[wasm] Allow multi-table initialization in the wasm-module-builder

This CL just adds a parameter to addElementSegment and adjusts all
existing tests.

Note that addElementSegment contains some convenience code to construct
one initial table if it does not exist yet. I did not extend that code
to multiple tables. If you want to use multiple tables, you have to
create them first before calling addElementSegment.

R=clemensh@chromium.org

Bug: v8:7581
Change-Id: Ie131fd5dc19856703ab5cfb2fa8f7d576f70a18b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1520709Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60211}

test/mjsunit/regress/wasm/regress-739768.js

@@ -24,7 +24,7 @@ let builder1 = new WasmModuleBuilder();
 builder1.setName('module_1');
 builder1.addFunction('main', kSig_i_v).addBody([kExprUnreachable]);
 builder1.addImportedTable('z', 'table');
-builder1.addElementSegment(0, false, [0], true);
+builder1.addElementSegment(0, 0, false, [0], true);
 let module1 = new WebAssembly.Module(builder1.toBuffer());
 let instance1 =
     new WebAssembly.Instance(module1, {z: {table: instance0.exports.table}});

test/mjsunit/regress/wasm/regress-803788.js

@@ -11,7 +11,7 @@ let q_table = builder.addImportedTable("q", "table")
 let q_base = builder.addImportedGlobal("q", "base", kWasmI32);
 let q_fun = builder.addImport("q", "fun", kSig_v_v);
 builder.addType(kSig_i_ii);
-builder.addElementSegment(q_base, true, [ q_fun ])
+builder.addElementSegment(0, q_base, true, [ q_fun ])
 let module = new WebAssembly.Module(builder.toBuffer());
 let table = new WebAssembly.Table({
   element: "anyfunc",

test/mjsunit/regress/wasm/regress-817380.js

@@ -19,6 +19,6 @@ const builder2 = new WasmModuleBuilder();
 const mul_import = builder2.addImport('q', 'wasm_mul', kSig_i_ii);
 builder2.addImportedTable('q', 'table');
 const glob_import = builder2.addImportedGlobal('q', 'glob', kWasmI32);
-builder2.addElementSegment(glob_import, true, [mul_import]);
+builder2.addElementSegment(0, glob_import, true, [mul_import]);
 builder2.instantiate(
     {q: {glob: 0, js_div: i => i, wasm_mul: mul, table: table}});

test/mjsunit/regress/wasm/regress-834619.js

@@ -32,7 +32,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
         kExprCallIndirect, 0, kTableZero
       ])
       .exportFunc();
-    builder.addElementSegment(0, false, [0, 1, 1, 0]);
+    builder.addElementSegment(0, 0, false, [0, 1, 1, 0]);
 
     return builder.instantiate({q: {f2: i1.exports.f2, f1: i1.exports.f1}});
   })();

test/mjsunit/wasm/bulk-memory.js

@@ -409,7 +409,7 @@ function getMemoryFill(mem) {
 (function TestElemDropActive() {
   const builder = new WasmModuleBuilder();
   builder.setTableBounds(5, 5);
-  builder.addElementSegment(0, false, [0, 0, 0]);
+  builder.addElementSegment(0, 0, false, [0, 0, 0]);
   builder.addFunction('drop', kSig_v_v)
       .addBody([
         kNumericPrefix, kExprElemDrop,

test/mjsunit/wasm/compiled-module-serialization.js

@@ -218,7 +218,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
       .exportAs("main");
 
     builder.setTableBounds(kTableSize, kTableSize);
-    builder.addElementSegment(0, false, [f1.index]);
+    builder.addElementSegment(0, 0, false, [f1.index]);
     builder.addExportOfKind("table", kExternalTable, 0);
 
     return new WebAssembly.Module(builder.toBuffer());
@@ -239,7 +239,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
     .exportAs("main");
 
   builder.addImportedTable("z", "table", kTableSize, kTableSize);
-  builder.addElementSegment(1, false, [f2.index], true);
+  builder.addElementSegment(0, 1, false, [f2.index], true);
   var m2_bytes = builder.toBuffer();
   var m2 = new WebAssembly.Module(m2_bytes);
 

