Line data    Source code

       1             : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
       2             :  * vim: set ts=8 sts=4 et sw=4 tw=99:
       3             :  * This Source Code Form is subject to the terms of the Mozilla Public
       4             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       5             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
       6             : 
       7             : #ifndef jit_BytecodeAnalysis_h
       8             : #define jit_BytecodeAnalysis_h
       9             : 
      10             : #include "jsscript.h"
      11             : #include "jit/JitAllocPolicy.h"
      12             : #include "js/Vector.h"
      13             : 
      14             : namespace js {
      15             : namespace jit {
      16             : 
      17             : // Basic information about bytecodes in the script.  Used to help baseline compilation.
      18             : struct BytecodeInfo
      19             : {
      20             :     static const uint16_t MAX_STACK_DEPTH = 0xffffU;
      21             :     uint16_t stackDepth;
      22             :     bool initialized : 1;
      23             :     bool jumpTarget : 1;
      24             : 
      25             :     // If true, this is a JSOP_LOOPENTRY op inside a catch or finally block.
      26             :     bool loopEntryInCatchOrFinally : 1;
      27             : 
      28      108979 :     void init(unsigned depth) {
      29      108979 :         MOZ_ASSERT(depth <= MAX_STACK_DEPTH);
      30      108979 :         MOZ_ASSERT_IF(initialized, stackDepth == depth);
      31      108979 :         initialized = true;
      32      108979 :         stackDepth = depth;
      33      108979 :     }
      34             : };
      35             : 
      36         947 : class BytecodeAnalysis
      37             : {
      38             :     JSScript* script_;
      39             :     Vector<BytecodeInfo, 0, JitAllocPolicy> infos_;
      40             : 
      41             :     bool usesEnvironmentChain_;
      42             :     bool hasTryFinally_;
      43             :     bool hasSetArg_;
      44             : 
      45             :   public:
      46             :     explicit BytecodeAnalysis(TempAllocator& alloc, JSScript* script);
      47             : 
      48             :     MOZ_MUST_USE bool init(TempAllocator& alloc, GSNCache& gsn);
      49             : 
      50        1109 :     BytecodeInfo& info(jsbytecode* pc) {
      51        1109 :         MOZ_ASSERT(infos_[script_->pcToOffset(pc)].initialized);
      52        1109 :         return infos_[script_->pcToOffset(pc)];
      53             :     }
      54             : 
      55       81416 :     BytecodeInfo* maybeInfo(jsbytecode* pc) {
      56       81416 :         if (infos_[script_->pcToOffset(pc)].initialized)
      57       80699 :             return &infos_[script_->pcToOffset(pc)];
      58         717 :         return nullptr;
      59             :     }
      60             : 
      61          82 :     bool usesEnvironmentChain() const {
      62          82 :         return usesEnvironmentChain_;
      63             :     }
      64             : 
      65          10 :     bool hasTryFinally() const {
      66          10 :         return hasTryFinally_;
      67             :     }
      68             : 
      69          21 :     bool hasSetArg() const {
      70          21 :         return hasSetArg_;
      71             :     }
      72             : };
      73             : 
      74             : 
      75             : } // namespace jit
      76             : } // namespace js
      77             : 
      78             : #endif /* jit_BytecodeAnalysis_h */