From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Tue, 4 Feb 2020 18:11:25 +0000 (+0000)
Subject: remove comments, sort out string name, add __init__.pys
X-Git-Tag: ls180-24jan2020~281
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=326ce92262bb16955b3c67f7e81f81f4ce2ceebb;p=ieee754fpu.git

remove comments, sort out string name, add __init__.pys
---

diff --git a/src/ieee754/part_cmp/__init__.py b/src/ieee754/part_cmp/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/src/ieee754/part_cmp/equal_ortree.py b/src/ieee754/part_cmp/equal_ortree.py
index d9ed392e..24c88cf3 100644
--- a/src/ieee754/part_cmp/equal_ortree.py
+++ b/src/ieee754/part_cmp/equal_ortree.py
@@ -17,7 +17,8 @@ from nmigen import Signal, Module, Elaboratable, Cat, C, Mux, Repl
 from nmigen.cli import main
 
 from ieee754.part_mul_add.partpoints import PartitionPoints
-from eq_combiner import Twomux
+from ieee754.part_cmp.experiments.eq_combiner import Twomux
+
 
 class PartitionedEq(Elaboratable):
 
@@ -37,25 +38,6 @@ class PartitionedEq(Elaboratable):
         m = Module()
         comb = m.d.comb
 
-        # ok first thing to note, before reading this (read the wiki page
-        # first), according to boolean algebra, these two are equivalent:
-        # (~[~eq0, ~eq1, ~eq2].bool()) is the same as (eq0 AND eq1 AND eq2)
-        # where bool() is the *OR* of all bits in the list.
-        #
-        # given that ~eqN is neN (not equal), we first create a series
-        # of != comparisons on the partitions, then chain the relevant
-        # ones together depending on partition points, BOOL those together
-        # and invert the result.
-        #
-        # the outer loop is on the partition value.  the preparation phase
-        # (idx array) is to work out how and when the eqs (ne's) are to be
-        # chained together.  finally an inner loop - one per bit - grabs
-        # each chain, on a per-output-bit basis.
-        #
-        # the result is that for each partition-point permutation you get
-        # a different set of output results for each bit.  it's... messy
-        # but functional.
-
         # make a series of "not-eqs", splitting a and b into partition chunks
         nes = Signal(self.mwidth, reset_less=True)
         nel = []
@@ -63,7 +45,7 @@ class PartitionedEq(Elaboratable):
         start = 0
         for i in range(len(keys)):
             end = keys[i]
-            nel.append(self.a[start:end] != self.b[start:end]) # see bool below
+            nel.append(self.a[start:end] != self.b[start:end])
             start = end # for next time round loop
         comb += nes.eq(Cat(*nel))
 
@@ -75,7 +57,7 @@ class PartitionedEq(Elaboratable):
         prevresult = nes[-1]
 
         for bit in range(self.mwidth-1, 0, -1): # counts down from mwidth-1 to 1
-            m.submodules["mux{}".format(bit)] = mux = Twomux()
+            m.submodules["mux%d" % bit] = mux = Twomux()
             comb += mux.ina.eq(prevresult)
             comb += mux.inb.eq(0)
             comb += mux.sel.eq(~part_points[bit-1])