/*

 * Armv8 Neon optimizations for libjpeg-turbo

 *

 * Copyright (C) 2009-2011, Nokia Corporation and/or its subsidiary(-ies).

 *                          All Rights Reserved.

 * Author:  Siarhei Siamashka <siarhei.siamashka@nokia.com></siarhei.siamashka@nokia.com>

 * Copyright (C) 2013-2014, Linaro Limited.  All Rights Reserved.

 * Author:  Ragesh Radhakrishnan <ragesh.r@linaro.org></ragesh.r@linaro.org>

 * Copyright (C) 2014-2016, 2020, D. R. Commander.  All Rights Reserved.

 * Copyright (C) 2015-2016, 2018, Matthieu Darbois.  All Rights Reserved.

 * Copyright (C) 2016, Siarhei Siamashka.  All Rights Reserved.

 *

 * This software is provided 'as-is', without any express or implied

 * warranty.  In no event will the authors be held liable for any damages

 * arising from the use of this software.

 *

 * Permission is granted to anyone to use this software for any purpose,

 * including commercial applications, and to alter it and redistribute it

 * freely, subject to the following restrictions:

 *

 * 1. The origin of this software must not be misrepresented; you must not

 *    claim that you wrote the original software. If you use this software

 *    in a product, an acknowledgment in the product documentation would be

 *    appreciated but is not required.

 * 2. Altered source versions must be plainly marked as such, and must not be

 *    misrepresented as being the original software.

 * 3. This notice may not be removed or altered from any source distribution.

 */

#if defined(__linux__) && defined(__ELF__)

.section .note.GNU-stack, "", %progbits  /* mark stack as non-executable */

#endif

#if defined(__APPLE__)

.section __DATA, __const

#elif defined(_WIN32)

.section .rdata

#else

.section .rodata, "a", %progbits

#endif

/* Constants for jsimd_idct_islow_neon() */

#define F_0_298   2446  /* FIX(0.298631336) */

#define F_0_390   3196  /* FIX(0.390180644) */

#define F_0_541   4433  /* FIX(0.541196100) */

#define F_0_765   6270  /* FIX(0.765366865) */

#define F_0_899   7373  /* FIX(0.899976223) */

#define F_1_175   9633  /* FIX(1.175875602) */

#define F_1_501  12299  /* FIX(1.501321110) */

#define F_1_847  15137  /* FIX(1.847759065) */

#define F_1_961  16069  /* FIX(1.961570560) */

#define F_2_053  16819  /* FIX(2.053119869) */

#define F_2_562  20995  /* FIX(2.562915447) */

#define F_3_072  25172  /* FIX(3.072711026) */

.balign 16

Ljsimd_idct_islow_neon_consts:

  .short F_0_298

  .short -F_0_390

  .short F_0_541

  .short F_0_765

  .short - F_0_899

  .short F_1_175

  .short F_1_501

  .short - F_1_847

  .short - F_1_961

  .short F_2_053

  .short - F_2_562

  .short F_3_072

  .short 0          /* padding */

  .short 0

  .short 0

  .short 0

#undef F_0_298

#undef F_0_390

#undef F_0_541

#undef F_0_765

#undef F_0_899

#undef F_1_175

#undef F_1_501

#undef F_1_847

#undef F_1_961

#undef F_2_053

#undef F_2_562

#undef F_3_072

/* Constants for jsimd_idct_ifast_neon() */

.balign 16

Ljsimd_idct_ifast_neon_consts:

  .short (277 * 128 - 256 * 128)  /* XFIX_1_082392200 */

  .short (362 * 128 - 256 * 128)  /* XFIX_1_414213562 */

  .short (473 * 128 - 256 * 128)  /* XFIX_1_847759065 */

  .short (669 * 128 - 512 * 128)  /* XFIX_2_613125930 */

/* Constants for jsimd_idct_4x4_neon() and jsimd_idct_2x2_neon() */

#define CONST_BITS  13

#define FIX_0_211164243  (1730)   /* FIX(0.211164243) */

#define FIX_0_509795579  (4176)   /* FIX(0.509795579) */

#define FIX_0_601344887  (4926)   /* FIX(0.601344887) */

#define FIX_0_720959822  (5906)   /* FIX(0.720959822) */

#define FIX_0_765366865  (6270)   /* FIX(0.765366865) */

#define FIX_0_850430095  (6967)   /* FIX(0.850430095) */

#define FIX_0_899976223  (7373)   /* FIX(0.899976223) */

#define FIX_1_061594337  (8697)   /* FIX(1.061594337) */

#define FIX_1_272758580  (10426)  /* FIX(1.272758580) */

#define FIX_1_451774981  (11893)  /* FIX(1.451774981) */

#define FIX_1_847759065  (15137)  /* FIX(1.847759065) */

#define FIX_2_172734803  (17799)  /* FIX(2.172734803) */

#define FIX_2_562915447  (20995)  /* FIX(2.562915447) */

#define FIX_3_624509785  (29692)  /* FIX(3.624509785) */

.balign 16

Ljsimd_idct_4x4_neon_consts:

  .short FIX_1_847759065        /* v0.h[0] */

  .short -FIX_0_765366865       /* v0.h[1] */

  .short -FIX_0_211164243       /* v0.h[2] */

  .short FIX_1_451774981        /* v0.h[3] */

  .short -FIX_2_172734803       /* d1[0] */

  .short FIX_1_061594337        /* d1[1] */

  .short -FIX_0_509795579       /* d1[2] */

  .short -FIX_0_601344887       /* d1[3] */

  .short FIX_0_899976223        /* v2.h[0] */

  .short FIX_2_562915447        /* v2.h[1] */

  .short 1 << (CONST_BITS + 1)  /* v2.h[2] */

  .short 0                      /* v2.h[3] */

.balign 8

Ljsimd_idct_2x2_neon_consts:

  .short -FIX_0_720959822  /* v14[0] */

  .short FIX_0_850430095   /* v14[1] */

  .short -FIX_1_272758580  /* v14[2] */

  .short FIX_3_624509785   /* v14[3] */

/* Constants for jsimd_ycc_*_neon() */

.balign 16

Ljsimd_ycc_rgb_neon_consts:

  .short 0,      0,     0,      0

  .short 22971, -11277, -23401, 29033

  .short -128,  -128,   -128,   -128

  .short -128,  -128,   -128,   -128

/* Constants for jsimd_*_ycc_neon() */

.balign 16

Ljsimd_rgb_ycc_neon_consts:

  .short 19595, 38470, 7471, 11059

  .short 21709, 32768, 27439, 5329

  .short 32767, 128, 32767, 128

  .short 32767, 128, 32767, 128

/* Constants for jsimd_fdct_islow_neon() */

#define F_0_298   2446  /* FIX(0.298631336) */

#define F_0_390   3196  /* FIX(0.390180644) */

#define F_0_541   4433  /* FIX(0.541196100) */

#define F_0_765   6270  /* FIX(0.765366865) */

#define F_0_899   7373  /* FIX(0.899976223) */

#define F_1_175   9633  /* FIX(1.175875602) */

#define F_1_501  12299  /* FIX(1.501321110) */

#define F_1_847  15137  /* FIX(1.847759065) */

#define F_1_961  16069  /* FIX(1.961570560) */

#define F_2_053  16819  /* FIX(2.053119869) */

#define F_2_562  20995  /* FIX(2.562915447) */

#define F_3_072  25172  /* FIX(3.072711026) */

.balign 16

Ljsimd_fdct_islow_neon_consts:

