diff -r 000000000000 -r 6474c204b198 js/src/jit/TypePolicy.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit/TypePolicy.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,348 @@
+/* -*- 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_TypePolicy_h
+#define jit_TypePolicy_h
+
+#include "jit/IonAllocPolicy.h"
+#include "jit/IonTypes.h"
+
+namespace js {
+namespace jit {
+
+class MInstruction;
+class MDefinition;
+
+// A type policy directs the type analysis phases, which insert conversion,
+// boxing, unboxing, and type changes as necessary.
+class TypePolicy
+{
+  public:
+    // Analyze the inputs of the instruction and perform one of the following
+    // actions for each input:
+    //  * Nothing; the input already type-checks.
+    //  * If untyped, optionally ask the input to try and specialize its value.
+    //  * Replace the operand with a conversion instruction.
+    //  * Insert an unconditional deoptimization (no conversion possible).
+    virtual bool adjustInputs(TempAllocator &alloc, MInstruction *def) = 0;
+};
+
+class BoxInputsPolicy : public TypePolicy
+{
+  protected:
+    static MDefinition *boxAt(TempAllocator &alloc, MInstruction *at, MDefinition *operand);
+
+  public:
+    static MDefinition *alwaysBoxAt(TempAllocator &alloc, MInstruction *at, MDefinition *operand);
+    virtual bool adjustInputs(TempAllocator &alloc, MInstruction *def);
+};
+
+class ArithPolicy : public BoxInputsPolicy
+{
+  protected:
+    // Specifies three levels of specialization:
+    //  - < Value. This input is expected and required.
+    //  - == Any. Inputs are probably primitive.
+    //  - == None. This op should not be specialized.
+    MIRType specialization_;
+
+  public:
+    bool adjustInputs(TempAllocator &alloc, MInstruction *def);
+};
+
+class BitwisePolicy : public BoxInputsPolicy
+{
+  protected:
+    // Specifies three levels of specialization:
+    //  - < Value. This input is expected and required.
+    //  - == Any. Inputs are probably primitive.
+    //  - == None. This op should not be specialized.
+    MIRType specialization_;
+
+  public:
+    bool adjustInputs(TempAllocator &alloc, MInstruction *def);
+
+    MIRType specialization() const {
+        return specialization_;
+    }
+};
+
+class ComparePolicy : public BoxInputsPolicy
+{
+    bool adjustInputs(TempAllocator &alloc, MInstruction *def);
+};
+
+// Policy for MTest instructions.
+class TestPolicy : public BoxInputsPolicy
+{
+  public:
+    bool adjustInputs(TempAllocator &alloc, MInstruction *ins);
+};
+
+class TypeBarrierPolicy : public BoxInputsPolicy
+{
+  public:
+    bool adjustInputs(TempAllocator &alloc, MInstruction *ins);
+};
+
+class CallPolicy : public BoxInputsPolicy
+{
+  public:
+    bool adjustInputs(TempAllocator &alloc, MInstruction *def);
+};
+
+// Policy for MPow. First operand Double; second Double or Int32.
+class PowPolicy : public BoxInputsPolicy
+{
+    MIRType specialization_;
+
+  public:
+    PowPolicy(MIRType specialization)
+      : specialization_(specialization)
+    { }
+
+    bool adjustInputs(TempAllocator &alloc, MInstruction *ins);
+};
+
+// Expect a string for operand Op. If the input is a Value, it is unboxed.
+template <unsigned Op>
+class StringPolicy : public BoxInputsPolicy
+{
+  public:
+    static bool staticAdjustInputs(TempAllocator &alloc, MInstruction *def);
+    bool adjustInputs(TempAllocator &alloc, MInstruction *def) {
+        return staticAdjustInputs(alloc, def);
+    }
+};
+
+// Expect a string for operand Op. Else a ToString instruction is inserted.
