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/* filter_vsx_intrinsics.c - PowerPC optimised filter functions
*
* Copyright (c) 2018 Cosmin Truta
* Copyright (c) 2017 Glenn Randers-Pehrson
* Written by Vadim Barkov, 2017.
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
* and license in png.h
*/
#include <stdio.h>
#include <stdint.h>
#include "../pngpriv.h"
#ifdef PNG_READ_SUPPORTED
/* This code requires -maltivec and -mvsx on the command line: */
#if PNG_POWERPC_VSX_IMPLEMENTATION == 1 /* intrinsics code from pngpriv.h */
#include <altivec.h>
#if PNG_POWERPC_VSX_OPT > 0
#ifndef __VSX__
# error "This code requires VSX support (POWER7 and later). Please provide -mvsx compiler flag."
#endif
#define vec_ld_unaligned(vec,data) vec = vec_vsx_ld(0,data)
#define vec_st_unaligned(vec,data) vec_vsx_st(vec,0,data)
/* Functions in this file look at most 3 pixels (a,b,c) to predict the 4th (d).
* They're positioned like this:
* prev: c b
* row: a d
* The Sub filter predicts d=a, Avg d=(a+b)/2, and Paeth predicts d to be
* whichever of a, b, or c is closest to p=a+b-c.
* ( this is taken from ../intel/filter_sse2_intrinsics.c )
*/
#define vsx_declare_common_vars(row_info,row,prev_row,offset) \
png_byte i;\
png_bytep rp = row + offset;\
png_const_bytep pp = prev_row;\
size_t unaligned_top = 16 - (((size_t)rp % 16));\
size_t istop;\
if(unaligned_top == 16)\
unaligned_top = 0;\
istop = row_info->rowbytes;\
if((unaligned_top < istop))\
istop -= unaligned_top;\
else{\
unaligned_top = istop;\
istop = 0;\
}
void png_read_filter_row_up_vsx(png_row_infop row_info, png_bytep row,
png_const_bytep prev_row)
{
vector unsigned char rp_vec;
vector unsigned char pp_vec;
vsx_declare_common_vars(row_info,row,prev_row,0)
/* Altivec operations require 16-byte aligned data
* but input can be unaligned. So we calculate
* unaligned part as usual.
*/
for (i = 0; i < unaligned_top; i++)
{
*rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
rp++;
}
/* Using SIMD while we can */
while( istop >= 16 )
{
rp_vec = vec_ld(0,rp);
vec_ld_unaligned(pp_vec,pp);
rp_vec = vec_add(rp_vec,pp_vec);
vec_st(rp_vec,0,rp);
pp += 16;
rp += 16;
istop -= 16;
}
if(istop > 0)
{
/* If byte count of row is not divisible by 16
* we will process remaining part as usual
*/
for (i = 0; i < istop; i++)
{
*rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
rp++;
}
}
}
static const vector unsigned char VSX_LEFTSHIFTED1_4 = {16,16,16,16, 0, 1, 2, 3,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_LEFTSHIFTED2_4 = {16,16,16,16,16,16,16,16, 4, 5, 6, 7,16,16,16,16};
static const vector unsigned char VSX_LEFTSHIFTED3_4 = {16,16,16,16,16,16,16,16,16,16,16,16, 8, 9,10,11};
static const vector unsigned char VSX_LEFTSHIFTED1_3 = {16,16,16, 0, 1, 2,16,16,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_LEFTSHIFTED2_3 = {16,16,16,16,16,16, 3, 4, 5,16,16,16,16,16,16,16};
static const vector unsigned char VSX_LEFTSHIFTED3_3 = {16,16,16,16,16,16,16,16,16, 6, 7, 8,16,16,16,16};
static const vector unsigned char VSX_LEFTSHIFTED4_3 = {16,16,16,16,16,16,16,16,16,16,16,16, 9,10,11,16};
static const vector unsigned char VSX_NOT_SHIFTED1_4 = {16,16,16,16, 4, 5, 6, 7,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_NOT_SHIFTED2_4 = {16,16,16,16,16,16,16,16, 8, 9,10,11,16,16,16,16};
static const vector unsigned char VSX_NOT_SHIFTED3_4 = {16,16,16,16,16,16,16,16,16,16,16,16,12,13,14,15};
