feat(compiler): Use Binaryen's bulk memory polyfill (#2334)

Author: spotandjake

compiler/src/codegen/compcore.re

@@ -37,6 +37,17 @@ let gensym_label = s => {
 };
 let reset_labels = () => gensym_counter := 0;
 
+/* Binaryen Features */
+let features = [
+  Module.Feature.mvp,
+  Module.Feature.multivalue,
+  Module.Feature.tail_call,
+  Module.Feature.sign_ext,
+  Module.Feature.mutable_globals,
+  Module.Feature.bulk_memory,
+  Module.Feature.bulk_memory_opt,
+];
+
 /* Number of swap variables to allocate */
 let swap_slots_i32 = [|Type.int32, Type.int32, Type.int32|];
 let swap_slots_i64 = [|Type.int64|];
@@ -3456,23 +3467,6 @@ let compile_wasm_module =
     );
   let wasm_mod = Module.create();
 
-  let default_features = [
-    Module.Feature.mvp,
-    Module.Feature.multivalue,
-    Module.Feature.tail_call,
-    Module.Feature.sign_ext,
-    Module.Feature.mutable_globals,
-  ];
-  let features =
-    if (Config.bulk_memory^) {
-      [
-        Module.Feature.bulk_memory,
-        Module.Feature.bulk_memory_opt,
-        ...default_features,
-      ];
-    } else {
-      default_features;
-    };
   let _ = Module.set_features(wasm_mod, features);
   // we set low_memory_unused := true if and only if the user has not specified a memory base.
   // This is because in many use cases in which this is specified (e.g. wasm4), users
@@ -3538,6 +3532,11 @@ let compile_wasm_module =
 
   validate_module(~name?, wasm_mod);
 
+  // Binaryen pass for polyfilling for memory.copy/fill if bulk memory is not enabled
+  if (! Config.bulk_memory^) {
+    Module.run_passes(wasm_mod, [Passes.llvm_memory_copy_fill_lowering]);
+  };
+
   switch (Config.profile^) {
   | Some(Release) => Optimize_mod.optimize(wasm_mod)
   | None => ()

compiler/src/codegen/compcore.rei

@@ -3,6 +3,8 @@ open Grain_middle_end;
 open Mashtree;
 open Binaryen;
 
+let features: list(Module.Feature.t);
+
 exception WasmRunnerError(Module.t, option(string), string);
 
 let validate_module: (~name: string=?, Module.t) => unit;

compiler/src/middle_end/analyze_inline_wasm.re

@@ -6,7 +6,6 @@ let analysis_passes = [
   Analyze_manual_memory_management.analyze,
   Analyze_purity.analyze,
   Analyze_tail_calls.analyze,
-  Analyze_inline_wasm.analyze,
   Analyze_free_vars.analyze,
   Analyze_closure_scoped_vars.analyze,
   Analyze_mutable_vars.analyze,
@@ -20,7 +19,6 @@ let optimization_passes = [
   Optimize_dead_assignments.optimize,
   Optimize_dead_branches.optimize,
   Optimize_dead_statements.optimize,
-  Optimize_inline_wasm.optimize,
   Optimize_local_mutations.optimize,
 ];
 

compiler/src/middle_end/analyze_inline_wasm.rei

@@ -368,16 +368,16 @@ let primn_type =
   | WasmMemoryCopy =>
     prim_type(
       [
-        ("source", Builtin_types.type_wasmi32),
-        ("destination", Builtin_types.type_wasmi32),
+        ("dest", Builtin_types.type_wasmi32),
+        ("src", Builtin_types.type_wasmi32),
         ("length", Builtin_types.type_wasmi32),
       ],
       Builtin_types.type_void,
     )
   | WasmMemoryFill =>
     prim_type(
       [
-        ("ptr", Builtin_types.type_wasmi32),
+        ("dest", Builtin_types.type_wasmi32),
         ("value", Builtin_types.type_wasmi32),
         ("length", Builtin_types.type_wasmi32),
       ],

compiler/src/middle_end/optimize.re

@@ -0,0 +1,54 @@
+open Grain_tests.TestFramework;
+open Grain_tests.Runner;
+open Grain_codegen;
+open Binaryen;
+
+let load_module = fullpath => {
+  let ic = open_in_bin(fullpath);
+  let length = in_channel_length(ic);
+  let module_bytes = Bytes.create(length);
+  really_input(ic, module_bytes, 0, length);
+  close_in(ic);
+  Module.read(module_bytes);
+};
+
+describe("flags", ({test, testSkip}) => {
+  // Test --no-bulk-memory polyfill
+  test("no_bulk_memory_calls", ({expect}) => {
+    let name = "no_bulk_memory_calls";
+    let outfile = wasmfile(name);
+    ignore @@
+    compile(
+      ~link=true,
+      ~config_fn=() => {Grain_utils.Config.bulk_memory := false},
+      name,
+      {|
+      module NoBulkMemoryCalls
+
+      from "runtime/unsafe/memory" include Memory
+      @unsafe
+      provide let foo = Memory.fill
+      @unsafe
+      provide let bar = Memory.copy
+      |},
+    );
+    let wasm_mod = load_module(outfile);
+    Module.set_features(
+      wasm_mod,
+      List.filter(
+        f =>
+          f != Module.Feature.bulk_memory
+          && f != Module.Feature.bulk_memory_opt,
+        Compcore.features,
+      ),
+    );
+    expect.bool(
+      List.mem(Module.Feature.bulk_memory, Module.get_features(wasm_mod)),
+    ).
+      toBe(
+      false,
+    );
+    // The module will fail validation if bulk memory opcodes are still present
+    expect.int(Module.validate(wasm_mod)).toBe(1);
+  })
+});