diff --git a/.circleci/config.yml b/.circleci/config.yml
index dffff08b436fd..520a08d52a8c7 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -817,6 +817,7 @@ jobs:
             browser64_4gb.test_audio_worklet*
             browser64_4gb.test_emscripten_log
             browser64_4gb.test_clientside_vertex_arrays_es3
+            browser64_4gb.test_emscripten_animate_canvas_element_size*
             "
   test-browser-firefox:
     executor: bionic
diff --git a/src/library_html5_webgl.js b/src/library_html5_webgl.js
index 468fe487c6423..85f3cf103dce0 100644
--- a/src/library_html5_webgl.js
+++ b/src/library_html5_webgl.js
@@ -30,12 +30,12 @@ var LibraryHtml5WebGL = {
       HEAP32[a+i] = 0;
     }
 
-    HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.alpha }}}>>2)] =
-    HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.depth }}}>>2)] =
-    HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.antialias }}}>>2)] =
-    HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.premultipliedAlpha }}}>>2)] =
-    HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.majorVersion }}}>>2)] =
-    HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.enableExtensionsByDefault }}}>>2)] = 1;
+    HEAP8[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.alpha }}})] =
+    HEAP8[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.depth }}})] =
+    HEAP8[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.antialias }}})] =
+    HEAP8[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.premultipliedAlpha }}})] =
+    HEAP8[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.majorVersion }}})] =
+    HEAP8[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.enableExtensionsByDefault }}})] = 1;
 
 #if PTHREADS
     // Default context initialization state (user can override):
@@ -80,25 +80,25 @@ var LibraryHtml5WebGL = {
 #if ASSERTIONS
     assert(attributes);
 #endif
-    var a = attributes >> 2;
-    var powerPreference = HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.powerPreference }}}>>2)];
+    var powerPreference = {{{ makeGetValue('attributes', C_STRUCTS.EmscriptenWebGLContextAttributes.powerPreference, 'i32') }}};
     var contextAttributes = {
-      'alpha': !!HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.alpha }}}>>2)],
-      'depth': !!HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.depth }}}>>2)],
-      'stencil': !!HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.stencil }}}>>2)],
-      'antialias': !!HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.antialias }}}>>2)],
-      'premultipliedAlpha': !!HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.premultipliedAlpha }}}>>2)],
-      'preserveDrawingBuffer': !!HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.preserveDrawingBuffer }}}>>2)],
+      'alpha': !!{{{ makeGetValue('attributes', C_STRUCTS.EmscriptenWebGLContextAttributes.alpha, 'i32') }}},
+      'depth': !!{{{ makeGetValue('attributes', C_STRUCTS.EmscriptenWebGLContextAttributes.depth, 'i32') }}},
+      'stencil': !!{{{ makeGetValue('attributes', C_STRUCTS.EmscriptenWebGLContextAttributes.stencil, 'i32') }}},
+      'antialias': !!{{{ makeGetValue('attributes', C_STRUCTS.EmscriptenWebGLContextAttributes.antialias, 'i32') }}},
+      'premultipliedAlpha': !!{{{ makeGetValue('attributes', C_STRUCTS.EmscriptenWebGLContextAttributes.premultipliedAlpha, 'i32') }}},
+      'preserveDrawingBuffer': !!{{{ makeGetValue('attributes', C_STRUCTS.EmscriptenWebGLContextAttributes.preserveDrawingBuffer, 'i32') }}},
       'powerPreference': emscripten_webgl_power_preferences[powerPreference],
-      'failIfMajorPerformanceCaveat': !!HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.failIfMajorPerformanceCaveat }}}>>2)],
+      'failIfMajorPerformanceCaveat': !!{{{ makeGetValue('attributes', C_STRUCTS.EmscriptenWebGLContextAttributes.failIfMajorPerformanceCaveat, 'i32') }}},
       // The following are not predefined WebGL context attributes in the WebGL specification, so the property names can be minified by Closure.
-      majorVersion: HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.majorVersion }}}>>2)],
-      minorVersion: HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.minorVersion }}}>>2)],
-      enableExtensionsByDefault: HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.enableExtensionsByDefault }}}>>2)],
-      explicitSwapControl: HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.explicitSwapControl }}}>>2)],
-      proxyContextToMainThread: HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.proxyContextToMainThread }}}>>2)],
-      renderViaOffscreenBackBuffer: HEAP32[a + ({{{ C_STRUCTS.EmscriptenWebGLContextAttributes.renderViaOffscreenBackBuffer }}}>>2)]
+      majorVersion: {{{ makeGetValue('attributes', C_STRUCTS.EmscriptenWebGLContextAttributes.majorVersion, 'i32') }}},
+      minorVersion: {{{ makeGetValue('attributes', C_STRUCTS.EmscriptenWebGLContextAttributes.minorVersion, 'i32') }}},
+      enableExtensionsByDefault: {{{ makeGetValue('attributes', C_STRUCTS.EmscriptenWebGLContextAttributes.enableExtensionsByDefault, 'i32') }}},
+      explicitSwapControl: {{{ makeGetValue('attributes', C_STRUCTS.EmscriptenWebGLContextAttributes.explicitSwapControl, 'i32') }}},
+      proxyContextToMainThread: {{{ makeGetValue('attributes', C_STRUCTS.EmscriptenWebGLContextAttributes.proxyContextToMainThread, 'i32') }}},
+      renderViaOffscreenBackBuffer: {{{ makeGetValue('attributes', C_STRUCTS.EmscriptenWebGLContextAttributes.renderViaOffscreenBackBuffer, 'i32') }}}
     };
+    err(contextAttributes);
 