static const vector unsigned char VSX_NOT_SHIFTED1_3 = {16,16,16, 3, 4, 5,16,16,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_NOT_SHIFTED2_3 = {16,16,16,16,16,16, 6, 7, 8,16,16,16,16,16,16,16};
static const vector unsigned char VSX_NOT_SHIFTED3_3 = {16,16,16,16,16,16,16,16,16, 9,10,11,16,16,16,16};
static const vector unsigned char VSX_NOT_SHIFTED4_3 = {16,16,16,16,16,16,16,16,16,16,16,16,12,13,14,16};
static const vector unsigned char VSX_CHAR_ZERO = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
#ifdef __LITTLE_ENDIAN__
static const vector unsigned char VSX_CHAR_TO_SHORT1_4 = { 4,16, 5,16, 6,16, 7,16,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_CHAR_TO_SHORT2_4 = { 8,16, 9,16,10,16,11,16,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_CHAR_TO_SHORT3_4 = {12,16,13,16,14,16,15,16,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_SHORT_TO_CHAR1_4 = {16,16,16,16, 0, 2, 4, 6,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_SHORT_TO_CHAR2_4 = {16,16,16,16,16,16,16,16, 0, 2, 4, 6,16,16,16,16};
static const vector unsigned char VSX_SHORT_TO_CHAR3_4 = {16,16,16,16,16,16,16,16,16,16,16,16, 0, 2, 4, 6};
static const vector unsigned char VSX_CHAR_TO_SHORT1_3 = { 3,16, 4,16, 5,16,16,16,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_CHAR_TO_SHORT2_3 = { 6,16, 7,16, 8,16,16,16,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_CHAR_TO_SHORT3_3 = { 9,16,10,16,11,16,16,16,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_CHAR_TO_SHORT4_3 = {12,16,13,16,14,16,16,16,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_SHORT_TO_CHAR1_3 = {16,16,16, 0, 2, 4,16,16,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_SHORT_TO_CHAR2_3 = {16,16,16,16,16,16, 0, 2, 4,16,16,16,16,16,16,16};
static const vector unsigned char VSX_SHORT_TO_CHAR3_3 = {16,16,16,16,16,16,16,16,16, 0, 2, 4,16,16,16,16};
static const vector unsigned char VSX_SHORT_TO_CHAR4_3 = {16,16,16,16,16,16,16,16,16,16,16,16, 0, 2, 4,16};
#elif defined(__BIG_ENDIAN__)
static const vector unsigned char VSX_CHAR_TO_SHORT1_4 = {16, 4,16, 5,16, 6,16, 7,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_CHAR_TO_SHORT2_4 = {16, 8,16, 9,16,10,16,11,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_CHAR_TO_SHORT3_4 = {16,12,16,13,16,14,16,15,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_SHORT_TO_CHAR1_4 = {16,16,16,16, 1, 3, 5, 7,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_SHORT_TO_CHAR2_4 = {16,16,16,16,16,16,16,16, 1, 3, 5, 7,16,16,16,16};
static const vector unsigned char VSX_SHORT_TO_CHAR3_4 = {16,16,16,16,16,16,16,16,16,16,16,16, 1, 3, 5, 7};
static const vector unsigned char VSX_CHAR_TO_SHORT1_3 = {16, 3,16, 4,16, 5,16,16,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_CHAR_TO_SHORT2_3 = {16, 6,16, 7,16, 8,16,16,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_CHAR_TO_SHORT3_3 = {16, 9,16,10,16,11,16,16,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_CHAR_TO_SHORT4_3 = {16,12,16,13,16,14,16,16,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_SHORT_TO_CHAR1_3 = {16,16,16, 1, 3, 5,16,16,16,16,16,16,16,16,16,16};
static const vector unsigned char VSX_SHORT_TO_CHAR2_3 = {16,16,16,16,16,16, 1, 3, 5,16,16,16,16,16,16,16};
static const vector unsigned char VSX_SHORT_TO_CHAR3_3 = {16,16,16,16,16,16,16,16,16, 1, 3, 5,16,16,16,16};
static const vector unsigned char VSX_SHORT_TO_CHAR4_3 = {16,16,16,16,16,16,16,16,16,16,16,16, 1, 3, 5,16};
#endif