  .short F_0_298

  .short -F_0_390

  .short F_0_541

  .short F_0_765

  .short - F_0_899

  .short F_1_175

  .short F_1_501

  .short - F_1_847

  .short - F_1_961

  .short F_2_053

  .short - F_2_562

  .short F_3_072

  .short 0          /* padding */

  .short 0

  .short 0

  .short 0

#undef F_0_298

#undef F_0_390

#undef F_0_541

#undef F_0_765

#undef F_0_899

#undef F_1_175

#undef F_1_501

#undef F_1_847

#undef F_1_961

#undef F_2_053

#undef F_2_562

#undef F_3_072

/* Constants for jsimd_fdct_ifast_neon() */

.balign 16

Ljsimd_fdct_ifast_neon_consts:

  .short (98 * 128)               /* XFIX_0_382683433 */

  .short (139 * 128)              /* XFIX_0_541196100 */

  .short (181 * 128)              /* XFIX_0_707106781 */

  .short (334 * 128 - 256 * 128)  /* XFIX_1_306562965 */

/* Constants for jsimd_h2*_downsample_neon() */

.balign 16

Ljsimd_h2_downsample_neon_consts:

  .byte 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, \

        0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F  /* diff 0 */

  .byte 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, \

        0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0E  /* diff 1 */

  .byte 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, \

        0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0D, 0x0D  /* diff 2 */

  .byte 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, \

        0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0C, 0x0C, 0x0C  /* diff 3 */

  .byte 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, \

        0x08, 0x09, 0x0A, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B  /* diff 4 */

  .byte 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, \

        0x08, 0x09, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A  /* diff 5 */

  .byte 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, \

        0x08, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09  /* diff 6 */

  .byte 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, \

        0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08  /* diff 7 */

  .byte 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, \

        0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07  /* diff 8 */

  .byte 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x06, \

        0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06  /* diff 9 */

  .byte 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x05, 0x05, \

        0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05  /* diff 10 */

  .byte 0x00, 0x01, 0x02, 0x03, 0x04, 0x04, 0x04, 0x04, \

        0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04  /* diff 11 */

  .byte 0x00, 0x01, 0x02, 0x03, 0x03, 0x03, 0x03, 0x03, \

        0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03  /* diff 12 */

  .byte 0x00, 0x01, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, \

        0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02  /* diff 13 */

  .byte 0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, \

        0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01  /* diff 14 */

  .byte 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \

        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00  /* diff 15 */

/* Constants for jsimd_huff_encode_one_block_neon() */

.balign 16

Ljsimd_huff_encode_one_block_neon_consts:

    .byte 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, \

          0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80

    .byte    0,   1,   2,   3,  16,  17,  32,  33, \

            18,  19,   4,   5,   6,   7,  20,  21  /* L0 => L3 : 4 lines OK */

    .byte   34,  35,  48,  49, 255, 255,  50,  51, \

            36,  37,  22,  23,   8,   9,  10,  11  /* L0 => L3 : 4 lines OK */

    .byte    8,   9,  22,  23,  36,  37,  50,  51, \

           255, 255, 255, 255, 255, 255,  52,  53  /* L1 => L4 : 4 lines OK */

    .byte   54,  55,  40,  41,  26,  27,  12,  13, \

            14,  15,  28,  29,  42,  43,  56,  57  /* L0 => L3 : 4 lines OK */

    .byte    6,   7,  20,  21,  34,  35,  48,  49, \

            50,  51,  36,  37,  22,  23,   8,   9  /* L4 => L7 : 4 lines OK */

    .byte   42,  43,  28,  29,  14,  15,  30,  31, \

            44,  45,  58,  59, 255, 255, 255, 255  /* L1 => L4 : 4 lines OK */

    .byte  255, 255, 255, 255,  56,  57,  42,  43, \

            28,  29,  14,  15,  30,  31,  44,  45  /* L3 => L6 : 4 lines OK */

    .byte   26,  27,  40,  41,  42,  43,  28,  29, \

            14,  15,  30,  31,  44,  45,  46,  47  /* L5 => L7 : 3 lines OK */

    .byte  255, 255, 255, 255,   0,   1, 255, 255, \

           255, 255, 255, 255, 255, 255, 255, 255  /* L4 : 1 lines OK */

    .byte  255, 255, 255, 255, 255, 255, 255, 255, \

             0,   1,  16,  17,   2,   3, 255, 255  /* L5 => L6 : 2 lines OK */

    .byte  255, 255, 255, 255, 255, 255, 255, 255, \

           255, 255, 255, 255,   8,   9,  22,  23  /* L5 => L6 : 2 lines OK */

    .byte    4,   5,   6,   7, 255, 255, 255, 255, \

           255, 255, 255, 255, 255, 255, 255, 255  /* L7 : 1 line OK */

.text

#define RESPECT_STRICT_ALIGNMENT  1

/*****************************************************************************/

/* Supplementary macro for setting function attributes */

.macro asm_function fname

#ifdef __APPLE__

    .private_extern _\fname

    .globl _\fname

_\fname:

#else

    .global \fname

#ifdef __ELF__

    .hidden \fname

    .type \fname, %function

#endif

\fname:

#endif

.endm

/* Get symbol location */

.macro get_symbol_loc reg, symbol

#ifdef __APPLE__

    adrp            \reg, \symbol@PAGE

    add             \reg, \reg, \symbol@PAGEOFF

#else

    adrp            \reg, \symbol

    add             \reg, \reg, :lo12:\symbol

#endif

.endm

/* Transpose elements of single 128 bit registers */

.macro transpose_single x0, x1, xi, xilen, literal

    ins             \xi\xilen[0], \x0\xilen[0]

    ins             \x1\xilen[0], \x0\xilen[1]