     var canvas = findCanvasEventTarget(target);
 
@@ -243,10 +243,8 @@ var LibraryHtml5WebGL = {
   },
 
   emscripten_webgl_do_commit_frame: () => {
-#if TRACE_WEBGL_CALLS
     var threadId = (typeof _pthread_self != 'undefined') ? _pthread_self : () => 1;
     err(`[Thread ${threadId()}, GL ctx: ${GL.currentContext.handle}]: emscripten_webgl_do_commit_frame()`);
-#endif
     if (!GL.currentContext || !GL.currentContext.GLctx) {
 #if GL_DEBUG
       dbg('emscripten_webgl_commit_frame() failed: no GL context set current via emscripten_webgl_make_context_current()!');
diff --git a/src/library_webgl.js b/src/library_webgl.js
index c4c507255a2c3..bb9d4e1ef80a1 100644
--- a/src/library_webgl.js
+++ b/src/library_webgl.js
@@ -136,7 +136,7 @@ for (/**@suppress{duplicate}*/var i = 0; i < {{{ GL_POOL_TEMP_BUFFERS_SIZE }}};
   emscripten_webgl_enable_WEBGL_multi_draw: (ctx) => webgl_enable_WEBGL_multi_draw(GL.contexts[ctx].GLctx),
 
   $getEmscriptenSupportedExtensions__internal: true,
-  $getEmscriptenSupportedExtensions: function(ctx) {
+  $getEmscriptenSupportedExtensions: (ctx) => {
     // Restrict the list of advertised extensions to those that we actually
     // support.
     var supportedExtensions = [
@@ -280,7 +280,7 @@ for (/**@suppress{duplicate}*/var i = 0; i < {{{ GL_POOL_TEMP_BUFFERS_SIZE }}};
     // glGetError() to fetch it. As per GLES2 spec, only the first error is
     // remembered, and subsequent errors are discarded until the user has
     // cleared the stored error by a call to glGetError().
-    recordError: function recordError(errorCode) {
+    recordError: (errorCode) => {
 #if GL_TRACK_ERRORS
       if (!GL.lastError) {
         GL.lastError = errorCode;
@@ -370,7 +370,7 @@ for (/**@suppress{duplicate}*/var i = 0; i < {{{ GL_POOL_TEMP_BUFFERS_SIZE }}};
       }
     },
 