+template <unsigned Op>
+class ConvertToStringPolicy : public BoxInputsPolicy
+{
+  public:
+    static bool staticAdjustInputs(TempAllocator &alloc, MInstruction *def);
+    bool adjustInputs(TempAllocator &alloc, MInstruction *def) {
+        return staticAdjustInputs(alloc, def);
+    }
+};
+
+// Expect an Int for operand Op. If the input is a Value, it is unboxed.
+template <unsigned Op>
+class IntPolicy : public BoxInputsPolicy
+{
+  public:
+    static bool staticAdjustInputs(TempAllocator &alloc, MInstruction *def);
+    bool adjustInputs(TempAllocator &alloc, MInstruction *def) {
+        return staticAdjustInputs(alloc, def);
+    }
+};
+
+// Expect an Int for operand Op. Else a ToInt32 instruction is inserted.
+template <unsigned Op>
+class ConvertToInt32Policy : public BoxInputsPolicy
+{
+  public:
+    static bool staticAdjustInputs(TempAllocator &alloc, MInstruction *def);
+    bool adjustInputs(TempAllocator &alloc, MInstruction *def) {
+        return staticAdjustInputs(alloc, def);
+    }
+};
+
+// Expect a double for operand Op. If the input is a Value, it is unboxed.
+template <unsigned Op>
+class DoublePolicy : public BoxInputsPolicy
+{
+  public:
+    static bool staticAdjustInputs(TempAllocator &alloc, MInstruction *def);
+    bool adjustInputs(TempAllocator &alloc, MInstruction *def) {
+        return staticAdjustInputs(alloc, def);
+    }
+};
+
+// Expect a float32 for operand Op. If the input is a Value, it is unboxed.
+template <unsigned Op>
+class Float32Policy : public BoxInputsPolicy
+{
+  public:
+    static bool staticAdjustInputs(TempAllocator &alloc, MInstruction *def);
+    bool adjustInputs(TempAllocator &alloc, MInstruction *def) {
+        return staticAdjustInputs(alloc, def);
+    }
+};
+
+// Expect a float32 OR a double for operand Op, but will prioritize Float32
+// if the result type is set as such. If the input is a Value, it is unboxed.
+template <unsigned Op>
+class FloatingPointPolicy : public TypePolicy
+{
+    MIRType policyType_;
+
+  public:
+    bool adjustInputs(TempAllocator &alloc, MInstruction *def) {
+        if (policyType_ == MIRType_Double)
+            return DoublePolicy<Op>::staticAdjustInputs(alloc, def);
+        return Float32Policy<Op>::staticAdjustInputs(alloc, def);
+    }
+    void setPolicyType(MIRType type) {
+        policyType_ = type;
+    }
+};
+
+template <unsigned Op>
+class NoFloatPolicy : public TypePolicy
+{
+  public:
+    static bool staticAdjustInputs(TempAllocator &alloc, MInstruction *def);
+    bool adjustInputs(TempAllocator &alloc, MInstruction *def) {
+        return staticAdjustInputs(alloc, def);
+    }
+};
+
+// Box objects or strings as an input to a ToDouble instruction.
+class ToDoublePolicy : public BoxInputsPolicy
+{
+  public:
+    static bool staticAdjustInputs(TempAllocator &alloc, MInstruction *def);
+    bool adjustInputs(TempAllocator &alloc, MInstruction *def) {
+        return staticAdjustInputs(alloc, def);
+    }
+};
+
+// Box objects, strings and undefined as input to a ToInt32 instruction.
+class ToInt32Policy : public BoxInputsPolicy
+{
+  public:
+    static bool staticAdjustInputs(TempAllocator &alloc, MInstruction *def);
+    bool adjustInputs(TempAllocator &alloc, MInstruction *def) {
+        return staticAdjustInputs(alloc, def);
+    }
+};
+
+template <unsigned Op>
+class ObjectPolicy : public BoxInputsPolicy
+{
+  public:
+    static bool staticAdjustInputs(TempAllocator &alloc, MInstruction *ins);
+    bool adjustInputs(TempAllocator &alloc, MInstruction *ins) {
+        return staticAdjustInputs(alloc, ins);
+    }
+};
+
+// Single-object input. If the input is a Value, it is unboxed. If it is
+// a primitive, we use ValueToNonNullObject.
