_name=field.name,
 168                                           sig=repr(sig),
 169                                           sig_shape=repr(sig.shape()),
 170                                           value=hex(value),
 171                                           ref_value=ref_value_str):
 172                             if isinstance(ref_value, int):
 173                                 self.assertEqual(value, ref_value)
 174                             else:
 175                                 assert isinstance(ref_value, FixedPoint)
 176                                 self.assertEqual(value, ref_value.bits)
 177
 178         def check_outputs():
 179             yield Tick()
 180             for _ in range(dut.total_pipeline_registers):
 181                 yield Tick()
 182             for n, d in self.cases(io_width, cases):
 183                 yield Delay(0.1e-6)
 184                 expected_q, expected_r = divmod(n, d)
 185                 with self.subTest(n=hex(n), d=hex(d),
 186                                   expected_q=hex(expected_q),
 187                                   expected_r=hex(expected_r)):
 188                     q = yield dut.q
 189                     r = yield dut.r
 190                     with self.subTest(q=hex(q), r=hex(r)):
 191                         self.assertEqual((q, r), (expected_q, expected_r))
 192                     yield from check_interals(n, d)
 193
 194                 yield Tick()
 195
 196         with self.subTest(params=str(params)):
 197             with do_sim(self, m, (dut.n, dut.d, dut.q, dut.r)) as sim:
 198                 sim.add_clock(1e-6)
 199                 sim.add_process(inputs_proc)
 200                 sim.add_process(check_outputs)
 201                 sim.run()
 202
 203     def test_1_through_4(self):
 204         for io_width in range(1, 4 + 1):
 205             with self.subTest(io_width=io_width):
 206                 self.tst(io_width)
 207
 208     def test_5(self):
 209         self.tst(5)
 210
 211     def test_6(self):
 212         self.tst(6)
 213
 214     def test_8(self):
 215         self.tst(8)
 216
 217     def test_16(self):
 218         self.tst(16)
 219
 220     def test_32(self):
 221         self.tst(32)
 222
 223     def test_64(self):
 224         self.tst(64)
 225
 226     def test_sim_5(self):
 227         self.tst_sim(5)
 228
 229     def test_sim_8(self):
 230         self.tst_sim(8)
 231
 232     def test_sim_16(self):
 233         self.tst_sim(16)
 234
 235     def test_sim_32(self):
 236         self.tst_sim(32)
 237
 238     def test_sim_64(self):
 239         self.tst_sim(64)
 240
 241     def tst_params(self, io_width):
 242         assert isinstance(io_width, int)
 243         params = GoldschmidtDivParams.get(io_width)
 244         print()
 245         print(params)
 246
 247     def test_params_1(self):
 248         self.tst_params(1)
 249
 250     def test_params_2(self):
 251         self.tst_params(2)
 252
 253     def test_params_3(self):
 254         self.tst_params(3)
 255
 256     def test_params_4(self):
 257         self.tst_params(4)
 258
 259     def test_params_5(self):
 260         self.tst_params(5)
 261
 262     def test_params_6(self):
 263         self.tst_params(6)
 264
 265     def test_params_7(self):
 266         self.tst_params(7)
 267
 268     def test_params_8(self):
 269         self.tst_params(8)
 270
 271     def test_params_9(self):
 272         self.tst_params(9)
 273
 274     def test_params_10(self):
 275         self.tst_params(10)
 276
 277     def test_params_11(self):
 278         self.tst_params(11)
 279
 280     def test_params_12(self):
 281         self.tst_params(12)
 282
 283     def test_params_13(self):
 284         self.tst_params(13)
 285
 286     def test_params_14(self):
 287         self.tst_params(14)
 288
 289     def test_params_15(self):
 290         self.tst_params(15)
 291
 292     def test_params_16(self):
 293         self.tst_params(16)
 294
 295     def test_params_17(self):
 296         self.tst_params(17)
 297
 298     def test_params_18(self):
 299         self.tst_params(18)
 300
 301     def test_params_19(self):
 302         self.tst_params(19)
 303
 304     def test_params_20(self):
 305         self.tst_params(20)
 306
 307     def test_params_21(self):
 308         self.tst_params(21)
 309
 310     def test_params_22(self):
 311         self.tst_params(22)
 312
 313     def test_params_23(self):
 314         self.tst_params(23)
 315
 316     def test_params_24(self):
 317         self.tst_params(24)
 318
 319     def test_params_25(self):
 320         self.tst_params(25)
 321
 322     def test_params_26(self):
 323         self.tst_params(26)
 324
 325     def test_params_27(self):
 326         self.tst_params(27)
 327
 328     def test_params_28(self):
 329         self.tst_params(28)
 330