-    getTempVertexBuffer: function getTempVertexBuffer(sizeBytes) {
+    getTempVertexBuffer: (sizeBytes) => {
       var idx = GL.log2ceilLookup(sizeBytes);
       var ringbuffer = GL.currentContext.tempVertexBuffers1[idx];
       var nextFreeBufferIndex = GL.currentContext.tempVertexBufferCounters1[idx];
@@ -387,7 +387,7 @@ for (/**@suppress{duplicate}*/var i = 0; i < {{{ GL_POOL_TEMP_BUFFERS_SIZE }}};
       return ringbuffer[nextFreeBufferIndex];
     },
 
-    getTempIndexBuffer: function getTempIndexBuffer(sizeBytes) {
+    getTempIndexBuffer: (sizeBytes) => {
       var idx = GL.log2ceilLookup(sizeBytes);
       var ibo = GL.currentContext.tempIndexBuffers[idx];
       if (ibo) {
@@ -405,7 +405,7 @@ for (/**@suppress{duplicate}*/var i = 0; i < {{{ GL_POOL_TEMP_BUFFERS_SIZE }}};
     // doublebuffered temp VB memory pointers, so that every second frame
     // utilizes different set of temp buffers. The aim is to keep the set of
     // buffers being rendered, and the set of buffers being updated disjoint.
-    newRenderingFrameStarted: function newRenderingFrameStarted() {
+    newRenderingFrameStarted: () => {
       if (!GL.currentContext) {
         return;
       }
@@ -450,13 +450,13 @@ for (/**@suppress{duplicate}*/var i = 0; i < {{{ GL_POOL_TEMP_BUFFERS_SIZE }}};
 
 #if GL_FFP_ONLY
     enabledClientAttribIndices: [],
-    enableVertexAttribArray: function enableVertexAttribArray(index) {
+    enableVertexAttribArray: (index) => {
       if (!GL.enabledClientAttribIndices[index]) {
         GL.enabledClientAttribIndices[index] = true;
         GLctx.enableVertexAttribArray(index);
       }
     },
-    disableVertexAttribArray: function disableVertexAttribArray(index) {
+    disableVertexAttribArray: (index) => {
       if (GL.enabledClientAttribIndices[index]) {
         GL.enabledClientAttribIndices[index] = false;
         GLctx.disableVertexAttribArray(index);
@@ -465,7 +465,7 @@ for (/**@suppress{duplicate}*/var i = 0; i < {{{ GL_POOL_TEMP_BUFFERS_SIZE }}};
 #endif
 
 #if FULL_ES2
-    calcBufLength: function calcBufLength(size, type, stride, count) {
+    calcBufLength: (size, type, stride, count) => {
       if (stride > 0) {
         return count * stride;  // XXXvlad this is not exactly correct I don't think
       }
@@ -475,7 +475,7 @@ for (/**@suppress{duplicate}*/var i = 0; i < {{{ GL_POOL_TEMP_BUFFERS_SIZE }}};
 
     usedTempBuffers: [],
 
-    preDrawHandleClientVertexAttribBindings: function preDrawHandleClientVertexAttribBindings(count) {
+    preDrawHandleClientVertexAttribBindings: (count) => {
       GL.resetBufferBinding = false;
 
       // TODO: initial pass to detect ranges we need to upload, might not need
@@ -499,7 +499,7 @@ for (/**@suppress{duplicate}*/var i = 0; i < {{{ GL_POOL_TEMP_BUFFERS_SIZE }}};
       }
     },
 
