ref: 7ac3acf762ca450140d51616c15ca006e9e1df13
dir: /vpx_dsp/ppc/transpose_vsx.h/
/*
* Copyright (c) 2017 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.
*/
#ifndef VPX_DSP_PPC_TRANSPOSE_VSX_H_
#define VPX_DSP_PPC_TRANSPOSE_VSX_H_
#include "./vpx_config.h"
#include "vpx_dsp/ppc/types_vsx.h"
static INLINE void vpx_transpose_s16_8x8(int16x8_t v[8]) {
// d = vec_mergeh(a,b):
// The even elements of the result are obtained left-to-right,
// from the high elements of a.
// The odd elements of the result are obtained left-to-right,
// from the high elements of b.
//
// d = vec_mergel(a,b):
// The even elements of the result are obtained left-to-right,
// from the low elements of a.
// The odd elements of the result are obtained left-to-right,
// from the low elements of b.
// Example, starting with:
// v[0]: 00 01 02 03 04 05 06 07
// v[1]: 10 11 12 13 14 15 16 17
// v[2]: 20 21 22 23 24 25 26 27
// v[3]: 30 31 32 33 34 35 36 37
// v[4]: 40 41 42 43 44 45 46 47
// v[5]: 50 51 52 53 54 55 56 57
// v[6]: 60 61 62 63 64 65 66 67
// v[7]: 70 71 72 73 74 75 76 77
int16x8_t b0, b1, b2, b3, b4, b5, b6, b7;
int16x8_t c0, c1, c2, c3, c4, c5, c6, c7;
b0 = vec_mergeh(v[0], v[4]);
b1 = vec_mergel(v[0], v[4]);
b2 = vec_mergeh(v[1], v[5]);
b3 = vec_mergel(v[1], v[5]);
b4 = vec_mergeh(v[2], v[6]);
b5 = vec_mergel(v[2], v[6]);
b6 = vec_mergeh(v[3], v[7]);
b7 = vec_mergel(v[3], v[7]);
// After first merge operation
// b0: 00 40 01 41 02 42 03 43
// b1: 04 44 05 45 06 46 07 47
// b2: 10 50 11 51 12 52 13 53
// b3: 14 54 15 55 16 56 17 57
// b4: 20 60 21 61 22 62 23 63
// b5: 24 64 25 65 26 66 27 67
// b6: 30 70 31 71 32 62 33 73
// b7: 34 74 35 75 36 76 37 77
c0 = vec_mergeh(b0, b4);
c1 = vec_mergel(b0, b4);
c2 = vec_mergeh(b1, b5);
c3 = vec_mergel(b1, b5);
c4 = vec_mergeh(b2, b6);
c5 = vec_mergel(b2, b6);
c6 = vec_mergeh(b3, b7);
c7 = vec_mergel(b3, b7);
// After second merge operation
// c0: 00 20 40 60 01 21 41 61
// c1: 02 22 42 62 03 23 43 63
// c2: 04 24 44 64 05 25 45 65
// c3: 06 26 46 66 07 27 47 67
// c4: 10 30 50 70 11 31 51 71
// c5: 12 32 52 72 13 33 53 73
// c6: 14 34 54 74 15 35 55 75
// c7: 16 36 56 76 17 37 57 77
v[0] = vec_mergeh(c0, c4);
v[1] = vec_mergel(c0, c4);
v[2] = vec_mergeh(c1, c5);
v[3] = vec_mergel(c1, c5);
v[4] = vec_mergeh(c2, c6);
v[5] = vec_mergel(c2, c6);
v[6] = vec_mergeh(c3, c7);
v[7] = vec_mergel(c3, c7);
// After last merge operation
// v[0]: 00 10 20 30 40 50 60 70
// v[1]: 01 11 21 31 41 51 61 71
// v[2]: 02 12 22 32 42 52 62 72
// v[3]: 03 13 23 33 43 53 63 73
// v[4]: 04 14 24 34 44 54 64 74
// v[5]: 05 15 25 35 45 55 65 75
// v[6]: 06 16 26 36 46 56 66 76
// v[7]: 07 17 27 37 47 57 67 77
}
#endif // VPX_DSP_PPC_TRANSPOSE_VSX_H_