1 # IEEE Floating Point Adder (Single Precision)
2 # Copyright (C) Jonathan P Dawson 2013
5 from nmigen
import Module
, Signal
, Cat
6 from nmigen
.cli
import main
, verilog
8 from fpbase
import FPNumIn
, FPNumOut
, FPOp
, Overflow
, FPBase
, FPNumBase
11 class FPState(FPBase
):
12 def __init__(self
, state_from
):
13 self
.state_from
= state_from
15 def set_inputs(self
, inputs
):
17 for k
,v
in inputs
.items():
20 def set_outputs(self
, outputs
):
21 self
.outputs
= outputs
22 for k
,v
in outputs
.items():
27 def __init__(self
, width
):
28 self
.in_op
= FPOp(width
)
29 self
.out_op
= FPNumIn(self
.in_op
, width
)
30 self
.out_decode
= Signal(reset_less
=True)
32 def setup(self
, m
, in_op
, out_op
, out_decode
):
33 """ links module to inputs and outputs
35 m
.d
.comb
+= self
.in_op
.copy(in_op
)
36 m
.d
.comb
+= out_op
.v
.eq(self
.out_op
.v
)
37 m
.d
.comb
+= out_decode
.eq(self
.out_decode
)
39 def elaborate(self
, platform
):
41 m
.d
.comb
+= self
.out_decode
.eq((self
.in_op
.ack
) & (self
.in_op
.stb
))
42 #m.submodules.get_op_in = self.in_op
43 m
.submodules
.get_op_out
= self
.out_op
44 with m
.If(self
.out_decode
):
46 self
.out_op
.decode(self
.in_op
.v
),
51 class FPGetOp(FPState
):
55 def __init__(self
, in_state
, out_state
, in_op
, width
):
56 FPState
.__init
__(self
, in_state
)
57 self
.out_state
= out_state
58 self
.mod
= FPGetOpMod(width
)
60 self
.out_op
= FPNumIn(in_op
, width
)
61 self
.out_decode
= Signal(reset_less
=True)
64 with m
.If(self
.out_decode
):
65 m
.next
= self
.out_state
68 self
.out_op
.copy(self
.mod
.out_op
)
71 m
.d
.sync
+= self
.in_op
.ack
.eq(1)
74 class FPGetOpB(FPState
):
78 def __init__(self
, in_b
, width
):
79 FPState
.__init
__(self
, "get_b")
81 self
.b
= FPNumIn(self
.in_b
, width
)
84 self
.get_op(m
, self
.in_b
, self
.b
, "special_cases")
87 class FPAddSpecialCasesMod
:
88 """ special cases: NaNs, infs, zeros, denormalised
89 NOTE: some of these are unique to add. see "Special Operations"
90 https://steve.hollasch.net/cgindex/coding/ieeefloat.html
93 def __init__(self
, width
):
94 self
.in_a
= FPNumBase(width
)
95 self
.in_b
= FPNumBase(width
)
96 self
.out_z
= FPNumOut(width
, False)
97 self
.out_do_z
= Signal(reset_less
=True)
99 def setup(self
, m
, in_a
, in_b
, out_z
, out_do_z
):
100 """ links module to inputs and outputs
102 m
.d
.comb
+= self
.in_a
.copy(in_a
)
103 m
.d
.comb
+= self
.in_b
.copy(in_b
)
104 m
.d
.comb
+= out_z
.v
.eq(self
.out_z
.v
)
105 m
.d
.comb
+= out_do_z
.eq(self
.out_do_z
)
107 def elaborate(self
, platform
):
110 m
.submodules
.sc_in_a
= self
.in_a
111 m
.submodules
.sc_in_b
= self
.in_b
112 m
.submodules
.sc_out_z
= self
.out_z
115 m
.d
.comb
+= s_nomatch
.eq(self
.in_a
.s
!= self
.in_b
.s
)
118 m
.d
.comb
+= m_match
.eq(self
.in_a
.m
== self
.in_b
.m
)
120 # if a is NaN or b is NaN return NaN
121 with m
.If(self
.in_a
.is_nan | self
.in_b
.is_nan
):
122 m
.d
.comb
+= self
.out_do_z
.eq(1)