-    postDrawHandleClientVertexAttribBindings: function postDrawHandleClientVertexAttribBindings() {
+    postDrawHandleClientVertexAttribBindings: () => {
       if (GL.resetBufferBinding) {
         GLctx.bindBuffer(0x8892 /*GL_ARRAY_BUFFER*/, GL.buffers[GLctx.currentArrayBufferBinding]);
       }
@@ -1607,6 +1607,7 @@ for (/**@suppress{duplicate}*/var i = 0; i < {{{ GL_POOL_TEMP_BUFFERS_SIZE }}};
 #endif
   ],
   glTexImage2D: (target, level, internalFormat, width, height, border, format, type, pixels) => {
+    err("glTexImage2D", pixels);
 #if MAX_WEBGL_VERSION >= 2
 #if WEBGL2_BACKWARDS_COMPATIBILITY_EMULATION
     if ({{{ isCurrentContextWebGL2() }}}) {
@@ -3100,6 +3101,7 @@ for (/**@suppress{duplicate}*/var i = 0; i < {{{ GL_POOL_TEMP_BUFFERS_SIZE }}};
 #if GL_ASSERTIONS
     GL.validateGLObjectID(GL.shaders, shader, 'glShaderSource', 'shader');
 #endif
+    out('glShaderSource', shader, count, string, length);
     var source = GL.getSource(shader, count, string, length);
 
 #if WEBGL2_BACKWARDS_COMPATIBILITY_EMULATION
@@ -3673,7 +3675,7 @@ for (/**@suppress{duplicate}*/var i = 0; i < {{{ GL_POOL_TEMP_BUFFERS_SIZE }}};
   , '$emulGlGenVertexArrays'
 #endif
   ],
-  glGenVertexArrays: function (n, arrays) {
+  glGenVertexArrays: (n, arrays) => {
 #if LEGACY_GL_EMULATION
     emulGlGenVertexArrays(n, arrays);
 #else
diff --git a/test/float_tex.cpp b/test/float_tex.cpp
index 6c14f5168cf3a..f0e426bd9d2b7 100644
--- a/test/float_tex.cpp
+++ b/test/float_tex.cpp
@@ -9,10 +9,9 @@
 #include <cmath>
 #include <iostream>
 #include <vector>
-extern "C" {
 #include <GL/gl.h>
 #include <GL/glut.h>
-}
+
 static const char vertex_shader[] =
         "#ifdef GL_ES\n"
         "precision lowp float;\n"
@@ -44,6 +43,7 @@ static const char fragment_shader[] =
         "}\n"
         "if ( dst > 0.5) discard;\n"
         "}";
+
 struct NodeInfo { //structure that we want to transmit to our shaders
     float x;
     float y;
@@ -55,8 +55,9 @@ GLuint nodeSamplerLocation; //shader sampler address
 GLuint indicesAttributeLocation; //shader attribute address
 GLuint indicesVBO; //Vertex Buffer Object Id;
 const int nbNodes = 512;
-NodeInfo * data = new NodeInfo[nbNodes]; //our data that will be transmitted using float texture.
+NodeInfo data[nbNodes]; //our data that will be transmitted using float texture.
 double alpha = 0; //use to make a simple funny effect;
+
 static void updateFloatTexture() {
     int count = 0;
     for (float x=0; x < nbNodes; ++x ) {
@@ -79,7 +80,9 @@ static void updateFloatTexture() {
     glBindTexture(GL_TEXTURE_2D, 0);
     alpha -= 0.001;
 }
+
 static void glut_draw_callback(void) {
+    printf("glut_draw_callback\n");
     glDisable(GL_CULL_FACE);
     glDisable(GL_DEPTH_TEST);
     glEnable(GL_BLEND);
@@ -96,6 +99,7 @@ static void glut_draw_callback(void) {
     glDrawArrays(GL_POINTS, 0, nbNodes);
     glutSwapBuffers();
 }
+
 GLuint createShader(const char source[], int type) {
     GLint status;
     char msg[512];
@@ -110,6 +114,7 @@ GLuint createShader(const char source[], int type) {
     assert(status == GL_TRUE);
     return shader;
 }
+
 static void gl_init(void) {
     GLuint program = glCreateProgram();
     glAttachShader(program, createShader(vertex_shader  , GL_VERTEX_SHADER));
@@ -145,6 +150,7 @@ static void gl_init(void) {
     glEnable(GL_POINT_SPRITE);
 #endif
 }
+
 int main(int argc, char *argv[]) {
     glutInit(&argc, argv);
     glutInitWindowSize(640, 480);
@@ -153,6 +159,7 @@ int main(int argc, char *argv[]) {
     /* Set up glut callback functions */
     glutDisplayFunc(glut_draw_callback      );
     gl_init();
+    printf("done setup\n");
     glutMainLoop();
     return 0;
 }
diff --git a/test/test_browser.py b/test/test_browser.py
index b38a3a85385cb..bbafa2c13493b 100644
--- a/test/test_browser.py
+++ b/test/test_browser.py
@@ -1812,6 +1812,7 @@ def test_glgears_animation(self):
       self.run_browser('something.html', '/report_gl_result?true')
 
