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** contained in the Technology Preview License Agreement accompanying
** this package.
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****************************************************************************/

#include <private/qdrawhelper_p.h>
#include <private/qblendfunctions_p.h>
#include <private/qmath_p.h>

#ifdef QT_HAVE_NEON

#include <private/qdrawhelper_neon_p.h>
#include <private/qpaintengine_raster_p.h>
#include <arm_neon.h>

QT_BEGIN_NAMESPACE

static inline uint16x8_t qvdiv_255_u16(uint16x8_t x, uint16x8_t half)
{
    // result = (x + (x >> 8) + 0x80) >> 8

    const uint16x8_t temp = vshrq_n_u16(x, 8); // x >> 8
    const uint16x8_t sum_part = vaddq_u16(x, half); // x + 0x80
    const uint16x8_t sum = vaddq_u16(temp, sum_part);

    return vshrq_n_u16(sum, 8);
}

static inline uint16x8_t qvbyte_mul_u16(uint16x8_t x, uint16x8_t alpha, uint16x8_t half)
{
    // t = qRound(x * alpha / 255.0)

    const uint16x8_t t = vmulq_u16(x, alpha); // t
    return qvdiv_255_u16(t, half);
}

static inline uint16x8_t qvinterpolate_pixel_255(uint16x8_t x, uint16x8_t a, uint16x8_t y, uint16x8_t b, uint16x8_t half)
{
    // t = x * a + y * b

    const uint16x8_t ta = vmulq_u16(x, a);
    const uint16x8_t tb = vmulq_u16(y, b);

    return qvdiv_255_u16(vaddq_u16(ta, tb), half);
}

static inline uint16x8_t qvsource_over_u16(uint16x8_t src16, uint16x8_t dst16, uint16x8_t half, uint16x8_t full)
{
    const uint16x4_t alpha16_high = vdup_lane_u16(vget_high_u16(src16), 3);
    const uint16x4_t alpha16_low = vdup_lane_u16(vget_low_u16(src16), 3);

    const uint16x8_t alpha16 = vsubq_u16(full, vcombine_u16(alpha16_low, alpha16_high));

    return vaddq_u16(src16, qvbyte_mul_u16(dst16, alpha16, half));
}

extern "C" void
pixman_composite_over_8888_0565_asm_neon (int32_t   w,
                                          int32_t   h,
                                          uint16_t *dst,
                                          int32_t   dst_stride,
                                          uint32_t *src,
                                          int32_t   src_stride);

extern "C" void
pixman_composite_over_8888_8888_asm_neon (int32_t   w,
                                          int32_t   h,
                                          uint32_t *dst,
                                          int32_t   dst_stride,
                                          uint32_t *src,
                                          int32_t   src_stride);

extern "C" void
pixman_composite_src_0565_8888_asm_neon (int32_t   w,
                                         int32_t   h,
                                         uint32_t *dst,
                                         int32_t   dst_stride,
                                         uint16_t *src,
                                         int32_t   src_stride);

extern "C" void
pixman_composite_over_n_8_0565_asm_neon (int32_t    w,
                                         int32_t    h,
                                         uint16_t  *dst,
                                         int32_t    dst_stride,
                                         uint32_t   src,
                                         int32_t    unused,
                                         uint8_t   *mask,
                                         int32_t    mask_stride);

extern "C" void
pixman_composite_scanline_over_asm_neon (int32_t         w,
                                         const uint32_t *dst,
                                         const uint32_t *src);

// qblendfunctions.cpp
void qt_blend_argb32_on_rgb16_const_alpha(uchar *destPixels, int dbpl,
                                          const uchar *srcPixels, int sbpl,
                                          int w, int h,
                                          int const_alpha);

void qt_blend_rgb16_on_argb32_neon(uchar *destPixels, int dbpl,
                                   const uchar *srcPixels, int sbpl,
                                   int w, int h,
                                   int const_alpha)
{
    dbpl /= 4;
    sbpl /= 2;

    quint32 *dst = (quint32 *) destPixels;
    quint16 *src = (quint16 *) srcPixels;

    if (const_alpha != 256) {
        quint8 a = (255 * const_alpha) >> 8;
        quint8 ia = 255 - a;

        while (h--) {
            for (int x=0; x<w; ++x)
                dst[x] = INTERPOLATE_PIXEL_255(qt_colorConvert(src[x], dst[x]), a, dst[x], ia);
            dst += dbpl;
            src += sbpl;
        }
        return;
    }

