LCOV - code coverage report
Current view: directory - js/src/methodjit - ICRepatcher.h (source / functions) Found Hit Coverage
Test: app.info Lines: 19 19 100.0 %
Date: 2012-06-02 Functions: 6 6 100.0 %

       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 Mandelin <dmandelin@mozilla.com>
      25                 :  *   David Anderson <danderson@mozilla.com>
      26                 :  *   Chris Leary <cdleary@mozilla.com>
      27                 :  *   Jacob Bramley <Jacob.Bramely@arm.com>
      28                 :  *
      29                 :  * Alternatively, the contents of this file may be used under the terms of
      30                 :  * either of the GNU General Public License Version 2 or later (the "GPL"),
      31                 :  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
      32                 :  * in which case the provisions of the GPL or the LGPL are applicable instead
      33                 :  * of those above. If you wish to allow use of your version of this file only
      34                 :  * under the terms of either the GPL or the LGPL, and not to allow others to
      35                 :  * use your version of this file under the terms of the MPL, indicate your
      36                 :  * decision by deleting the provisions above and replace them with the notice
      37                 :  * and other provisions required by the GPL or the LGPL. If you do not delete
      38                 :  * the provisions above, a recipient may use your version of this file under
      39                 :  * the terms of any one of the MPL, the GPL or the LGPL.
      40                 :  *
      41                 :  * ***** END LICENSE BLOCK ***** */
      42                 : 
      43                 : #if !defined jsjaeger_icrepatcher_h__ && defined JS_METHODJIT
      44                 : #define jsjaeger_icrepatcher_h__
      45                 : 
      46                 : #include "assembler/assembler/RepatchBuffer.h"
      47                 : #include "assembler/moco/MocoStubs.h"
      48                 : #include "methodjit/ICChecker.h"
      49                 : 
      50                 : namespace js {
      51                 : namespace mjit {
      52                 : namespace ic {
      53                 : 
      54                 : class Repatcher : public JSC::RepatchBuffer
      55          721245 : {
      56                 :     typedef JSC::CodeLocationLabel  CodeLocationLabel;
      57                 :     typedef JSC::CodeLocationCall   CodeLocationCall;
      58                 :     typedef JSC::FunctionPtr        FunctionPtr;
      59                 : 
      60                 :     CodeLocationLabel label;
      61                 : 
      62                 :   public:
      63          468755 :     explicit Repatcher(JITChunk *js)
      64          468755 :       : JSC::RepatchBuffer(js->code), label(js->code.m_code.executableAddress())
      65          468755 :     { }
      66                 : 
      67          252490 :     explicit Repatcher(const JSC::JITCode &code)
      68          252490 :       : JSC::RepatchBuffer(code), label(code.start())
      69          252490 :     { }
      70                 : 
      71                 :     using JSC::RepatchBuffer::relink;
      72                 : 
      73                 :     /* Patch a stub call. */
      74           66466 :     void relink(CodeLocationCall call, FunctionPtr stub) {
      75                 : #if defined JS_CPU_X64 || defined JS_CPU_X86 || defined JS_CPU_SPARC
      76           66466 :         JSC::RepatchBuffer::relink(call, stub);
      77                 : #elif defined JS_CPU_ARM
      78                 :         /*
      79                 :          * Stub calls on ARM look like this:
      80                 :          *
      81                 :          *                  ldr     ip, =stub
      82                 :          * call label ->    ldr     r8, =JaegerStubVeneer
      83                 :          *                  blx     r8
      84                 :          *
      85                 :          * ARM has to run stub calls through a veneer in order for THROW to
      86                 :          * work properly. The address that must be patched is the load into
      87                 :          * 'ip', not the load into 'r8'.
      88                 :          */
      89                 :         CheckIsStubCall(call.labelAtOffset(0));
      90                 :         JSC::RepatchBuffer::relink(call.callAtOffset(-4), stub);
      91                 : #elif defined JS_CPU_MIPS
      92                 :         /*
      93                 :          * Stub calls on MIPS look like this:
      94                 :          *
      95                 :          *                  lui     v0, hi(stub)
      96                 :          *                  ori     v0, v0, lo(stub)
      97                 :          *                  lui     t9, hi(JaegerStubVeneer)
      98                 :          *                  ori     t9, t9, lo(JaegerStubVeneer)
      99                 :          *                  jalr    t9
     100                 :          *                  nop
     101                 :          * call label ->    xxx
     102                 :          *
     103                 :          * MIPS has to run stub calls through a veneer in order for THROW to
     104                 :          * work properly. The address that must be patched is the load into
     105                 :          * 'v0', not the load into 't9'.
