From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Wed, 31 Jul 2019 12:15:32 +0000 (+0100)
Subject: tidyup, use FPModBaseChain and FPModBase
X-Git-Tag: ls180-24jan2020~633
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=2cf4eb423fe183b573991b375b2292025b52b907;p=ieee754fpu.git

tidyup, use FPModBaseChain and FPModBase
---

diff --git a/src/ieee754/fpmul/specialcases.py b/src/ieee754/fpmul/specialcases.py
index eb3fe50a..d4eb3c82 100644
--- a/src/ieee754/fpmul/specialcases.py
+++ b/src/ieee754/fpmul/specialcases.py
@@ -1,28 +1,25 @@
 # 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)
@@ -30,19 +27,9 @@ class FPMulSpecialCasesMod(Elaboratable):
     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
@@ -50,87 +37,67 @@ class FPMulSpecialCasesMod(Elaboratable):
         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]