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
35namespace JSC {
36
37static 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
58static 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
66MacroAssemblerCodePtr 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->jitStubs->ctiNativeCall());
72}
73
74MacroAssemblerCodePtr 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->jitStubs->ctiNativeCall());
81}
82
83MacroAssemblerCodePtr 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->jitStubs->ctiNativeCall());
91}
92
93MacroAssemblerCodePtr 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->jitStubs->ctiNativeCall());
103}
104
105static const double oneConstant = 1.0;
106static const double negativeHalfConstant = -0.5;
107
108MacroAssemblerCodePtr 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->jitStubs->ctiNativeCall());
158}
159
160}
161
162#endif // ENABLE(JIT)
163