From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Sat, 15 Feb 2020 15:04:49 +0000 (+0000)
Subject: really annoying simulation bug, dont know whats going on
X-Git-Tag: ls180-24jan2020~155
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=7b3fbeadefd3e52e926418d70b53326726858676;p=ieee754fpu.git

really annoying simulation bug, dont know whats going on
---

diff --git a/src/ieee754/part_shift/part_shift_dynamic.py b/src/ieee754/part_shift/part_shift_dynamic.py
index ccfc5d04..96334e7c 100644
--- a/src/ieee754/part_shift/part_shift_dynamic.py
+++ b/src/ieee754/part_shift/part_shift_dynamic.py
@@ -63,14 +63,16 @@ class PartitionedDynamicShift(Elaboratable):
         for i in range(len(b_intervals)):
             mask = Signal(b_intervals[i].shape(), name="shift_mask%d" % i,
                           reset_less=True)
-            bits = Signal(gates.width-i+1, name="bits%d" % i, reset_less=True)
+            bits = Signal(pwid-i, name="bits%d" % i, reset_less=True)
             bl = []
-            for j in range(i, gates.width):
-                if bl:
-                    bl.append(~gates[j] & bits[j-i-1])
+            for idx, j in enumerate(range(i, pwid)):
+                if idx != 0:
+                    bl.append((~gates[j]) & bits[idx-1])
                 else:
                     bl.append(~gates[j])
-            comb += bits.eq(Cat(*bl))
+            # XXX ARGH, really annoying: simulation bug, can't use Cat(*bl).
+            for j in range(bits.shape()[0]):
+                comb += bits[j].eq(bl[j])
             comb += mask.eq(Cat((1 << min_bits)-1, bits)
                             & ((1 << max_bits)-1))
             shifter_masks.append(mask)