src/third_party/mozjs/js/src/jit/BaselineInspector.h

/* -*- 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_BaselineInspector_h
#define jit_BaselineInspector_h

#ifdef JS_ION

#include "jscntxt.h"
#include "jscompartment.h"

#include "BaselineJIT.h"
#include "BaselineIC.h"
#include "MIR.h"

namespace js {
namespace jit {

class BaselineInspector;

class ICInspector
{
  protected:
    BaselineInspector *inspector_;
    jsbytecode *pc_;
    ICEntry *icEntry_;

    ICInspector(BaselineInspector *inspector, jsbytecode *pc, ICEntry *icEntry)
      : inspector_(inspector), pc_(pc), icEntry_(icEntry)
    { }
};

class SetElemICInspector : public ICInspector
{
  public:
    SetElemICInspector(BaselineInspector *inspector, jsbytecode *pc, ICEntry *icEntry)
      : ICInspector(inspector, pc, icEntry)
    { }

    bool sawOOBDenseWrite() const;
    bool sawOOBTypedArrayWrite() const;
    bool sawDenseWrite() const;
};

class BaselineInspector
{
  private:
    RootedScript script;
    ICEntry *prevLookedUpEntry;

  public:
    BaselineInspector(JSContext *cx, JSScript *rawScript)
      : script(cx, rawScript), prevLookedUpEntry(NULL)
    {
        JS_ASSERT(script);
    }

    bool hasBaselineScript() const {
        return script->hasBaselineScript();
    }

    BaselineScript *baselineScript() const {
        return script->baselineScript();
    }

  private:
#ifdef DEBUG
    bool isValidPC(jsbytecode *pc) {
        return (pc >= script->code) && (pc < script->code + script->length);
    }
#endif

    ICEntry &icEntryFromPC(jsbytecode *pc) {
        JS_ASSERT(hasBaselineScript());
        JS_ASSERT(isValidPC(pc));
        ICEntry &ent = baselineScript()->icEntryFromPCOffset(pc - script->code, prevLookedUpEntry);
        JS_ASSERT(ent.isForOp());
        prevLookedUpEntry = &ent;
        return ent;
    }

    template <typename ICInspectorType>
    ICInspectorType makeICInspector(jsbytecode *pc, ICStub::Kind expectedFallbackKind) {
        ICEntry *ent = NULL;
        if (hasBaselineScript()) {
            ent = &icEntryFromPC(pc);
            JS_ASSERT(ent->fallbackStub()->kind() == expectedFallbackKind);
        }
        return ICInspectorType(this, pc, ent);
    }

    ICStub *monomorphicStub(jsbytecode *pc);
    bool dimorphicStub(jsbytecode *pc, ICStub **pfirst, ICStub **psecond);

  public:
    bool maybeShapesForPropertyOp(jsbytecode *pc, Vector<Shape *> &shapes);

    SetElemICInspector setElemICInspector(jsbytecode *pc) {
        return makeICInspector<SetElemICInspector>(pc, ICStub::SetElem_Fallback);
    }

    MIRType expectedResultType(jsbytecode *pc);
    MCompare::CompareType expectedCompareType(jsbytecode *pc);
    MIRType expectedBinaryArithSpecialization(jsbytecode *pc);

    bool hasSeenNonNativeGetElement(jsbytecode *pc);
    bool hasSeenNegativeIndexGetElement(jsbytecode *pc);
    bool hasSeenAccessedGetter(jsbytecode *pc);
    bool hasSeenDoubleResult(jsbytecode *pc);
};

} // namespace jit
} // namespace js

#endif // JS_ION

#endif /* jit_BaselineInspector_h */