Masks for zero-width fields of mems should be width zero. (#763)

Closes #666.

1 files changed, 28 insertions, 0 deletions

diff --git a/src/test/resources/features/ZeroWidthMem.fir b/src/test/resources/features/ZeroWidthMem.fir
new file mode 100644
index 00000000..c56f8390
--- /dev/null
+++ b/src/test/resources/features/ZeroWidthMem.fir
@@ -0,0 +1,28 @@
+; See LICENSE for license details.
+circuit ZeroWidthMem :
+  module ZeroWidthMem :
+    input clock : Clock
+    input reset : UInt<1>
+    input waddr : UInt<4>
+    input in   : {0: UInt<10>, 1: UInt<0>}
+    input raddr : UInt<4>
+    output out : {0: UInt<10>, 1: UInt<0>}
+
+    cmem ram : {0: UInt<10>, 1: UInt<0>}[16]
+    infer mport ramin = ram[waddr], clock
+    infer mport ramout = ram[raddr], clock
+
+    ramin.0 <= in.0
+    ramin.1 <= in.1
+    out <= ramout
+
+    wire foo : UInt<32>
+    foo <= UInt<32>("hdeadbeef")
+
+    when not(reset) :
+      when eq(foo, UInt<32>("hdeadbeef")) :
+        stop(clock, UInt(1), 0) ; Success !
+      else :
+        printf(clock, UInt(1), "Assertion failed!\n")
+        stop(clock, UInt(1), 1) ; Failure!
+