--- /dev/null
+# IEEE Floating Point Adder (Single Precision)
+# Copyright (C) Jonathan P Dawson 2013
+# 2013-12-12
+
+from nmigen import Module, Signal, Cat, Mux, Array, Const
+from nmigen.lib.coding import PriorityEncoder
+from nmigen.cli import main, verilog
+from math import log
+
+from fpbase import FPNumIn, FPNumOut, FPOp, Overflow, FPBase, FPNumBase
+from fpbase import MultiShiftRMerge, Trigger
+from singlepipe import (ControlBase, StageChain, UnbufferedPipeline,
+ PassThroughStage)
+from multipipe import CombMuxOutPipe
+from multipipe import PriorityCombMuxInPipe
+
+from fpbase import FPState, FPID
+from fpcommon.getop import FPADDBaseData
+from fpcommon.denorm import (FPSCData, FPAddDeNormMod, FPAddDeNorm)
+
+
+class FPAddSpecialCasesMod:
+ """ special cases: NaNs, infs, zeros, denormalised
+ NOTE: some of these are unique to add. see "Special Operations"
+ https://steve.hollasch.net/cgindex/coding/ieeefloat.html
+ """
+
+ def __init__(self, width, id_wid):
+ self.width = width
+ self.id_wid = id_wid
+ self.i = self.ispec()
+ self.o = self.ospec()
+
+ def ispec(self):
+ return FPADDBaseData(self.width, self.id_wid)
+
+ def ospec(self):
+ return FPSCData(self.width, self.id_wid)
+
+ 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
+
+ # decode: XXX really should move to separate stage
+ a1 = FPNumIn(None, self.width)
+ b1 = FPNumIn(None, self.width)
+ m.submodules.sc_decode_a = a1
+ m.submodules.sc_decode_b = b1
+ m.d.comb += [a1.decode(self.i.a),
+ b1.decode(self.i.b),
+ ]
+
+ s_nomatch = Signal()
+ m.d.comb += s_nomatch.eq(a1.s != b1.s)
+
+ m_match = Signal()
+ m.d.comb += m_match.eq(a1.m == b1.m)
+
+ # if a is NaN or b is NaN return NaN
+ with m.If(a1.is_nan | b1.is_nan):
+ m.d.comb += self.o.out_do_z.eq(1)
+ m.d.comb += self.o.z.nan(0)
+
+ # XXX WEIRDNESS for FP16 non-canonical NaN handling
+ # under review
+
+ ## if a is zero and b is NaN return -b
+ #with m.If(a.is_zero & (a.s==0) & b.is_nan):
+ # m.d.comb += self.o.out_do_z.eq(1)
+ # m.d.comb += z.create(b.s, b.e, Cat(b.m[3:-2], ~b.m[0]))
+
+ ## if b is zero and a is NaN return -a
+ #with m.Elif(b.is_zero & (b.s==0) & a.is_nan):
+ # m.d.comb += self.o.out_do_z.eq(1)
+ # m.d.comb += z.create(a.s, a.e, Cat(a.m[3:-2], ~a.m[0]))
+
+ ## if a is -zero and b is NaN return -b
+ #with m.Elif(a.is_zero & (a.s==1) & b.is_nan):
+ # m.d.comb += self.o.out_do_z.eq(1)
+ # m.d.comb += z.create(a.s & b.s, b.e, Cat(b.m[3:-2], 1))
+
+ ## if b is -zero and a is NaN return -a
+ #with m.Elif(b.is_zero & (b.s==1) & a.is_nan):
+ # m.d.comb += self.o.out_do_z.eq(1)
+ # m.d.comb += z.create(a.s & b.s, a.e, Cat(a.m[3:-2], 1))
+
+ # 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(a1.s)
+ # if a is inf and signs don't match return NaN
+ with m.If(b1.exp_128 & s_nomatch):
+ m.d.comb += self.o.z.nan(0)
+
+ # if b is inf return inf
+ with m.Elif(b1.is_inf):
+ m.d.comb += self.o.out_do_z.eq(1)
+ m.d.comb += self.o.z.inf(b1.s)