test/mjsunit/wasm/import-table.js

@@ -41,8 +41,8 @@ let kTableSize = 50;
     let f17 = addConstFunc(builder, 17);
     builder.addExport("f15", f15);
     builder.addExport("f17", f17);
-    builder.addElementSegment(15, false, [f15], true);
-    builder.addElementSegment(1, false, [call.index], true);
+    builder.addElementSegment(0, 15, false, [f15], true);
+    builder.addElementSegment(0, 1, false, [call.index], true);
 
     var mod1 = builder.toModule();
   }
@@ -62,10 +62,10 @@ let kTableSize = 50;
         ])
         .exportAs("call");
     let f26 = addConstFunc(builder, 26);
-    builder.addElementSegment(17, false, [f17], true);
-    builder.addElementSegment(21, false, [f21], true);
-    builder.addElementSegment(26, false, [f26], true);
-    builder.addElementSegment(5, false, [call.index], true);
+    builder.addElementSegment(0, 17, false, [f17], true);
+    builder.addElementSegment(0, 21, false, [f21], true);
+    builder.addElementSegment(0, 26, false, [f26], true);
+    builder.addElementSegment(0, 5, false, [call.index], true);
 
     var mod2 = builder.toModule();
   }
@@ -113,8 +113,8 @@ function addConstFuncUsingGlobal(builder, val) {
     let f18 = addConstFuncUsingGlobal(builder, 18);
     builder.addExport("f14", f14);
     builder.addExport("f18", f18);
-    builder.addElementSegment(14, false, [f14], true);
-    builder.addElementSegment(1, false, [call.index], true);
+    builder.addElementSegment(0, 14, false, [f14], true);
+    builder.addElementSegment(0, 1, false, [call.index], true);
 
     var mod1 = builder.toModule();
   }
@@ -134,10 +134,10 @@ function addConstFuncUsingGlobal(builder, val) {
         ])
         .exportAs("call");
     let f28 = addConstFuncUsingGlobal(builder, 28);
-    builder.addElementSegment(18, false, [f18], true);
-    builder.addElementSegment(22, false, [f22], true);
-    builder.addElementSegment(28, false, [f28], true);
-    builder.addElementSegment(5, false, [call.index], true);
+    builder.addElementSegment(0, 18, false, [f18], true);
+    builder.addElementSegment(0, 22, false, [f22], true);
+    builder.addElementSegment(0, 28, false, [f28], true);
+    builder.addElementSegment(0, 5, false, [call.index], true);
 
     var mod2 = builder.toModule();
   }
@@ -193,8 +193,8 @@ function addConstFuncUsingMemory(builder, val) {
     let f19 = addConstFuncUsingMemory(builder, 19);
     builder.addExport("f13", f13);
     builder.addExport("f19", f19);
-    builder.addElementSegment(13, false, [f13], true);
-    builder.addElementSegment(1, false, [call.index], true);
+    builder.addElementSegment(0, 13, false, [f13], true);
+    builder.addElementSegment(0, 1, false, [call.index], true);
 
     var mod1 = builder.toModule();
   }
@@ -216,10 +216,10 @@ function addConstFuncUsingMemory(builder, val) {
         ])
         .exportAs("call");
     let f29 = addConstFuncUsingMemory(builder, 29);
-    builder.addElementSegment(19, false, [f19], true);
-    builder.addElementSegment(23, false, [f23], true);
-    builder.addElementSegment(29, false, [f29], true);
-    builder.addElementSegment(5, false, [call.index], true);
+    builder.addElementSegment(0, 19, false, [f19], true);
+    builder.addElementSegment(0, 23, false, [f23], true);
+    builder.addElementSegment(0, 29, false, [f29], true);
+    builder.addElementSegment(0, 5, false, [call.index], true);
 
     var mod2 = builder.toModule();
   }

test/mjsunit/wasm/indirect-calls.js

@@ -169,7 +169,7 @@ function AddFunctions(builder) {
       .exportAs("main");
 
     builder.setTableBounds(length, length);
-    builder.addElementSegment(base, false, [f.add.index, f.sub.index, f.mul.index]);
+    builder.addElementSegment(0, base, false, [f.add.index, f.sub.index, f.mul.index]);
 
     return builder.instantiate();
   }
@@ -207,7 +207,7 @@ function AddFunctions(builder) {
 