    trn1            \x0\literal, \x0\literal, \x1\literal

    trn2            \x1\literal, \xi\literal, \x1\literal

.endm

/* Transpose elements of 2 different registers */

.macro transpose x0, x1, xi, xilen, literal

    mov             \xi\xilen, \x0\xilen

    trn1            \x0\literal, \x0\literal, \x1\literal

    trn2            \x1\literal, \xi\literal, \x1\literal

.endm

/* Transpose a block of 4x4 coefficients in four 64-bit registers */

.macro transpose_4x4_32 x0, x0len, x1, x1len, x2, x2len, x3, x3len, xi, xilen

    mov             \xi\xilen, \x0\xilen

    trn1            \x0\x0len, \x0\x0len, \x2\x2len

    trn2            \x2\x2len, \xi\x0len, \x2\x2len

    mov             \xi\xilen, \x1\xilen

    trn1            \x1\x1len, \x1\x1len, \x3\x3len

    trn2            \x3\x3len, \xi\x1len, \x3\x3len

.endm

.macro transpose_4x4_16 x0, x0len, x1, x1len, x2, x2len, x3, x3len, xi, xilen

    mov             \xi\xilen, \x0\xilen

    trn1            \x0\x0len, \x0\x0len, \x1\x1len

    trn2            \x1\x2len, \xi\x0len, \x1\x2len

    mov             \xi\xilen, \x2\xilen

    trn1            \x2\x2len, \x2\x2len, \x3\x3len

    trn2            \x3\x2len, \xi\x1len, \x3\x3len

.endm

.macro transpose_4x4 x0, x1, x2, x3, x5

    transpose_4x4_16 \x0, .4h, \x1, .4h, \x2, .4h, \x3, .4h, \x5, .16b

    transpose_4x4_32 \x0, .2s, \x1, .2s, \x2, .2s, \x3, .2s, \x5, .16b

.endm

.macro transpose_8x8 l0, l1, l2, l3, l4, l5, l6, l7, t0, t1, t2, t3

    trn1            \t0\().8h, \l0\().8h, \l1\().8h

    trn1            \t1\().8h, \l2\().8h, \l3\().8h

    trn1            \t2\().8h, \l4\().8h, \l5\().8h

    trn1            \t3\().8h, \l6\().8h, \l7\().8h

    trn2            \l1\().8h, \l0\().8h, \l1\().8h

    trn2            \l3\().8h, \l2\().8h, \l3\().8h

    trn2            \l5\().8h, \l4\().8h, \l5\().8h

    trn2            \l7\().8h, \l6\().8h, \l7\().8h

    trn1            \l4\().4s, \t2\().4s, \t3\().4s

    trn2            \t3\().4s, \t2\().4s, \t3\().4s

    trn1            \t2\().4s, \t0\().4s, \t1\().4s

    trn2            \l2\().4s, \t0\().4s, \t1\().4s

    trn1            \t0\().4s, \l1\().4s, \l3\().4s

    trn2            \l3\().4s, \l1\().4s, \l3\().4s

    trn2            \t1\().4s, \l5\().4s, \l7\().4s

    trn1            \l5\().4s, \l5\().4s, \l7\().4s

    trn2            \l6\().2d, \l2\().2d, \t3\().2d

    trn1            \l0\().2d, \t2\().2d, \l4\().2d

    trn1            \l1\().2d, \t0\().2d, \l5\().2d

    trn2            \l7\().2d, \l3\().2d, \t1\().2d

    trn1            \l2\().2d, \l2\().2d, \t3\().2d

    trn2            \l4\().2d, \t2\().2d, \l4\().2d

    trn1            \l3\().2d, \l3\().2d, \t1\().2d

    trn2            \l5\().2d, \t0\().2d, \l5\().2d

.endm

#define CENTERJSAMPLE  128

/*****************************************************************************/

/*

 * Perform dequantization and inverse DCT on one block of coefficients.

 *

 * GLOBAL(void)

 * jsimd_idct_islow_neon(void *dct_table, JCOEFPTR coef_block,

 *                       JSAMPARRAY output_buf, JDIMENSION output_col)

 */

#define CONST_BITS  13

#define PASS1_BITS  2

#define XFIX_P_0_298  v0.h[0]

#define XFIX_N_0_390  v0.h[1]

#define XFIX_P_0_541  v0.h[2]

#define XFIX_P_0_765  v0.h[3]

#define XFIX_N_0_899  v0.h[4]

#define XFIX_P_1_175  v0.h[5]

#define XFIX_P_1_501  v0.h[6]

#define XFIX_N_1_847  v0.h[7]

#define XFIX_N_1_961  v1.h[0]

#define XFIX_P_2_053  v1.h[1]

#define XFIX_N_2_562  v1.h[2]

#define XFIX_P_3_072  v1.h[3]

asm_function jsimd_idct_islow_neon

    DCT_TABLE       .req x0

    COEF_BLOCK      .req x1

    OUTPUT_BUF      .req x2

    OUTPUT_COL      .req x3

    TMP1            .req x0

    TMP2            .req x1

    TMP3            .req x9

    TMP4            .req x10

    TMP5            .req x11

    TMP6            .req x12

    TMP7            .req x13

    TMP8            .req x14

    /* OUTPUT_COL is a JDIMENSION (unsigned int) argument, so the ABI doesn't

       guarantee that the upper (unused) 32 bits of x3 are valid.  This

       instruction ensures that those bits are set to zero. */

    uxtw x3, w3

    sub             sp, sp, #64

    get_symbol_loc  x15, Ljsimd_idct_islow_neon_consts

    mov             x10, sp

    st1             {v8.8b, v9.8b, v10.8b, v11.8b}, [x10], #32

    st1             {v12.8b, v13.8b, v14.8b, v15.8b}, [x10], #32

    ld1             {v0.8h, v1.8h}, [x15]

    ld1             {v2.8h, v3.8h, v4.8h, v5.8h}, [COEF_BLOCK], #64

    ld1             {v18.8h, v19.8h, v20.8h, v21.8h}, [DCT_TABLE], #64

    ld1             {v6.8h, v7.8h, v8.8h, v9.8h}, [COEF_BLOCK], #64

    ld1             {v22.8h, v23.8h, v24.8h, v25.8h}, [DCT_TABLE], #64

    cmeq            v16.8h, v3.8h, #0

    cmeq            v26.8h, v4.8h, #0

    cmeq            v27.8h, v5.8h, #0

    cmeq            v28.8h, v6.8h, #0

    cmeq            v29.8h, v7.8h, #0

    cmeq            v30.8h, v8.8h, #0

    cmeq            v31.8h, v9.8h, #0

    and             v10.16b, v16.16b, v26.16b

    and             v11.16b, v27.16b, v28.16b

    and             v12.16b, v29.16b, v30.16b

    and             v13.16b, v31.16b, v10.16b

    and             v14.16b, v11.16b, v12.16b

    mul             v2.8h, v2.8h, v18.8h

    and             v15.16b, v13.16b, v14.16b

    shl             v10.8h, v2.8h, #(PASS1_BITS)

    sqxtn           v16.8b, v15.8h

    mov             TMP1, v16.d[0]

    mvn             TMP2, TMP1

    cbnz            TMP2, 2f

    /* case all AC coeffs are zeros */

    dup             v2.2d, v10.d[0]

    dup             v6.2d, v10.d[1]

    mov             v3.16b, v2.16b

    mov             v7.16b, v6.16b

    mov             v4.16b, v2.16b

    mov             v8.16b, v6.16b

    mov             v5.16b, v2.16b

    mov             v9.16b, v6.16b

1:

    /* for this transpose, we should organise data like this:

     * 00, 01, 02, 03, 40, 41, 42, 43

     * 10, 11, 12, 13, 50, 51, 52, 53

     * 20, 21, 22, 23, 60, 61, 62, 63

     * 30, 31, 32, 33, 70, 71, 72, 73

     * 04, 05, 06, 07, 44, 45, 46, 47

     * 14, 15, 16, 17, 54, 55, 56, 57

     * 24, 25, 26, 27, 64, 65, 66, 67

     * 34, 35, 36, 37, 74, 75, 76, 77

     */

    trn1            v28.8h, v2.8h, v3.8h

    trn1            v29.8h, v4.8h, v5.8h

    trn1            v30.8h, v6.8h, v7.8h

    trn1            v31.8h, v8.8h, v9.8h

    trn2            v16.8h, v2.8h, v3.8h

    trn2            v17.8h, v4.8h, v5.8h

    trn2            v18.8h, v6.8h, v7.8h

    trn2            v19.8h, v8.8h, v9.8h

    trn1            v2.4s, v28.4s, v29.4s

    trn1            v6.4s, v30.4s, v31.4s

    trn1            v3.4s, v16.4s, v17.4s

    trn1            v7.4s, v18.4s, v19.4s

    trn2            v4.4s, v28.4s, v29.4s

    trn2            v8.4s, v30.4s, v31.4s

    trn2            v5.4s, v16.4s, v17.4s

    trn2            v9.4s, v18.4s, v19.4s

    /* Even part: reverse the even part of the forward DCT. */

    add             v18.8h, v4.8h, v8.8h           /* z2 + z3 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]) + DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]) */