+
+ # if a is zero and b zero return signed-a/b
+ with m.Elif(a1.is_zero & b1.is_zero):
+ m.d.comb += self.o.out_do_z.eq(1)
+ m.d.comb += self.o.z.create(a1.s & b1.s, b1.e, b1.m[3:-1])
+
+ # if a is zero return b
+ with m.Elif(a1.is_zero):
+ m.d.comb += self.o.out_do_z.eq(1)
+ m.d.comb += self.o.z.create(b1.s, b1.e, b1.m[3:-1])
+
+ # if b is zero return a
+ with m.Elif(b1.is_zero):
+ m.d.comb += self.o.out_do_z.eq(1)
+ m.d.comb += self.o.z.create(a1.s, a1.e, a1.m[3:-1])
+
+ # if a equal to -b return zero (+ve zero)
+ with m.Elif(s_nomatch & m_match & (a1.e == b1.e)):
+ m.d.comb += self.o.out_do_z.eq(1)
+ m.d.comb += self.o.z.zero(0)
+
+ # Denormalised Number checks next, so pass a/b data through
+ with m.Else():
+ m.d.comb += self.o.out_do_z.eq(0)
+ m.d.comb += self.o.a.eq(a1)
+ m.d.comb += self.o.b.eq(b1)
+
+ m.d.comb += self.o.oz.eq(self.o.z.v)
+ m.d.comb += self.o.mid.eq(self.i.mid)
+
+ return m
+
+
+class FPAddSpecialCases(FPState):
+ """ special cases: NaNs, infs, zeros, denormalised
+ NOTE: some of these are unique to add. see "Special Operations"
+ https://steve.hollasch.net/cgindex/coding/ieeefloat.html
+ """
+
+ def __init__(self, width, id_wid):
+ FPState.__init__(self, "special_cases")
+ self.mod = FPAddSpecialCasesMod(width)
+ self.out_z = self.mod.ospec()
+ self.out_do_z = Signal(reset_less=True)
+
+ def setup(self, m, i):
+ """ links module to inputs and outputs
+ """
+ self.mod.setup(m, i, self.out_do_z)
+ m.d.sync += self.out_z.v.eq(self.mod.out_z.v) # only take the output
+ m.d.sync += self.out_z.mid.eq(self.mod.o.mid) # (and mid)
+
+ def action(self, m):
+ self.idsync(m)
+ with m.If(self.out_do_z):
+ m.next = "put_z"
+ with m.Else():
+ m.next = "denormalise"
+
+
+class FPAddSpecialCasesDeNorm(FPState, UnbufferedPipeline):
+ """ special cases: NaNs, infs, zeros, denormalised
+ NOTE: some of these are unique to add. see "Special Operations"
+ https://steve.hollasch.net/cgindex/coding/ieeefloat.html
+ """
+
+ def __init__(self, width, id_wid):
+ FPState.__init__(self, "special_cases")
+ self.width = width
+ self.id_wid = id_wid
+ UnbufferedPipeline.__init__(self, self) # pipe is its own stage
+ self.out = self.ospec()
+
+ def ispec(self):
+ return FPADDBaseData(self.width, self.id_wid) # SpecialCases ispec
+
+ def ospec(self):
+ return FPSCData(self.width, self.id_wid) # DeNorm ospec
+
+ def setup(self, m, i):
+ """ links module to inputs and outputs
+ """
+ smod = FPAddSpecialCasesMod(self.width, self.id_wid)
+ dmod = FPAddDeNormMod(self.width, self.id_wid)
+
+ chain = StageChain([smod, dmod])
+ chain.setup(m, i)
+
+ # only needed for break-out (early-out)
+ # self.out_do_z = smod.o.out_do_z
+
+ self.o = dmod.o
+
+ def process(self, i):
+ return self.o
+
+ def action(self, m):
+ # for break-out (early-out)
+ #with m.If(self.out_do_z):
+ # m.next = "put_z"
+ #with m.Else():
+ m.d.sync += self.out.eq(self.process(None))
+ m.next = "align"
+
+