   builder.setTableBounds(10, 10);
   var g = builder.addImportedGlobal("fff", "base", kWasmI32);
-  builder.addElementSegment(g, true, [f.mul.index, f.add.index, f.sub.index]);
+  builder.addElementSegment(0, g, true, [f.mul.index, f.add.index, f.sub.index]);
 
   var module = new WebAssembly.Module(builder.toBuffer());
 

test/mjsunit/wasm/indirect-tables.js

@@ -51,7 +51,7 @@ function js_div(a, b) { return (a / b) | 0; }
   builder.setTableBounds(10, 10);
   let g = builder.addImportedGlobal("q", "base", kWasmI32);
   builder.addElementSegment(
-      g, true, [f.mul.index, f.add.index, f.sub.index, d]);
+      0, g, true, [f.mul.index, f.add.index, f.sub.index, d]);
   builder.addExportOfKind("table", kExternalTable, 0);
 
   let module = new WebAssembly.Module(builder.toBuffer());
@@ -110,7 +110,7 @@ function js_div(a, b) { return (a / b) | 0; }
   builder.setTableBounds(kTableSize, kTableSize);
   let g = builder.addImportedGlobal("q", "base", kWasmI32);
   builder.addElementSegment(
-      g, true, [f.mul.index, f.add.index, f.sub.index, d]);
+      0, g, true, [f.mul.index, f.add.index, f.sub.index, d]);
   builder.addExportOfKind("table", kExternalTable, 0);
 
   let m1 = new WebAssembly.Module(builder.toBuffer());
@@ -180,7 +180,7 @@ function js_div(a, b) { return (a / b) | 0; }
   let g = builder.addImportedGlobal("q", "base", kWasmI32);
   let f = AddFunctions(builder);
   builder.addElementSegment(
-      g, true, [f.mul.index, f.add.index, f.sub.index, d]);
+      0, g, true, [f.mul.index, f.add.index, f.sub.index, d]);
   builder.addFunction("main", kSig_i_ii)
     .addBody([
       kExprI32Const, 55,  // --
@@ -256,7 +256,7 @@ function js_div(a, b) { return (a / b) | 0; }
       kExprGetLocal, 0,
       kExprCallIndirect, sig_index, kTableZero])  // --
     .exportAs("main");
-  builder.addElementSegment(g, true, [f.index]);
+  builder.addElementSegment(0, g, true, [f.index]);
 
   let module = new WebAssembly.Module(builder.toBuffer());
 
@@ -297,7 +297,7 @@ function js_div(a, b) { return (a / b) | 0; }
     .exportAs("main");
 
   builder.setTableBounds(kTableSize, kTableSize);
-  builder.addElementSegment(0, false, [f1.index]);
+  builder.addElementSegment(0, 0, false, [f1.index]);
   builder.addExportOfKind("table", kExternalTable, 0);
 
   var m1 = new WebAssembly.Module(builder.toBuffer());
@@ -316,7 +316,7 @@ function js_div(a, b) { return (a / b) | 0; }
     .exportAs("main");
 
   builder.addImportedTable("z", "table", kTableSize, kTableSize);
-  builder.addElementSegment(1, false, [f2.index], true);
+  builder.addElementSegment(0, 1, false, [f2.index], true);
 
   var m2 = new WebAssembly.Module(builder.toBuffer());
 
@@ -411,7 +411,7 @@ function js_div(a, b) { return (a / b) | 0; }
       kExprGetLocal, 0,
       kExprCallIndirect, sig_index, kTableZero])  // --
     .exportAs("main");
-  builder.addElementSegment(g, true, [g]);
+  builder.addElementSegment(0, g, true, [g]);
   let module = new WebAssembly.Module(builder.toBuffer());
 
   var instances = [];
@@ -542,7 +542,7 @@ function js_div(a, b) { return (a / b) | 0; }
       let offset = i + 1;
       let len = i + 2;
       let index = indexes[i];
-      builder.addElementSegment(offset, false, new Array(len).fill(index));
+      builder.addElementSegment(0, offset, false, new Array(len).fill(index));
     }
 