+class SingleObjectPolicy : public ObjectPolicy<0>
+{ };
+
+template <unsigned Op>
+class BoxPolicy : public BoxInputsPolicy
+{
+  public:
+    static bool staticAdjustInputs(TempAllocator &alloc, MInstruction *ins);
+    bool adjustInputs(TempAllocator &alloc, MInstruction *ins) {
+        return staticAdjustInputs(alloc, ins);
+    }
+};
+
+// Boxes everything except inputs of type Type.
+template <unsigned Op, MIRType Type>
+class BoxExceptPolicy : public TypePolicy
+{
+  public:
+    static bool staticAdjustInputs(TempAllocator &alloc, MInstruction *ins);
+    bool adjustInputs(TempAllocator &alloc, MInstruction *ins) {
+        return staticAdjustInputs(alloc, ins);
+    }
+};
+
+// Combine multiple policies.
+template <class Lhs, class Rhs>
+class MixPolicy : public TypePolicy
+{
+  public:
+    static bool staticAdjustInputs(TempAllocator &alloc, MInstruction *ins) {
+        return Lhs::staticAdjustInputs(alloc, ins) && Rhs::staticAdjustInputs(alloc, ins);
+    }
+    virtual bool adjustInputs(TempAllocator &alloc, MInstruction *ins) {
+        return staticAdjustInputs(alloc, ins);
+    }
+};
+
+// Combine three policies.
+template <class Policy1, class Policy2, class Policy3>
+class Mix3Policy : public TypePolicy
+{
+  public:
+    static bool staticAdjustInputs(TempAllocator &alloc, MInstruction *ins) {
+        return Policy1::staticAdjustInputs(alloc, ins) &&
+               Policy2::staticAdjustInputs(alloc, ins) &&
+               Policy3::staticAdjustInputs(alloc, ins);
+    }
+    virtual bool adjustInputs(TempAllocator &alloc, MInstruction *ins) {
+        return staticAdjustInputs(alloc, ins);
+    }
+};
+
+class CallSetElementPolicy : public SingleObjectPolicy
+{
+  public:
+    bool adjustInputs(TempAllocator &alloc, MInstruction *def);
+};
+
+// First operand will be boxed to a Value (except for an object)
+// Second operand (if specified) will forcefully be unboxed to an object
+class InstanceOfPolicy : public TypePolicy
+{
+  public:
+    bool adjustInputs(TempAllocator &alloc, MInstruction *def);
+};
+
+class StoreTypedArrayPolicy : public BoxInputsPolicy
+{
+  protected:
+    bool adjustValueInput(TempAllocator &alloc, MInstruction *ins, int arrayType, MDefinition *value, int valueOperand);
+
+  public:
+    bool adjustInputs(TempAllocator &alloc, MInstruction *ins);
+};
+
+class StoreTypedArrayHolePolicy : public StoreTypedArrayPolicy
+{
+  public:
+    bool adjustInputs(TempAllocator &alloc, MInstruction *ins);
+};
+
+class StoreTypedArrayElementStaticPolicy : public StoreTypedArrayPolicy
+{
+  public:
+    bool adjustInputs(TempAllocator &alloc, MInstruction *ins);
+};
+
+// Accepts integers and doubles. Everything else is boxed.
+class ClampPolicy : public BoxInputsPolicy
+{
+  public:
+    bool adjustInputs(TempAllocator &alloc, MInstruction *ins);
+};
+
+class FilterTypeSetPolicy : public BoxInputsPolicy
+{
+  public:
+    bool adjustInputs(TempAllocator &alloc, MInstruction *ins);
+};
+
+static inline bool
+CoercesToDouble(MIRType type)
+{
+    if (type == MIRType_Undefined || IsFloatingPointType(type))
+        return true;
+    return false;
+}
+
+
+} // namespace jit
+} // namespace js
+
+#endif /* jit_TypePolicy_h */