/*

 * Copyright (C) 2010 Apple Inc. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''

 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS

 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF

 * THE POSSIBILITY OF SUCH DAMAGE.

 */

#include "config.h"

#include "ThunkGenerators.h"

#include "CodeBlock.h"

#include <wtf/text/StringImpl.h>

#include "SpecializedThunkJIT.h"

#if ENABLE(JIT)

namespace JSC {

static void stringCharLoad(SpecializedThunkJIT& jit)

{

    // load string

    jit.loadJSStringArgument(SpecializedThunkJIT::ThisArgument, SpecializedThunkJIT::regT0);

    // regT0 now contains this, and is a non-rope JSString*

    // Load string length to regT2, and start the process of loading the data pointer into regT0

    jit.load32(MacroAssembler::Address(SpecializedThunkJIT::regT0, ThunkHelpers::jsStringLengthOffset()), SpecializedThunkJIT::regT2);

    jit.loadPtr(MacroAssembler::Address(SpecializedThunkJIT::regT0, ThunkHelpers::jsStringValueOffset()), SpecializedThunkJIT::regT0);

    jit.loadPtr(MacroAssembler::Address(SpecializedThunkJIT::regT0, ThunkHelpers::stringImplDataOffset()), SpecializedThunkJIT::regT0);

    // load index

    jit.loadInt32Argument(0, SpecializedThunkJIT::regT1); // regT1 contains the index

    // Do an unsigned compare to simultaneously filter negative indices as well as indices that are too large

    jit.appendFailure(jit.branch32(MacroAssembler::AboveOrEqual, SpecializedThunkJIT::regT1, SpecializedThunkJIT::regT2));

    // Load the character

    jit.load16(MacroAssembler::BaseIndex(SpecializedThunkJIT::regT0, SpecializedThunkJIT::regT1, MacroAssembler::TimesTwo, 0), SpecializedThunkJIT::regT0);

}

static void charToString(SpecializedThunkJIT& jit, JSGlobalData* globalData, MacroAssembler::RegisterID src, MacroAssembler::RegisterID dst, MacroAssembler::RegisterID scratch)

{

    jit.appendFailure(jit.branch32(MacroAssembler::AboveOrEqual, src, MacroAssembler::Imm32(0x100)));

    jit.move(MacroAssembler::ImmPtr(globalData->smallStrings.singleCharacterStrings()), scratch);

    jit.loadPtr(MacroAssembler::BaseIndex(scratch, src, MacroAssembler::ScalePtr, 0), dst);

    jit.appendFailure(jit.branchTestPtr(MacroAssembler::Zero, dst));

}

MacroAssemblerCodePtr charCodeAtThunkGenerator(JSGlobalData* globalData, ExecutablePool* pool)

{

    SpecializedThunkJIT jit(1, globalData, pool);

    stringCharLoad(jit);

    jit.returnInt32(SpecializedThunkJIT::regT0);

    return jit.finalize(globalData->jitStubs->ctiNativeCall());

}

MacroAssemblerCodePtr charAtThunkGenerator(JSGlobalData* globalData, ExecutablePool* pool)

{

    SpecializedThunkJIT jit(1, globalData, pool);

    stringCharLoad(jit);

    charToString(jit, globalData, SpecializedThunkJIT::regT0, SpecializedThunkJIT::regT0, SpecializedThunkJIT::regT1);

    jit.returnJSCell(SpecializedThunkJIT::regT0);

    return jit.finalize(globalData->jitStubs->ctiNativeCall());

}

MacroAssemblerCodePtr fromCharCodeThunkGenerator(JSGlobalData* globalData, ExecutablePool* pool)

{

    SpecializedThunkJIT jit(1, globalData, pool);

    // load char code

    jit.loadInt32Argument(0, SpecializedThunkJIT::regT0);

    charToString(jit, globalData, SpecializedThunkJIT::regT0, SpecializedThunkJIT::regT0, SpecializedThunkJIT::regT1);

    jit.returnJSCell(SpecializedThunkJIT::regT0);

    return jit.finalize(globalData->jitStubs->ctiNativeCall());

}

MacroAssemblerCodePtr sqrtThunkGenerator(JSGlobalData* globalData, ExecutablePool* pool)

