--- gcc/move-if-change	2018/04/24 17:51:20	1.1.1.1
+++ gcc/move-if-change	2018/04/24 18:00:34	1.1.1.2
@@ -1,4 +1,6 @@
 #!/bin/sh
+# Like mv $1 $2, but if the files are the same, just delete $1.
+# Status is 0 if $2 is changed, 1 otherwise.
 if
 test -r $2
 then