    pixman_composite_src_0565_8888_asm_neon(w, h, dst, dbpl, src, sbpl);
}

extern "C" void blend_8_pixels_argb32_on_rgb16_neon(quint16 *dst, const quint32 *src, int const_alpha);

void qt_blend_argb32_on_rgb16_neon(uchar *destPixels, int dbpl,
                                   const uchar *srcPixels, int sbpl,
                                   int w, int h,
                                   int const_alpha)
{
    quint16 *dst = (quint16 *) destPixels;
    quint32 *src = (quint32 *) srcPixels;

    if (const_alpha != 256) {
        for (int y=0; y<h; ++y) {
            int i = 0;
            for (; i < w-7; i += 8)
                blend_8_pixels_argb32_on_rgb16_neon(&dst[i], &src[i], const_alpha);

            if (i < w) {
                int tail = w - i;

                quint16 dstBuffer[8];
                quint32 srcBuffer[8];

                for (int j = 0; j < tail; ++j) {
                    dstBuffer[j] = dst[i + j];
                    srcBuffer[j] = src[i + j];
                }

                blend_8_pixels_argb32_on_rgb16_neon(dstBuffer, srcBuffer, const_alpha);

                for (int j = 0; j < tail; ++j) {
                    dst[i + j] = dstBuffer[j];
                    src[i + j] = srcBuffer[j];
                }
            }

            dst = (quint16 *)(((uchar *) dst) + dbpl);
            src = (quint32 *)(((uchar *) src) + sbpl);
        }
        return;
    }

    pixman_composite_over_8888_0565_asm_neon(w, h, dst, dbpl / 2, src, sbpl / 4);
}

void qt_blend_argb32_on_argb32_scanline_neon(uint *dest, const uint *src, int length, uint const_alpha)
{
    if (const_alpha == 255) {
        pixman_composite_scanline_over_asm_neon(length, dest, src);
    } else {
        qt_blend_argb32_on_argb32_neon((uchar *)dest, 4 * length, (uchar *)src, 4 * length, length, 1, (const_alpha * 256) / 255);
    }
}

void qt_blend_argb32_on_argb32_neon(uchar *destPixels, int dbpl,
                                    const uchar *srcPixels, int sbpl,
                                    int w, int h,
                                    int const_alpha)
{
    const uint *src = (const uint *) srcPixels;
    uint *dst = (uint *) destPixels;
    uint16x8_t half = vdupq_n_u16(0x80);
    uint16x8_t full = vdupq_n_u16(0xff);
    if (const_alpha == 256) {
        pixman_composite_over_8888_8888_asm_neon(w, h, (uint32_t *)destPixels, dbpl / 4, (uint32_t *)srcPixels, sbpl / 4);
    } else if (const_alpha != 0) {
        const_alpha = (const_alpha * 255) >> 8;
        uint16x8_t const_alpha16 = vdupq_n_u16(const_alpha);
        for (int y = 0; y < h; ++y) {
            int x = 0;
            for (; x < w-3; x += 4) {
                if (src[x] | src[x+1] | src[x+2] | src[x+3]) {
                    uint32x4_t src32 = vld1q_u32((uint32_t *)&src[x]);
                    uint32x4_t dst32 = vld1q_u32((uint32_t *)&dst[x]);

                    const uint8x16_t src8 = vreinterpretq_u8_u32(src32);
                    const uint8x16_t dst8 = vreinterpretq_u8_u32(dst32);

                    const uint8x8_t src8_low = vget_low_u8(src8);
                    const uint8x8_t dst8_low = vget_low_u8(dst8);

                    const uint8x8_t src8_high = vget_high_u8(src8);
                    const uint8x8_t dst8_high = vget_high_u8(dst8);

                    const uint16x8_t src16_low = vmovl_u8(src8_low);
                    const uint16x8_t dst16_low = vmovl_u8(dst8_low);

                    const uint16x8_t src16_high = vmovl_u8(src8_high);
                    const uint16x8_t dst16_high = vmovl_u8(dst8_high);

                    const uint16x8_t srcalpha16_low = qvbyte_mul_u16(src16_low, const_alpha16, half);
                    const uint16x8_t srcalpha16_high = qvbyte_mul_u16(src16_high, const_alpha16, half);

                    const uint16x8_t result16_low = qvsource_over_u16(srcalpha16_low, dst16_low, half, full);
                    const uint16x8_t result16_high = qvsource_over_u16(srcalpha16_high, dst16_high, half, full);

                    const uint32x2_t result32_low = vreinterpret_u32_u8(vmovn_u16(result16_low));
                    const uint32x2_t result32_high = vreinterpret_u32_u8(vmovn_u16(result16_high));

                    vst1q_u32((uint32_t *)&dst[x], vcombine_u32(result32_low, result32_high));
                }
            }
            for (; x<w; ++x) {
                uint s = src[x];
                if (s != 0) {
                    s = BYTE_MUL(s, const_alpha);
                    dst[x] = s + BYTE_MUL(dst[x], qAlpha(~s));
                }
            }
            dst = (quint32 *)(((uchar *) dst) + dbpl);
            src = (const quint32 *)(((const uchar *) src) + sbpl);
        }
    }
}

