sped up division tests

Author: jvanburen

testsuite/tests/basic/division_by_constant.ml

@@ -16,19 +16,27 @@ let test_cases =
       ListLabels.concat_map
         [pred bit; bit; succ bit; rand ()]
         ~f:(fun x -> [x; lognot x; sub max_int x; lognot (sub max_int x)]))
-  |> List.concat |> List.sort_uniq compare
+  |> List.concat |> List.sort_uniq compare |> Array.of_list
 
 let[@inline never] check_result ~dividend ~divisor ~quotient ~remainder =
-  assert (divisor <> 0n);
-  assert (quotient = div dividend divisor);
-  assert (remainder = rem dividend divisor);
-  assert (dividend = add (mul quotient divisor) remainder);
-  assert (
+  let[@inline] sign x = if x < 0n then -1 else if x = 0n then 0 else 1 in
+  let identity = dividend = add (mul quotient divisor) remainder in
+  let magnitude =
     if divisor = min_int
     then remainder <> min_int
-    else abs remainder < abs divisor);
-  let[@inline] sign x = if x < 0n then -1 else if x = 0n then 0 else 1 in
-  assert (remainder = 0n || sign remainder = sign dividend)
+    else abs remainder < abs divisor
+  in
+  let sign = (remainder = 0n || sign remainder = sign dividend) in
+  if not (identity && magnitude && sign) then (
+    Printf.fprintf
+      stderr
+      "FAILED: dividend=%nd, divisor=%nd, quotient=%nd, remainder=%nd\n%!"
+      dividend
+      divisor
+      quotient
+      remainder;
+    exit 1)
+
 
 (* test that the order of side effects are preserved in all cases *)
 
@@ -88,9 +96,9 @@ let () =
 let[@inline always] check ~divisor =
   let[@inline always] quotient ~dividend = div dividend divisor in
   let[@inline always] remainder ~dividend = rem dividend divisor in
-  ListLabels.iter test_cases ~f:(fun dividend ->
-      check_result ~dividend ~divisor ~quotient:(quotient ~dividend)
-        ~remainder:(remainder ~dividend))
+  ArrayLabels.iter test_cases ~f:(fun dividend ->
+    check_result ~dividend ~divisor ~quotient:(quotient ~dividend)
+      ~remainder:(remainder ~dividend))
 
 (* manual tests *)
 
@@ -103,7 +111,7 @@ let () = check ~divisor:(-7n)
 let () = check ~divisor:65537n
 let () = check ~divisor:(-65537n)
 
-(* These tests are generated by a manual run of test_cases with seed
+(* The following tests are generated by a manual run of test_cases with seed
    [[| int_size |]] to test against a hard-coded list of dividends. *)
 
 let () = check ~divisor:0x1n