     let instance = builder.instantiate();
@@ -586,7 +586,7 @@ function js_div(a, b) { return (a / b) | 0; }
   builder1.setName('module_1');
   builder1.addFunction('f', kSig_i_i).addBody([kExprGetLocal, 0]);
   builder1.addImportedTable('z', 'table');
-  builder1.addElementSegment(0, false, [0], true);
+  builder1.addElementSegment(0, 0, false, [0], true);
   let module1 = new WebAssembly.Module(builder1.toBuffer());
   let instance1 =
       new WebAssembly.Instance(module1, {z: {table: instance0.exports.table}});
@@ -624,7 +624,7 @@ function js_div(a, b) { return (a / b) | 0; }
   builder = new WasmModuleBuilder();
   builder.addFunction('main', kSig_i_v).addBody([kExprI32Const, 0, kExprI32LoadMem, 0, 0]);
   builder.addImportedTable('', 'table');
-  builder.addElementSegment(0, false, [0], true);
+  builder.addElementSegment(0, 0, false, [0], true);
   builder.addImportedMemory('', 'memory', 1);
 
 
@@ -732,7 +732,7 @@ function js_div(a, b) { return (a / b) | 0; }
 
   builder.setTableBounds(10, 10);
   let g = builder.addImportedGlobal("q", "base", kWasmI32);
-  builder.addElementSegment(g, true, [j, w]);
+  builder.addElementSegment(0, g, true, [j, w]);
 
   let module = new WebAssembly.Module(builder.toBuffer());
   for (var i = 0; i < 5; i++) {
@@ -781,7 +781,7 @@ function js_div(a, b) { return (a / b) | 0; }
     .exportAs("main");
 
   let g = builder.addImportedGlobal("q", "base", kWasmI32);
-  builder.addElementSegment(g, true, [j, w]);
+  builder.addElementSegment(0, g, true, [j, w]);
 
   let module = new WebAssembly.Module(builder.toBuffer());
   for (var i = 0; i < 5; i++) {
@@ -820,7 +820,7 @@ function js_div(a, b) { return (a / b) | 0; }
         kExprCallIndirect, 0, kTableZero
       ])
       .exportFunc();
-    builder.addElementSegment(0, false, [0, 1, 1, 0]);
+    builder.addElementSegment(0, 0, false, [0, 1, 1, 0]);
 
     return builder.instantiate({q: {f2: i1.exports.f2, f1: i1.exports.f1}});
   })();
@@ -882,7 +882,7 @@ function js_div(a, b) { return (a / b) | 0; }
       ])
       .exportFunc();
     builder.exportMemoryAs("memory");
-    builder.addElementSegment(0, false, [0, 1, 2, 3]);
+    builder.addElementSegment(0, 0, false, [0, 1, 2, 3]);
     var instance = builder.instantiate({q: {f1: f100, f2: f200, f3: f300}});
     setMemI32(instance, 0, 5000000);
     setMemI32(instance, 4, 6000000);

test/mjsunit/wasm/interpreter.js

@@ -537,7 +537,7 @@ function checkStack(stack, expected_lines) {
   const builder1 = new WasmModuleBuilder();
   builder1.addFunction('main', kSig_i_v).addBody([kExprUnreachable]);
   builder1.addImportedTable('z', 'table');
-  builder1.addElementSegment(0, false, [0], true);
+  builder1.addElementSegment(0, 0, false, [0], true);
   const module1 = new WebAssembly.Module(builder1.toBuffer());
   const instance1 =
       new WebAssembly.Instance(module1, {z: {table: instance0.exports.table}});

test/mjsunit/wasm/return-calls.js

@@ -135,7 +135,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
   let pick = builder.addImport("q", "pick", sig_i_iii);
   const tableIndex = 3; // Arbitrary location of import
 
-  builder.addElementSegment(tableIndex,false,[pick]);
+  builder.addElementSegment(0, tableIndex,false,[pick]);
 
   let main = builder.addFunction("main", kSig_i_iii)
         .addBody([

test/mjsunit/wasm/table-copy.js

@@ -62,7 +62,7 @@ function assertTable(obj, ...elems) {
 
   {
     let o = addFunctions(builder, kTableSize);
-    builder.addElementSegment(0, false,
+    builder.addElementSegment(0, 0, false,
        [o.f0.index, o.f1.index, o.f2.index, o.f3.index, o.f4.index]);
   }
 