// qblendfunctions.cpp
void qt_blend_rgb32_on_rgb32(uchar *destPixels, int dbpl,
                             const uchar *srcPixels, int sbpl,
                             int w, int h,
                             int const_alpha);

void qt_blend_rgb32_on_rgb32_neon(uchar *destPixels, int dbpl,
                                  const uchar *srcPixels, int sbpl,
                                  int w, int h,
                                  int const_alpha)
{
    if (const_alpha != 256) {
        if (const_alpha != 0) {
            const uint *src = (const uint *) srcPixels;
            uint *dst = (uint *) destPixels;
            uint16x8_t half = vdupq_n_u16(0x80);
            const_alpha = (const_alpha * 255) >> 8;
            int one_minus_const_alpha = 255 - const_alpha;
            uint16x8_t const_alpha16 = vdupq_n_u16(const_alpha);
            uint16x8_t one_minus_const_alpha16 = vdupq_n_u16(255 - const_alpha);
            for (int y = 0; y < h; ++y) {
                int x = 0;
                for (; x < w-3; x += 4) {
                    uint32x4_t src32 = vld1q_u32((uint32_t *)&src[x]);
                    uint32x4_t dst32 = vld1q_u32((uint32_t *)&dst[x]);

                    const uint8x16_t src8 = vreinterpretq_u8_u32(src32);
                    const uint8x16_t dst8 = vreinterpretq_u8_u32(dst32);

                    const uint8x8_t src8_low = vget_low_u8(src8);
                    const uint8x8_t dst8_low = vget_low_u8(dst8);

                    const uint8x8_t src8_high = vget_high_u8(src8);
                    const uint8x8_t dst8_high = vget_high_u8(dst8);

                    const uint16x8_t src16_low = vmovl_u8(src8_low);
                    const uint16x8_t dst16_low = vmovl_u8(dst8_low);

                    const uint16x8_t src16_high = vmovl_u8(src8_high);
                    const uint16x8_t dst16_high = vmovl_u8(dst8_high);

                    const uint16x8_t result16_low = qvinterpolate_pixel_255(src16_low, const_alpha16, dst16_low, one_minus_const_alpha16, half);
                    const uint16x8_t result16_high = qvinterpolate_pixel_255(src16_high, const_alpha16, dst16_high, one_minus_const_alpha16, half);

                    const uint32x2_t result32_low = vreinterpret_u32_u8(vmovn_u16(result16_low));
                    const uint32x2_t result32_high = vreinterpret_u32_u8(vmovn_u16(result16_high));

                    vst1q_u32((uint32_t *)&dst[x], vcombine_u32(result32_low, result32_high));
                }
                for (; x<w; ++x) {
                    uint s = src[x];
                    s = BYTE_MUL(s, const_alpha);
                    dst[x] = INTERPOLATE_PIXEL_255(src[x], const_alpha, dst[x], one_minus_const_alpha);
                }
                dst = (quint32 *)(((uchar *) dst) + dbpl);
                src = (const quint32 *)(((const uchar *) src) + sbpl);
            }
        }
    } else {
        qt_blend_rgb32_on_rgb32(destPixels, dbpl, srcPixels, sbpl, w, h, const_alpha);
    }
}

void qt_alphamapblit_quint16_neon(QRasterBuffer *rasterBuffer,
                                  int x, int y, quint32 color,
                                  const uchar *bitmap,
                                  int mapWidth, int mapHeight, int mapStride,
                                  const QClipData *)
{
    quint16 *dest = reinterpret_cast<quint16*>(rasterBuffer->scanLine(y)) + x;
    const int destStride = rasterBuffer->bytesPerLine() / sizeof(quint16);

    uchar *mask = const_cast<uchar *>(bitmap);

    pixman_composite_over_n_8_0565_asm_neon(mapWidth, mapHeight, dest, destStride, color, 0, mask, mapStride);
}

extern "C" void blend_8_pixels_rgb16_on_rgb16_neon(quint16 *dst, const quint16 *src, int const_alpha);

