Bug 1697904 - Migrate more JIT prefs to StaticPrefs. r=jandem

Also relax the type on large_arraybuffers to plain bool since it is only read
once on startup.

Differential Revision: https://phabricator.services.mozilla.com/D108106

js/xpconnect/src/XPCJSContext.cpp

@@ -833,13 +833,6 @@ static void LoadStartupJSPrefs(XPCJSContext* xpccx) {
   bool disableWasmHugeMemory = Preferences::GetBool(
       JS_OPTIONS_DOT_STR "wasm_disable_huge_memory", false);
 
-  bool offthreadIonCompilation =
-      Preferences::GetBool(JS_OPTIONS_DOT_STR "ion.offthread_compilation");
-#ifdef DEBUG
-  bool fullJitDebugChecks =
-      Preferences::GetBool(JS_OPTIONS_DOT_STR "jit.full_debug_checks");
-#endif
-
   bool spectreIndexMasking =
       Preferences::GetBool(JS_OPTIONS_DOT_STR "spectre.index_masking");
   bool spectreObjectMitigations =
@@ -886,7 +879,9 @@ static void LoadStartupJSPrefs(XPCJSContext* xpccx) {
         StaticPrefs::javascript_options_native_regexp_AtStartup());
   }
 
-  JS_SetOffthreadIonCompilationEnabled(cx, offthreadIonCompilation);
+  JS_SetOffthreadIonCompilationEnabled(
+      cx,
+      StaticPrefs::javascript_options_ion_offthread_compilation_AtStartup());
 
   JS_SetGlobalJitCompilerOption(
       cx, JSJITCOMPILER_BASELINE_INTERPRETER_WARMUP_TRIGGER,
@@ -903,8 +898,9 @@ static void LoadStartupJSPrefs(XPCJSContext* xpccx) {
           javascript_options_ion_frequent_bailout_threshold_AtStartup());
 
 #ifdef DEBUG
-  JS_SetGlobalJitCompilerOption(cx, JSJITCOMPILER_FULL_DEBUG_CHECKS,
-                                fullJitDebugChecks);
+  JS_SetGlobalJitCompilerOption(
+      cx, JSJITCOMPILER_FULL_DEBUG_CHECKS,
+      StaticPrefs::javascript_options_jit_full_debug_checks_AtStartup());
 #endif
 
   JS_SetGlobalJitCompilerOption(cx, JSJITCOMPILER_SPECTRE_INDEX_MASKING,
@@ -917,13 +913,14 @@ static void LoadStartupJSPrefs(XPCJSContext* xpccx) {
                                 spectreValueMasking);
   JS_SetGlobalJitCompilerOption(cx, JSJITCOMPILER_SPECTRE_JIT_TO_CXX_CALLS,
                                 spectreJitToCxxCalls);
+
   if (disableWasmHugeMemory) {
     bool disabledHugeMemory = JS::DisableWasmHugeMemory();
     MOZ_RELEASE_ASSERT(disabledHugeMemory);
   }
 
   JS::SetLargeArrayBuffersEnabled(
-      StaticPrefs::javascript_options_large_arraybuffers());
+      StaticPrefs::javascript_options_large_arraybuffers_AtStartup());
 }
 
 static void ReloadPrefsCallback(const char* pref, void* aXpccx) {

modules/libpref/init/StaticPrefList.yaml

@@ -5355,6 +5355,21 @@
   value: 1500
   mirror: once
 
+# Enable off-main-thread Warp compilation.
+- name: javascript.options.ion.offthread_compilation
+  type: bool
+  value: true
+  mirror: once
+
+#ifdef DEBUG
+  # Enable extra correctness checks in the JITs that are slow and only available
+  # in debug builds.
+-   name: javascript.options.jit.full_debug_checks
+    type: bool
+    value: false
+    mirror: once
+#endif
+
 # Heuristic threshold for Warp/Ion to decide that too many bailouts are
 # happening and an IonScript should be discarded.
 #
@@ -5527,10 +5542,11 @@
   mirror: always
 #endif
 
+# Experimental support for ArrayBuffers larger than 2 GB.
 - name: javascript.options.large_arraybuffers
-  type: RelaxedAtomicBool
+  type: bool
   value: false
-  mirror: always
+  mirror: once
 
 #---------------------------------------------------------------------------
 # Prefs starting with "layers."

modules/libpref/init/all.js

@@ -1112,10 +1112,6 @@ pref("javascript.options.asyncstack", true);
 pref("javascript.options.asyncstack_capture_debuggee_only", true);
 
 pref("javascript.options.throw_on_asmjs_validation_failure", false);
-pref("javascript.options.ion.offthread_compilation", true);
-#ifdef DEBUG
-  pref("javascript.options.jit.full_debug_checks", false);
-#endif
 // This preference instructs the JS engine to discard the
 // source of any privileged JS after compilation. This saves
 // memory, but makes things like Function.prototype.toSource()