@@ -116,7 +116,7 @@ function assertCall(call, ...elems) {
 
   {
     let o = addFunctions(builder, 5);
-    builder.addElementSegment(0, false,
+    builder.addElementSegment(0, 0, false,
        [o.f0.index, o.f1.index, o.f2.index, o.f3.index, o.f4.index]);
   }
 
@@ -158,7 +158,7 @@ function assertCall(call, ...elems) {
 
   {
     let o = addFunctions(builder, kTableSize);
-    builder.addElementSegment(0, false,
+    builder.addElementSegment(0, 0, false,
        [o.f0.index, o.f1.index, o.f2.index]);
   }
 

test/mjsunit/wasm/table-get.js

@@ -11,7 +11,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
   const f1 = builder.addFunction('f', kSig_i_v).addBody([kExprI32Const, 11]);
   const f2 = builder.addFunction('f', kSig_i_v).addBody([kExprI32Const, 22]);
   const offset = 3;
-  builder.addElementSegment(offset, false, [f1.index, f2.index], false);
+  builder.addElementSegment(0, offset, false, [f1.index, f2.index], false);
 
   const instance = builder.instantiate();
 
@@ -27,7 +27,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
   const f2 = builder.addFunction('f', kSig_i_v).addBody([kExprI32Const, 22])
                     .exportAs("f2");
   const offset = 3;
-  builder.addElementSegment(offset, false, [f1.index, f2.index], false);
+  builder.addElementSegment(0, offset, false, [f1.index, f2.index], false);
 
   const instance = builder.instantiate();
 
@@ -42,8 +42,8 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
   const f1 = builder.addFunction('f', kSig_i_v).addBody([kExprI32Const, 11]);
   const f2 = builder.addFunction('f', kSig_i_v).addBody([kExprI32Const, 22]);
   const offset = 3;
-  builder.addElementSegment(offset, false, [f1.index, f2.index], false);
-  builder.addElementSegment(offset + 1, false, [f1.index, f2.index], false);
+  builder.addElementSegment(0, offset, false, [f1.index, f2.index], false);
+  builder.addElementSegment(0, offset + 1, false, [f1.index, f2.index], false);
 
   const instance = builder.instantiate();
 
@@ -58,7 +58,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
   const f1 = builder.addFunction('f', kSig_i_v).addBody([kExprI32Const, 11]).exportAs("f1");
   const f2 = builder.addFunction('f', kSig_i_v).addBody([kExprI32Const, 22]);
   const offset = 3;
-  builder.addElementSegment(offset, false, [f1.index, f1.index, f1.index], false);
+  builder.addElementSegment(0, offset, false, [f1.index, f1.index, f1.index], false);
 
   const instance = builder.instantiate();
 
@@ -78,7 +78,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
   const f1 = builder.addFunction('f', kSig_i_v).addBody([kExprI32Const, 11]);
   const f2 = builder.addFunction('f', kSig_i_v).addBody([kExprI32Const, 22]);
   const offset = 3;
-  builder.addElementSegment(offset, false, [f1.index, f1.index, f1.index], false);
+  builder.addElementSegment(0, offset, false, [f1.index, f1.index, f1.index], false);
 
   const instance = builder.instantiate();
 
@@ -97,7 +97,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
   const f1 = builder.addFunction('f', kSig_i_v).addBody([kExprI32Const, 11]);
   const f2 = builder.addFunction('f', kSig_i_v).addBody([kExprI32Const, 22]);
   const offset = 3;
-  builder.addElementSegment(offset, false, [f1.index, f1.index, f1.index], false);
+  builder.addElementSegment(0, offset, false, [f1.index, f1.index, f1.index], false);
 
   const instance = builder.instantiate();
   assertEquals(null, instance.exports.table.get(offset - 1));
@@ -111,7 +111,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
   const f1 = builder.addFunction('f', kSig_i_v).addBody([kExprI32Const, 11]);
   const f2 = builder.addFunction('f', kSig_i_v).addBody([kExprI32Const, 22]);
   const offset = 3;
-  builder.addElementSegment(offset, false, [f1.index, f1.index, f1.index], false);
+  builder.addElementSegment(0, offset, false, [f1.index, f1.index, f1.index], false);
 