template <typename SRC, typename BlendFunc>
struct Blend_on_RGB16_SourceAndConstAlpha_Neon {
    Blend_on_RGB16_SourceAndConstAlpha_Neon(BlendFunc blender, int const_alpha)
        : m_index(0)
        , m_blender(blender)
        , m_const_alpha(const_alpha)
    {
    }

    inline void write(quint16 *dst, quint32 src)
    {
        srcBuffer[m_index++] = src;

        if (m_index == 8) {
            m_blender(dst - 7, srcBuffer, m_const_alpha);
            m_index = 0;
        }
    }

    inline void flush(quint16 *dst)
    {
        if (m_index > 0) {
            quint16 dstBuffer[8];
            for (int i = 0; i < m_index; ++i)
                dstBuffer[i] = dst[i - m_index];

            m_blender(dstBuffer, srcBuffer, m_const_alpha);

            for (int i = 0; i < m_index; ++i)
                dst[i - m_index] = dstBuffer[i];

            m_index = 0;
        }
    }

    SRC srcBuffer[8];

    int m_index;
    BlendFunc m_blender;
    int m_const_alpha;
};

template <typename SRC, typename BlendFunc>
Blend_on_RGB16_SourceAndConstAlpha_Neon<SRC, BlendFunc>
Blend_on_RGB16_SourceAndConstAlpha_Neon_create(BlendFunc blender, int const_alpha)
{
    return Blend_on_RGB16_SourceAndConstAlpha_Neon<SRC, BlendFunc>(blender, const_alpha);
}

void qt_scale_image_argb32_on_rgb16_neon(uchar *destPixels, int dbpl,
                                         const uchar *srcPixels, int sbpl,
                                         const QRectF &targetRect,
                                         const QRectF &sourceRect,
                                         const QRect &clip,
                                         int const_alpha)
{
    if (const_alpha == 0)
        return;

    qt_scale_image_16bit<quint32>(destPixels, dbpl, srcPixels, sbpl, targetRect, sourceRect, clip,
        Blend_on_RGB16_SourceAndConstAlpha_Neon_create<quint32>(blend_8_pixels_argb32_on_rgb16_neon, const_alpha));
}

void qt_scale_image_rgb16_on_rgb16(uchar *destPixels, int dbpl,
                                   const uchar *srcPixels, int sbpl,
                                   const QRectF &targetRect,
                                   const QRectF &sourceRect,
                                   const QRect &clip,
                                   int const_alpha);

void qt_scale_image_rgb16_on_rgb16_neon(uchar *destPixels, int dbpl,
                                        const uchar *srcPixels, int sbpl,
                                        const QRectF &targetRect,
                                        const QRectF &sourceRect,
                                        const QRect &clip,
                                        int const_alpha)
{
    if (const_alpha == 0)
        return;

    if (const_alpha == 256) {
        qt_scale_image_rgb16_on_rgb16(destPixels, dbpl, srcPixels, sbpl, targetRect, sourceRect, clip, const_alpha);
        return;
    }

    qt_scale_image_16bit<quint16>(destPixels, dbpl, srcPixels, sbpl, targetRect, sourceRect, clip,
        Blend_on_RGB16_SourceAndConstAlpha_Neon_create<quint16>(blend_8_pixels_rgb16_on_rgb16_neon, const_alpha));
}

extern void qt_transform_image_rgb16_on_rgb16(uchar *destPixels, int dbpl,
                                              const uchar *srcPixels, int sbpl,
                                              const QRectF &targetRect,
                                              const QRectF &sourceRect,
                                              const QRect &clip,
                                              const QTransform &targetRectTransform,
                                              int const_alpha);

void qt_transform_image_rgb16_on_rgb16_neon(uchar *destPixels, int dbpl,
                                            const uchar *srcPixels, int sbpl,
                                            const QRectF &targetRect,
                                            const QRectF &sourceRect,
                                            const QRect &clip,
                                            const QTransform &targetRectTransform,
                                            int const_alpha)
{
    if (const_alpha == 0)
        return;

    if (const_alpha == 256) {
        qt_transform_image_rgb16_on_rgb16(destPixels, dbpl, srcPixels, sbpl, targetRect, sourceRect, clip, targetRectTransform, const_alpha);
        return;
    }

    qt_transform_image(reinterpret_cast<quint16 *>(destPixels), dbpl,
                       reinterpret_cast<const quint16 *>(srcPixels), sbpl, targetRect, sourceRect, clip, targetRectTransform,
        Blend_on_RGB16_SourceAndConstAlpha_Neon_create<quint16>(blend_8_pixels_rgb16_on_rgb16_neon, const_alpha));
}