123 m
.d
.comb
+= self
.out_z
.nan(0)
125 # XXX WEIRDNESS for FP16 non-canonical NaN handling
128 ## if a is zero and b is NaN return -b
129 #with m.If(a.is_zero & (a.s==0) & b.is_nan):
130 # m.d.comb += self.out_do_z.eq(1)
131 # m.d.comb += z.create(b.s, b.e, Cat(b.m[3:-2], ~b.m[0]))
133 ## if b is zero and a is NaN return -a
134 #with m.Elif(b.is_zero & (b.s==0) & a.is_nan):
135 # m.d.comb += self.out_do_z.eq(1)
136 # m.d.comb += z.create(a.s, a.e, Cat(a.m[3:-2], ~a.m[0]))
138 ## if a is -zero and b is NaN return -b
139 #with m.Elif(a.is_zero & (a.s==1) & b.is_nan):
140 # m.d.comb += self.out_do_z.eq(1)
141 # m.d.comb += z.create(a.s & b.s, b.e, Cat(b.m[3:-2], 1))
143 ## if b is -zero and a is NaN return -a
144 #with m.Elif(b.is_zero & (b.s==1) & a.is_nan):
145 # m.d.comb += self.out_do_z.eq(1)
146 # m.d.comb += z.create(a.s & b.s, a.e, Cat(a.m[3:-2], 1))
148 # if a is inf return inf (or NaN)
149 with m
.Elif(self
.in_a
.is_inf
):
150 m
.d
.comb
+= self
.out_do_z
.eq(1)
151 m
.d
.comb
+= self
.out_z
.inf(self
.in_a
.s
)
152 # if a is inf and signs don't match return NaN
153 with m
.If(self
.in_b
.exp_128
& s_nomatch
):
154 m
.d
.comb
+= self
.out_z
.nan(0)
156 # if b is inf return inf
157 with m
.Elif(self
.in_b
.is_inf
):
158 m
.d
.comb
+= self
.out_do_z
.eq(1)
159 m
.d
.comb
+= self
.out_z
.inf(self
.in_b
.s
)
161 # if a is zero and b zero return signed-a/b
162 with m
.Elif(self
.in_a
.is_zero
& self
.in_b
.is_zero
):
163 m
.d
.comb
+= self
.out_do_z
.eq(1)
164 m
.d
.comb
+= self
.out_z
.create(self
.in_a
.s
& self
.in_b
.s
,
168 # if a is zero return b
169 with m
.Elif(self
.in_a
.is_zero
):
170 m
.d
.comb
+= self
.out_do_z
.eq(1)
171 m
.d
.comb
+= self
.out_z
.create(self
.in_b
.s
, self
.in_b
.e
,
174 # if b is zero return a
175 with m
.Elif(self
.in_b
.is_zero
):
176 m
.d
.comb
+= self
.out_do_z
.eq(1)
177 m
.d
.comb
+= self
.out_z
.create(self
.in_a
.s
, self
.in_a
.e
,
180 # if a equal to -b return zero (+ve zero)
181 with m
.Elif(s_nomatch
& m_match
& (self
.in_a
.e
== self
.in_b
.e
)):
182 m
.d
.comb
+= self
.out_do_z
.eq(1)
183 m
.d
.comb
+= self
.out_z
.zero(0)
185 # Denormalised Number checks
187 m
.d
.comb
+= self
.out_do_z
.eq(0)
192 class FPAddSpecialCases(FPState
):
193 """ special cases: NaNs, infs, zeros, denormalised
194 NOTE: some of these are unique to add. see "Special Operations"
195 https://steve.hollasch.net/cgindex/coding/ieeefloat.html
198 def __init__(self
, width
):
199 FPState
.__init
__(self
, "special_cases")
200 self
.mod
= FPAddSpecialCasesMod(width
)
201 self
.out_z
= FPNumOut(width
, False)
202 self
.out_do_z
= Signal(reset_less
=True)
205 with m
.If(self
.out_do_z
):
206 m
.d
.sync
+= self
.z
.v
.eq(self
.out_z
.v
) # only take the output
209 m
.next
= "denormalise"
212 class FPAddDeNormMod(FPState
):
214 def __init__(self
, width
):
215 self
.in_a
= FPNumBase(width
)
216 self
.in_b
= FPNumBase(width
)
217 self
.out_a
= FPNumBase(width