    add             v22.8h, v2.8h, v6.8h           /* z2 + z3 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) + DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]) */

    smull2          v19.4s, v18.8h, XFIX_P_0_541   /* z1h z1 = MULTIPLY(z2 + z3, FIX_0_541196100); */

    sub             v26.8h, v2.8h, v6.8h           /* z2 - z3 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) - DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]) */

    smull           v18.4s, v18.4h, XFIX_P_0_541   /* z1l z1 = MULTIPLY(z2 + z3, FIX_0_541196100); */

    sshll2          v23.4s, v22.8h, #(CONST_BITS)  /* tmp0h tmp0 = LEFT_SHIFT(z2 + z3, CONST_BITS); */

    mov             v21.16b, v19.16b               /* tmp3 = z1 */

    mov             v20.16b, v18.16b               /* tmp3 = z1 */

    smlal2          v19.4s, v8.8h, XFIX_N_1_847    /* tmp2h tmp2 = z1 + MULTIPLY(z3, -FIX_1_847759065); */

    smlal           v18.4s, v8.4h, XFIX_N_1_847    /* tmp2l tmp2 = z1 + MULTIPLY(z3, -FIX_1_847759065); */

    sshll2          v27.4s, v26.8h, #(CONST_BITS)  /* tmp1h tmp1 = LEFT_SHIFT(z2 - z3, CONST_BITS); */

    smlal2          v21.4s, v4.8h, XFIX_P_0_765    /* tmp3h tmp3 = z1 + MULTIPLY(z2, FIX_0_765366865); */

    smlal           v20.4s, v4.4h, XFIX_P_0_765    /* tmp3l tmp3 = z1 + MULTIPLY(z2, FIX_0_765366865); */

    sshll           v22.4s, v22.4h, #(CONST_BITS)  /* tmp0l tmp0 = LEFT_SHIFT(z2 + z3, CONST_BITS); */

    sshll           v26.4s, v26.4h, #(CONST_BITS)  /* tmp1l tmp1 = LEFT_SHIFT(z2 - z3, CONST_BITS); */

    add             v2.4s, v22.4s, v20.4s          /* tmp10l tmp10 = tmp0 + tmp3; */

    sub             v6.4s, v22.4s, v20.4s          /* tmp13l tmp13 = tmp0 - tmp3; */

    add             v8.4s, v26.4s, v18.4s          /* tmp11l tmp11 = tmp1 + tmp2; */

    sub             v4.4s, v26.4s, v18.4s          /* tmp12l tmp12 = tmp1 - tmp2; */

    add             v28.4s, v23.4s, v21.4s         /* tmp10h tmp10 = tmp0 + tmp3; */

    sub             v31.4s, v23.4s, v21.4s         /* tmp13h tmp13 = tmp0 - tmp3; */

    add             v29.4s, v27.4s, v19.4s         /* tmp11h tmp11 = tmp1 + tmp2; */

    sub             v30.4s, v27.4s, v19.4s         /* tmp12h tmp12 = tmp1 - tmp2; */

    /* Odd part per figure 8; the matrix is unitary and hence its

     * transpose is its inverse.  i0..i3 are y7,y5,y3,y1 respectively.

     */

    add             v22.8h, v9.8h, v5.8h    /* z3 = tmp0 + tmp2 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]) + DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]) */

    add             v24.8h, v7.8h, v3.8h    /* z4 = tmp1 + tmp3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]) + DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]) */

    add             v18.8h, v9.8h, v3.8h    /* z1 = tmp0 + tmp3 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]) + DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]) */

    add             v20.8h, v7.8h, v5.8h    /* z2 = tmp1 + tmp2 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]) + DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]) */

    add             v26.8h, v22.8h, v24.8h  /* z5 = z3 + z4 */

    smull2          v11.4s, v9.8h, XFIX_P_0_298   /* tmp0 = MULTIPLY(tmp0, FIX_0_298631336) */

    smull2          v13.4s, v7.8h, XFIX_P_2_053   /* tmp1 = MULTIPLY(tmp1, FIX_2_053119869) */

    smull2          v15.4s, v5.8h, XFIX_P_3_072   /* tmp2 = MULTIPLY(tmp2, FIX_3_072711026) */

    smull2          v17.4s, v3.8h, XFIX_P_1_501   /* tmp3 = MULTIPLY(tmp3, FIX_1_501321110) */

    smull2          v27.4s, v26.8h, XFIX_P_1_175  /* z5h z5 = MULTIPLY(z3 + z4, FIX_1_175875602) */

    smull2          v23.4s, v22.8h, XFIX_N_1_961  /* z3 = MULTIPLY(z3, -FIX_1_961570560) */

    smull2          v25.4s, v24.8h, XFIX_N_0_390  /* z4 = MULTIPLY(z4, -FIX_0_390180644) */

    smull2          v19.4s, v18.8h, XFIX_N_0_899  /* z1 = MULTIPLY(z1, -FIX_0_899976223) */

    smull2          v21.4s, v20.8h, XFIX_N_2_562  /* z2 = MULTIPLY(z2, -FIX_2_562915447) */

    smull           v10.4s, v9.4h, XFIX_P_0_298   /* tmp0 = MULTIPLY(tmp0, FIX_0_298631336) */

    smull           v12.4s, v7.4h, XFIX_P_2_053   /* tmp1 = MULTIPLY(tmp1, FIX_2_053119869) */

    smull           v14.4s, v5.4h, XFIX_P_3_072   /* tmp2 = MULTIPLY(tmp2, FIX_3_072711026) */

    smull           v16.4s, v3.4h, XFIX_P_1_501   /* tmp3 = MULTIPLY(tmp3, FIX_1_501321110) */

    smull           v26.4s, v26.4h, XFIX_P_1_175  /* z5l z5 = MULTIPLY(z3 + z4, FIX_1_175875602) */

    smull           v22.4s, v22.4h, XFIX_N_1_961  /* z3 = MULTIPLY(z3, -FIX_1_961570560) */

    smull           v24.4s, v24.4h, XFIX_N_0_390  /* z4 = MULTIPLY(z4, -FIX_0_390180644) */

    smull           v18.4s, v18.4h, XFIX_N_0_899  /* z1 = MULTIPLY(z1, -FIX_0_899976223) */

    smull           v20.4s, v20.4h, XFIX_N_2_562  /* z2 = MULTIPLY(z2, -FIX_2_562915447) */