   @requires_graphics_hardware
+  @no_4gb('assertion fails')
   def test_fulles2_sdlproc(self):
     self.btest_exit('full_es2_sdlproc.c', assert_returncode=1, args=['-sGL_TESTING', '-DHAVE_BUILTIN_SINCOS', '-sFULL_ES2', '-lGL', '-lSDL', '-lglut', '-sGL_ENABLE_GET_PROC_ADDRESS'])
 
@@ -1822,6 +1823,7 @@ def test_glgears_deriv(self):
     assert 'gl-matrix' not in read_file('test.html'), 'Should not include glMatrix when not needed'
 
   @requires_graphics_hardware
+  @no_4gb('fails to render')
   def test_glbook(self):
     self.emcc_args.append('-Wno-int-conversion')
     self.emcc_args.append('-Wno-pointer-sign')
@@ -2013,6 +2015,7 @@ def test_gl_glteximage(self):
   })
   @requires_graphics_hardware
   @requires_threads
+  @no_4gb('assertion failure')
   def test_gl_textures(self, args):
     self.btest_exit('gl_textures.cpp', args=['-lGL', '-g', '-sSTACK_SIZE=1MB'] + args)
 
@@ -2047,14 +2050,17 @@ def test_gl_renderers(self):
     self.btest('gl_renderers.c', reference='gl_renderers.png', args=['-sGL_UNSAFE_OPTS=0', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
+  @no_4gb('render fails')
   def test_gl_stride(self):
     self.btest('gl_stride.c', reference='gl_stride.png', args=['-sGL_UNSAFE_OPTS=0', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
+  @no_4gb('assertion failure')
   def test_gl_vertex_buffer_pre(self):
     self.btest('gl_vertex_buffer_pre.c', reference='gl_vertex_buffer_pre.png', args=['-sGL_UNSAFE_OPTS=0', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
+  @no_4gb('assertion failure')
   def test_gl_vertex_buffer(self):
     self.btest('gl_vertex_buffer.c', reference='gl_vertex_buffer.png', args=['-sGL_UNSAFE_OPTS=0', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'], reference_slack=1)
 
@@ -2337,6 +2343,7 @@ def test_tex_nonbyte(self):
     self.btest('tex_nonbyte.c', reference='tex_nonbyte.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
+  @no_4gb('fails to render')
   def test_float_tex(self):
     self.btest('float_tex.cpp', reference='float_tex.png', args=['-lGL', '-lglut'])
 
@@ -4821,6 +4828,7 @@ def test_preallocated_heap(self):
 
   # Tests emscripten_fetch() usage to XHR data directly to memory without persisting results to IndexedDB.
   @also_with_wasm2js
+  @no_4gb('TODO: fetch + wasm64_4gb support')
   def test_fetch_to_memory(self):
     # Test error reporting in the negative case when the file URL doesn't exist. (http 404)
     self.btest_exit('fetch/to_memory.cpp',
@@ -4838,6 +4846,7 @@ def test_fetch_to_memory(self):
   })
   @no_firefox('https://github.com/emscripten-core/emscripten/issues/16868')
   @requires_threads
+  @no_4gb('TODO: fetch + wasm64_4gb support')
   def test_fetch_from_thread(self, args):
     shutil.copyfile(test_file('gears.png'), 'gears.png')
     self.btest_exit('fetch/from_thread.cpp',
@@ -4845,6 +4854,7 @@ def test_fetch_from_thread(self, args):
                     also_wasm2js=True)
 
