# IEEE Floating Point Multiplier
-from nmigen import Module, Signal, Cat, Const, Elaboratable
+from nmigen import Module, Signal, Cat, Const
from nmigen.cli import main, verilog
from math import log
from ieee754.fpcommon.fpbase import FPNumDecode, FPNumBaseRecord
-from nmutil.singlepipe import StageChain
-from ieee754.pipeline import DynamicPipe
+from ieee754.fpcommon.modbase import FPModBase, FPModBaseChain
from ieee754.fpcommon.getop import FPADDBaseData
from ieee754.fpcommon.denorm import (FPSCData, FPAddDeNormMod)
from ieee754.fpmul.align import FPAlignModSingle
-class FPMulSpecialCasesMod(Elaboratable):
+class FPMulSpecialCasesMod(FPModBase):
""" special cases: NaNs, infs, zeros, denormalised
see "Special Operations"
https://steve.hollasch.net/cgindex/coding/ieeefloat.html
"""
def __init__(self, pspec):
- self.pspec = pspec
- self.i = self.ispec()
- self.o = self.ospec()
+ super().__init__(pspec, "specialcases")
def ispec(self):
return FPADDBaseData(self.pspec)
def ospec(self):
return FPSCData(self.pspec, False)
- def setup(self, m, i):
- """ links module to inputs and outputs
- """
- m.submodules.specialcases = self
- m.d.comb += self.i.eq(i)
-
- def process(self, i):
- return self.o
-
def elaborate(self, platform):
m = Module()
-
- #m.submodules.sc_out_z = self.o.z
+ comb = m.d.comb
# decode: XXX really should move to separate stage
width = self.pspec.width
b1 = FPNumBaseRecord(width, False)
m.submodules.sc_decode_a = a1 = FPNumDecode(None, a1)
m.submodules.sc_decode_b = b1 = FPNumDecode(None, b1)
- m.d.comb += [a1.v.eq(self.i.a),
+ comb += [a1.v.eq(self.i.a),
b1.v.eq(self.i.b),
self.o.a.eq(a1),
self.o.b.eq(b1)
]
obz = Signal(reset_less=True)
- m.d.comb += obz.eq(a1.is_zero | b1.is_zero)
+ comb += obz.eq(a1.is_zero | b1.is_zero)
sabx = Signal(reset_less=True) # sign a xor b (sabx, get it?)
- m.d.comb += sabx.eq(a1.s ^ b1.s)
+ comb += sabx.eq(a1.s ^ b1.s)
abnan = Signal(reset_less=True)
- m.d.comb += abnan.eq(a1.is_nan | b1.is_nan)
+ comb += abnan.eq(a1.is_nan | b1.is_nan)
# if a is NaN or b is NaN return NaN
with m.If(abnan):
- m.d.comb += self.o.out_do_z.eq(1)
- m.d.comb += self.o.z.nan(0)
+ comb += self.o.out_do_z.eq(1)
+ comb += self.o.z.nan(0)
# if a is inf return inf (or NaN)
with m.Elif(a1.is_inf):
- m.d.comb += self.o.out_do_z.eq(1)
- m.d.comb += self.o.z.inf(sabx)
+ comb += self.o.out_do_z.eq(1)
+ comb += self.o.z.inf(sabx)
# b is zero return NaN
with m.If(b1.is_zero):
- m.d.comb += self.o.z.nan(0)
+ comb += self.o.z.nan(0)
# if b is inf return inf (or NaN)
with m.Elif(b1.is_inf):
- m.d.comb += self.o.out_do_z.eq(1)
- m.d.comb += self.o.z.inf(sabx)
+ comb += self.o.out_do_z.eq(1)
+ comb += self.o.z.inf(sabx)
# a is zero return NaN
with m.If(a1.is_zero):
- m.d.comb += self.o.z.nan(0)
+ comb += self.o.z.nan(0)
# if a is zero or b zero return signed-a/b
with m.Elif(obz):
- m.d.comb += self.o.out_do_z.eq(1)
- m.d.comb += self.o.z.zero(sabx)
+ comb += self.o.out_do_z.eq(1)
+ comb += self.o.z.zero(sabx)
# Denormalised Number checks next, so pass a/b data through
with m.Else():
- m.d.comb += self.o.out_do_z.eq(0)
+ comb += self.o.out_do_z.eq(0)
- m.d.comb += self.o.oz.eq(self.o.z.v)
- m.d.comb += self.o.ctx.eq(self.i.ctx)
+ comb += self.o.oz.eq(self.o.z.v)
+ comb += self.o.ctx.eq(self.i.ctx)
return m
-class FPMulSpecialCasesDeNorm(DynamicPipe):
+class FPMulSpecialCasesDeNorm(FPModBaseChain):
""" special cases: NaNs, infs, zeros, denormalised
"""
- def __init__(self, pspec):
- self.pspec = pspec
- super().__init__(pspec)
- self.out = self.ospec()
-
- def ispec(self):
- return FPADDBaseData(self.pspec)
-
- def ospec(self):
- return FPSCData(self.pspec, False)
-
- def setup(self, m, i):
- """ links module to inputs and outputs
+ def get_chain(self):
+ """ gets chain of modules
"""
smod = FPMulSpecialCasesMod(self.pspec)
dmod = FPAddDeNormMod(self.pspec, False)
amod = FPAlignModSingle(self.pspec, False)
- chain = StageChain([smod, dmod, amod])
- chain.setup(m, i)
-
- # only needed for break-out (early-out)
- # self.out_do_z = smod.o.out_do_z
-
- self.o = amod.o # output is from last .o in the chain
-
- def process(self, i):
- return self.o
+ return [smod, dmod, amod]