LCOV - code coverage report
Current view: directory - js/src/methodjit - ImmutableSync.h (source / functions) Found Hit Coverage
Test: app.info Lines: 8 8 100.0 %
Date: 2012-06-02 Functions: 1 1 100.0 %

       1                 : /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
       2                 :  * vim: set ts=4 sw=4 et tw=99:
       3                 :  *
       4                 :  * ***** BEGIN LICENSE BLOCK *****
       5                 :  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
       6                 :  *
       7                 :  * The contents of this file are subject to the Mozilla Public License Version
       8                 :  * 1.1 (the "License"); you may not use this file except in compliance with
       9                 :  * the License. You may obtain a copy of the License at
      10                 :  * http://www.mozilla.org/MPL/
      11                 :  *
      12                 :  * Software distributed under the License is distributed on an "AS IS" basis,
      13                 :  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
      14                 :  * for the specific language governing rights and limitations under the
      15                 :  * License.
      16                 :  *
      17                 :  * The Original Code is Mozilla SpiderMonkey JavaScript 1.9 code, released
      18                 :  * May 28, 2008.
      19                 :  *
      20                 :  * The Initial Developer of the Original Code is
      21                 :  *   Brendan Eich <brendan@mozilla.org>
      22                 :  *
      23                 :  * Contributor(s):
      24                 :  *   David Anderson <danderson@mozilla.com>
      25                 :  *
      26                 :  * Alternatively, the contents of this file may be used under the terms of
      27                 :  * either of the GNU General Public License Version 2 or later (the "GPL"),
      28                 :  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
      29                 :  * in which case the provisions of the GPL or the LGPL are applicable instead
      30                 :  * of those above. If you wish to allow use of your version of this file only
      31                 :  * under the terms of either the GPL or the LGPL, and not to allow others to
      32                 :  * use your version of this file under the terms of the MPL, indicate your
      33                 :  * decision by deleting the provisions above and replace them with the notice
      34                 :  * and other provisions required by the GPL or the LGPL. If you do not delete
      35                 :  * the provisions above, a recipient may use your version of this file under
      36                 :  * the terms of any one of the MPL, the GPL or the LGPL.
      37                 :  *
      38                 :  * ***** END LICENSE BLOCK ***** */
      39                 : 
      40                 : #if !defined jsjaeger_imm_sync_h__ && defined JS_METHODJIT && defined JS_NUNBOX32
      41                 : #define jsjaeger_imm_sync_h__
      42                 : 
      43                 : #include "methodjit/MachineRegs.h"
      44                 : #include "methodjit/FrameEntry.h"
      45                 : #include "CodeGenIncludes.h"
      46                 : 
      47                 : namespace js {
      48                 : namespace mjit {
      49                 : 
      50                 : class FrameState;
      51                 : 
      52                 : /*
      53                 :  * This is a structure nestled within the FrameState used for safely syncing
      54                 :  * registers to memory during transitions from the fast path into a slow path
      55                 :  * stub call. During this process, the frame itself is immutable, and we may
      56                 :  * run out of registers needed to remat copies.
      57                 :  *
      58                 :  * This structure maintains a mapping of the tracker used to perform ad-hoc
      59                 :  * register allocation.
      60                 :  */
      61                 : class ImmutableSync
      62                 : {
      63                 :     typedef JSC::MacroAssembler::RegisterID RegisterID;
      64                 :     typedef JSC::MacroAssembler::Address Address;
      65                 : 
      66                 :     struct SyncEntry {
      67                 :         /*
      68                 :          * NB: clobbered and sync mean the same thing: the register associated
      69                 :          * in the FrameEntry is no longer valid, and has been written back.
      70                 :          *
      71                 :          * They are separated for readability.
      72                 :          */
      73                 :         uint32_t generation;
      74                 :         bool dataClobbered;
      75                 :         bool typeClobbered;
      76                 :         bool hasDataReg;
      77                 :         bool hasTypeReg;
      78                 :         bool learnedType;
      79                 :         RegisterID dataReg;
      80                 :         RegisterID typeReg;
      81                 :         JSValueType type;
      82                 : 
      83          557367 :         void reset(uint32_t gen) {
      84          557367 :             dataClobbered = false;
      85          557367 :             typeClobbered = false;
      86          557367 :             hasDataReg = false;
      87          557367 :             hasTypeReg = false;
      88          557367 :             learnedType = false;
      89          557367 :             generation = gen;
      90          557367 :         }
      91                 :     };
      92                 : 
      93                 :   public:
      94                 :     ImmutableSync();
      95                 :     ~ImmutableSync();
      96                 :     bool init(JSContext *cx, const FrameState &frame, uint32_t nentries);
      97                 : 
      98                 :     void reset(Assembler *masm, Registers avail, FrameEntry *top, FrameEntry *bottom);
      99                 :     void sync(FrameEntry *fe);
     100                 : 
     101                 :   private:
     102                 :     void syncCopy(FrameEntry *fe);
     103                 :     void syncNormal(FrameEntry *fe);
     104                 :     RegisterID ensureDataReg(FrameEntry *fe, SyncEntry &e);
     105                 :     RegisterID ensureTypeReg(FrameEntry *fe, SyncEntry &e);
     106                 : 
     107                 :     RegisterID allocReg();
     108                 :     void freeReg(RegisterID reg);
     109                 : 
     110                 :     /* To be called only by allocReg. */
     111                 :     RegisterID doAllocReg();
     112                 : 
     113                 :     inline SyncEntry &entryFor(FrameEntry *fe);
     114                 : 
     115                 :     bool shouldSyncType(FrameEntry *fe, SyncEntry &e);
     116                 :     bool shouldSyncData(FrameEntry *fe, SyncEntry &e);
     117                 : 
     118                 :   private:
     119                 :     JSContext *cx;
     120                 :     SyncEntry *entries;
     121                 :     const FrameState *frame;
     122                 :     uint32_t nentries;
     123                 :     Registers avail;
     124                 :     Assembler *masm;
     125                 :     SyncEntry *regs[Assembler::TotalRegisters];
     126                 :     FrameEntry *top;
     127                 :     FrameEntry *bottom;
     128                 :     uint32_t generation;
     129                 : };
     130                 : 
     131                 : } /* namespace mjit */
     132                 : } /* namespace js */
     133                 : 
     134                 : #endif /* jsjaeger_imm_sync_h__ */
     135                 : 

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