#define vsx_char_to_short(vec,offset,bpp) (vector unsigned short)vec_perm((vec),VSX_CHAR_ZERO,VSX_CHAR_TO_SHORT##offset##_##bpp)
#define vsx_short_to_char(vec,offset,bpp) vec_perm(((vector unsigned char)(vec)),VSX_CHAR_ZERO,VSX_SHORT_TO_CHAR##offset##_##bpp)
#ifdef PNG_USE_ABS
# define vsx_abs(number) abs(number)
#else
# define vsx_abs(number) (number > 0) ? (number) : -(number)
#endif
void png_read_filter_row_sub4_vsx(png_row_infop row_info, png_bytep row,
png_const_bytep prev_row)
{
png_byte bpp = 4;
vector unsigned char rp_vec;
vector unsigned char part_vec;
vsx_declare_common_vars(row_info,row,prev_row,bpp)
PNG_UNUSED(pp)
/* Altivec operations require 16-byte aligned data
* but input can be unaligned. So we calculate
* unaligned part as usual.
*/
for (i = 0; i < unaligned_top; i++)
{
*rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
rp++;
}
/* Using SIMD while we can */
while( istop >= 16 )
{
for(i=0;i < bpp ; i++)
{
*rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
rp++;
}
rp -= bpp;
rp_vec = vec_ld(0,rp);
part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED1_4);
rp_vec = vec_add(rp_vec,part_vec);
part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED2_4);
rp_vec = vec_add(rp_vec,part_vec);
part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED3_4);
rp_vec = vec_add(rp_vec,part_vec);
vec_st(rp_vec,0,rp);
rp += 16;
istop -= 16;
}
if(istop > 0)
for (i = 0; i < istop % 16; i++)
{
*rp = (png_byte)(((int)(*rp) + (int)(*(rp - bpp))) & 0xff);
rp++;
}
}
void png_read_filter_row_sub3_vsx(png_row_infop row_info, png_bytep row,
png_const_bytep prev_row)
{
png_byte bpp = 3;
vector unsigned char rp_vec;
vector unsigned char part_vec;
vsx_declare_common_vars(row_info,row,prev_row,bpp)
PNG_UNUSED(pp)
/* Altivec operations require 16-byte aligned data
* but input can be unaligned. So we calculate
* unaligned part as usual.
*/
for (i = 0; i < unaligned_top; i++)
{
*rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
rp++;
}
/* Using SIMD while we can */
while( istop >= 16 )
{
for(i=0;i < bpp ; i++)
{
*rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
rp++;
}
rp -= bpp;
rp_vec = vec_ld(0,rp);
part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED1_3);
rp_vec = vec_add(rp_vec,part_vec);
part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED2_3);
rp_vec = vec_add(rp_vec,part_vec);
part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED3_3);
rp_vec = vec_add(rp_vec,part_vec);
part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED4_3);
rp_vec = vec_add(rp_vec,part_vec);
vec_st(rp_vec,0,rp);
rp += 15;
istop -= 16;
/* Since 16 % bpp = 16 % 3 = 1, last element of array must
* be proceeded manually
*/
*rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
rp++;
}
if(istop > 0)
for (i = 0; i < istop % 16; i++)
{
*rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
rp++;
}
}
void png_read_filter_row_avg4_vsx(png_row_infop row_info, png_bytep row,
png_const_bytep prev_row)
{
png_byte bpp = 4;
vector unsigned char rp_vec;
vector unsigned char pp_vec;
vector unsigned char pp_part_vec;
vector unsigned char rp_part_vec;
vector unsigned char avg_vec;
vsx_declare_common_vars(row_info,row,prev_row,bpp)
rp -= bpp;
if(istop >= bpp)
istop -= bpp;
for (i = 0; i < bpp; i++)
{
*rp = (png_byte)(((int)(*rp) +
((int)(*pp++) / 2 )) & 0xff);
rp++;
}
/* Altivec operations require 16-byte aligned data
* but input can be unaligned. So we calculate
* unaligned part as usual.
