libvpx: Pull from upstream

source/libvpx/vp9/common/arm/neon/vp9_idct4x4_add_neon.asm

-;
-;  Copyright (c) 2013 The WebM project authors. All Rights Reserved.
-;
-;  Use of this source code is governed by a BSD-style license
-;  that can be found in the LICENSE file in the root of the source
-;  tree. An additional intellectual property rights grant can be found
-;  in the file PATENTS.  All contributing project authors may
-;  be found in the AUTHORS file in the root of the source tree.
-;
-
-    EXPORT  |vp9_idct4x4_16_add_neon|
-    ARM
-    REQUIRE8
-    PRESERVE8
-
-    AREA ||.text||, CODE, READONLY, ALIGN=2
-
-    AREA     Block, CODE, READONLY ; name this block of code
-;void vp9_idct4x4_16_add_neon(int16_t *input, uint8_t *dest, int dest_stride)
-;
-; r0  int16_t input
-; r1  uint8_t *dest
-; r2  int dest_stride)
-
-|vp9_idct4x4_16_add_neon| PROC
-
-    ; The 2D transform is done with two passes which are actually pretty
-    ; similar. We first transform the rows. This is done by transposing
-    ; the inputs, doing an SIMD column transform (the columns are the
-    ; transposed rows) and then transpose the results (so that it goes back
-    ; in normal/row positions). Then, we transform the columns by doing
-    ; another SIMD column transform.
-    ; So, two passes of a transpose followed by a column transform.
-
-    ; load the inputs into q8-q9, d16-d19
-    vld1.s16        {q8,q9}, [r0]!
-
-    ; generate scalar constants
-    ; cospi_8_64 = 15137 = 0x3b21
-    mov             r0, #0x3b00
-    add             r0, #0x21
-    ; cospi_16_64 = 11585 = 0x2d41
-    mov             r3, #0x2d00
-    add             r3, #0x41
-    ; cospi_24_64 = 6270 = 0x 187e
-    mov             r12, #0x1800
-    add             r12, #0x7e
-
-    ; transpose the input data
-    ; 00 01 02 03   d16
-    ; 10 11 12 13   d17
-    ; 20 21 22 23   d18
-    ; 30 31 32 33   d19
-    vtrn.16         d16, d17
-    vtrn.16         d18, d19
-
-    ; generate constant vectors
-    vdup.16         d20, r0         ; replicate cospi_8_64
-    vdup.16         d21, r3         ; replicate cospi_16_64
-
-    ; 00 10 02 12   d16
-    ; 01 11 03 13   d17
-    ; 20 30 22 32   d18
-    ; 21 31 23 33   d19
-    vtrn.32         q8, q9
-    ; 00 10 20 30   d16
-    ; 01 11 21 31   d17
-    ; 02 12 22 32   d18
-    ; 03 13 23 33   d19
-
-    vdup.16         d22, r12        ; replicate cospi_24_64
-
-    ; do the transform on transposed rows
-
-    ; stage 1
-    vadd.s16  d23, d16, d18         ; (input[0] + input[2])
-    vsub.s16  d24, d16, d18         ; (input[0] - input[2])
-
-    vmull.s16 q15, d17, d22         ; input[1] * cospi_24_64
-    vmull.s16 q1,  d17, d20         ; input[1] * cospi_8_64
-
-    ; (input[0] + input[2]) * cospi_16_64;
-    ; (input[0] - input[2]) * cospi_16_64;
-    vmull.s16 q13, d23, d21
-    vmull.s16 q14, d24, d21
-
-    ; input[1] * cospi_24_64 - input[3] * cospi_8_64;
-    ; input[1] * cospi_8_64  + input[3] * cospi_24_64;
