From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Sat, 16 Feb 2019 09:12:14 +0000 (+0000)
Subject: create pack function
X-Git-Tag: ls180-24jan2020~1962
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=5107bbe121ee49a600b48f6467502a69a29d1df4;p=ieee754fpu.git

create pack function
---

diff --git a/src/add/nmigen_add_experiment.py b/src/add/nmigen_add_experiment.py
index 676d8381..8a7ef0ea 100644
--- a/src/add/nmigen_add_experiment.py
+++ b/src/add/nmigen_add_experiment.py
@@ -160,6 +160,15 @@ class FPADD:
             with m.If(z.m == z.m1s): # all 1s
                 m.d.sync += z.e.eq(z.e + 1) # exponent rounds up
 
+    def corrections(self, m, z, next_state):
+        m.next = next_state
+        # denormalised, correct exponent to zero
+        with m.If(z.is_denormalised()):
+            m.d.sync += z.m.eq(-127)
+        # FIX SIGN BUG: -a + a = +0.
+        with m.If((z.e == z.N126) & (z.m[0:] == 0)):
+            m.d.sync += z.s.eq(0)
+
     def get_fragment(self, platform=None):
         m = Module()
 
@@ -342,13 +351,7 @@ class FPADD:
             # correction stage
 
             with m.State("corrections"):
-                m.next = "pack"
-                # denormalised, correct exponent to zero
-                with m.If(z.is_denormalised()):
-                    m.d.sync += z.m.eq(-127)
-                # FIX SIGN BUG: -a + a = +0.
-                with m.If((z.e == z.N126) & (z.m[0:] == 0)):
-                    m.d.sync += z.s.eq(0)
+                self.corrections(m, z, "pack")
 
             # ******
             # pack stage