From 26ad367b410d1342521ee7d47657930b04497cdc Mon Sep 17 00:00:00 2001
From: Katelyn Gadd <kg@luminance.org>
Date: Thu, 5 Sep 2024 08:06:43 -0700
Subject: [PATCH] Use native wasm atomic fence instead of calling C for memory
 barriers

---
 src/mono/browser/runtime/jiterpreter-trace-generator.ts | 4 ++--
 src/mono/browser/runtime/jiterpreter.ts                 | 6 ------
 src/mono/mono/mini/interp/jiterpreter.c                 | 5 -----
 3 files changed, 2 insertions(+), 13 deletions(-)

diff --git a/src/mono/browser/runtime/jiterpreter-trace-generator.ts b/src/mono/browser/runtime/jiterpreter-trace-generator.ts
index 8b7ae0afeb2fd6..6122678c158a3d 100644
--- a/src/mono/browser/runtime/jiterpreter-trace-generator.ts
+++ b/src/mono/browser/runtime/jiterpreter-trace-generator.ts
@@ -10,7 +10,7 @@ import {
 } from "./memory";
 import {
     WasmOpcode, WasmSimdOpcode, WasmValtype,
-    getOpcodeName, MintOpArgType
+    getOpcodeName, MintOpArgType, WasmAtomicOpcode
 } from "./jiterpreter-opcodes";
 import {
     MintOpcode, SimdInfo,
@@ -3956,7 +3956,7 @@ function emit_atomics (
 ) {
     if (opcode === MintOpcode.MINT_MONO_MEMORY_BARRIER) {
         if (WasmEnableThreads)
-            builder.callImport("membar");
+            builder.appendAtomic(WasmAtomicOpcode.atomic_fence);
         return true;
     }
 
diff --git a/src/mono/browser/runtime/jiterpreter.ts b/src/mono/browser/runtime/jiterpreter.ts
index c4f865e452aa6c..6b934b879c320f 100644
--- a/src/mono/browser/runtime/jiterpreter.ts
+++ b/src/mono/browser/runtime/jiterpreter.ts
@@ -286,7 +286,6 @@ function getTraceImports () {
         ["stelemr_tc", "stelemr", getRawCwrap("mono_jiterp_stelem_ref")],
         importDef("fma", getRawCwrap("fma")),
         importDef("fmaf", getRawCwrap("fmaf")),
-        importDef("membar", getRawCwrap("mono_jiterp_memory_barrier")),
     ];
 
     if (instrumentedMethodNames.length > 0) {
@@ -664,11 +663,6 @@ function initialize_builder (builder: WasmBuilder) {
         },
         WasmValtype.void, true
     );
-    builder.defineType(
-        "membar",
-        {},
-        WasmValtype.void, true
-    );
 
     const traceImports = getTraceImports();
 
diff --git a/src/mono/mono/mini/interp/jiterpreter.c b/src/mono/mono/mini/interp/jiterpreter.c
index 2bb2204accbf76..fa75f766cec02b 100644
--- a/src/mono/mono/mini/interp/jiterpreter.c
+++ b/src/mono/mono/mini/interp/jiterpreter.c
@@ -1165,11 +1165,6 @@ mono_jiterp_stelem_ref (
 	return 1;
 }
 
-EMSCRIPTEN_KEEPALIVE void
-mono_jiterp_memory_barrier () {
-	mono_memory_barrier ();
-}
-
 
 // keep in sync with jiterpreter-enums.ts JiterpMember
 enum {