 331     def test_params_29(self):
 332         self.tst_params(29)
 333
 334     def test_params_30(self):
 335         self.tst_params(30)
 336
 337     def test_params_31(self):
 338         self.tst_params(31)
 339
 340     def test_params_32(self):
 341         self.tst_params(32)
 342
 343     def test_params_33(self):
 344         self.tst_params(33)
 345
 346     def test_params_34(self):
 347         self.tst_params(34)
 348
 349     def test_params_35(self):
 350         self.tst_params(35)
 351
 352     def test_params_36(self):
 353         self.tst_params(36)
 354
 355     def test_params_37(self):
 356         self.tst_params(37)
 357
 358     def test_params_38(self):
 359         self.tst_params(38)
 360
 361     def test_params_39(self):
 362         self.tst_params(39)
 363
 364     def test_params_40(self):
 365         self.tst_params(40)
 366
 367     def test_params_41(self):
 368         self.tst_params(41)
 369
 370     def test_params_42(self):
 371         self.tst_params(42)
 372
 373     def test_params_43(self):
 374         self.tst_params(43)
 375
 376     def test_params_44(self):
 377         self.tst_params(44)
 378
 379     def test_params_45(self):
 380         self.tst_params(45)
 381
 382     def test_params_46(self):
 383         self.tst_params(46)
 384
 385     def test_params_47(self):
 386         self.tst_params(47)
 387
 388     def test_params_48(self):
 389         self.tst_params(48)
 390
 391     def test_params_49(self):
 392         self.tst_params(49)
 393
 394     def test_params_50(self):
 395         self.tst_params(50)
 396
 397     def test_params_51(self):
 398         self.tst_params(51)
 399
 400     def test_params_52(self):
 401         self.tst_params(52)
 402
 403     def test_params_53(self):
 404         self.tst_params(53)
 405
 406     def test_params_54(self):
 407         self.tst_params(54)
 408
 409     def test_params_55(self):
 410         self.tst_params(55)
 411
 412     def test_params_56(self):
 413         self.tst_params(56)
 414
 415     def test_params_57(self):
 416         self.tst_params(57)
 417
 418     def test_params_58(self):
 419         self.tst_params(58)
 420
 421     def test_params_59(self):
 422         self.tst_params(59)
 423
 424     def test_params_60(self):
 425         self.tst_params(60)
 426
 427     def test_params_61(self):
 428         self.tst_params(61)
 429
 430     def test_params_62(self):
 431         self.tst_params(62)
 432
 433     def test_params_63(self):
 434         self.tst_params(63)
 435
 436     def test_params_64(self):
 437         self.tst_params(64)
 438
 439
 440 class TestGoldschmidtSqrtRSqrt(FHDLTestCase):
 441     def tst(self, io_width, frac_wid, extra_precision,
 442             table_addr_bits, table_data_bits, iter_count):
 443         assert isinstance(io_width, int)
 444         assert isinstance(frac_wid, int)
 445         assert isinstance(extra_precision, int)
 446         assert isinstance(table_addr_bits, int)
 447         assert isinstance(table_data_bits, int)
 448         assert isinstance(iter_count, int)
 449         with self.subTest(io_width=io_width, frac_wid=frac_wid,
 450                           extra_precision=extra_precision,
 451                           table_addr_bits=table_addr_bits,
 452                           table_data_bits=table_data_bits,
 453                           iter_count=iter_count):
 454             for bits in range(1 << io_width):
 455                 radicand = FixedPoint(bits, frac_wid)
 456                 expected_sqrt = radicand.sqrt(RoundDir.DOWN)
 457                 expected_rsqrt = FixedPoint(0, frac_wid)
 458                 if radicand > 0:
 459                     expected_rsqrt = radicand.rsqrt(RoundDir.DOWN)
 460                 with self.subTest(radicand=repr(radicand),
 461                                   expected_sqrt=repr(expected_sqrt),
 462                                   expected_rsqrt=repr(expected_rsqrt)):
 463                     sqrt, rsqrt = goldschmidt_sqrt_rsqrt(
 464                         radicand=radicand, io_width=io_width,
 465                         frac_wid=frac_wid,
 466                         extra_precision=extra_precision,
 467                         table_addr_bits=table_addr_bits,
 468                         table_data_bits=table_data_bits,
 469                         iter_count=iter_count)
 470                     with self.subTest(sqrt=repr(sqrt), rsqrt=repr(rsqrt)):
 471                         self.assertEqual((sqrt, rsqrt),
 472                                          (expected_sqrt, expected_rsqrt))
 473
 474     def test1(self):
 475         self.tst(io_width=16, frac_wid=8, extra_precision=20,
 476                  table_addr_bits=4, table_data_bits=28, iter_count=4)
 477
 478
 479 if __name__ == "__main__":
 480     unittest.main()