)
218 self
.out_b
= FPNumBase(width
)
220 def setup(self
, m
, in_a
, in_b
, out_a
, out_b
):
221 """ links module to inputs and outputs
223 m
.d
.comb
+= self
.in_a
.copy(in_a
)
224 m
.d
.comb
+= self
.in_b
.copy(in_b
)
225 m
.d
.comb
+= out_a
.copy(self
.out_a
)
226 m
.d
.comb
+= out_b
.copy(self
.out_b
)
228 def elaborate(self
, platform
):
230 m
.submodules
.denorm_in_a
= self
.in_a
231 m
.submodules
.denorm_in_b
= self
.in_b
232 m
.submodules
.denorm_out_a
= self
.out_a
233 m
.submodules
.denorm_out_b
= self
.out_b
234 # hmmm, don't like repeating identical code
235 m
.d
.comb
+= self
.out_a
.copy(self
.in_a
)
236 with m
.If(self
.in_a
.exp_n127
):
237 m
.d
.comb
+= self
.out_a
.e
.eq(self
.in_a
.N126
) # limit a exponent
239 m
.d
.comb
+= self
.out_a
.m
[-1].eq(1) # set top mantissa bit
241 m
.d
.comb
+= self
.out_b
.copy(self
.in_b
)
242 with m
.If(self
.in_b
.exp_n127
):
243 m
.d
.comb
+= self
.out_b
.e
.eq(self
.in_b
.N126
) # limit a exponent
245 m
.d
.comb
+= self
.out_b
.m
[-1].eq(1) # set top mantissa bit
250 class FPAddDeNorm(FPState
):
252 def __init__(self
, width
):
253 FPState
.__init
__(self
, "denormalise")
254 self
.mod
= FPAddDeNormMod(width
)
255 self
.out_a
= FPNumBase(width
)
256 self
.out_b
= FPNumBase(width
)
259 # Denormalised Number checks
261 m
.d
.sync
+= self
.a
.copy(self
.out_a
)
262 m
.d
.sync
+= self
.b
.copy(self
.out_b
)
265 class FPAddAlignMultiMod(FPState
):
267 def __init__(self
, width
):
268 self
.in_a
= FPNumBase(width
)
269 self
.in_b
= FPNumBase(width
)
270 self
.out_a
= FPNumIn(None, width
)
271 self
.out_b
= FPNumIn(None, width
)
272 self
.exp_eq
= Signal(reset_less
=True)
274 def setup(self
, m
, in_a
, in_b
, out_a
, out_b
, exp_eq
):
275 """ links module to inputs and outputs
277 m
.d
.comb
+= self
.in_a
.copy(in_a
)
278 m
.d
.comb
+= self
.in_b
.copy(in_b
)
279 m
.d
.comb
+= out_a
.copy(self
.out_a
)
280 m
.d
.comb
+= out_b
.copy(self
.out_b
)
281 m
.d
.comb
+= exp_eq
.eq(self
.exp_eq
)
283 def elaborate(self
, platform
):
284 # This one however (single-cycle) will do the shift
289 #m.submodules.align_in_a = self.in_a
290 #m.submodules.align_in_b = self.in_b
291 m
.submodules
.align_out_a
= self
.out_a
292 m
.submodules
.align_out_b
= self
.out_b
294 # NOTE: this does *not* do single-cycle multi-shifting,
295 # it *STAYS* in the align state until exponents match
297 # exponent of a greater than b: shift b down
298 m
.d
.comb
+= self
.exp_eq
.eq(0)
299 m
.d
.comb
+= self
.out_a
.copy(self
.in_a
)
300 m
.d
.comb
+= self
.out_b
.copy(self
.in_b
)
301 agtb
= Signal(reset_less
=True)
302 altb
= Signal(reset_less
=True)
303 m
.d
.comb
+= agtb
.eq(self
.in_a
.e
> self
.in_b
.e
)
304 m
.d
.comb
+= altb
.eq(self
.in_a
.e
< self
.in_b
.e
)
306 m
.d
.comb
+= self
.out_b
.shift_down(self
.in_b
)
307 # exponent of b greater than a: shift a down
309 m
.d
.comb
+= self
.out_a
.shift_down(self
.in_a
)
310 # exponents equal: move to next stage.