*/
for (i = 0; i < unaligned_top; i++)
{
*rp = (png_byte)(((int)(*rp) +
(int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
rp++;
}
/* Using SIMD while we can */
while( istop >= 16 )
{
for(i=0;i < bpp ; i++)
{
*rp = (png_byte)(((int)(*rp) +
(int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
rp++;
}
rp -= bpp;
pp -= bpp;
vec_ld_unaligned(pp_vec,pp);
rp_vec = vec_ld(0,rp);
rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED1_4);
pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED1_4);
avg_vec = vec_avg(rp_part_vec,pp_part_vec);
avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1)));
rp_vec = vec_add(rp_vec,avg_vec);
rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED2_4);
pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED2_4);
avg_vec = vec_avg(rp_part_vec,pp_part_vec);
avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1)));
rp_vec = vec_add(rp_vec,avg_vec);
rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED3_4);
pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED3_4);
avg_vec = vec_avg(rp_part_vec,pp_part_vec);
avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1)));
rp_vec = vec_add(rp_vec,avg_vec);
vec_st(rp_vec,0,rp);
rp += 16;
pp += 16;
istop -= 16;
}
if(istop > 0)
for (i = 0; i < istop % 16; i++)
{
*rp = (png_byte)(((int)(*rp) +
(int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
rp++;
}
}
void png_read_filter_row_avg3_vsx(png_row_infop row_info, png_bytep row,
png_const_bytep prev_row)
{
png_byte bpp = 3;
vector unsigned char rp_vec;
vector unsigned char pp_vec;
vector unsigned char pp_part_vec;
vector unsigned char rp_part_vec;
vector unsigned char avg_vec;
vsx_declare_common_vars(row_info,row,prev_row,bpp)
rp -= bpp;
if(istop >= bpp)
istop -= bpp;
for (i = 0; i < bpp; i++)
{
*rp = (png_byte)(((int)(*rp) +
((int)(*pp++) / 2 )) & 0xff);
rp++;
}
/* Altivec operations require 16-byte aligned data
* but input can be unaligned. So we calculate
* unaligned part as usual.
*/
for (i = 0; i < unaligned_top; i++)
{
*rp = (png_byte)(((int)(*rp) +
(int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
rp++;
}
/* Using SIMD while we can */
while( istop >= 16 )
{
for(i=0;i < bpp ; i++)
{
*rp = (png_byte)(((int)(*rp) +
(int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
rp++;
}
rp -= bpp;
pp -= bpp;
vec_ld_unaligned(pp_vec,pp);
rp_vec = vec_ld(0,rp);
rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED1_3);
pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED1_3);
avg_vec = vec_avg(rp_part_vec,pp_part_vec);
avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1)));
rp_vec = vec_add(rp_vec,avg_vec);
rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED2_3);
pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED2_3);
avg_vec = vec_avg(rp_part_vec,pp_part_vec);
avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1)));
rp_vec = vec_add(rp_vec,avg_vec);
rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED3_3);
pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED3_3);
avg_vec = vec_avg(rp_part_vec,pp_part_vec);
avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1)));
rp_vec = vec_add(rp_vec,avg_vec);
rp_part_vec = vec_perm(rp_vec,VSX_CHAR_ZERO,VSX_LEFTSHIFTED4_3);
pp_part_vec = vec_perm(pp_vec,VSX_CHAR_ZERO,VSX_NOT_SHIFTED4_3);
avg_vec = vec_avg(rp_part_vec,pp_part_vec);
avg_vec = vec_sub(avg_vec, vec_and(vec_xor(rp_part_vec,pp_part_vec),vec_splat_u8(1)));
