jit/ThunkGenerators.cpp

   1 /*
   2  * Copyright (C) 2010 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  14  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  15  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  17  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  18  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  19  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  20  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  21  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  22  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  23  * THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27 #include "ThunkGenerators.h"
  28
  29 #include "CodeBlock.h"
  30 #include <wtf/text/StringImpl.h>
  31 #include "SpecializedThunkJIT.h"
  32
  33 #if ENABLE(JIT)
  34
  35 namespace JSC {
  36
  37 static void stringCharLoad(SpecializedThunkJIT& jit)
  38 {
  39     // load string
  40     jit.loadJSStringArgument(SpecializedThunkJIT::ThisArgument, SpecializedThunkJIT::regT0);
  41     // regT0 now contains this, and is a non-rope JSString*
  42
  43     // Load string length to regT2, and start the process of loading the data pointer into regT0
  44     jit.load32(MacroAssembler::Address(SpecializedThunkJIT::regT0, ThunkHelpers::jsStringLengthOffset()), SpecializedThunkJIT::regT2);
  45     jit.loadPtr(MacroAssembler::Address(SpecializedThunkJIT::regT0, ThunkHelpers::jsStringValueOffset()), SpecializedThunkJIT::regT0);
  46     jit.loadPtr(MacroAssembler::Address(SpecializedThunkJIT::regT0, ThunkHelpers::stringImplDataOffset()), SpecializedThunkJIT::regT0);
  47
  48     // load index
  49     jit.loadInt32Argument(0, SpecializedThunkJIT::regT1); // regT1 contains the index
  50
  51     // Do an unsigned compare to simultaneously filter negative indices as well as indices that are too large
  52     jit.appendFailure(jit.branch32(MacroAssembler::AboveOrEqual, SpecializedThunkJIT::regT1, SpecializedThunkJIT::regT2));
  53
  54     // Load the character
  55     jit.load16(MacroAssembler::BaseIndex(SpecializedThunkJIT::regT0, SpecializedThunkJIT::regT1, MacroAssembler::TimesTwo, 0), SpecializedThunkJIT::regT0);
  56 }
  57
  58 static void charToString(SpecializedThunkJIT& jit, JSGlobalData* globalData, MacroAssembler::RegisterID src, MacroAssembler::RegisterID dst, MacroAssembler::RegisterID scratch)
  59 {
  60     jit.appendFailure(jit.branch32(MacroAssembler::AboveOrEqual, src, MacroAssembler::TrustedImm32(0x100)));
  61     jit.move(MacroAssembler::TrustedImmPtr(globalData->smallStrings.singleCharacterStrings()), scratch);
  62     jit.loadPtr(MacroAssembler::BaseIndex(scratch, src, MacroAssembler::ScalePtr, 0), dst);
  63     jit.appendFailure(jit.branchTestPtr(MacroAssembler::Zero, dst));
  64 }
  65
  66 MacroAssemblerCodePtr charCodeAtThunkGenerator(JSGlobalData* globalData, ExecutablePool* pool)
  67 {
  68     SpecializedThunkJIT jit(1, globalData, pool);
  69     stringCharLoad(jit);
  70     jit.returnInt32(SpecializedThunkJIT::regT0);
  71     return jit.finalize(*globalData, globalData->jitStubs->ctiNativeCall());
  72 }
  73
  74 MacroAssemblerCodePtr charAtThunkGenerator(JSGlobalData* globalData, ExecutablePool* pool)
  75 {
  76     SpecializedThunkJIT jit(1, globalData, pool);
  77     stringCharLoad(jit);
  78     charToString(jit, globalData, SpecializedThunkJIT::regT0, SpecializedThunkJIT::regT0, SpecializedThunkJIT::regT1);
  79     jit.returnJSCell(SpecializedThunkJIT::regT0);
  80     return jit.finalize(*globalData, globalData->jitStubs->ctiNativeCall());
  81 }
  82
  83 MacroAssemblerCodePtr fromCharCodeThunkGenerator(JSGlobalData* globalData, ExecutablePool* pool)
  84 {
  85     SpecializedThunkJIT jit(1, globalData, pool);
  86     // load char code
  87     jit.loadInt32Argument(0, SpecializedThunkJIT::regT0);
  88     charToString(jit, globalData, SpecializedThunkJIT::regT0, SpecializedThunkJIT::regT0, SpecializedThunkJIT::regT1);
