js/src/methodjit/TrampolineCompiler.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  * vim: set ts=4 sw=4 et tw=99:
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   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
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  10  * http://www.mozilla.org/MPL/
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  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
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  15  * License.
  16  *
  17  * The Original Code is Mozilla Jaegermonkey.
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  19  * The Initial Developer of the Original Code is the Mozilla Foundation.
  20  *
  21  * Portions created by the Initial Developer are Copyright (C) 2010
  22  * the Initial Developer. All Rights Reserved.
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  24  * Contributor(s):
  25  *   Andrew Drake <drakedevel@gmail.com>
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  27  * Alternatively, the contents of this file may be used under the terms of
  28  * either the GNU General Public License Version 2 or later (the "GPL"), or
  29  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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  39  * ***** END LICENSE BLOCK ***** */
  40
  41 #include "TrampolineCompiler.h"
  42 #include "StubCalls.h"
  43 #include "assembler/assembler/LinkBuffer.h"
  44
  45 namespace js {
  46 namespace mjit {
  47
  48 #define CHECK_RESULT(x) if (!(x)) return false
  49 #define COMPILE(which, pool, how) CHECK_RESULT(compileTrampoline(&(which), &pool, how))
  50 #define RELEASE(which, pool) JS_BEGIN_MACRO \
  51     which = NULL;                           \
  52     if (pool)                               \
  53         pool->release();                    \
  54     pool = NULL;                            \
  55 JS_END_MACRO
  56
  57 typedef JSC::MacroAssembler::Address Address;
  58 typedef JSC::MacroAssembler::Label Label;
  59 typedef JSC::MacroAssembler::Jump Jump;
  60 typedef JSC::MacroAssembler::ImmPtr ImmPtr;
  61 typedef JSC::MacroAssembler::Imm32 Imm32;
  62 typedef JSC::MacroAssembler::Address Address;
  63
  64 bool
  65 TrampolineCompiler::compile()
  66 {
  67 #ifdef JS_METHODJIT_SPEW
  68     JMCheckLogging();
  69 #endif
  70
  71     COMPILE(trampolines->forceReturn, trampolines->forceReturnPool, generateForceReturn);
  72 #if (defined(JS_NO_FASTCALL) && defined(JS_CPU_X86)) || defined(_WIN64)
  73     COMPILE(trampolines->forceReturnFast, trampolines->forceReturnFastPool, generateForceReturnFast);
  74 #endif
  75
  76     return true;
  77 }
  78
  79 void
  80 TrampolineCompiler::release(Trampolines *tramps)
  81 {
  82     RELEASE(tramps->forceReturn, tramps->forceReturnPool);
  83 #if (defined(JS_NO_FASTCALL) && defined(JS_CPU_X86)) || defined(_WIN64)
  84     RELEASE(tramps->forceReturnFast, tramps->forceReturnFastPool);
  85 #endif
  86 }
  87
  88 bool
  89 TrampolineCompiler::compileTrampoline(Trampolines::TrampolinePtr *where, JSC::ExecutablePool **pool,
  90                                       TrampolineGenerator generator)
  91 {
  92     Assembler masm;
  93
  94     Label entry = masm.label();
  95     CHECK_RESULT(generator(masm));
  96     JS_ASSERT(entry.isValid());
  97
  98     *pool = execPool->poolForSize(masm.size());
  99     if (!*pool)
 100         return false;
 101
 102     JSC::LinkBuffer buffer(&masm, *pool);
 103     masm.finalize(buffer);
 104     uint8 *result = (uint8*)buffer.finalizeCodeAddendum().dataLocation();
 105     *where = JS_DATA_TO_FUNC_PTR(Trampolines::TrampolinePtr, result + masm.distanceOf(entry));
 106
 107     return true;
 108 }
 109
 110 /*
 111  * This is shamelessly copied from emitReturn, but with several changes:
 112  * - There was always at least one inline call.
 113  * - We don't know if there is a call object, so we always check.
 114  * - We don't know where we came from, so we don't know frame depth or PC.
 115  * - There is no stub buffer.
 116  */
 117 bool
 118 TrampolineCompiler::generateForceReturn(Assembler &masm)
 119 {
 120     /* if (hasArgsObj() || hasCallObj()) stubs::PutActivationObjects() */
 121     Jump noActObjs = masm.branchTest32(Assembler::Zero, FrameFlagsAddress(),
 122                                        Imm32(JSFRAME_HAS_CALL_OBJ | JSFRAME_HAS_ARGS_OBJ));
 123     masm.fallibleVMCall(JS_FUNC_TO_DATA_PTR(void *, stubs::PutActivationObjects), NULL, 0);
 124     noActObjs.linkTo(masm.label(), &masm);
 125
 126     /* Store any known return value */
 127     masm.loadValueAsComponents(UndefinedValue(), JSReturnReg_Type, JSReturnReg_Data);
 128     Jump rvalClear = masm.branchTest32(Assembler::Zero,
 129                                        FrameFlagsAddress(), Imm32(JSFRAME_HAS_RVAL));
 130     Address rvalAddress(JSFrameReg, JSStackFrame::offsetOfReturnValue());
 131     masm.loadValueAsComponents(rvalAddress, JSReturnReg_Type, JSReturnReg_Data);
 132     rvalClear.linkTo(masm.label(), &masm);
 133
 134     /* Return to the caller */
 135     masm.loadPtr(Address(JSFrameReg, JSStackFrame::offsetOfncode()), Registers::ReturnReg);
 136     masm.jump(Registers::ReturnReg);
 137     return true;
 138 }
 139
 140 #if (defined(JS_NO_FASTCALL) && defined(JS_CPU_X86)) || defined(_WIN64)
 141 bool
 142 TrampolineCompiler::generateForceReturnFast(Assembler &masm)
 143 {
 144 #ifdef _WIN64
 145     masm.addPtr(Imm32(32), Registers::StackPointer);
 146 #else
 147     // In case of no fast call, when we change the return address,
 148     // we need to make sure add esp by 8.
 149     masm.addPtr(Imm32(16), Registers::StackPointer);
 150 #endif
 151     return generateForceReturn(masm);
 152 }
 153 #endif
 154
 155 } /* namespace mjit */
 156 } /* namespace js */
 157