Fix Verilog backend for mixed signed-unsigned ops

Code like

    add(UInt<1>(1), SInt<1>(1))

was resulting in Verilog like

    $signed(1'h1) + $signed(1'sh1)

which is incorrect: it computes -2, not 0.  The fix is to zero-extend the
unsigned operand, e.g.

    $signed({1'b0,1'h1}) + $signed(1'sh1)

1 files changed, 9 insertions, 9 deletions

diff --git a/src/main/stanza/verilog.stanza b/src/main/stanza/verilog.stanza
index 1223026e..993f5e5a 100644
--- a/src/main/stanza/verilog.stanza
+++ b/src/main/stanza/verilog.stanza
@@ -85,15 +85,15 @@ defn emit (e:Expression) -> String :
          ;val sargs = map(emit-as-type{_,type(e)},args(e))
          ;val xargs = map(emit-signed-if-any{_,args(e)},args(e))
          string-join $ switch {_ == op(e)} :
-            ADD-OP : [emit-as-type(args(e)[0],type(e)) " + " emit-as-type(args(e)[1],type(e))]
-            SUB-OP : [emit-as-type(args(e)[0],type(e)) " - " emit-as-type(args(e)[1],type(e))]
-            MUL-OP : [emit-as-type(args(e)[0],type(e)) " * " emit-as-type(args(e)[1],type(e)) ]
-            DIV-OP : [emit-as-type(args(e)[0],type(e)) " / " emit-as-type(args(e)[1],type(e)) ]
-            MOD-OP : [emit-as-type(args(e)[0],type(e)) " % " emit-as-type(args(e)[1],type(e)) ]
-            QUO-OP : [emit-as-type(args(e)[0],type(e)) " / " emit-as-type(args(e)[1],type(e)) ]
-            REM-OP : [emit-as-type(args(e)[0],type(e)) " % " emit-as-type(args(e)[1],type(e)) ]
-            ADD-WRAP-OP : [emit-as-type(args(e)[0],type(e)), " + " emit-as-type(args(e)[1],type(e))]
-            SUB-WRAP-OP : [emit-as-type(args(e)[0],type(e)), " - " emit-as-type(args(e)[1],type(e))]
+            ADD-OP : [emit-signed-if-any(args(e)[0],args(e)) " + " emit-signed-if-any(args(e)[1],args(e))]
+            SUB-OP : [emit-signed-if-any(args(e)[0],args(e)) " - " emit-signed-if-any(args(e)[1],args(e))]
+            MUL-OP : [emit-signed-if-any(args(e)[0],args(e)) " * " emit-signed-if-any(args(e)[1],args(e)) ]
+            DIV-OP : [emit-signed-if-any(args(e)[0],args(e)) " / " emit-signed-if-any(args(e)[1],args(e)) ]
+            MOD-OP : [emit-signed-if-any(args(e)[0],args(e)) " % " emit-signed-if-any(args(e)[1],args(e)) ]
+            QUO-OP : [emit-signed-if-any(args(e)[0],args(e)) " / " emit-signed-if-any(args(e)[1],args(e)) ]
+            REM-OP : [emit-signed-if-any(args(e)[0],args(e)) " % " emit-signed-if-any(args(e)[1],args(e)) ]
+            ADD-WRAP-OP : [emit-signed-if-any(args(e)[0],args(e)), " + " emit-signed-if-any(args(e)[1],args(e))]
+            SUB-WRAP-OP : [emit-signed-if-any(args(e)[0],args(e)), " - " emit-signed-if-any(args(e)[1],args(e))]
             LESS-OP : [emit-signed-if-any(args(e)[0],args(e)) " < " emit-signed-if-any(args(e)[1],args(e))]
             LESS-EQ-OP : [emit-signed-if-any(args(e)[0],args(e)) " <= " emit-signed-if-any(args(e)[1],args(e))]
             GREATER-OP : [emit-signed-if-any(args(e)[0],args(e)) " > " emit-signed-if-any(args(e)[1],args(e))]