312 m
.d
.comb
+= self
.exp_eq
.eq(1)
316 class FPAddAlignMulti(FPState
):
318 def __init__(self
, width
):
319 FPState
.__init
__(self
, "align")
320 self
.mod
= FPAddAlignMultiMod(width
)
321 self
.out_a
= FPNumIn(None, width
)
322 self
.out_b
= FPNumIn(None, width
)
323 self
.exp_eq
= Signal(reset_less
=True)
326 m
.d
.sync
+= self
.a
.copy(self
.out_a
)
327 m
.d
.sync
+= self
.b
.copy(self
.out_b
)
328 with m
.If(self
.exp_eq
):
332 class FPAddAlignSingleMod
:
334 def __init__(self
, width
):
335 self
.in_a
= FPNumBase(width
)
336 self
.in_b
= FPNumBase(width
)
337 self
.out_a
= FPNumIn(None, width
)
338 self
.out_b
= FPNumIn(None, width
)
339 #self.out_a = FPNumBase(width)
340 #self.out_b = FPNumBase(width)
342 def setup(self
, m
, in_a
, in_b
, out_a
, out_b
):
343 """ links module to inputs and outputs
345 m
.d
.comb
+= self
.in_a
.copy(in_a
)
346 m
.d
.comb
+= self
.in_b
.copy(in_b
)
347 m
.d
.comb
+= out_a
.copy(self
.out_a
)
348 m
.d
.comb
+= out_b
.copy(self
.out_b
)
350 def elaborate(self
, platform
):
351 # This one however (single-cycle) will do the shift
356 #m.submodules.align_in_a = self.in_a
357 #m.submodules.align_in_b = self.in_b
358 m
.submodules
.align_out_a
= self
.out_a
359 m
.submodules
.align_out_b
= self
.out_b
361 # XXX TODO: the shifter used here is quite expensive
362 # having only one would be better
364 ediff
= Signal((len(self
.in_a
.e
), True), reset_less
=True)
365 ediffr
= Signal((len(self
.in_a
.e
), True), reset_less
=True)
366 m
.d
.comb
+= ediff
.eq(self
.in_a
.e
- self
.in_b
.e
)
367 m
.d
.comb
+= ediffr
.eq(self
.in_b
.e
- self
.in_a
.e
)
368 m
.d
.comb
+= self
.out_a
.copy(self
.in_a
)
369 m
.d
.comb
+= self
.out_b
.copy(self
.in_b
)
370 with m
.If(ediff
> 0):
371 m
.d
.comb
+= self
.out_b
.shift_down_multi(ediff
)
372 # exponent of b greater than a: shift a down
373 with m
.Elif(ediff
< 0):
374 m
.d
.comb
+= self
.out_a
.shift_down_multi(ediffr
)
378 class FPAddAlignSingle(FPState
):
380 def __init__(self
, width
):
381 FPState
.__init
__(self
, "align")
382 self
.mod
= FPAddAlignSingleMod(width
)
383 self
.out_a
= FPNumIn(None, width
)
384 self
.out_b
= FPNumIn(None, width
)
387 m
.d
.sync
+= self
.a
.copy(self
.out_a
)
388 m
.d
.sync
+= self
.b
.copy(self
.out_b
)
392 class FPAddStage0Mod
:
394 def __init__(self
, width
):
395 self
.in_a
= FPNumBase(width
)
396 self
.in_b
= FPNumBase(width
)
397 self
.in_z
= FPNumBase(width
, False)
398 self
.out_z
= FPNumBase(width
, False)
399 self
.out_tot
= Signal(self
.out_z
.m_width
+ 4, reset_less
=True)
401 def setup(self
, m
, in_a
, in_b
, in_z
, out_z
, out_tot
):
402 """ links module to inputs and outputs
404 m
.d
.comb
+= self
.in_a
.copy(in_a
)
405 m
.d
.comb
+= self
.in_b
.copy(in_b
)
406 m
.d
.comb
+= self
.in_z
.copy(in_z
)
407 m
.d
.comb
+= out_z
.copy(self
.out_z
)
408 m
.d
.comb
+= out_tot
.eq(self
.out_tot
)
410 def elaborate(self
, platform
):
412 m
.submodules
.add0_in_a
= self
.in_a
413 m
.submodules
.add0_in_b
= self
.in_b
414 #m.submodules.add0_in_z = self.in_z
415 #m.submodules.add0_out_z = self.out_z
417 m
.d
.comb
+= self
.out_z
.e
.eq(self
.in_a
.e
)
419 # store intermediate tests (and zero-extended mantissas)
420 seq
= Signal(reset_less
=True)
421 mge
= Signal(reset_less
=True)
422 am0
= Signal(len(self
.in_a
.m
)+1, reset_less
=True)
423 bm0
= Signal(len(self
.in_b
.m
)+1, reset_less
=True)
424 m
.d
.comb
+= [seq
.eq(self
.in_a
.s
== self
.in_b
.s
),
425 mge
.eq(self
.in_a
.m
>= self
.in_b
.m
),
426 am0
.eq(Cat(self
.in_a
.m
, 0)),
427 bm0
.eq(Cat(self
.in_b
.m
, 0))
429 # same-sign (both negative or both positive) add mantissas
432 self
.out_tot
.eq(am0
+ bm0
),
433 self
.out_z
.s
.eq(self
.in_a
.s
)
435 # a mantissa greater than b, use a
438 self
.out_tot
.eq(am0
- bm0
),
439 self
.out_z
.s
.eq(self
.in_a
.s
)
441 # b mantissa greater than a, use b
444 self
.out_tot
.eq(bm0
- am0
),
445 self
.out_z
.s
.eq(self
.in_b
.s
)
450 class FPAddStage0(FPState
):
451 """ First stage of add. covers same-sign (add) and subtract
452 special-casing when mantissas are greater or equal, to
453 give greatest accuracy.
