--- /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.denorm import (FPSCData, FPAddDeNormMod, FPAddDeNorm)
+from fpcommon.postcalc import FPAddStage1Data
+from fpcommon.postnormalise import (FPNorm1Data, FPNorm1ModSingle,
+ FPNorm1ModMulti, FPNorm1Single, FPNorm1Multi)
+from fpcommon.roundz import (FPRoundData, FPRoundMod, FPRound)
+from fpcommon.corrections import (FPCorrectionsMod, FPCorrections)
+from fpcommon.pack import (FPPackData, FPPackMod, FPPack)
+from fpcommon.normtopack import FPNormToPack
+from fpcommon.putz import (FPPutZ, FPPutZIdx)
+
+from fpadd.specialcases import (FPAddSpecialCasesMod, FPAddSpecialCases,
+ FPAddSpecialCasesDeNorm)
+from fpadd.align import (FPAddAlignMulti, FPAddAlignMultiMod, FPNumIn2Ops,
+ FPAddAlignSingleMod, FPAddAlignSingle)
+from fpadd.add0 import (FPAddStage0Data, FPAddStage0Mod, FPAddStage0)
+
+
+class FPAddStage1Mod(FPState):
+ """ Second stage of add: preparation for normalisation.
+ detects when tot sum is too big (tot[27] is kinda a carry bit)
+ """
+
+ 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 FPAddStage0Data(self.width, self.id_wid)
+
+ def ospec(self):
+ return FPAddStage1Data(self.width, self.id_wid)
+
+ def process(self, i):
+ return self.o
+
+ def setup(self, m, i):
+ """ links module to inputs and outputs
+ """
+ m.submodules.add1 = self
+ m.submodules.add1_out_overflow = self.o.of
+
+ m.d.comb += self.i.eq(i)
+
+ def elaborate(self, platform):
+ m = Module()
+ m.d.comb += self.o.z.eq(self.i.z)
+ # tot[-1] (MSB) gets set when the sum overflows. shift result down
+ with m.If(~self.i.out_do_z):
+ with m.If(self.i.tot[-1]):
+ m.d.comb += [
+ self.o.z.m.eq(self.i.tot[4:]),
+ self.o.of.m0.eq(self.i.tot[4]),
+ self.o.of.guard.eq(self.i.tot[3]),
+ self.o.of.round_bit.eq(self.i.tot[2]),
+ self.o.of.sticky.eq(self.i.tot[1] | self.i.tot[0]),
+ self.o.z.e.eq(self.i.z.e + 1)
+ ]
+ # tot[-1] (MSB) zero case
+ with m.Else():
+ m.d.comb += [
+ self.o.z.m.eq(self.i.tot[3:]),
+ self.o.of.m0.eq(self.i.tot[3]),
+ self.o.of.guard.eq(self.i.tot[2]),
+ self.o.of.round_bit.eq(self.i.tot[1]),
+ self.o.of.sticky.eq(self.i.tot[0])
+ ]
+
+ m.d.comb += self.o.out_do_z.eq(self.i.out_do_z)
+ m.d.comb += self.o.oz.eq(self.i.oz)
+ m.d.comb += self.o.mid.eq(self.i.mid)
+
+ return m
+
+
+class FPAddStage1(FPState):
+
+ def __init__(self, width, id_wid):
+ FPState.__init__(self, "add_1")
+ self.mod = FPAddStage1Mod(width)
+ self.out_z = FPNumBase(width, False)
+ self.out_of = Overflow()
+ self.norm_stb = Signal()
+
+ def setup(self, m, i):
+ """ links module to inputs and outputs
+ """
+ self.mod.setup(m, i)
+
+ m.d.sync += self.norm_stb.eq(0) # sets to zero when not in add1 state
+
+ m.d.sync += self.out_of.eq(self.mod.out_of)
+ m.d.sync += self.out_z.eq(self.mod.out_z)
+ m.d.sync += self.norm_stb.eq(1)
+
+ def action(self, m):
+ m.next = "normalise_1"
+
from fpadd.align import (FPAddAlignMulti, FPAddAlignMultiMod, FPNumIn2Ops,
FPAddAlignSingleMod, FPAddAlignSingle)
from fpadd.add0 import (FPAddStage0Data, FPAddStage0Mod, FPAddStage0)
+from fpadd.add1 import (FPAddStage1Mod, FPAddStage1)
class FPAddAlignSingleAdd(FPState, UnbufferedPipeline):
m.next = "normalise_1"
-
-
-class FPAddStage1Mod(FPState):
- """ Second stage of add: preparation for normalisation.
- detects when tot sum is too big (tot[27] is kinda a carry bit)
- """
-
- 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 FPAddStage0Data(self.width, self.id_wid)
-
- def ospec(self):
- return FPAddStage1Data(self.width, self.id_wid)
-
- def process(self, i):
- return self.o
-
- def setup(self, m, i):
- """ links module to inputs and outputs
- """
- m.submodules.add1 = self
- m.submodules.add1_out_overflow = self.o.of
-
- m.d.comb += self.i.eq(i)
-
- def elaborate(self, platform):
- m = Module()
- m.d.comb += self.o.z.eq(self.i.z)
- # tot[-1] (MSB) gets set when the sum overflows. shift result down
- with m.If(~self.i.out_do_z):
- with m.If(self.i.tot[-1]):
- m.d.comb += [
- self.o.z.m.eq(self.i.tot[4:]),
- self.o.of.m0.eq(self.i.tot[4]),
- self.o.of.guard.eq(self.i.tot[3]),
- self.o.of.round_bit.eq(self.i.tot[2]),
- self.o.of.sticky.eq(self.i.tot[1] | self.i.tot[0]),
- self.o.z.e.eq(self.i.z.e + 1)
- ]
- # tot[-1] (MSB) zero case
- with m.Else():
- m.d.comb += [
- self.o.z.m.eq(self.i.tot[3:]),
- self.o.of.m0.eq(self.i.tot[3]),
- self.o.of.guard.eq(self.i.tot[2]),
- self.o.of.round_bit.eq(self.i.tot[1]),
- self.o.of.sticky.eq(self.i.tot[0])
- ]
-
- m.d.comb += self.o.out_do_z.eq(self.i.out_do_z)
- m.d.comb += self.o.oz.eq(self.i.oz)
- m.d.comb += self.o.mid.eq(self.i.mid)
-
- return m
-
-
-class FPAddStage1(FPState):
-
- def __init__(self, width, id_wid):
- FPState.__init__(self, "add_1")
- self.mod = FPAddStage1Mod(width)
- self.out_z = FPNumBase(width, False)
- self.out_of = Overflow()
- self.norm_stb = Signal()
-
- def setup(self, m, i):
- """ links module to inputs and outputs
- """
- self.mod.setup(m, i)
-
- m.d.sync += self.norm_stb.eq(0) # sets to zero when not in add1 state
-
- m.d.sync += self.out_of.eq(self.mod.out_of)
- m.d.sync += self.out_z.eq(self.mod.out_z)
- m.d.sync += self.norm_stb.eq(1)
-
- def action(self, m):
- m.next = "normalise_1"
-
-
-
-
class FPOpData:
def __init__(self, width, id_wid):
self.z = FPOp(width)