diff -r 000000000000 -r 6474c204b198 js/src/jit/JitOptions.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit/JitOptions.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,88 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef jit_JitOptions_h
+#define jit_JitOptions_h
+
+#include "jit/IonTypes.h"
+#include "js/TypeDecls.h"
+
+#ifdef JS_ION
+
+namespace js {
+namespace jit {
+
+// Longer scripts can only be compiled off thread, as these compilations
+// can be expensive and stall the main thread for too long.
+static const uint32_t MAX_OFF_THREAD_SCRIPT_SIZE = 100 * 1000;
+static const uint32_t MAX_MAIN_THREAD_SCRIPT_SIZE = 2 * 1000;
+static const uint32_t MAX_MAIN_THREAD_LOCALS_AND_ARGS = 256;
+
+// DOM Worker runtimes don't have off thread compilation, but can also compile
+// larger scripts since this doesn't stall the main thread.
+static const uint32_t MAX_DOM_WORKER_SCRIPT_SIZE = 16 * 1000;
+static const uint32_t MAX_DOM_WORKER_LOCALS_AND_ARGS = 2048;
+
+// Possible register allocators which may be used.
+enum IonRegisterAllocator {
+    RegisterAllocator_LSRA,
+    RegisterAllocator_Backtracking,
+    RegisterAllocator_Stupid
+};
+
+enum IonGvnKind {
+    GVN_Optimistic,
+    GVN_Pessimistic
+};
+
+struct JitOptions
+{
+    bool checkGraphConsistency;
+#ifdef CHECK_OSIPOINT_REGISTERS
+    bool checkOsiPointRegisters;
+#endif
+    bool checkRangeAnalysis;
+    bool compileTryCatch;
+    bool disableGvn;
+    bool disableLicm;
+    bool disableInlining;
+    bool disableEdgeCaseAnalysis;
+    bool disableRangeAnalysis;
+    bool disableUce;
+    bool disableEaa;
+    bool eagerCompilation;
+    bool forceDefaultIonUsesBeforeCompile;
+    uint32_t forcedDefaultIonUsesBeforeCompile;
+    bool forceGvnKind;
+    IonGvnKind forcedGvnKind;
+    bool forceRegisterAllocator;
+    IonRegisterAllocator forcedRegisterAllocator;
+    bool limitScriptSize;
+    bool osr;
+    uint32_t baselineUsesBeforeCompile;
+    uint32_t exceptionBailoutThreshold;
+    uint32_t frequentBailoutThreshold;
+    uint32_t maxStackArgs;
+    uint32_t osrPcMismatchesBeforeRecompile;
+    uint32_t smallFunctionMaxBytecodeLength_;
+    uint32_t usesBeforeCompilePar;
+    bool profileInlineFrames;
+
+    JitOptions();
+    bool isSmallFunction(JSScript *script) const;
+    void setEagerCompilation();
+    void setUsesBeforeCompile(uint32_t useCount);
+    void resetUsesBeforeCompile();
+};
+
+extern JitOptions js_JitOptions;
+
+} // namespace jit
+} // namespace js
+
+#endif // JS_ION
+
+#endif /* jit_JitOptions_h */