456 def __init__(self
, width
):
457 FPState
.__init
__(self
, "add_0")
458 self
.mod
= FPAddStage0Mod(width
)
459 self
.out_z
= FPNumBase(width
, False)
460 self
.out_tot
= Signal(self
.out_z
.m_width
+ 4, reset_less
=True)
464 m
.d
.sync
+= self
.z
.copy(self
.out_z
)
467 class FPAddStage1Mod(FPState
):
468 """ Second stage of add: preparation for normalisation.
469 detects when tot sum is too big (tot[27] is kinda a carry bit)
472 def __init__(self
, width
):
473 self
.out_norm
= Signal(reset_less
=True)
474 self
.in_z
= FPNumBase(width
, False)
475 self
.in_tot
= Signal(self
.in_z
.m_width
+ 4, reset_less
=True)
476 self
.out_z
= FPNumBase(width
, False)
477 self
.out_of
= Overflow()
479 def setup(self
, m
, in_tot
, in_z
, out_z
, out_of
):
480 """ links module to inputs and outputs
482 m
.d
.comb
+= self
.in_z
.copy(in_z
)
483 m
.d
.comb
+= self
.in_tot
.eq(in_tot
)
484 #m.d.comb += out_z.copy(self.out_z)
485 #m.d.comb += out_of.copy(self.out_of)
487 def elaborate(self
, platform
):
489 #m.submodules.norm1_in_overflow = self.in_of
490 #m.submodules.norm1_out_overflow = self.out_of
491 #m.submodules.norm1_in_z = self.in_z
492 #m.submodules.norm1_out_z = self.out_z
493 m
.d
.comb
+= self
.out_z
.copy(self
.in_z
)
494 # tot[27] gets set when the sum overflows. shift result down
495 with m
.If(self
.in_tot
[-1]):
497 self
.out_z
.m
.eq(self
.in_tot
[4:]),
498 self
.out_of
.m0
.eq(self
.in_tot
[4]),
499 self
.out_of
.guard
.eq(self
.in_tot
[3]),
500 self
.out_of
.round_bit
.eq(self
.in_tot
[2]),
501 self
.out_of
.sticky
.eq(self
.in_tot
[1] | self
.in_tot
[0]),
502 self
.out_z
.e
.eq(self
.in_z
.e
+ 1)
507 self
.out_z
.m
.eq(self
.in_tot
[3:]),
508 self
.out_of
.m0
.eq(self
.in_tot
[3]),
509 self
.out_of
.guard
.eq(self
.in_tot
[2]),
510 self
.out_of
.round_bit
.eq(self
.in_tot
[1]),
511 self
.out_of
.sticky
.eq(self
.in_tot
[0])
516 class FPAddStage1(FPState
):
518 def __init__(self
, width
):
519 FPState
.__init
__(self
, "add_1")
520 self
.mod
= FPAddStage1Mod(width
)
521 self
.out_z
= FPNumBase(width
, False)
522 self
.out_of
= Overflow()
523 self
.norm_stb
= Signal()
526 m
.submodules
.add1_out_overflow
= self
.out_of
527 m
.d
.sync
+= self
.out_of
.copy(self
.mod
.out_of
)
528 m
.d
.sync
+= self
.out_z
.copy(self
.mod
.out_z
)
529 m
.d
.sync
+= self
.norm_stb
.eq(1)
530 m
.next
= "normalise_1"
535 def __init__(self
, width
):
537 self
.in_select
= Signal(reset_less
=True)
538 self
.out_norm
= Signal(reset_less
=True)
539 self
.in_z
= FPNumBase(width
, False)
540 self
.in_of
= Overflow()
541 self
.temp_z
= FPNumBase(width
, False)
542 self
.temp_of
= Overflow()
543 self
.out_z
= FPNumBase(width
, False)
544 self
.out_of
= Overflow()
546 def elaborate(self
, platform
):
548 m
.submodules
.norm1_out_z
= self
.out_z
549 m
.submodules
.norm1_out_overflow
= self
.out_of
550 m
.submodules
.norm1_temp_z
= self
.temp_z
551 m
.submodules
.norm1_temp_of
= self
.temp_of
552 m
.submodules
.norm1_in_z
= self
.in_z
553 m
.submodules
.norm1_in_overflow
= self
.in_of
554 in_z
= FPNumBase(self
.width
