u64

tsconfig.json

@@ -11,7 +11,7 @@
     // "disableReferencedProjectLoad": true,             /* Reduce the number of projects loaded automatically by TypeScript. */
 
     /* Language and Environment */
-    "target": "es2016" /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */,
+    "target": "es2020" /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */,
     // "lib": [],                                        /* Specify a set of bundled library declaration files that describe the target runtime environment. */
     "jsx": "react" /* Specify what JSX code is generated. */,
     // "experimentalDecorators": true,                   /* Enable experimental support for TC39 stage 2 draft decorators. */

wasm/code.ts

@@ -273,10 +273,14 @@ interface InstrMem {
   align: number;
   offset: number;
 }
-interface InstrConstInt {
-  op: Instr.i32_const | Instr.i64_const;
+interface InstrConstInt32 {
+  op: Instr.i32_const;
   n: number;
 }
+interface InstrConstInt64 {
+  op: Instr.i64_const;
+  n: bigint;
+}
 interface InstrConstFloat {
   op: Instr.f32_const | Instr.f64_const;
   z: number;
@@ -300,7 +304,8 @@ type InstructionWithFields =
   | InstrLocal
   | InstrGlobal
   | InstrMem
-  | InstrConstInt
+  | InstrConstInt32
+  | InstrConstInt64
   | InstrConstFloat
   | InstrRefNull
   | InstrRefFunc;
@@ -475,7 +480,7 @@ function readInstruction(r: Reader): Instruction {
     case 0x41:
       return { op: Instr.i32_const, n: r.readUint() };
     case 0x42:
-      return { op: Instr.i64_const, n: r.readUint() };
+      return { op: Instr.i64_const, n: r.readUintBig() };
     case 0x43:
       return { op: Instr.f32_const, z: r.readF32() };
     case 0x44:

wasm/reader.ts

@@ -39,8 +39,20 @@ export class Reader {
     let shift = 0;
     while (true) {
       const b = this.read8();
-      n |= (b & 0x7f) << shift;
-      if ((b & 0x80) === 0) break;
+      n |= (b & 0b0111_1111) << shift;
+      if ((b & 0b1000_0000) === 0) break;
+      shift += 7;
+    }
+    return n;
+  }
+
+  readUintBig(): bigint {
+    let n = 0n;
+    let shift = 0;
+    while (true) {
+      const b = this.read8();
+      n |= BigInt(b & 0b0111_1111) << BigInt(shift);
+      if ((b & 0b1000_0000) === 0) break;
       shift += 7;
     }
     return n;