   @also_with_wasm2js
+  @no_4gb('TODO: fetch + wasm64_4gb support')
   def test_fetch_to_indexdb(self):
     shutil.copyfile(test_file('gears.png'), 'gears.png')
     self.btest_exit('fetch/to_indexeddb.cpp',
@@ -4852,6 +4862,7 @@ def test_fetch_to_indexdb(self):
 
   # Tests emscripten_fetch() usage to persist an XHR into IndexedDB and subsequently load up from there.
   @also_with_wasm2js
+  @no_4gb('TODO: fetch + wasm64_4gb support')
   def test_fetch_cached_xhr(self):
     shutil.copyfile(test_file('gears.png'), 'gears.png')
     self.btest_exit('fetch/cached_xhr.cpp',
@@ -4861,12 +4872,14 @@ def test_fetch_cached_xhr(self):
   @no_firefox('https://github.com/emscripten-core/emscripten/issues/16868')
   @also_with_wasm2js
   @requires_threads
+  @no_4gb('TODO: fetch + wasm64_4gb support')
   def test_fetch_response_headers(self):
     shutil.copyfile(test_file('gears.png'), 'gears.png')
     self.btest_exit('fetch/response_headers.cpp', args=['-sFETCH_DEBUG', '-sFETCH', '-pthread', '-sPROXY_TO_PTHREAD'])
 
   # Test emscripten_fetch() usage to stream a XHR in to memory without storing the full file in memory
   @also_with_wasm2js
+  @no_4gb('TODO: fetch + wasm64_4gb support')
   def test_fetch_stream_file(self):
     self.skipTest('moz-chunked-arraybuffer was firefox-only and has been removed')
     # Strategy: create a large 128MB file, and compile with a small 16MB Emscripten heap, so that the tested file
@@ -4880,9 +4893,11 @@ def test_fetch_stream_file(self):
     self.btest_exit('fetch/stream_file.cpp',
                     args=['-sFETCH_DEBUG', '-sFETCH', '-sINITIAL_MEMORY=536870912'])
 
+  @no_4gb('TODO: fetch + wasm64_4gb support')
   def test_fetch_headers_received(self):
     self.btest_exit('fetch/headers_received.cpp', args=['-sFETCH_DEBUG', '-sFETCH'])
 
+  @no_4gb('TODO: fetch + wasm64_4gb support')
   def test_fetch_xhr_abort(self):
     shutil.copyfile(test_file('gears.png'), 'gears.png')
     self.btest_exit('fetch/xhr_abort.cpp', args=['-sFETCH_DEBUG', '-sFETCH'])
@@ -4892,6 +4907,7 @@ def test_fetch_xhr_abort(self):
   @no_firefox('https://github.com/emscripten-core/emscripten/issues/16868')
   @also_with_wasm2js
   @requires_threads
+  @no_4gb('TODO: fetch + wasm64_4gb support')
   def test_fetch_sync_xhr(self):
     shutil.copyfile(test_file('gears.png'), 'gears.png')
     self.btest_exit('fetch/sync_xhr.cpp', args=['-sFETCH_DEBUG', '-sFETCH', '-pthread', '-sPROXY_TO_PTHREAD'])
@@ -4900,6 +4916,7 @@ def test_fetch_sync_xhr(self):
   # In that case, in append is implicitly understood.
   @no_firefox('https://github.com/emscripten-core/emscripten/issues/16868')
   @requires_threads
+  @no_4gb('TODO: fetch + wasm64_4gb support')
   def test_fetch_implicit_append(self):
     shutil.copyfile(test_file('gears.png'), 'gears.png')
     self.btest_exit('fetch/example_synchronous_fetch.c', args=['-sFETCH', '-pthread', '-sPROXY_TO_PTHREAD'])
@@ -4907,6 +4924,7 @@ def test_fetch_implicit_append(self):
   # Tests synchronous emscripten_fetch() usage from wasm pthread in fastcomp.
   @no_firefox('https://github.com/emscripten-core/emscripten/issues/16868')
   @requires_threads
+  @no_4gb('TODO: fetch + wasm64_4gb support')
   def test_fetch_sync_xhr_in_wasm(self):
     shutil.copyfile(test_file('gears.png'), 'gears.png')
     self.btest_exit('fetch/example_synchronous_fetch.c', args=['-sFETCH', '-pthread', '-sPROXY_TO_PTHREAD'])
@@ -4915,6 +4933,7 @@ def test_fetch_sync_xhr_in_wasm(self):
   @no_firefox('https://github.com/emscripten-core/emscripten/issues/16868')
   @also_with_wasm2js
   @requires_threads
+  @no_4gb('TODO: fetch + wasm64_4gb support')
   def test_fetch_sync_xhr_in_proxy_to_worker(self):
     shutil.copyfile(test_file('gears.png'), 'gears.png')
     self.btest_exit('fetch/sync_xhr.cpp',
@@ -4938,6 +4957,7 @@ def test_fetch_idb_delete(self):
     shutil.copyfile(test_file('gears.png'), 'gears.png')
     self.btest_exit('fetch/idb_delete.cpp', args=['-pthread', '-sFETCH_DEBUG', '-sFETCH', '-sWASM=0', '-sPROXY_TO_PTHREAD'])
 