from multipipe import PriorityCombMuxInPipe
from fpbase import FPState, FPID
-from fpcommon.getop import (FPGetOpMod, FPGetOp, FPNumBase2Ops, FPADDBaseData, FPGet2OpMod, FPGet2Op)
+from fpcommon.getop import (FPGetOpMod, FPGetOp, FPNumBase2Ops, FPADDBaseData,
+ FPGet2OpMod, FPGet2Op)
+from fpadd.specialcases import (FPAddSpecialCasesMod, FPAddSpecialCases,
+ FPAddSpecialCasesDeNorm)
from fpcommon.denorm import (FPSCData, FPAddDeNormMod, FPAddDeNorm)
from fpcommon.postcalc import FPAddStage1Data
from fpcommon.postnormalise import (FPNorm1Data, FPNorm1ModSingle,
from fpcommon.putz import (FPPutZ, FPPutZIdx)
-class FPAddSpecialCasesMod:
- """ special cases: NaNs, infs, zeros, denormalised
- NOTE: some of these are unique to add. see "Special Operations"
- https://steve.hollasch.net/cgindex/coding/ieeefloat.html
- """
-
- def __init__(self, width, id_wid):
- self.width = width
- self.id_wid = id_wid
- self.i = self.ispec()
- self.o = self.ospec()
-
- def ispec(self):
- return FPADDBaseData(self.width, self.id_wid)
-
- def ospec(self):
- return FPSCData(self.width, self.id_wid)
-
- 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
-
- # decode: XXX really should move to separate stage
- a1 = FPNumIn(None, self.width)
- b1 = FPNumIn(None, self.width)
- m.submodules.sc_decode_a = a1
- m.submodules.sc_decode_b = b1
- m.d.comb += [a1.decode(self.i.a),
- b1.decode(self.i.b),
- ]
-
- s_nomatch = Signal()
- m.d.comb += s_nomatch.eq(a1.s != b1.s)
-
- m_match = Signal()
- m.d.comb += m_match.eq(a1.m == b1.m)
-
- # if a is NaN or b is NaN return NaN
- with m.If(a1.is_nan | b1.is_nan):
- m.d.comb += self.o.out_do_z.eq(1)
- m.d.comb += self.o.z.nan(0)
-
- # XXX WEIRDNESS for FP16 non-canonical NaN handling
- # under review
-
- ## if a is zero and b is NaN return -b
- #with m.If(a.is_zero & (a.s==0) & b.is_nan):
- # m.d.comb += self.o.out_do_z.eq(1)
- # m.d.comb += z.create(b.s, b.e, Cat(b.m[3:-2], ~b.m[0]))
-
- ## if b is zero and a is NaN return -a
- #with m.Elif(b.is_zero & (b.s==0) & a.is_nan):
- # m.d.comb += self.o.out_do_z.eq(1)
- # m.d.comb += z.create(a.s, a.e, Cat(a.m[3:-2], ~a.m[0]))
-
- ## if a is -zero and b is NaN return -b
- #with m.Elif(a.is_zero & (a.s==1) & b.is_nan):
- # m.d.comb += self.o.out_do_z.eq(1)
- # m.d.comb += z.create(a.s & b.s, b.e, Cat(b.m[3:-2], 1))
-
- ## if b is -zero and a is NaN return -a
- #with m.Elif(b.is_zero & (b.s==1) & a.is_nan):
- # m.d.comb += self.o.out_do_z.eq(1)
- # m.d.comb += z.create(a.s & b.s, a.e, Cat(a.m[3:-2], 1))
-
- # 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(a1.s)
- # if a is inf and signs don't match return NaN
- with m.If(b1.exp_128 & s_nomatch):
- m.d.comb += self.o.z.nan(0)
-
- # if b is inf return inf
- with m.Elif(b1.is_inf):
- m.d.comb += self.o.out_do_z.eq(1)
- m.d.comb += self.o.z.inf(b1.s)
-
- # if a is zero and b zero return signed-a/b
- with m.Elif(a1.is_zero & b1.is_zero):
- m.d.comb += self.o.out_do_z.eq(1)