-    vmlsl.s16 q15, d19, d20
-    vmlal.s16 q1,  d19, d22
-
-    ; dct_const_round_shift
-    vqrshrn.s32 d26, q13, #14
-    vqrshrn.s32 d27, q14, #14
-    vqrshrn.s32 d29, q15, #14
-    vqrshrn.s32 d28, q1,  #14
-
-    ; stage 2
-    ; output[0] = step[0] + step[3];
-    ; output[1] = step[1] + step[2];
-    ; output[3] = step[0] - step[3];
-    ; output[2] = step[1] - step[2];
-    vadd.s16 q8,  q13, q14
-    vsub.s16 q9,  q13, q14
-    vswp     d18, d19
-
-    ; transpose the results
-    ; 00 01 02 03   d16
-    ; 10 11 12 13   d17
-    ; 20 21 22 23   d18
-    ; 30 31 32 33   d19
-    vtrn.16         d16, d17
-    vtrn.16         d18, d19
-    ; 00 10 02 12   d16
-    ; 01 11 03 13   d17
-    ; 20 30 22 32   d18
-    ; 21 31 23 33   d19
-    vtrn.32         q8, q9
-    ; 00 10 20 30   d16
-    ; 01 11 21 31   d17
-    ; 02 12 22 32   d18
-    ; 03 13 23 33   d19
-
-    ; do the transform on columns
-
-    ; stage 1
-    vadd.s16  d23, d16, d18         ; (input[0] + input[2])
-    vsub.s16  d24, d16, d18         ; (input[0] - input[2])
-
-    vmull.s16 q15, d17, d22         ; input[1] * cospi_24_64
-    vmull.s16 q1,  d17, d20         ; input[1] * cospi_8_64
-
-    ; (input[0] + input[2]) * cospi_16_64;
-    ; (input[0] - input[2]) * cospi_16_64;
-    vmull.s16 q13, d23, d21
-    vmull.s16 q14, d24, d21
-
-    ; input[1] * cospi_24_64 - input[3] * cospi_8_64;
-    ; input[1] * cospi_8_64  + input[3] * cospi_24_64;
-    vmlsl.s16 q15, d19, d20
-    vmlal.s16 q1,  d19, d22
-
-    ; dct_const_round_shift
-    vqrshrn.s32 d26, q13, #14
-    vqrshrn.s32 d27, q14, #14
-    vqrshrn.s32 d29, q15, #14
-    vqrshrn.s32 d28, q1,  #14
-
-    ; stage 2
-    ; output[0] = step[0] + step[3];
-    ; output[1] = step[1] + step[2];
-    ; output[3] = step[0] - step[3];
-    ; output[2] = step[1] - step[2];
-    vadd.s16 q8,  q13, q14
-    vsub.s16 q9,  q13, q14
-
-    ; The results are in two registers, one of them being swapped. This will
-    ; be taken care of by loading the 'dest' value in a swapped fashion and
-    ; also storing them in the same swapped fashion.
-    ; temp_out[0, 1] = d16, d17 = q8
-    ; temp_out[2, 3] = d19, d18 = q9 swapped
-
-    ; ROUND_POWER_OF_TWO(temp_out[j], 4)
-    vrshr.s16 q8, q8, #4
-    vrshr.s16 q9, q9, #4
-
-    vld1.32 {d26[0]}, [r1], r2
-    vld1.32 {d26[1]}, [r1], r2
-    vld1.32 {d27[1]}, [r1], r2
-    vld1.32 {d27[0]}, [r1]  ; no post-increment
-
-    ; ROUND_POWER_OF_TWO(temp_out[j], 4) + dest[j * dest_stride + i]
-    vaddw.u8 q8, q8, d26
-    vaddw.u8 q9, q9, d27
-
-    ; clip_pixel
-    vqmovun.s16 d26, q8
-    vqmovun.s16 d27, q9
-
-    ; do the stores in reverse order with negative post-increment, by changing
-    ; the sign of the stride
-    rsb r2, r2, #0
-    vst1.32 {d27[0]}, [r1], r2
-    vst1.32 {d27[1]}, [r1], r2
-    vst1.32 {d26[1]}, [r1], r2
-    vst1.32 {d26[0]}, [r1]  ; no post-increment
-    bx              lr
-    ENDP  ; |vp9_idct4x4_16_add_neon|
-
-    END