michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
michael@0:  * vim: set ts=8 sts=4 et sw=4 tw=99:
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef jit_BytecodeAnalysis_h
michael@0: #define jit_BytecodeAnalysis_h
michael@0: 
michael@0: #include "jsscript.h"
michael@0: #include "jit/IonAllocPolicy.h"
michael@0: #include "js/Vector.h"
michael@0: 
michael@0: namespace js {
michael@0: namespace jit {
michael@0: 
michael@0: // Basic information about bytecodes in the script.  Used to help baseline compilation.
michael@0: struct BytecodeInfo
michael@0: {
michael@0:     static const uint16_t MAX_STACK_DEPTH = 0xffffU;
michael@0:     uint16_t stackDepth;
michael@0:     bool initialized : 1;
michael@0:     bool jumpTarget : 1;
michael@0:     bool jumpFallthrough : 1;
michael@0:     bool fallthrough : 1;
michael@0: 
michael@0:     // If true, this is a JSOP_LOOPENTRY op inside a catch or finally block.
michael@0:     bool loopEntryInCatchOrFinally : 1;
michael@0: 
michael@0:     void init(unsigned depth) {
michael@0:         JS_ASSERT(depth <= MAX_STACK_DEPTH);
michael@0:         JS_ASSERT_IF(initialized, stackDepth == depth);
michael@0:         initialized = true;
michael@0:         stackDepth = depth;
michael@0:     }
michael@0: };
michael@0: 
michael@0: class BytecodeAnalysis
michael@0: {
michael@0:     JSScript *script_;
michael@0:     Vector<BytecodeInfo, 0, IonAllocPolicy> infos_;
michael@0: 
michael@0:     bool usesScopeChain_;
michael@0:     bool hasTryFinally_;
michael@0:     bool hasSetArg_;
michael@0: 
michael@0:   public:
michael@0:     explicit BytecodeAnalysis(TempAllocator &alloc, JSScript *script);
michael@0: 
michael@0:     bool init(TempAllocator &alloc, GSNCache &gsn);
michael@0: 
michael@0:     BytecodeInfo &info(jsbytecode *pc) {
michael@0:         JS_ASSERT(infos_[script_->pcToOffset(pc)].initialized);
michael@0:         return infos_[script_->pcToOffset(pc)];
michael@0:     }
michael@0: 
michael@0:     BytecodeInfo *maybeInfo(jsbytecode *pc) {
michael@0:         if (infos_[script_->pcToOffset(pc)].initialized)
michael@0:             return &infos_[script_->pcToOffset(pc)];
michael@0:         return nullptr;
michael@0:     }
michael@0: 
michael@0:     bool usesScopeChain() const {
michael@0:         return usesScopeChain_;
michael@0:     }
michael@0: 
michael@0:     bool hasTryFinally() const {
michael@0:         return hasTryFinally_;
michael@0:     }
michael@0: 
michael@0:     bool hasSetArg() const {
michael@0:         return hasSetArg_;
michael@0:     }
michael@0: };
michael@0: 
michael@0: 
michael@0: } // namespace jit
michael@0: } // namespace js
michael@0: 
michael@0: #endif /* jit_BytecodeAnalysis_h */