    add             v23.4s, v23.4s, v27.4s  /* z3 += z5 */

    add             v22.4s, v22.4s, v26.4s  /* z3 += z5 */

    add             v25.4s, v25.4s, v27.4s  /* z4 += z5 */

    add             v24.4s, v24.4s, v26.4s  /* z4 += z5 */

    add             v11.4s, v11.4s, v19.4s  /* tmp0 += z1 */

    add             v10.4s, v10.4s, v18.4s  /* tmp0 += z1 */

    add             v13.4s, v13.4s, v21.4s  /* tmp1 += z2 */

    add             v12.4s, v12.4s, v20.4s  /* tmp1 += z2 */

    add             v15.4s, v15.4s, v21.4s  /* tmp2 += z2 */

    add             v14.4s, v14.4s, v20.4s  /* tmp2 += z2 */

    add             v17.4s, v17.4s, v19.4s  /* tmp3 += z1 */

    add             v16.4s, v16.4s, v18.4s  /* tmp3 += z1 */

    add             v11.4s, v11.4s, v23.4s  /* tmp0 += z3 */

    add             v10.4s, v10.4s, v22.4s  /* tmp0 += z3 */

    add             v13.4s, v13.4s, v25.4s  /* tmp1 += z4 */

    add             v12.4s, v12.4s, v24.4s  /* tmp1 += z4 */

    add             v17.4s, v17.4s, v25.4s  /* tmp3 += z4 */

    add             v16.4s, v16.4s, v24.4s  /* tmp3 += z4 */

    add             v15.4s, v15.4s, v23.4s  /* tmp2 += z3 */

    add             v14.4s, v14.4s, v22.4s  /* tmp2 += z3 */

    /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */

    add             v18.4s, v2.4s, v16.4s   /* tmp10 + tmp3 */

    add             v19.4s, v28.4s, v17.4s  /* tmp10 + tmp3 */

    sub             v20.4s, v2.4s, v16.4s   /* tmp10 - tmp3 */

    sub             v21.4s, v28.4s, v17.4s  /* tmp10 - tmp3 */

    add             v22.4s, v8.4s, v14.4s   /* tmp11 + tmp2 */

    add             v23.4s, v29.4s, v15.4s  /* tmp11 + tmp2 */

    sub             v24.4s, v8.4s, v14.4s   /* tmp11 - tmp2 */

    sub             v25.4s, v29.4s, v15.4s  /* tmp11 - tmp2 */

    add             v26.4s, v4.4s, v12.4s   /* tmp12 + tmp1 */

    add             v27.4s, v30.4s, v13.4s  /* tmp12 + tmp1 */

    sub             v28.4s, v4.4s, v12.4s   /* tmp12 - tmp1 */

    sub             v29.4s, v30.4s, v13.4s  /* tmp12 - tmp1 */

    add             v14.4s, v6.4s, v10.4s   /* tmp13 + tmp0 */

    add             v15.4s, v31.4s, v11.4s  /* tmp13 + tmp0 */

    sub             v16.4s, v6.4s, v10.4s   /* tmp13 - tmp0 */

    sub             v17.4s, v31.4s, v11.4s  /* tmp13 - tmp0 */

    shrn            v2.4h, v18.4s, #16  /* wsptr[DCTSIZE*0] = (int)DESCALE(tmp10 + tmp3, CONST_BITS+PASS1_BITS+3) */

    shrn            v9.4h, v20.4s, #16  /* wsptr[DCTSIZE*7] = (int)DESCALE(tmp10 - tmp3, CONST_BITS+PASS1_BITS+3) */

    shrn            v3.4h, v22.4s, #16  /* wsptr[DCTSIZE*1] = (int)DESCALE(tmp11 + tmp2, CONST_BITS+PASS1_BITS+3) */

    shrn            v8.4h, v24.4s, #16  /* wsptr[DCTSIZE*6] = (int)DESCALE(tmp11 - tmp2, CONST_BITS+PASS1_BITS+3) */

    shrn            v4.4h, v26.4s, #16  /* wsptr[DCTSIZE*2] = (int)DESCALE(tmp12 + tmp1, CONST_BITS+PASS1_BITS+3) */

    shrn            v7.4h, v28.4s, #16  /* wsptr[DCTSIZE*5] = (int)DESCALE(tmp12 - tmp1, CONST_BITS+PASS1_BITS+3) */

    shrn            v5.4h, v14.4s, #16  /* wsptr[DCTSIZE*3] = (int)DESCALE(tmp13 + tmp0, CONST_BITS+PASS1_BITS+3) */

    shrn            v6.4h, v16.4s, #16  /* wsptr[DCTSIZE*4] = (int)DESCALE(tmp13 - tmp0, CONST_BITS+PASS1_BITS+3) */

    shrn2           v2.8h, v19.4s, #16  /* wsptr[DCTSIZE*0] = (int)DESCALE(tmp10 + tmp3, CONST_BITS+PASS1_BITS+3) */

    shrn2           v9.8h, v21.4s, #16  /* wsptr[DCTSIZE*7] = (int)DESCALE(tmp10 - tmp3, CONST_BITS+PASS1_BITS+3) */

    shrn2           v3.8h, v23.4s, #16  /* wsptr[DCTSIZE*1] = (int)DESCALE(tmp11 + tmp2, CONST_BITS+PASS1_BITS+3) */

    shrn2           v8.8h, v25.4s, #16  /* wsptr[DCTSIZE*6] = (int)DESCALE(tmp11 - tmp2, CONST_BITS+PASS1_BITS+3) */

    shrn2           v4.8h, v27.4s, #16  /* wsptr[DCTSIZE*2] = (int)DESCALE(tmp12 + tmp1, CONST_BITS+PASS1_BITS+3) */

    shrn2           v7.8h, v29.4s, #16  /* wsptr[DCTSIZE*5] = (int)DESCALE(tmp12 - tmp1, CONST_BITS+PASS1_BITS+3) */

    shrn2           v5.8h, v15.4s, #16  /* wsptr[DCTSIZE*3] = (int)DESCALE(tmp13 + tmp0, CONST_BITS+PASS1_BITS+3) */

    shrn2           v6.8h, v17.4s, #16  /* wsptr[DCTSIZE*4] = (int)DESCALE(tmp13 - tmp0, CONST_BITS+PASS1_BITS+3) */

    movi            v0.16b, #(CENTERJSAMPLE)

    /* Prepare pointers (dual-issue with Neon instructions) */

      ldp             TMP1, TMP2, [OUTPUT_BUF], 16

    sqrshrn         v28.8b, v2.8h, #(CONST_BITS + PASS1_BITS + 3 - 16)

      ldp             TMP3, TMP4, [OUTPUT_BUF], 16

    sqrshrn         v29.8b, v3.8h, #(CONST_BITS + PASS1_BITS + 3 - 16)

      add             TMP1, TMP1, OUTPUT_COL

    sqrshrn         v30.8b, v4.8h, #(CONST_BITS + PASS1_BITS + 3 - 16)

      add             TMP2, TMP2, OUTPUT_COL

    sqrshrn         v31.8b, v5.8h, #(CONST_BITS + PASS1_BITS + 3 - 16)

      add             TMP3, TMP3, OUTPUT_COL

    sqrshrn2        v28.16b, v6.8h, #(CONST_BITS + PASS1_BITS + 3 - 16)

      add             TMP4, TMP4, OUTPUT_COL

    sqrshrn2        v29.16b, v7.8h, #(CONST_BITS + PASS1_BITS + 3 - 16)

      ldp             TMP5, TMP6, [OUTPUT_BUF], 16

    sqrshrn2        v30.16b, v8.8h, #(CONST_BITS + PASS1_BITS + 3 - 16)

      ldp             TMP7, TMP8, [OUTPUT_BUF], 16

    sqrshrn2        v31.16b, v9.8h, #(CONST_BITS + PASS1_BITS + 3 - 16)

