From: whitequark <whitequark@whitequark.org>
Date: Sun, 21 Apr 2019 06:41:35 +0000 (+0000)
Subject: back.rtlil: only expand legalized values in Array/Part context on RHS.
X-Git-Tag: working~10
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=083016d747f25b67a6e06fab9d29fa46b4fe4d1b;p=nmigen.git

back.rtlil: only expand legalized values in Array/Part context on RHS.

Otherwise the following code fails to compile:

    index = Signal(1)
    array = Array(range(2))
    with m.If(0 == array[index]):
        m.d.sync += index.eq(0)

Fixes #51.
---

diff --git a/nmigen/back/rtlil.py b/nmigen/back/rtlil.py
index fd3bfe8..9778f4b 100644
--- a/nmigen/back/rtlil.py
+++ b/nmigen/back/rtlil.py
@@ -299,9 +299,6 @@ class _ValueCompiler(xfrm.ValueVisitor):
     def __init__(self, state):
         self.s = state
 
-    def on_value(self, value):
-        return super().on_value(self.s.expand(value))
-
     def on_unknown(self, value):
         if value is None:
             return None
@@ -375,6 +372,9 @@ class _RHSValueCompiler(_ValueCompiler):
         (3, "m"):    "$mux",
     }
 
+    def on_value(self, value):
+        return super().on_value(self.s.expand(value))
+
     def on_Const(self, value):
         if isinstance(value.value, str):
             return "{}'{}".format(value.nbits, value.value)