- m.d.comb += self.o.z.create(a1.s & b1.s, b1.e, b1.m[3:-1])
-
- # if a is zero return b
- with m.Elif(a1.is_zero):
- m.d.comb += self.o.out_do_z.eq(1)
- m.d.comb += self.o.z.create(b1.s, b1.e, b1.m[3:-1])
-
- # if b is zero return a
- with m.Elif(b1.is_zero):
- m.d.comb += self.o.out_do_z.eq(1)
- m.d.comb += self.o.z.create(a1.s, a1.e, a1.m[3:-1])
-
- # if a equal to -b return zero (+ve zero)
- with m.Elif(s_nomatch & m_match & (a1.e == b1.e)):
- m.d.comb += self.o.out_do_z.eq(1)
- m.d.comb += self.o.z.zero(0)
-
- # Denormalised Number checks next, so pass a/b data through
- with m.Else():
- m.d.comb += self.o.out_do_z.eq(0)
- m.d.comb += self.o.a.eq(a1)
- m.d.comb += self.o.b.eq(b1)
-
- m.d.comb += self.o.oz.eq(self.o.z.v)
- m.d.comb += self.o.mid.eq(self.i.mid)
-
- return m
-
-
-class FPAddSpecialCases(FPState):
- """ special cases: NaNs, infs, zeros, denormalised
- NOTE: some of these are unique to add. see "Special Operations"
- https://steve.hollasch.net/cgindex/coding/ieeefloat.html
- """
-
- def __init__(self, width, id_wid):
- FPState.__init__(self, "special_cases")
- self.mod = FPAddSpecialCasesMod(width)
- self.out_z = self.mod.ospec()
- self.out_do_z = Signal(reset_less=True)
-
- def setup(self, m, i):
- """ links module to inputs and outputs
- """
- self.mod.setup(m, i, self.out_do_z)
- m.d.sync += self.out_z.v.eq(self.mod.out_z.v) # only take the output
- m.d.sync += self.out_z.mid.eq(self.mod.o.mid) # (and mid)
-
- def action(self, m):
- self.idsync(m)
- with m.If(self.out_do_z):
- m.next = "put_z"
- with m.Else():
- m.next = "denormalise"
-
-
-class FPAddSpecialCasesDeNorm(FPState, UnbufferedPipeline):
- """ special cases: NaNs, infs, zeros, denormalised
- NOTE: some of these are unique to add. see "Special Operations"
- https://steve.hollasch.net/cgindex/coding/ieeefloat.html
- """
-
- def __init__(self, width, id_wid):
- FPState.__init__(self, "special_cases")
- self.width = width
- self.id_wid = id_wid
- UnbufferedPipeline.__init__(self, self) # pipe is its own stage
- self.out = self.ospec()
-
- def ispec(self):
- return FPADDBaseData(self.width, self.id_wid) # SpecialCases ispec
-
- def ospec(self):
- return FPSCData(self.width, self.id_wid) # DeNorm ospec
-
- def setup(self, m, i):
- """ links module to inputs and outputs
- """
- smod = FPAddSpecialCasesMod(self.width, self.id_wid)
- dmod = FPAddDeNormMod(self.width, self.id_wid)
-
- chain = StageChain([smod, dmod])
- chain.setup(m, i)
-
- # only needed for break-out (early-out)
- # self.out_do_z = smod.o.out_do_z
-
- self.o = dmod.o
-
- def process(self, i):
- return self.o
-
- def action(self, m):
- # for break-out (early-out)
- #with m.If(self.out_do_z):
- # m.next = "put_z"
- #with m.Else():
- m.d.sync += self.out.eq(self.process(None))
- m.next = "align"
-
-
class FPAddAlignMultiMod(FPState):
def __init__(self, width):
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