      add             TMP5, TMP5, OUTPUT_COL

    add             v16.16b, v28.16b, v0.16b

      add             TMP6, TMP6, OUTPUT_COL

    add             v18.16b, v29.16b, v0.16b

      add             TMP7, TMP7, OUTPUT_COL

    add             v20.16b, v30.16b, v0.16b

      add             TMP8, TMP8, OUTPUT_COL

    add             v22.16b, v31.16b, v0.16b

    /* Transpose the final 8-bit samples */

    trn1            v28.16b, v16.16b, v18.16b

    trn1            v30.16b, v20.16b, v22.16b

    trn2            v29.16b, v16.16b, v18.16b

    trn2            v31.16b, v20.16b, v22.16b

    trn1            v16.8h, v28.8h, v30.8h

    trn2            v18.8h, v28.8h, v30.8h

    trn1            v20.8h, v29.8h, v31.8h

    trn2            v22.8h, v29.8h, v31.8h

    uzp1            v28.4s, v16.4s, v18.4s

    uzp2            v30.4s, v16.4s, v18.4s

    uzp1            v29.4s, v20.4s, v22.4s

    uzp2            v31.4s, v20.4s, v22.4s

    /* Store results to the output buffer */

    st1             {v28.d}[0], [TMP1]

    st1             {v29.d}[0], [TMP2]

    st1             {v28.d}[1], [TMP3]

    st1             {v29.d}[1], [TMP4]

    st1             {v30.d}[0], [TMP5]

    st1             {v31.d}[0], [TMP6]

    st1             {v30.d}[1], [TMP7]

    st1             {v31.d}[1], [TMP8]

    ld1             {v8.8b, v9.8b, v10.8b, v11.8b}, [sp], #32

    ld1             {v12.8b, v13.8b, v14.8b, v15.8b}, [sp], #32

    blr             x30

.balign 16

2:

    mul             v3.8h, v3.8h, v19.8h

    mul             v4.8h, v4.8h, v20.8h

    mul             v5.8h, v5.8h, v21.8h

    add             TMP4, xzr, TMP2, LSL #32

    mul             v6.8h, v6.8h, v22.8h

    mul             v7.8h, v7.8h, v23.8h

    adds            TMP3, xzr, TMP2, LSR #32

    mul             v8.8h, v8.8h, v24.8h

    mul             v9.8h, v9.8h, v25.8h

    b.ne            3f

    /* Right AC coef is zero */

    dup             v15.2d, v10.d[1]

    /* Even part: reverse the even part of the forward DCT. */

    add             v18.4h, v4.4h, v8.4h           /* z2 + z3 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]) + DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]) */

    add             v22.4h, v2.4h, v6.4h           /* z2 + z3 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) + DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]) */

    sub             v26.4h, v2.4h, v6.4h           /* z2 - z3 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) - DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]) */

    smull           v18.4s, v18.4h, XFIX_P_0_541   /* z1l z1 = MULTIPLY(z2 + z3, FIX_0_541196100); */

    sshll           v22.4s, v22.4h, #(CONST_BITS)  /* tmp0l tmp0 = LEFT_SHIFT(z2 + z3, CONST_BITS); */

    mov             v20.16b, v18.16b               /* tmp3 = z1 */

    sshll           v26.4s, v26.4h, #(CONST_BITS)  /* tmp1l tmp1 = LEFT_SHIFT(z2 - z3, CONST_BITS); */

    smlal           v18.4s, v8.4h, XFIX_N_1_847    /* tmp2l tmp2 = z1 + MULTIPLY(z3, -FIX_1_847759065); */

    smlal           v20.4s, v4.4h, XFIX_P_0_765    /* tmp3l tmp3 = z1 + MULTIPLY(z2, FIX_0_765366865); */

    add             v2.4s, v22.4s, v20.4s          /* tmp10l tmp10 = tmp0 + tmp3; */

    sub             v6.4s, v22.4s, v20.4s          /* tmp13l tmp13 = tmp0 - tmp3; */

    add             v8.4s, v26.4s, v18.4s          /* tmp11l tmp11 = tmp1 + tmp2; */

    sub             v4.4s, v26.4s, v18.4s          /* tmp12l tmp12 = tmp1 - tmp2; */

    /* Odd part per figure 8; the matrix is unitary and hence its

     * transpose is its inverse.  i0..i3 are y7,y5,y3,y1 respectively.

     */

    add             v22.4h, v9.4h, v5.4h    /* z3 = tmp0 + tmp2 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]) + DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]) */

    add             v24.4h, v7.4h, v3.4h    /* z4 = tmp1 + tmp3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]) + DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]) */

    add             v18.4h, v9.4h, v3.4h    /* z1 = tmp0 + tmp3 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]) + DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]) */

    add             v20.4h, v7.4h, v5.4h    /* z2 = tmp1 + tmp2 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]) + DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]) */

    add             v26.4h, v22.4h, v24.4h  /* z5 = z3 + z4 */

    smull           v10.4s, v9.4h, XFIX_P_0_298   /* tmp0 = MULTIPLY(tmp0, FIX_0_298631336) */

    smull           v12.4s, v7.4h, XFIX_P_2_053   /* tmp1 = MULTIPLY(tmp1, FIX_2_053119869) */

    smull           v14.4s, v5.4h, XFIX_P_3_072   /* tmp2 = MULTIPLY(tmp2, FIX_3_072711026) */

    smull           v16.4s, v3.4h, XFIX_P_1_501   /* tmp3 = MULTIPLY(tmp3, FIX_1_501321110) */

    smull           v26.4s, v26.4h, XFIX_P_1_175  /* z5l z5 = MULTIPLY(z3 + z4, FIX_1_175875602) */

    smull           v22.4s, v22.4h, XFIX_N_1_961  /* z3 = MULTIPLY(z3, -FIX_1_961570560) */

    smull           v24.4s, v24.4h, XFIX_N_0_390  /* z4 = MULTIPLY(z4, -FIX_0_390180644) */

    smull           v18.4s, v18.4h, XFIX_N_0_899  /* z1 = MULTIPLY(z1, -FIX_0_899976223) */

    smull           v20.4s, v20.4h, XFIX_N_2_562  /* z2 = MULTIPLY(z2, -FIX_2_562915447) */

    add             v22.4s, v22.4s, v26.4s  /* z3 += z5 */

    add             v24.4s, v24.4s, v26.4s  /* z4 += z5 */

    add             v10.4s, v10.4s, v18.4s  /* tmp0 += z1 */

    add             v12.4s, v12.4s, v20.4s  /* tmp1 += z2 */

    add             v14.4s, v14.4s, v20.4s  /* tmp2 += z2 */

    add             v16.4s, v16.4s, v18.4s  /* tmp3 += z1 */

    add             v10.4s, v10.4s, v22.4s  /* tmp0 += z3 */

    add             v12.4s, v12.4s, v24.4s  /* tmp1 += z4 */

    add             v16.4s, v16.4s, v24.4s  /* tmp3 += z4 */

    add             v14.4s, v14.4s, v22.4s  /* tmp2 += z3 */

    /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */

    add             v18.4s, v2.4s, v16.4s  /* tmp10 + tmp3 */

    sub             v20.4s, v2.4s, v16.4s  /* tmp10 - tmp3 */

    add             v22.4s, v8.4s, v14.4s  /* tmp11 + tmp2 */

    sub             v24.4s, v8.4s, v14.4s  /* tmp11 - tmp2 */

    add             v26.4s, v4.4s, v12.4s  /* tmp12 + tmp1 */

    sub             v28.4s, v4.4s, v12.4s  /* tmp12 - tmp1 */

    add             v14.4s, v6.4s, v10.4s  /* tmp13 + tmp0 */

    sub             v16.4s, v6.4s, v10.4s  /* tmp13 - tmp0 */

    rshrn           v2.4h, v18.4s, #(CONST_BITS - PASS1_BITS)  /* wsptr[DCTSIZE*0] = (int)DESCALE(tmp10 + tmp3, CONST_BITS-PASS1_BITS) */

