More test programs to track down Format / overflow bug.

[fedora-mingw.git] / ocaml / test_overflow.ml

diff --git a/ocaml/test_overflow.ml b/ocaml/test_overflow.ml
new file mode 100644 (file)
index 0000000..e9a8cf1
--- /dev/null
+++ b/ocaml/test_overflow.ml
@@ -0,0 +1,23 @@
+(* Look for assembler errors like this:
+ * 'Warning: 9223372036854775807 shortened to 4294967295'
+ * Try to reproduce and fix.
+ *)
+
+open Printf
+
+let () =
+  let i = max_int in                   (* Different on 32 & 64 bit platforms.*)
+  printf "max_int = %d\n" i;
+  let i = min_int in
+  printf "min_int = %d\n" i;
+  let i64 = Int64.max_int in           (* Same on all platforms. *)
+  printf "Int64.max_int = %Ld\n" i64;
+  let i32 = Int32.max_int in
+  printf "Int32.max_int = %ld\n" i32;
+
+  (* This is how the stdlib computes min_int:
+   *   min_int = 1 lsl (if 1 lsl 31 = 0 (* ie. 32 bit *) then 30 else 62)
+   *)
+  printf "1 lsl 31 = %d\n" (1 lsl 31);
+  printf "1 lsl 30 = %d\n" (1 lsl 30);
+  printf "1 lsl 62 = %d\n" (1 lsl 62)