{

#if USE(JSVALUE64) || USE(JSVALUE32_64)

    SpecializedThunkJIT jit(1, globalData, pool);

    if (!jit.supportsFloatingPointSqrt())

        return globalData->jitStubs->ctiNativeCall();

    jit.loadDoubleArgument(0, SpecializedThunkJIT::fpRegT0, SpecializedThunkJIT::regT0);

    jit.sqrtDouble(SpecializedThunkJIT::fpRegT0, SpecializedThunkJIT::fpRegT0);

    jit.returnDouble(SpecializedThunkJIT::fpRegT0);

    return jit.finalize(globalData->jitStubs->ctiNativeCall());

#else

    UNUSED_PARAM(pool);

    return globalData->jitStubs->ctiNativeCall();

#endif

}

static const double oneConstant = 1.0;

static const double negativeHalfConstant = -0.5;

MacroAssemblerCodePtr powThunkGenerator(JSGlobalData* globalData, ExecutablePool* pool)

{

#if USE(JSVALUE64) || USE(JSVALUE32_64)

    SpecializedThunkJIT jit(2, globalData, pool);

    if (!jit.supportsFloatingPoint())

        return globalData->jitStubs->ctiNativeCall();

    jit.loadDouble(&oneConstant, SpecializedThunkJIT::fpRegT1);

    jit.loadDoubleArgument(0, SpecializedThunkJIT::fpRegT0, SpecializedThunkJIT::regT0);

    MacroAssembler::Jump nonIntExponent;

    jit.loadInt32Argument(1, SpecializedThunkJIT::regT0, nonIntExponent);

    jit.appendFailure(jit.branch32(MacroAssembler::LessThan, SpecializedThunkJIT::regT0, MacroAssembler::Imm32(0)));

    MacroAssembler::Jump exponentIsZero = jit.branchTest32(MacroAssembler::Zero, SpecializedThunkJIT::regT0);

    MacroAssembler::Label startLoop(jit.label());

    MacroAssembler::Jump exponentIsEven = jit.branchTest32(MacroAssembler::Zero, SpecializedThunkJIT::regT0, MacroAssembler::Imm32(1));

    jit.mulDouble(SpecializedThunkJIT::fpRegT0, SpecializedThunkJIT::fpRegT1);

    exponentIsEven.link(&jit);

    jit.mulDouble(SpecializedThunkJIT::fpRegT0, SpecializedThunkJIT::fpRegT0);

    jit.rshift32(MacroAssembler::Imm32(1), SpecializedThunkJIT::regT0);

    jit.branchTest32(MacroAssembler::NonZero, SpecializedThunkJIT::regT0).linkTo(startLoop, &jit);

    exponentIsZero.link(&jit);

    jit.returnDouble(SpecializedThunkJIT::fpRegT1);

    if (jit.supportsFloatingPointSqrt()) {

        nonIntExponent.link(&jit);

        jit.loadDouble(&negativeHalfConstant, SpecializedThunkJIT::fpRegT3);

        jit.loadDoubleArgument(1, SpecializedThunkJIT::fpRegT2, SpecializedThunkJIT::regT0);

        jit.appendFailure(jit.branchDouble(MacroAssembler::DoubleLessThanOrEqual, SpecializedThunkJIT::fpRegT0, SpecializedThunkJIT::fpRegT1));

        jit.appendFailure(jit.branchDouble(MacroAssembler::DoubleNotEqualOrUnordered, SpecializedThunkJIT::fpRegT2, SpecializedThunkJIT::fpRegT3));

        jit.sqrtDouble(SpecializedThunkJIT::fpRegT0, SpecializedThunkJIT::fpRegT0);

        jit.divDouble(SpecializedThunkJIT::fpRegT0, SpecializedThunkJIT::fpRegT1);

        jit.returnDouble(SpecializedThunkJIT::fpRegT1);

    } else

        jit.appendFailure(nonIntExponent);

    return jit.finalize(globalData->jitStubs->ctiNativeCall());

#else

    UNUSED_PARAM(pool);

    return globalData->jitStubs->ctiNativeCall();

#endif

}

}

#endif // ENABLE(JIT)