    rshrn           v3.4h, v22.4s, #(CONST_BITS - PASS1_BITS)  /* wsptr[DCTSIZE*1] = (int)DESCALE(tmp11 + tmp2, CONST_BITS-PASS1_BITS) */

    rshrn           v4.4h, v26.4s, #(CONST_BITS - PASS1_BITS)  /* wsptr[DCTSIZE*2] = (int)DESCALE(tmp12 + tmp1, CONST_BITS-PASS1_BITS) */

    rshrn           v5.4h, v14.4s, #(CONST_BITS - PASS1_BITS)  /* wsptr[DCTSIZE*3] = (int)DESCALE(tmp13 + tmp0, CONST_BITS-PASS1_BITS) */

    rshrn2          v2.8h, v16.4s, #(CONST_BITS - PASS1_BITS)  /* wsptr[DCTSIZE*4] = (int)DESCALE(tmp13 - tmp0, CONST_BITS-PASS1_BITS) */

    rshrn2          v3.8h, v28.4s, #(CONST_BITS - PASS1_BITS)  /* wsptr[DCTSIZE*5] = (int)DESCALE(tmp12 - tmp1, CONST_BITS-PASS1_BITS) */

    rshrn2          v4.8h, v24.4s, #(CONST_BITS - PASS1_BITS)  /* wsptr[DCTSIZE*6] = (int)DESCALE(tmp11 - tmp2, CONST_BITS-PASS1_BITS) */

    rshrn2          v5.8h, v20.4s, #(CONST_BITS - PASS1_BITS)  /* wsptr[DCTSIZE*7] = (int)DESCALE(tmp10 - tmp3, CONST_BITS-PASS1_BITS) */

    mov             v6.16b, v15.16b

    mov             v7.16b, v15.16b

    mov             v8.16b, v15.16b

    mov             v9.16b, v15.16b

    b               1b

.balign 16

3:

    cbnz            TMP4, 4f

    /* Left AC coef is zero */

    dup             v14.2d, v10.d[0]

    /* Even part: reverse the even part of the forward DCT. */

    add             v18.8h, v4.8h, v8.8h           /* z2 + z3 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]) + DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]) */

    add             v22.8h, v2.8h, v6.8h           /* z2 + z3 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) + DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]) */

    smull2          v19.4s, v18.8h, XFIX_P_0_541   /* z1h z1 = MULTIPLY(z2 + z3, FIX_0_541196100); */

    sub             v26.8h, v2.8h, v6.8h           /* z2 - z3 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) - DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]) */

    sshll2          v23.4s, v22.8h, #(CONST_BITS)  /* tmp0h tmp0 = LEFT_SHIFT(z2 + z3, CONST_BITS); */

    mov             v21.16b, v19.16b               /* tmp3 = z1 */

    smlal2          v19.4s, v8.8h, XFIX_N_1_847    /* tmp2h tmp2 = z1 + MULTIPLY(z3, -FIX_1_847759065); */

    sshll2          v27.4s, v26.8h, #(CONST_BITS)  /* tmp1h tmp1 = LEFT_SHIFT(z2 - z3, CONST_BITS); */

    smlal2          v21.4s, v4.8h, XFIX_P_0_765    /* tmp3h tmp3 = z1 + MULTIPLY(z2, FIX_0_765366865); */

    add             v28.4s, v23.4s, v21.4s         /* tmp10h tmp10 = tmp0 + tmp3; */

    sub             v31.4s, v23.4s, v21.4s         /* tmp13h tmp13 = tmp0 - tmp3; */

    add             v29.4s, v27.4s, v19.4s         /* tmp11h tmp11 = tmp1 + tmp2; */

    sub             v30.4s, v27.4s, v19.4s         /* tmp12h tmp12 = tmp1 - tmp2; */

    /* Odd part per figure 8; the matrix is unitary and hence its

     * transpose is its inverse.  i0..i3 are y7,y5,y3,y1 respectively.

     */

    add             v22.8h, v9.8h, v5.8h    /* z3 = tmp0 + tmp2 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]) + DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]) */

    add             v24.8h, v7.8h, v3.8h    /* z4 = tmp1 + tmp3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]) + DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]) */

    add             v18.8h, v9.8h, v3.8h    /* z1 = tmp0 + tmp3 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]) + DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]) */

    add             v20.8h, v7.8h, v5.8h    /* z2 = tmp1 + tmp2 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]) + DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]) */

    add             v26.8h, v22.8h, v24.8h  /* z5 = z3 + z4 */

    smull2          v11.4s, v9.8h, XFIX_P_0_298   /* tmp0 = MULTIPLY(tmp0, FIX_0_298631336) */

    smull2          v13.4s, v7.8h, XFIX_P_2_053   /* tmp1 = MULTIPLY(tmp1, FIX_2_053119869) */

    smull2          v15.4s, v5.8h, XFIX_P_3_072   /* tmp2 = MULTIPLY(tmp2, FIX_3_072711026) */

    smull2          v17.4s, v3.8h, XFIX_P_1_501   /* tmp3 = MULTIPLY(tmp3, FIX_1_501321110) */

    smull2          v27.4s, v26.8h, XFIX_P_1_175  /* z5h z5 = MULTIPLY(z3 + z4, FIX_1_175875602) */

    smull2          v23.4s, v22.8h, XFIX_N_1_961  /* z3 = MULTIPLY(z3, -FIX_1_961570560) */

    smull2          v25.4s, v24.8h, XFIX_N_0_390  /* z4 = MULTIPLY(z4, -FIX_0_390180644) */

    smull2          v19.4s, v18.8h, XFIX_N_0_899  /* z1 = MULTIPLY(z1, -FIX_0_899976223) */

    smull2          v21.4s, v20.8h, XFIX_N_2_562  /* z2 = MULTIPLY(z2, -FIX_2_562915447) */

    add             v23.4s, v23.4s, v27.4s  /* z3 += z5 */

    add             v22.4s, v22.4s, v26.4s  /* z3 += z5 */

    add             v25.4s, v25.4s, v27.4s  /* z4 += z5 */

    add             v24.4s, v24.4s, v26.4s  /* z4 += z5 */

    add             v11.4s, v11.4s, v19.4s  /* tmp0 += z1 */

    add             v13.4s, v13.4s, v21.4s  /* tmp1 += z2 */

    add             v15.4s, v15.4s, v21.4s  /* tmp2 += z2 */

    add             v17.4s, v17.4s, v19.4s  /* tmp3 += z1 */

    add             v11.4s, v11.4s, v23.4s  /* tmp0 += z3 */

    add             v13.4s, v13.4s, v25.4s  /* tmp1 += z4 */

    add             v17.4s, v17.4s, v25.4s  /* tmp3 += z4 */

    add             v15.4s, v15.4s, v23.4s  /* tmp2 += z3 */

    /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */

    add             v19.4s, v28.4s, v17.4s  /* tmp10 + tmp3 */

    sub             v21.4s, v28.4s, v17.4s  /* tmp10 - tmp3 */

    add             v23.4s, v29.4s, v15.4s  /* tmp11 + tmp2 */

    sub             v25.4s, v29.4s, v15.4s  /* tmp11 - tmp2 */

    add             v27.4s, v30.4s, v13.4s  /* tmp12 + tmp1 */

    sub             v29.4s, v30.4s, v13.4s  /* tmp12 - tmp1 */

    add             v15.4s, v31.4s, v11.4s  /* tmp13 + tmp0 */

    sub             v17.4s, v31.4s, v11.4s  /* tmp13 - tmp0 */

    mov             v2.16b, v14.16b

    mov             v3.16b, v14.16b

    mov             v4.16b, v14.16b

    mov             v5.16b, v14.16b

    rshrn           v6.4h, v19.4s, #(CONST_BITS - PASS1_BITS)  /* wsptr[DCTSIZE*0] = (int)DESCALE(tmp10 + tmp3, CONST_BITS-PASS1_BITS) */