   const instance = builder.instantiate();
   assertThrows(() => instance.exports.table.get(size + 3), RangeError);
@@ -125,7 +125,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
   const import1 = builder.addImport("q", "fun", kSig_i_ii);
   const f1 = builder.addFunction('f', kSig_i_v).addBody([kExprI32Const, 11]);
   const offset = 3;
-  builder.addElementSegment(offset, false, [f1.index, import1], false);
+  builder.addElementSegment(0, offset, false, [f1.index, import1], false);
 
   const instance = builder.instantiate({q: {fun: () => 33}});
   assertEquals(33, instance.exports.table.get(offset + 1)());

test/mjsunit/wasm/table-grow.js

@@ -132,7 +132,7 @@ let id = (() => {  // identity exported function
 
   builder.addImportedTable("q", "table", 5, 32);
   let g = builder.addImportedGlobal("q", "base", kWasmI32);
-  builder.addElementSegment(g, true,
+  builder.addElementSegment(0, g, true,
       [funcs.mul.index, funcs.add.index, funcs.sub.index]);
   builder.addExportOfKind("table", kExternalTable, 0);
   let module = new WebAssembly.Module(builder.toBuffer());
@@ -179,9 +179,9 @@ let id = (() => {  // identity exported function
   let t = builder.addImport("q", "exp_ten", sig_i_v);
 
   builder.setTableBounds(7, 35);
-  // builder.addElementSegment(g1, true,
+  // builder.addElementSegment(0, g1, true,
   //     [funcs.mul.index, funcs.add.index, funcs.sub.index]);
-  builder.addElementSegment(g1, true, [a, i, t]);
+  builder.addElementSegment(0, g1, true, [a, i, t]);
 
   builder.addExportOfKind("table", kExternalTable, 0);
   let module = new WebAssembly.Module(builder.toBuffer());
@@ -214,7 +214,7 @@ let id = (() => {  // identity exported function
   let funcs = addFunctions(builder1);
 
   builder1.addImportedTable("q", "table", 6, 36);
-  builder1.addElementSegment(g, true,
+  builder1.addElementSegment(0, g, true,
       [funcs.mul.index, funcs.add.index, funcs.sub.index]);
   let module1 = new WebAssembly.Module(builder1.toBuffer());
 
@@ -266,7 +266,7 @@ let id = (() => {  // identity exported function
         kExprGetLocal, 0,
         kExprCallIndirect, index_i_ii, kTableZero])
       .exportAs("main");
-    builder.addElementSegment(0, false, [0], true);
+    builder.addElementSegment(0, 0, false, [0], true);
     return new WebAssembly.Module(builder.toBuffer());
   }
 

test/mjsunit/wasm/wasm-module-builder.js

@@ -863,11 +863,11 @@ class WasmModuleBuilder {
     this.exports.push({name: name, kind: kExternalMemory, index: 0});
   }
 
-  addElementSegment(base, is_global, array, is_import = false) {
+  addElementSegment(table, base, is_global, array, is_import = false) {
     if (this.tables.length + this.num_imported_tables == 0) {
       this.addTable(kWasmAnyFunc, 0);
     }
-    this.element_segments.push({base: base, is_global: is_global,
+    this.element_segments.push({table: table, base: base, is_global: is_global,
                                     array: array, is_active: true});
     if (!is_global) {
       var length = base + array.length;
@@ -895,7 +895,7 @@ class WasmModuleBuilder {
     if (this.tables.length == 0) {
       this.addTable(kWasmAnyFunc, 0);
     }
-    return this.addElementSegment(this.tables[0].initial_size, false, array);
+    return this.addElementSegment(0, this.tables[0].initial_size, false, array);
   }
 
   setTableBounds(min, max = undefined) {
@@ -1113,7 +1113,10 @@ class WasmModuleBuilder {
         for (let init of inits) {
           if (init.is_active) {
             // Active segment.
-            section.emit_u8(0);  // table index / flags
+            // TODO(ahaas): Adjust the encoding of != 0 table indices once
+            // the anyref proposal and the bulk-memory-operations proposal
+            // agree on it.
+            section.emit_u32v(init.table);  // table index / flags
             if (init.is_global) {
               section.emit_u8(kExprGetGlobal);
             } else {