From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Thu, 17 Sep 2015 06:39:36 +0000 (+0800)
Subject: sim: support eval of slice, cat and mux
X-Git-Tag: 24jan2021_ls180~2099^2~3^2~83
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=6e08df75ee8f2edccfacd74fa4524cd52b6fc8f0;p=litex.git

sim: support eval of slice, cat and mux
---

diff --git a/migen/sim.py b/migen/sim.py
index 1f0c5071..7f2035d1 100644
--- a/migen/sim.py
+++ b/migen/sim.py
@@ -2,7 +2,8 @@ import operator
 from collections import defaultdict
 
 from migen.fhdl.structure import *
-from migen.fhdl.structure import _Operator, _Assign, _Fragment
+from migen.fhdl.structure import _Operator, _Slice, _Assign, _Fragment
+from migen.fhdl.bitcontainer import flen
 from migen.fhdl.tools import list_inputs
 
 
@@ -87,10 +88,25 @@ class Evaluator:
                     return -operands[0]
                 else:
                     return operands[0] - operands[1]
+            elif node.op == "m":
+                return operands[1] if operands[0] else operands[2]
             else:
                 return str2op[node.op](*operands)
+        elif isinstance(node, _Slice):
+            v = self.eval(node.value)
+            idx = range(node.start, node.stop)
+            return sum(((v >> i) & 1) << j for j, i in enumerate(idx))
+        elif isinstance(node, Cat):
+            shift = 0
+            r = 0
+            for element in node.l:
+                nbits = flen(element)
+                # make value always positive
+                r |= (self.eval(element) & (2**nbits-1)) << shift
+                shift += nbits
+            return r
         else:
-            # TODO: Cat, Slice, Array, ClockSignal, ResetSignal, Memory
+            # TODO: Array, ClockSignal, ResetSignal, Memory
             raise NotImplementedError
 
     def assign(self, signal, value):