    rshrn           v7.4h, v23.4s, #(CONST_BITS - PASS1_BITS)  /* wsptr[DCTSIZE*1] = (int)DESCALE(tmp11 + tmp2, CONST_BITS-PASS1_BITS) */

    rshrn           v8.4h, v27.4s, #(CONST_BITS - PASS1_BITS)  /* wsptr[DCTSIZE*2] = (int)DESCALE(tmp12 + tmp1, CONST_BITS-PASS1_BITS) */

    rshrn           v9.4h, v15.4s, #(CONST_BITS - PASS1_BITS)  /* wsptr[DCTSIZE*3] = (int)DESCALE(tmp13 + tmp0, CONST_BITS-PASS1_BITS) */

    rshrn2          v6.8h, v17.4s, #(CONST_BITS - PASS1_BITS)  /* wsptr[DCTSIZE*4] = (int)DESCALE(tmp13 - tmp0, CONST_BITS-PASS1_BITS) */

    rshrn2          v7.8h, v29.4s, #(CONST_BITS - PASS1_BITS)  /* wsptr[DCTSIZE*5] = (int)DESCALE(tmp12 - tmp1, CONST_BITS-PASS1_BITS) */

    rshrn2          v8.8h, v25.4s, #(CONST_BITS - PASS1_BITS)  /* wsptr[DCTSIZE*6] = (int)DESCALE(tmp11 - tmp2, CONST_BITS-PASS1_BITS) */

    rshrn2          v9.8h, v21.4s, #(CONST_BITS - PASS1_BITS)  /* wsptr[DCTSIZE*7] = (int)DESCALE(tmp10 - tmp3, CONST_BITS-PASS1_BITS) */

    b               1b

.balign 16

4:

    /* "No" AC coef is zero */

    /* Even part: reverse the even part of the forward DCT. */

    add             v18.8h, v4.8h, v8.8h           /* z2 + z3 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]) + DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]) */

    add             v22.8h, v2.8h, v6.8h           /* z2 + z3 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) + DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]) */

    smull2          v19.4s, v18.8h, XFIX_P_0_541   /* z1h z1 = MULTIPLY(z2 + z3, FIX_0_541196100); */

    sub             v26.8h, v2.8h, v6.8h           /* z2 - z3 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) - DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]) */

    smull           v18.4s, v18.4h, XFIX_P_0_541   /* z1l z1 = MULTIPLY(z2 + z3, FIX_0_541196100); */

    sshll2          v23.4s, v22.8h, #(CONST_BITS)  /* tmp0h tmp0 = LEFT_SHIFT(z2 + z3, CONST_BITS); */

    mov             v21.16b, v19.16b               /* tmp3 = z1 */

    mov             v20.16b, v18.16b               /* tmp3 = z1 */

    smlal2          v19.4s, v8.8h, XFIX_N_1_847    /* tmp2h tmp2 = z1 + MULTIPLY(z3, -FIX_1_847759065); */

    smlal           v18.4s, v8.4h, XFIX_N_1_847    /* tmp2l tmp2 = z1 + MULTIPLY(z3, -FIX_1_847759065); */

    sshll2          v27.4s, v26.8h, #(CONST_BITS)  /* tmp1h tmp1 = LEFT_SHIFT(z2 - z3, CONST_BITS); */

    smlal2          v21.4s, v4.8h, XFIX_P_0_765    /* tmp3h tmp3 = z1 + MULTIPLY(z2, FIX_0_765366865); */

    smlal           v20.4s, v4.4h, XFIX_P_0_765    /* tmp3l tmp3 = z1 + MULTIPLY(z2, FIX_0_765366865); */

    sshll           v22.4s, v22.4h, #(CONST_BITS)  /* tmp0l tmp0 = LEFT_SHIFT(z2 + z3, CONST_BITS); */

    sshll           v26.4s, v26.4h, #(CONST_BITS)  /* tmp1l tmp1 = LEFT_SHIFT(z2 - z3, CONST_BITS); */

    add             v2.4s, v22.4s, v20.4s          /* tmp10l tmp10 = tmp0 + tmp3; */

    sub             v6.4s, v22.4s, v20.4s          /* tmp13l tmp13 = tmp0 - tmp3; */

    add             v8.4s, v26.4s, v18.4s          /* tmp11l tmp11 = tmp1 + tmp2; */

    sub             v4.4s, v26.4s, v18.4s          /* tmp12l tmp12 = tmp1 - tmp2; */

    add             v28.4s, v23.4s, v21.4s         /* tmp10h tmp10 = tmp0 + tmp3; */

    sub             v31.4s, v23.4s, v21.4s         /* tmp13h tmp13 = tmp0 - tmp3; */

    add             v29.4s, v27.4s, v19.4s         /* tmp11h tmp11 = tmp1 + tmp2; */

    sub             v30.4s, v27.4s, v19.4s         /* tmp12h tmp12 = tmp1 - tmp2; */

    /* Odd part per figure 8; the matrix is unitary and hence its

     * transpose is its inverse.  i0..i3 are y7,y5,y3,y1 respectively.

     */

    add             v22.8h, v9.8h, v5.8h    /* z3 = tmp0 + tmp2 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]) + DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]) */

    add             v24.8h, v7.8h, v3.8h    /* z4 = tmp1 + tmp3 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]) + DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]) */

    add             v18.8h, v9.8h, v3.8h    /* z1 = tmp0 + tmp3 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]) + DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]) */

    add             v20.8h, v7.8h, v5.8h    /* z2 = tmp1 + tmp2 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]) + DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]) */

    add             v26.8h, v22.8h, v24.8h  /* z5 = z3 + z4 */

    smull2          v11.4s, v9.8h, XFIX_P_0_298   /* tmp0 = MULTIPLY(tmp0, FIX_0_298631336) */

    smull2          v13.4s, v7.8h, XFIX_P_2_053   /* tmp1 = MULTIPLY(tmp1, FIX_2_053119869) */

    smull2          v15.4s, v5.8h, XFIX_P_3_072   /* tmp2 = MULTIPLY(tmp2, FIX_3_072711026) */

    smull2          v17.4s, v3.8h, XFIX_P_1_501   /* tmp3 = MULTIPLY(tmp3, FIX_1_501321110) */

    smull2          v27.4s, v26.8h, XFIX_P_1_175  /* z5h z5 = MULTIPLY(z3 + z4, FIX_1_175875602) */