Make Buffer read*/write* native functions with a DFG/FTL intrinsic

bench/snippets/buffer-read-write.mjs

@@ -0,0 +1,105 @@
+// Buffer.prototype.read* / write* — the fixed-width accessors that JSC JIT-compiles into
+// bounds-checked loads/stores (see JSBuffer.cpp / JavaScriptCore BufferAccessorRegistry).
+//
+// Three shapes:
+//   - a tight loop over one buffer (constant offset): mostly measures call/loop overhead
+//   - a loop over increasing offsets on one buffer: the load/store + bounds check per iteration
+//   - one access on each of many distinct buffers: previously paid a hidden DataView allocation
+//     plus a structure transition per buffer
+import { bench, group, run } from "../runner.mjs";
+
+const size = 4096;
+const buf = Buffer.alloc(size);
+for (let i = 0; i < size; i++) buf[i] = (i * 37 + 11) & 0xff;
+
+const many = Array.from({ length: 1024 }, () => Buffer.alloc(64));
+
+group("constant offset (10 accesses per iteration)", () => {
+  bench("readInt32LE(0)", () => {
+    let s = 0;
+    for (let i = 0; i < 10; i++) s += buf.readInt32LE(0);
+    return s;
+  });
+  bench("writeInt32LE(v, 0)", () => {
+    for (let i = 0; i < 10; i++) buf.writeInt32LE(i, 0);
+  });
+});
+
+group("varying offset over one buffer", () => {
+  bench("readInt8", () => {
+    let s = 0;
+    for (let i = 0; i < size; i++) s += buf.readInt8(i);
+    return s;
+  });
+  bench("readUInt8", () => {
+    let s = 0;
+    for (let i = 0; i < size; i++) s += buf.readUInt8(i);
+    return s;
+  });
+  bench("readInt16BE", () => {
+    let s = 0;
+    for (let i = 0; i < size; i += 2) s += buf.readInt16BE(i);
+    return s;
+  });
+  bench("readInt32LE", () => {
+    let s = 0;
+    for (let i = 0; i < size; i += 4) s += buf.readInt32LE(i);
+    return s;
+  });
+  bench("readUInt32BE", () => {
+    let s = 0;
+    for (let i = 0; i < size; i += 4) s += buf.readUInt32BE(i);
+    return s;
+  });
+  bench("readFloatLE", () => {
+    let s = 0;
+    for (let i = 0; i < size; i += 4) s += buf.readFloatLE(i);
+    return s;
+  });
+  bench("readDoubleLE", () => {
+    let s = 0;
+    for (let i = 0; i < size; i += 8) s += buf.readDoubleLE(i);
+    return s;
+  });
+  bench("readBigInt64LE", () => {
+    let s = 0n;
+    for (let i = 0; i < size; i += 8) s += buf.readBigInt64LE(i);
+    return s;
+  });
+  bench("writeUInt8", () => {
+    for (let i = 0; i < size; i++) buf.writeUInt8(i & 0xff, i);
+  });
+  bench("writeInt16BE", () => {
+    for (let i = 0; i < size; i += 2) buf.writeInt16BE(i, i);
+  });
+  bench("writeInt32LE", () => {
+    for (let i = 0; i < size; i += 4) buf.writeInt32LE(i, i);
+  });
+  bench("writeUInt32BE", () => {
+    for (let i = 0; i < size; i += 4) buf.writeUInt32BE(i, i);
+  });
+  bench("writeFloatLE", () => {
+    for (let i = 0; i < size; i += 4) buf.writeFloatLE(i + 0.5, i);
+  });
+  bench("writeDoubleLE", () => {
+    for (let i = 0; i < size; i += 8) buf.writeDoubleLE(i + 0.5, i);
+  });
+});
+
+group("one access on each of 1024 buffers", () => {
+  bench("readInt32LE", () => {
+    let s = 0;
+    for (let i = 0; i < many.length; i++) s += many[i].readInt32LE(0);
+    return s;
+  });
+  bench("writeInt32LE", () => {
+    for (let i = 0; i < many.length; i++) many[i].writeInt32LE(i, 0);
+  });
+  bench("readDoubleLE", () => {
+    let s = 0;
+    for (let i = 0; i < many.length; i++) s += many[i].readDoubleLE(0);
+    return s;
+  });
+});
+
+await run();

scripts/build/deps/webkit.ts

@@ -10,7 +10,7 @@
 // Windows ICU data table filtered + per-item zstd compressed, and Windows
 // unwind info (RtlAddGrowableFunctionTable) registered for the fixed JIT
 // pool (LLInt pending offlineasm .seh_* emission).
-export const WEBKIT_VERSION = "a40d462206e1caf8388062120acde61e37a4ae7d";
+export const WEBKIT_VERSION = "autobuild-preview-pr-330-be77ad70";
 
 /**
  * WebKit (JavaScriptCore) — the JS engine.

src/js/builtins.d.ts

@@ -338,7 +338,6 @@ declare function $controller(): TODO;
 declare function $createFIFO(): TODO;
 declare function $createUninitializedArrayBuffer(size: number): ArrayBuffer;
 declare function $data(): TODO;
-declare function $dataView(): TODO;
 declare function $decode(): TODO;
 declare function $dirname(): TODO;
 declare function $disturbed(): TODO;
@@ -692,8 +691,6 @@ declare function $toClass(fn: Function, name: string, base?: Function | undefine
 
 declare function $min(a: number, b: number): number;
 
-declare function $checkBufferRead(buf: Buffer, offset: number, byteLength: number): undefined;
-
 /**
  * Schedules a callback to be invoked as a microtask.
  */

src/js/builtins/BunBuiltinNames.h

@@ -61,7 +61,6 @@ using namespace JSC;
     macro(byobRequest) \
     macro(bytes) \
     macro(cancel) \
-    macro(checkBufferRead) \
     macro(checks) \
     macro(cloneArrayBuffer) \
     macro(close) \
@@ -74,7 +73,6 @@ using namespace JSC;
     macro(createUninitializedArrayBuffer) \
     macro(ctimeMs) \
     macro(data) \
-    macro(dataView) \
     macro(decode) \
     macro(dest) \
     macro(dirname) \