xform_expr_infer: support negation of conditional expressions.

pfalcon · Dec 30, 2017 · 129ecee · 129ecee
1 parent 1030abe
commit 129ecee
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/xform_expr_infer.py b/xform_expr_infer.py
@@ -98,6 +98,12 @@ def uni(ex, pat):
     lambda W: EXPR(W["rel_op"], W["x1"], expr_neg(W["x2"]))
 ))
 
+RULES.append((
+    EXPR("!", EXPR(V("rel_op"), V("x1"), V("x2"))),
+    lambda W: W["rel_op"] in ("==", "!=", "<", "<=", ">=", ">"),
+    lambda W: EXPR(COND.NEG[W["rel_op"]], W["x1"], W["x2"])
+))
+
 
 def simplify(ex):
     for r in RULES: