Remove POLYFILL_OLD_MATH_FUNCTIONS setting (#23262)

These polyfills are only needed on ancient browser versions that there
should be no need to support.

Author: sbc100

ChangeLog.md

@@ -48,6 +48,9 @@ See docs/process.md for more on how version tagging works.
   `--post-js` files will now be delayed until after module creation and after
   `main` runs.  This matches the existing behaviour when using sync instantation
   (`-sWASM_ASYNC_COMPILATION=0`) but is an observable difference. (#23157)
+- The `POLYFILL_OLD_MATH_FUNCTIONS` setting was removed.  The browser versions
+  that require these polyfills are no longer supported by emscripten so the
+  polyfills should never be needed. (#23262)
 
 3.1.74 - 12/14/24
 -----------------

src/preamble.js

@@ -328,8 +328,6 @@ function addOnPostRun(cb) {
   __ATPOSTRUN__.unshift(cb);
 }
 
-#include "runtime_math.js"
-
 // A counter of dependencies for calling run(). If we need to
 // do asynchronous work before running, increment this and
 // decrement it. Incrementing must happen in a place like

src/preamble_minimal.js

@@ -89,7 +89,6 @@ var runtimeExited = false;
 var runtimeInitialized = false;
 #endif
 
-#include "runtime_math.js"
 #include "memoryprofiler.js"
 #include "runtime_exceptions.js"
 #include "runtime_debug.js"

src/runtime_math.js

@@ -1 +1 @@
-8012
+7891

test/other/codesize/test_codesize_hello_O0.gzsize

@@ -1 +1 @@
-21588
+21016

test/other/codesize/test_codesize_hello_O0.jssize

@@ -1 +1 @@
-6554
+6435

test/other/codesize/test_codesize_minimal_O0.gzsize

@@ -1 +1 @@
-17637
+17061

test/other/codesize/test_codesize_minimal_O0.jssize

@@ -1 +1 @@
-53887
+52851

test/other/test_unoptimized_code_size.js.size

@@ -1 +1 @@
-29086
+28642

test/other/test_unoptimized_code_size_no_asserts.js.size

@@ -1 +1 @@
-52670
+51634

test/other/test_unoptimized_code_size_strict.js.size

@@ -4908,20 +4908,6 @@ def test_precompiled_headers(self, suffix):
     output = self.run_js('a.out.js')
     self.assertContained('|5|', output)
 
-  def test_LEGACY_VM_SUPPORT(self):
-    # when modern features are lacking, we can polyfill them or at least warn
-    create_file('pre.js', 'Math.imul = undefined;')
-
-    def test(expected, opts):
-      print(opts)
-      self.run_process([EMCC, test_file('hello_world.c'), '--pre-js', 'pre.js'] + opts)
-      self.assertContained(expected, self.run_js('a.out.js', assert_returncode=0 if opts else NON_ZERO))
-
-    # when legacy is needed, we show an error indicating so
-    test('build with LEGACY_VM_SUPPORT', [])
-    # legacy + disabling wasm works
-    test('hello, world!', ['-sLEGACY_VM_SUPPORT', '-sWASM=0'])
-
   @crossplatform
   def test_on_abort(self):
     expected_output = 'Module.onAbort was called'

test/test_other.py

@@ -1154,9 +1154,6 @@ def phase_linker_setup(options, state, newargs):  # noqa: C901, PLR0912, PLR0915
     if settings.MINIMAL_RUNTIME and options.oformat == OFormat.HTML and not settings.PTHREADS:
       settings.USE_READY_PROMISE = 0
 
-  if settings.WASM2JS and settings.LEGACY_VM_SUPPORT:
-    settings.POLYFILL_OLD_MATH_FUNCTIONS = 1
-
   check_browser_versions()
 
   if settings.MIN_NODE_VERSION >= 150000:
@@ -1199,10 +1196,6 @@ def phase_linker_setup(options, state, newargs):  # noqa: C901, PLR0912, PLR0915
     diagnostics.warning('transpile', '-sEXCEPTION_STACK_TRACES requires an engine that support ES6 classes.')
     settings.EXCEPTION_STACK_TRACES = 0
 
-  # Silently drop any individual backwards compatibility emulation flags that are known never to occur on browsers that support WebAssembly.
-  if not settings.WASM2JS:
-    settings.POLYFILL_OLD_MATH_FUNCTIONS = 0
-
   if settings.STB_IMAGE:
     state.append_link_flag('-lstb_image')
     settings.EXPORTED_FUNCTIONS += ['_stbi_load', '_stbi_load_from_memory', '_stbi_image_free']