, False)
556 m
.submodules
.norm1_insel_z
= in_z
557 m
.submodules
.norm1_insel_overflow
= in_of
558 # select which of temp or in z/of to use
559 with m
.If(self
.in_select
):
560 m
.d
.comb
+= in_z
.copy(self
.in_z
)
561 m
.d
.comb
+= in_of
.copy(self
.in_of
)
563 m
.d
.comb
+= in_z
.copy(self
.temp_z
)
564 m
.d
.comb
+= in_of
.copy(self
.temp_of
)
565 # initialise out from in (overridden below)
566 m
.d
.comb
+= self
.out_z
.copy(in_z
)
567 m
.d
.comb
+= self
.out_of
.copy(in_of
)
568 # normalisation increase/decrease conditions
569 decrease
= Signal(reset_less
=True)
570 increase
= Signal(reset_less
=True)
571 m
.d
.comb
+= decrease
.eq(in_z
.m_msbzero
& in_z
.exp_gt_n126
)
572 m
.d
.comb
+= increase
.eq(in_z
.exp_lt_n126
)
573 m
.d
.comb
+= self
.out_norm
.eq(decrease | increase
) # loop-end condition
577 self
.out_z
.e
.eq(in_z
.e
- 1), # DECREASE exponent
578 self
.out_z
.m
.eq(in_z
.m
<< 1), # shift mantissa UP
579 self
.out_z
.m
[0].eq(in_of
.guard
), # steal guard (was tot[2])
580 self
.out_of
.guard
.eq(in_of
.round_bit
), # round (was tot[1])
581 self
.out_of
.round_bit
.eq(0), # reset round bit
582 self
.out_of
.m0
.eq(in_of
.guard
),
587 self
.out_z
.e
.eq(in_z
.e
+ 1), # INCREASE exponent
588 self
.out_z
.m
.eq(in_z
.m
>> 1), # shift mantissa DOWN
589 self
.out_of
.guard
.eq(in_z
.m
[0]),
590 self
.out_of
.m0
.eq(in_z
.m
[1]),
591 self
.out_of
.round_bit
.eq(in_of
.guard
),
592 self
.out_of
.sticky
.eq(in_of
.sticky | in_of
.round_bit
)
598 class FPNorm1(FPState
):
600 def __init__(self
, width
):
601 FPState
.__init
__(self
, "normalise_1")
602 self
.mod
= FPNorm1Mod(width
)
603 self
.stb
= Signal(reset_less
=True)
604 self
.ack
= Signal(reset
=0, reset_less
=True)
605 self
.out_norm
= Signal(reset_less
=True)
606 self
.in_accept
= Signal(reset_less
=True)
607 self
.temp_z
= FPNumBase(width
)
608 self
.temp_of
= Overflow()
609 self
.out_z
= FPNumBase(width
)
610 self
.out_of
= Overflow()
612 def setup(self
, m
, in_z
, in_of
, norm_stb
):
613 """ links module to inputs and outputs
615 m
.submodules
.normalise_1
= self
.mod
617 m
.d
.comb
+= self
.mod
.in_z
.copy(in_z
)
618 m
.d
.comb
+= self
.mod
.in_of
.copy(in_of
)
620 m
.d
.comb
+= self
.mod
.in_select
.eq(self
.in_accept
)
621 m
.d
.comb
+= self
.mod
.temp_z
.copy(self
.temp_z
)
622 m
.d
.comb
+= self
.mod
.temp_of
.copy(self
.temp_of
)
624 m
.d
.comb
+= self
.out_z
.copy(self
.mod
.out_z
)
625 m
.d
.comb
+= self
.out_of
.copy(self
.mod
.out_of
)
626 m
.d
.comb
+= self
.out_norm
.eq(self
.mod
.out_norm
)
628 m
.d
.comb
+= self
.stb
.eq(norm_stb
)
629 m
.d
.sync
+= self
.ack
.eq(0) # sets to zero when not in normalise_1 state
632 m
.d
.comb
+= self
.in_accept
.eq((~self
.ack
) & (self
.stb
))
633 m
.d
.sync
+= self
.of
.copy(self
.out_of
)
634 m
.d
.sync
+= self
.z
.copy(self
.out_z
)
635 m
.d
.sync
+= self
.temp_of
.copy(self
.out_of
)
636 m
.d
.sync
+= self
.temp_z
.copy(self
.out_z
)
637 with m
.If(self
.out_norm
):
638 with m
.If(self
.in_accept
):
643 m
.d
.sync
+= self
.ack
.eq(0)
645 # normalisation not required (or done).