     106                 :          */
     107                 :         JSC::RepatchBuffer::relink(call.callAtOffset(-8), stub);
     108                 : #else
     109                 : # error
     110                 : #endif
     111           66466 :     }
     112                 : 
     113                 :     /* Patch the offset of a Value load emitted by loadValueWithAddressOffsetPatch. */
     114          285389 :     void patchAddressOffsetForValueLoad(CodeLocationLabel label, uint32_t offset) {
     115                 : #if defined JS_CPU_X64 || defined JS_CPU_ARM || defined JS_CPU_SPARC || defined JS_CPU_MIPS 
     116                 :         repatch(label.dataLabel32AtOffset(0), offset);
     117                 : #elif defined JS_CPU_X86
     118                 :         static const unsigned LOAD_TYPE_OFFSET = 6;
     119                 :         static const unsigned LOAD_DATA_OFFSET = 12;
     120                 : 
     121                 :         /*
     122                 :          * We have the following sequence to patch:
     123                 :          *
     124                 :          *      mov     <offset+4>($base), %<type>
     125                 :          *      mov     <offset+0>($base), %<data>
     126                 :          */
     127          285389 :         repatch(label.dataLabel32AtOffset(LOAD_DATA_OFFSET), offset);
     128          285389 :         repatch(label.dataLabel32AtOffset(LOAD_TYPE_OFFSET), offset + 4);
     129                 : #else
     130                 : # error
     131                 : #endif
     132          285389 :     }
     133                 : 
     134           50712 :     void patchAddressOffsetForValueStore(CodeLocationLabel label, uint32_t offset, bool typeConst) {
     135                 : #if defined JS_CPU_ARM || defined JS_CPU_X64 || defined JS_CPU_SPARC || defined JS_CPU_MIPS
     136                 :         (void) typeConst;
     137                 :         repatch(label.dataLabel32AtOffset(0), offset);
     138                 : #elif defined JS_CPU_X86
     139                 :         static const unsigned STORE_TYPE_OFFSET = 6;
     140                 :         static const unsigned STORE_DATA_CONST_TYPE_OFFSET = 16;
     141                 :         static const unsigned STORE_DATA_TYPE_OFFSET = 12;
     142                 : 
     143                 :         /*
     144                 :          * The type is stored first, then the payload. Both stores can vary in
     145                 :          * size, depending on whether or not the data is a constant in the
     146                 :          * instruction stream (though only the first store matters for the
     147                 :          * purpose of locating both offsets for patching).
     148                 :          *
     149                 :          * We have one of the following sequences to patch. Offsets are located
     150                 :          * before 6B into a given move instruction, but the mov instructions
     151                 :          * carrying constant payloads are 10B wide overall.
     152                 :          *
     153                 :          *  typeConst=false, dataConst=false
     154                 :          *      mov     %<type>, <offset+4>($base)  ; Length is 6
     155                 :          *      mov     %<data>, <offset+0>($base)  ; Offset @ len(prev) + 6 = 12
     156                 :          *  typeConst=true, dataConst=false
     157                 :          *      mov     $<type>, <offset+4>($base)  ; Length is 10
     158                 :          *      mov     %<data>, <offset+0>($base)  ; Offset @ len(prev) + 6 = 16
     159                 :          *  typeConst=true, dataConst=true
     160                 :          *      mov     $<type>, <offset+4>($base)  ; Length is 10
     161                 :          *      mov     $<data>, <offset+0>($base)  ; Offset @ len(prev) + 6 = 16
     162                 :          *
     163                 :          * Note that we only need to know whether type is const to determine the
     164                 :          * correct patch offsets. In all cases, the label points to the start
     165                 :          * of the sequence.
     166                 :          */
     167           50712 :         repatch(label.dataLabel32AtOffset(STORE_TYPE_OFFSET), offset + 4);
     168                 : 
     169           50712 :         unsigned payloadOffset = typeConst ? STORE_DATA_CONST_TYPE_OFFSET : STORE_DATA_TYPE_OFFSET;
     170           50712 :         repatch(label.dataLabel32AtOffset(payloadOffset), offset);
     171                 : #else
     172                 : # error
     173                 : #endif
     174           50712 :     }
     175                 : };
     176                 : 
     177                 : } /* namespace ic */
     178                 : } /* namespace mjit */
     179                 : } /* namespace js */
     180                 : 
     181                 : #endif

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