void qt_transform_image_argb32_on_rgb16_neon(uchar *destPixels, int dbpl,
                                             const uchar *srcPixels, int sbpl,
                                             const QRectF &targetRect,
                                             const QRectF &sourceRect,
                                             const QRect &clip,
                                             const QTransform &targetRectTransform,
                                             int const_alpha)
{
    if (const_alpha == 0)
        return;

    qt_transform_image(reinterpret_cast<quint16 *>(destPixels), dbpl,
                       reinterpret_cast<const quint32 *>(srcPixels), sbpl, targetRect, sourceRect, clip, targetRectTransform,
        Blend_on_RGB16_SourceAndConstAlpha_Neon_create<quint32>(blend_8_pixels_argb32_on_rgb16_neon, const_alpha));
}

static inline void convert_8_pixels_rgb16_to_argb32(quint32 *dst, const quint16 *src)
{
    asm volatile (
        "vld1.16     { d0, d1 }, [%[SRC]]\n\t"

        /* convert 8 r5g6b5 pixel data from {d0, d1} to planar 8-bit format
           and put data into d4 - red, d3 - green, d2 - blue */
        "vshrn.u16   d4,  q0,  #8\n\t"
        "vshrn.u16   d3,  q0,  #3\n\t"
        "vsli.u16    q0,  q0,  #5\n\t"
        "vsri.u8     d4,  d4,  #5\n\t"
        "vsri.u8     d3,  d3,  #6\n\t"
        "vshrn.u16   d2,  q0,  #2\n\t"

        /* fill d5 - alpha with 0xff */
        "mov         r2, #255\n\t"
        "vdup.8      d5, r2\n\t"

        "vst4.8      { d2, d3, d4, d5 }, [%[DST]]"
        : : [DST]"r" (dst), [SRC]"r" (src)
        : "memory", "r2", "d0", "d1", "d2", "d3", "d4", "d5"
    );
}

uint * QT_FASTCALL qt_destFetchRGB16_neon(uint *buffer, QRasterBuffer *rasterBuffer, int x, int y, int length)
{
    const ushort *data = (const ushort *)rasterBuffer->scanLine(y) + x;

    int i = 0;
    for (; i < length - 7; i += 8)
        convert_8_pixels_rgb16_to_argb32(&buffer[i], &data[i]);

    if (i < length) {
        quint16 srcBuffer[8];
        quint32 dstBuffer[8];

        int tail = length - i;
        for (int j = 0; j < tail; ++j)
            srcBuffer[j] = data[i + j];

        convert_8_pixels_rgb16_to_argb32(dstBuffer, srcBuffer);

        for (int j = 0; j < tail; ++j)
            buffer[i + j] = dstBuffer[j];
    }

    return buffer;
}

static inline void convert_8_pixels_argb32_to_rgb16(quint16 *dst, const quint32 *src)
{
    asm volatile (
        "vld4.8      { d0, d1, d2, d3 }, [%[SRC]]\n\t"

        /* convert to r5g6b5 and store it into {d28, d29} */
        "vshll.u8    q14, d2, #8\n\t"
        "vshll.u8    q8,  d1, #8\n\t"
        "vshll.u8    q9,  d0, #8\n\t"
        "vsri.u16    q14, q8, #5\n\t"
        "vsri.u16    q14, q9, #11\n\t"

        "vst1.16     { d28, d29 }, [%[DST]]"
        : : [DST]"r" (dst), [SRC]"r" (src)
        : "memory", "d0", "d1", "d2", "d3", "d16", "d17", "d18", "d19", "d28", "d29"
    );
}

void QT_FASTCALL qt_destStoreRGB16_neon(QRasterBuffer *rasterBuffer, int x, int y, const uint *buffer, int length)
{
    quint16 *data = (quint16*)rasterBuffer->scanLine(y) + x;

    int i = 0;
    for (; i < length - 7; i += 8)
        convert_8_pixels_argb32_to_rgb16(&data[i], &buffer[i]);

    if (i < length) {
        quint32 srcBuffer[8];
        quint16 dstBuffer[8];

        int tail = length - i;
        for (int j = 0; j < tail; ++j)
            srcBuffer[j] = buffer[i + j];

        convert_8_pixels_argb32_to_rgb16(dstBuffer, srcBuffer);

        for (int j = 0; j < tail; ++j)
            data[i + j] = dstBuffer[j];
    }
}

QT_END_NAMESPACE

#endif // QT_HAVE_NEON

