1 files changed, 3 insertions, 3 deletions
diff --git a/pp2cc.py b/pp2cc.py
index 5dce20c..b130356 100755
--- a/pp2cc.py
+++ b/pp2cc.py
@@ -622,9 +622,9 @@ class Parse(object):
         elif op == "-":
             lines.append(self.asm.binary_op("MULS", reg, "-1"))
         elif op == "~":
-            # XXX unsigned vs signed integers. Assume signed for now
-            mask = "1" * (self.WORDSIZE - 1)
-            lines.append(self.asm.binary_op("XOR", reg, "%0" + mask))
+            # Conforming K&R A7.4.6, signed types are treated as unsigned when
+            # applying ~
+            lines.append(self.asm.binary_op("XOR", reg, "%1"))
         elif op == "!":
             lbl_false = self.uniqLbl("not_false")
             lbl_true = self.uniqLbl("not_true")