Disable some SIMD tests when running under Rosetta2 (#2200)

* Disable some SIMD tests when running under Rosetta2.

* Fix build on non-macOS boxes.

* Revert previous commit - a module cannot appear in several `modules` stanza.

* Fix build on non-macOS boxes.

* Fix target list.

* Put helpers in a library.

Author: xclerc

tests/simd/dune

@@ -1,3 +1,10 @@
+; Helpers
+
+(library
+ (name simd_test_helpers)
+ (wrapped false)
+ (modules test_helpers))
+
 ; Stubs
 
 (foreign_library
@@ -12,6 +19,7 @@
 (executables
  (names basic ops arrays scalar_ops)
  (modules basic ops arrays scalar_ops)
+ (libraries simd_test_helpers)
  (foreign_archives stubs)
  (ocamlopt_flags
   (:standard -extension simd)))
@@ -118,6 +126,7 @@
   consts_internal
   arrays_internal
   scalar_ops_internal)
+ (libraries simd_test_helpers)
  (enabled_if
   (<> %{system} macosx))
  (foreign_archives stubs)

tests/simd/ops.ml

@@ -833,6 +833,7 @@ module Float32x4 = struct
         [@@noalloc] [@@unboxed] [@@builtin]
 
     let () =
+      Test_helpers.run_if_not_under_rosetta2 ~f:(fun () ->
         Float32.check_floats (fun f0 f1 ->
             failmsg := (fun () -> Printf.printf "%f | %f\n%!" (Int32.float_of_bits f0) (Int32.float_of_bits f1));
             let fv0 = Float32.to_float32x4 f0 f0 f1 f1 in
@@ -860,6 +861,7 @@ module Float32x4 = struct
             eq (float32x4_low_int64 result) (float32x4_high_int64 result)
                (float32x4_low_int64 expect) (float32x4_high_int64 expect)
         );
+      )
     ;;
 
     external dp : (int [@untagged]) -> (t [@unboxed]) -> (t [@unboxed]) -> (t [@unboxed]) = "caml_vec128_unreachable" "caml_sse41_float32x4_dp"
@@ -1036,6 +1038,7 @@ module Float64x2 = struct
         [@@noalloc] [@@unboxed] [@@builtin]
 
     let () =
+      Test_helpers.run_if_not_under_rosetta2 ~f:(fun () ->
         Float64.check_floats (fun f0 f1 ->
             failmsg := (fun () -> Printf.printf "%f | %f\n%!" f0 f1);
             let fv0 = to_float64x2 f0 f0 in
@@ -1063,6 +1066,7 @@ module Float64x2 = struct
             eq (float64x2_low_int64 result) (float64x2_high_int64 result)
                (float64x2_low_int64 expect) (float64x2_high_int64 expect)
         );
+      )
     ;;
 
     external dp : (int [@untagged]) -> (t [@unboxed]) -> (t [@unboxed]) -> (t [@unboxed]) = "caml_vec128_unreachable" "caml_sse41_float64x2_dp"

tests/simd/scalar_ops.ml

@@ -44,9 +44,10 @@ module Int64 = struct
       [@@noalloc] [@@unboxed] [@@builtin]
 
   let () =
-    eq' (bit_deposit 3L 4L) 0x4L;
-    eq' (bit_deposit 235L 522L) 0xAL;
-    eq' (bit_extract 3L 4L) 0x0L;
-    eq' (bit_extract 235L 522L) 0x3L
+    Test_helpers.run_if_not_under_rosetta2 ~f:(fun () ->
+        eq' (bit_deposit 3L 4L) 0x4L;
+        eq' (bit_deposit 235L 522L) 0xAL;
+        eq' (bit_extract 3L 4L) 0x0L;
+        eq' (bit_extract 235L 522L) 0x3L)
   ;;
 end

tests/simd/test_helpers.ml

@@ -0,0 +1,28 @@
+type rosetta2_status =
+  | Unknown
+  | Off
+  | On
+
+let get_rosetta2_status () =
+  let file_path = Filename.temp_file "ocaml-rosetta2" "sysctl" in
+  let command = Printf.sprintf "/usr/sbin/sysctl -n sysctl.proc_translated > %S 2> /dev/null" file_path in
+  let exit_code = Sys.command command in
+  match exit_code with
+  | 0 ->
+    begin try
+        let file_chan = open_in file_path in
+        let first_line = input_line file_chan in
+        match first_line with
+        | "0" -> Off
+        | "1" -> On
+        | _ -> Unknown
+      with _ ->
+        Unknown
+    end
+  | _ ->
+    Unknown
+
+let run_if_not_under_rosetta2 ~f =
+  match get_rosetta2_status () with
+  | Unknown | On -> ()
+  | Off -> f ()

tests/simd/test_helpers.mli

@@ -0,0 +1,8 @@
+type rosetta2_status =
+  | Unknown
+  | Off
+  | On
+
+val get_rosetta2_status : unit -> rosetta2_status
+
+val run_if_not_under_rosetta2 : f:(unit -> unit) -> unit