+  @no_4gb('TODO: fetch + wasm64_4gb support')
   def test_fetch_post(self):
     self.btest_exit('fetch/test_fetch_post.c', args=['-sFETCH'])
 
@@ -5588,6 +5608,7 @@ def test_4gb(self):
 
   # Tests that emmalloc supports up to 4GB Wasm heaps.
   @no_firefox('no 4GB support yet')
+  @no_4gb('depends on specific memory limits')
   def test_emmalloc_4gb(self):
     # For now, keep this in browser as this suite runs serially, which
     # means we don't compete for memory with anything else (and run it
@@ -5598,6 +5619,7 @@ def test_emmalloc_4gb(self):
   # Test that it is possible to malloc() a huge 3GB memory block in 4GB mode using emmalloc.
   # Also test emmalloc-memvalidate and emmalloc-memvalidate-verbose build configurations.
   @no_firefox('no 4GB support yet')
+  @no_4gb('depends on specific memory limits')
   @parameterized({
     '': (['-sMALLOC=emmalloc'],),
     'debug': (['-sMALLOC=emmalloc-debug'],),
@@ -5610,6 +5632,7 @@ def test_emmalloc_3gb(self, args):
 
   # Test that it is possible to malloc() a huge 3GB memory block in 4GB mode using dlmalloc.
   @no_firefox('no 4GB support yet')
+  @no_4gb('depends on specific memory limits')
   def test_dlmalloc_3gb(self):
     self.btest_exit('alloc_3gb.c',
                     args=['-sMALLOC=dlmalloc', '-sMAXIMUM_MEMORY=4GB', '-sALLOW_MEMORY_GROWTH=1'])
@@ -5665,6 +5688,7 @@ def test_wasmfs_opfs_errors(self):
     self.btest(test, args=args, expected="0")
 
   @no_firefox('no 4GB support yet')
+  @no_4gb('depends on specific memory limits')
   def test_emmalloc_memgrowth(self, *args):
     self.btest('emmalloc_memgrowth.cpp', expected='0', args=['-sMALLOC=emmalloc', '-sALLOW_MEMORY_GROWTH=1', '-sABORTING_MALLOC=0', '-sASSERTIONS=2', '-sMINIMAL_RUNTIME=1', '-sMAXIMUM_MEMORY=4GB'])
 
@@ -5917,4 +5941,6 @@ def setUp(self):
     self.set_setting('INITIAL_MEMORY', '4200mb')
     self.set_setting('GLOBAL_BASE', '4gb')
     self.emcc_args.append('-Wno-experimental')
+    # Without this we get a warning about GLOBAL_BASE being ignored when used with SIDE_MODULE
+    self.emcc_args.append('-Wno-unused-command-line-argument')
     self.require_wasm64()