647 m
.d
.sync
+= self
.ack
.eq(1)
652 def __init__(self
, width
):
653 self
.in_roundz
= Signal(reset_less
=True)
654 self
.in_z
= FPNumBase(width
, False)
655 self
.out_z
= FPNumBase(width
, False)
657 def setup(self
, m
, in_z
, out_z
, in_of
):
658 """ links module to inputs and outputs
660 m
.d
.comb
+= self
.in_z
.copy(in_z
)
661 m
.d
.comb
+= out_z
.copy(self
.out_z
)
662 m
.d
.comb
+= self
.in_roundz
.eq(in_of
.roundz
)
664 def elaborate(self
, platform
):
666 m
.d
.comb
+= self
.out_z
.copy(self
.in_z
)
667 with m
.If(self
.in_roundz
):
668 m
.d
.comb
+= self
.out_z
.m
.eq(self
.in_z
.m
+ 1) # mantissa rounds up
669 with m
.If(self
.in_z
.m
== self
.in_z
.m1s
): # all 1s
670 m
.d
.comb
+= self
.out_z
.e
.eq(self
.in_z
.e
+ 1) # exponent up
674 class FPRound(FPState
):
676 def __init__(self
, width
):
677 FPState
.__init
__(self
, "round")
678 self
.mod
= FPRoundMod(width
)
679 self
.out_z
= FPNumBase(width
)
682 m
.d
.sync
+= self
.z
.copy(self
.out_z
)
683 m
.next
= "corrections"
686 class FPCorrectionsMod
:
688 def __init__(self
, width
):
689 self
.in_z
= FPNumOut(width
, False)
690 self
.out_z
= FPNumOut(width
, False)
692 def setup(self
, m
, in_z
, out_z
):
693 """ links module to inputs and outputs
695 m
.d
.comb
+= self
.in_z
.copy(in_z
)
696 m
.d
.comb
+= out_z
.copy(self
.out_z
)
698 def elaborate(self
, platform
):
700 m
.submodules
.corr_in_z
= self
.in_z
701 m
.submodules
.corr_out_z
= self
.out_z
702 m
.d
.comb
+= self
.out_z
.copy(self
.in_z
)
703 with m
.If(self
.in_z
.is_denormalised
):
704 m
.d
.comb
+= self
.out_z
.e
.eq(self
.in_z
.N127
)
706 # with m.If(self.in_z.is_overflowed):
707 # m.d.comb += self.out_z.inf(self.in_z.s)
709 # m.d.comb += self.out_z.create(self.in_z.s, self.in_z.e, self.in_z.m)
713 class FPCorrections(FPState
):
715 def __init__(self
, width
):
716 FPState
.__init
__(self
, "corrections")
717 self
.mod
= FPCorrectionsMod(width
)
718 self
.out_z
= FPNumBase(width
)
721 m
.d
.sync
+= self
.z
.copy(self
.out_z
)
727 def __init__(self
, width
):
728 self
.in_z
= FPNumOut(width
, False)
729 self
.out_z
= FPNumOut(width
, False)
731 def setup(self
, m
, in_z
, out_z
):
732 """ links module to inputs and outputs
734 m
.d
.comb
+= self
.in_z
.copy(in_z
)
735 m
.d
.comb
+= out_z
.v
.eq(self
.out_z
.v
)
737 def elaborate(self
, platform
):
739 m
.submodules
.pack_in_z
= self
.in_z
740 with m
.If(self
.in_z
.is_overflowed
):
741 m
.d
.comb
+= self
.out_z
.inf(self
.in_z
.s
)
743 m
.d
.comb
+= self
.out_z
.create(self
.in_z
.s
, self
.in_z
.e
, self
.in_z
.m
)
747 class FPPack(FPState
):
749 def __init__(self
, width
):
750 FPState
.__init
__(self
, "pack")
751 self
.mod
= FPPackMod(width
)
752 self
.out_z
= FPNumOut(width
, False)
755 m
.d
.sync
+= self
.z
.v
.eq(self
.out_z
.v
)
756 m
.next
= "pack_put_z"
759 class FPPutZ(FPState
):
762 self
.put_z(m
, self
.z
, self
.out_z
, "get_a")
767 def __init__(self
, width
, single_cycle
=False):
769 self
.single_cycle
= single_cycle
771 self
.in_a
= FPOp(width
)
772 self
.in_b
= FPOp(width
)
773 self
.out_z
= FPOp(width
)
777 def add_state(self
, state
):
778 self
.states
.append(state
)
781 def get_fragment(self
, platform
=None):
782 """ creates the HDL code-fragment for FPAdd
787 z
= FPNumOut(self
.width
, False)
788 m
.submodules
.fpnum_z
= z
792 geta
= self
.add_state(FPGetOp("get_a", "get_b",
793 self
.in_a
, self
.width
))
795 geta
.mod
.setup(m
, self
.in_a
, geta
.out_op
