LCOV - app.info - js/src/methodjit/ImmutableSync.h

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: | 2012-04-07 | 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          297349 :         void reset(uint32_t gen) {
          84          297349 :             dataClobbered = false;
          85          297349 :             typeClobbered = false;
          86          297349 :             hasDataReg = false;
          87          297349 :             hasTypeReg = false;
          88          297349 :             learnedType = false;
          89          297349 :             generation = gen;
          90          297349 :         }
          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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