  89     jit.returnJSCell(SpecializedThunkJIT::regT0);
  90     return jit.finalize(*globalData, globalData->jitStubs->ctiNativeCall());
  91 }
  92
  93 MacroAssemblerCodePtr sqrtThunkGenerator(JSGlobalData* globalData, ExecutablePool* pool)
  94 {
  95     SpecializedThunkJIT jit(1, globalData, pool);
  96     if (!jit.supportsFloatingPointSqrt())
  97         return globalData->jitStubs->ctiNativeCall();
  98
  99     jit.loadDoubleArgument(0, SpecializedThunkJIT::fpRegT0, SpecializedThunkJIT::regT0);
 100     jit.sqrtDouble(SpecializedThunkJIT::fpRegT0, SpecializedThunkJIT::fpRegT0);
 101     jit.returnDouble(SpecializedThunkJIT::fpRegT0);
 102     return jit.finalize(*globalData, globalData->jitStubs->ctiNativeCall());
 103 }
 104
 105 static const double oneConstant = 1.0;
 106 static const double negativeHalfConstant = -0.5;
 107
 108 MacroAssemblerCodePtr powThunkGenerator(JSGlobalData* globalData, ExecutablePool* pool)
 109 {
 110     SpecializedThunkJIT jit(2, globalData, pool);
 111     if (!jit.supportsFloatingPoint())
 112         return globalData->jitStubs->ctiNativeCall();
 113
 114     jit.loadDouble(&oneConstant, SpecializedThunkJIT::fpRegT1);
 115     jit.loadDoubleArgument(0, SpecializedThunkJIT::fpRegT0, SpecializedThunkJIT::regT0);
 116     MacroAssembler::Jump nonIntExponent;
 117     jit.loadInt32Argument(1, SpecializedThunkJIT::regT0, nonIntExponent);
 118     jit.appendFailure(jit.branch32(MacroAssembler::LessThan, SpecializedThunkJIT::regT0, MacroAssembler::TrustedImm32(0)));
 119
 120     MacroAssembler::Jump exponentIsZero = jit.branchTest32(MacroAssembler::Zero, SpecializedThunkJIT::regT0);
 121     MacroAssembler::Label startLoop(jit.label());
 122
 123     MacroAssembler::Jump exponentIsEven = jit.branchTest32(MacroAssembler::Zero, SpecializedThunkJIT::regT0, MacroAssembler::TrustedImm32(1));
 124     jit.mulDouble(SpecializedThunkJIT::fpRegT0, SpecializedThunkJIT::fpRegT1);
 125     exponentIsEven.link(&jit);
 126     jit.mulDouble(SpecializedThunkJIT::fpRegT0, SpecializedThunkJIT::fpRegT0);
 127     jit.rshift32(MacroAssembler::TrustedImm32(1), SpecializedThunkJIT::regT0);
 128     jit.branchTest32(MacroAssembler::NonZero, SpecializedThunkJIT::regT0).linkTo(startLoop, &jit);
 129
 130     exponentIsZero.link(&jit);
 131
 132     {
 133         SpecializedThunkJIT::JumpList doubleResult;
 134         jit.branchConvertDoubleToInt32(SpecializedThunkJIT::fpRegT1, SpecializedThunkJIT::regT0, doubleResult, SpecializedThunkJIT::fpRegT0);
 135         jit.returnInt32(SpecializedThunkJIT::regT0);
 136         doubleResult.link(&jit);
 137         jit.returnDouble(SpecializedThunkJIT::fpRegT1);
 138     }
 139
 140     if (jit.supportsFloatingPointSqrt()) {
 141         nonIntExponent.link(&jit);
 142         jit.loadDouble(&negativeHalfConstant, SpecializedThunkJIT::fpRegT3);
 143         jit.loadDoubleArgument(1, SpecializedThunkJIT::fpRegT2, SpecializedThunkJIT::regT0);
 144         jit.appendFailure(jit.branchDouble(MacroAssembler::DoubleLessThanOrEqual, SpecializedThunkJIT::fpRegT0, SpecializedThunkJIT::fpRegT1));
 145         jit.appendFailure(jit.branchDouble(MacroAssembler::DoubleNotEqualOrUnordered, SpecializedThunkJIT::fpRegT2, SpecializedThunkJIT::fpRegT3));
 146         jit.sqrtDouble(SpecializedThunkJIT::fpRegT0, SpecializedThunkJIT::fpRegT0);
 147         jit.divDouble(SpecializedThunkJIT::fpRegT0, SpecializedThunkJIT::fpRegT1);
 148
 149         SpecializedThunkJIT::JumpList doubleResult;
 150         jit.branchConvertDoubleToInt32(SpecializedThunkJIT::fpRegT1, SpecializedThunkJIT::regT0, doubleResult, SpecializedThunkJIT::fpRegT0);
 151         jit.returnInt32(SpecializedThunkJIT::regT0);
 152         doubleResult.link(&jit);
 153         jit.returnDouble(SpecializedThunkJIT::fpRegT1);
 154     } else
 155         jit.appendFailure(nonIntExponent);
 156
 157     return jit.finalize(*globalData, globalData->jitStubs->ctiNativeCall());
 158 }
 159
 160 }
 161
 162 #endif // ENABLE(JIT)