, geta
.out_decode
)
796 m
.submodules
.get_a
= geta
.mod
798 getb
= self
.add_state(FPGetOp("get_b", "special_cases",
799 self
.in_b
, self
.width
))
801 getb
.mod
.setup(m
, self
.in_b
, getb
.out_op
, getb
.out_decode
)
802 m
.submodules
.get_b
= getb
.mod
804 sc
= self
.add_state(FPAddSpecialCases(self
.width
))
805 sc
.set_inputs({"a": a
, "b": b
})
806 sc
.set_outputs({"z": z
})
807 sc
.mod
.setup(m
, a
, b
, sc
.out_z
, sc
.out_do_z
)
808 m
.submodules
.specialcases
= sc
.mod
810 dn
= self
.add_state(FPAddDeNorm(self
.width
))
811 dn
.set_inputs({"a": a
, "b": b
})
812 #dn.set_outputs({"a": a, "b": b}) # XXX outputs same as inputs
813 dn
.mod
.setup(m
, a
, b
, dn
.out_a
, dn
.out_b
)
814 m
.submodules
.denormalise
= dn
.mod
816 if self
.single_cycle
:
817 alm
= self
.add_state(FPAddAlignSingle(self
.width
))
818 alm
.set_inputs({"a": a
, "b": b
})
819 alm
.set_outputs({"a": a
, "b": b
}) # XXX outputs same as inputs
820 alm
.mod
.setup(m
, a
, b
, alm
.out_a
, alm
.out_b
)
822 alm
= self
.add_state(FPAddAlignMulti(self
.width
))
823 alm
.set_inputs({"a": a
, "b": b
})
824 #alm.set_outputs({"a": a, "b": b}) # XXX outputs same as inputs
825 alm
.mod
.setup(m
, a
, b
, alm
.out_a
, alm
.out_b
, alm
.exp_eq
)
826 m
.submodules
.align
= alm
.mod
828 az1
= FPNumOut(self
.width
, False)
829 m
.submodules
.fpnum_az1
= az1
831 add0
= self
.add_state(FPAddStage0(self
.width
))
832 add0
.set_inputs({"a": alm
.out_a
, "b": alm
.out_b
})
833 add0
.set_outputs({"z": az1
})
834 add0
.mod
.setup(m
, alm
.out_a
, alm
.out_b
, az1
, add0
.out_z
, add0
.out_tot
)
835 m
.submodules
.add0
= add0
.mod
837 add1
= self
.add_state(FPAddStage1(self
.width
))
838 #add1.set_outputs({"z": az}) # XXX Z as output
839 add1
.mod
.setup(m
, add0
.out_tot
, az1
, None, add1
.out_of
)
840 m
.submodules
.add1
= add1
.mod
841 m
.d
.sync
+= add1
.norm_stb
.eq(0) # sets to zero when not in add1 state
845 n1
= self
.add_state(FPNorm1(self
.width
))
846 n1
.set_inputs({"z": az
, "of": add1
.out_of
}) # XXX Z as output
847 n1
.set_outputs({"z": az
}) # XXX Z as output
848 n1
.setup(m
, az
, add1
.out_of
, add1
.norm_stb
)
850 rnz
= FPNumOut(self
.width
, False)
851 m
.submodules
.fpnum_rnz
= rnz
853 rn
= self
.add_state(FPRound(self
.width
))
854 rn
.set_inputs({"of": n1
.out_of
})
855 rn
.set_outputs({"z": rnz
})
856 rn
.mod
.setup(m
, n1
.out_z
, rn
.out_z
, add1
.out_of
)
857 m
.submodules
.roundz
= rn
.mod
859 cor
= self
.add_state(FPCorrections(self
.width
))
860 cor
.set_inputs({"z": rnz
}) # XXX Z as output
861 cor
.mod
.setup(m
, rnz
, cor
.out_z
)
862 m
.submodules
.corrections
= cor
.mod
864 pa
= self
.add_state(FPPack(self
.width
))
865 pa
.set_inputs({"z": cor
.out_z
}) # XXX Z as output
866 pa
.mod
.setup(m
, cor
.out_z
, pa
.out_z
)
867 m
.submodules
.pack
= pa
.mod
869 ppz
= self
.add_state(FPPutZ("pack_put_z"))
870 ppz
.set_inputs({"z": pa
.out_z
})
871 ppz
.set_outputs({"out_z": self
.out_z
})
873 pz
= self
.add_state(FPPutZ("put_z"))
874 pz
.set_inputs({"z": z
})
875 pz
.set_outputs({"out_z": self
.out_z
})
879 for state
in self
.states
:
880 with m
.State(state
.state_from
):
886 if __name__
== "__main__":
887 alu
= FPADD(width
=32)
888 main(alu
, ports
=alu
.in_a
.ports() + alu
.in_b
.ports() + alu
.out_z
.ports())
891 # works... but don't use, just do "python fname.py convert -t v"
892 #print (verilog.convert(alu, ports=[
893 # ports=alu.in_a.ports() + \
894 # alu.in_b.ports() + \