From ab4fde0fc72ee30c296c4070a763b476ca8bebc3 Mon Sep 17 00:00:00 2001
From: guybedford <guybedford@gmail.com>
Date: Wed, 10 Jun 2015 14:46:30 +0200
Subject: [PATCH 1/2] implement bulk re-exports for instantiate setter perf

---
 src/codegeneration/InstantiateModuleTransformer.js | 14 +++++++++-----
 third_party/es6-module-loader/loader.js            | 11 ++++++++++-
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/src/codegeneration/InstantiateModuleTransformer.js b/src/codegeneration/InstantiateModuleTransformer.js
index 5d640be3e..d3320ad69 100644
--- a/src/codegeneration/InstantiateModuleTransformer.js
+++ b/src/codegeneration/InstantiateModuleTransformer.js
@@ -349,12 +349,14 @@ export class InstantiateModuleTransformer extends ModuleTransformer {
 
       // then do export bindings of re-exported dependencies
       if (externalExportBindings) {
+        let reexports = {};
         externalExportBindings.forEach(({exportName, importName}) => {
-          let statement = importName === null ?
-              parseStatement `$__export(${exportName}, $__m);` :
-              parseStatement `$__export(${exportName}, $__m.${importName});`;
-          setterStatements.push(statement);
+          reexports[exportName] = importName === null ?
+              parseExpression `$__m` : parseExpression `$__m.${importName}`;
         });
+        setterStatements.push(
+          parseStatement `$__export(${createObjectLiteral(reexports)})`
+        );
       }
 
       // create local module bindings
@@ -368,10 +370,12 @@ export class InstantiateModuleTransformer extends ModuleTransformer {
       // exported dependencies
       if (exportStarBinding) {
         setterStatements = setterStatements.concat(parseStatements `
+          var exportObj = {};
           Object.keys($__m).forEach(function(p) {
             if (p !== 'default' && !$__exportNames[p])
-              $__export(p, $__m[p]);
+              exportObj[p] = $__m[p];
           });
+          $__export(exportObj);
         `);
 
         let exportNames = {};
diff --git a/third_party/es6-module-loader/loader.js b/third_party/es6-module-loader/loader.js
index 3aa944fd7..e1b720d9f 100644
--- a/third_party/es6-module-loader/loader.js
+++ b/third_party/es6-module-loader/loader.js
@@ -687,7 +687,16 @@ function logloads(loads) {
         // NB This should be an Object.defineProperty, but that is very slow.
         //    By disaling this module write-protection we gain performance.
         //    It could be useful to allow an option to enable or disable this.
-        moduleObj[name] = value;
+
+        // bulk export object
+        if (typeof name == 'object') {
+          for (var p in name)
+            moduleObj[p] = name[p];
+        }
+        // single export name / value pair
+        else {
+          moduleObj[name] = value;
+        }
 
         for (var i = 0, l = module.importers.length; i < l; i++) {
           var importerModule = module.importers[i];

From 7abe36f441f73ca7752186f593b980c3a5cb9372 Mon Sep 17 00:00:00 2001
From: guybedford <guybedford@gmail.com>
Date: Thu, 11 Jun 2015 12:45:56 +0200
Subject: [PATCH 2/2] use Object.create(null), indenting

---
 src/codegeneration/InstantiateModuleTransformer.js | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/src/codegeneration/InstantiateModuleTransformer.js b/src/codegeneration/InstantiateModuleTransformer.js
index d3320ad69..01c3d9880 100644
--- a/src/codegeneration/InstantiateModuleTransformer.js
+++ b/src/codegeneration/InstantiateModuleTransformer.js
@@ -349,28 +349,26 @@ export class InstantiateModuleTransformer extends ModuleTransformer {
 
       // then do export bindings of re-exported dependencies
       if (externalExportBindings) {
-        let reexports = {};
+        let reexports = Object.create(null);
         externalExportBindings.forEach(({exportName, importName}) => {
           reexports[exportName] = importName === null ?
               parseExpression `$__m` : parseExpression `$__m.${importName}`;
         });
         setterStatements.push(
-          parseStatement `$__export(${createObjectLiteral(reexports)})`
-        );
+            parseStatement `$__export(${createObjectLiteral(reexports)})`);
       }
 
       // create local module bindings
       if (moduleBinding) {
         setterStatements.push(
-          parseStatement `${id(moduleBinding)} = $__m;`
-        );
+            parseStatement `${id(moduleBinding)} = $__m;`);
       }
 
       // finally run export * if applying to this dependency, for not-already
       // exported dependencies
       if (exportStarBinding) {
         setterStatements = setterStatements.concat(parseStatements `
-          var exportObj = {};
+          var exportObj = Object.create(null);
           Object.keys($__m).forEach(function(p) {
             if (p !== 'default' && !$__exportNames[p])
               exportObj[p] = $__m[p];