rp_vec = vec_add(rp_vec,avg_vec);
vec_st(rp_vec,0,rp);
rp += 15;
pp += 15;
istop -= 16;
/* Since 16 % bpp = 16 % 3 = 1, last element of array must
* be proceeded manually
*/
*rp = (png_byte)(((int)(*rp) +
(int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
rp++;
}
if(istop > 0)
for (i = 0; i < istop % 16; i++)
{
*rp = (png_byte)(((int)(*rp) +
(int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
rp++;
}
}
/* Bytewise c ? t : e. */
#define if_then_else(c,t,e) vec_sel(e,t,c)
#define vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp) {\
c = *(pp - bpp);\
a = *(rp - bpp);\
b = *pp++;\
p = b - c;\
pc = a - c;\
pa = vsx_abs(p);\
pb = vsx_abs(pc);\
pc = vsx_abs(p + pc);\
if (pb < pa) pa = pb, a = b;\
if (pc < pa) a = c;\
a += *rp;\
*rp++ = (png_byte)a;\
}
void png_read_filter_row_paeth4_vsx(png_row_infop row_info, png_bytep row,
png_const_bytep prev_row)
{
png_byte bpp = 4;
int a, b, c, pa, pb, pc, p;
vector unsigned char rp_vec;
vector unsigned char pp_vec;
vector unsigned short a_vec,b_vec,c_vec,nearest_vec;
vector signed short pa_vec,pb_vec,pc_vec,smallest_vec;
vsx_declare_common_vars(row_info,row,prev_row,bpp)
rp -= bpp;
if(istop >= bpp)
istop -= bpp;
/* Process the first pixel in the row completely (this is the same as 'up'
* because there is only one candidate predictor for the first row).
*/
for(i = 0; i < bpp ; i++)
{
*rp = (png_byte)( *rp + *pp);
rp++;
pp++;
}
for(i = 0; i < unaligned_top ; i++)
{
vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp)
}
while( istop >= 16)
{
for(i = 0; i < bpp ; i++)
{
vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp)
}
rp -= bpp;
pp -= bpp;
rp_vec = vec_ld(0,rp);
vec_ld_unaligned(pp_vec,pp);
a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED1_4),1,4);
b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED1_4),1,4);
c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED1_4),1,4);
pa_vec = (vector signed short) vec_sub(b_vec,c_vec);
pb_vec = (vector signed short) vec_sub(a_vec , c_vec);
pc_vec = vec_add(pa_vec,pb_vec);
pa_vec = vec_abs(pa_vec);
pb_vec = vec_abs(pb_vec);
pc_vec = vec_abs(pc_vec);
smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec));
nearest_vec = if_then_else(
vec_cmpeq(pa_vec,smallest_vec),
a_vec,
if_then_else(
vec_cmpeq(pb_vec,smallest_vec),
b_vec,
c_vec
)
);
rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,1,4)));
a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED2_4),2,4);
b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED2_4),2,4);
c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED2_4),2,4);
pa_vec = (vector signed short) vec_sub(b_vec,c_vec);
pb_vec = (vector signed short) vec_sub(a_vec , c_vec);
pc_vec = vec_add(pa_vec,pb_vec);
pa_vec = vec_abs(pa_vec);
pb_vec = vec_abs(pb_vec);
pc_vec = vec_abs(pc_vec);
smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec));
nearest_vec = if_then_else(
vec_cmpeq(pa_vec,smallest_vec),
a_vec,
if_then_else(
vec_cmpeq(pb_vec,smallest_vec),
b_vec,
c_vec
)
);
rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,2,4)));
a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED3_4),3,4);
b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED3_4),3,4);
c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED3_4),3,4);
pa_vec = (vector signed short) vec_sub(b_vec,c_vec);
pb_vec = (vector signed short) vec_sub(a_vec , c_vec);
pc_vec = vec_add(pa_vec,pb_vec);
pa_vec = vec_abs(pa_vec);
pb_vec = vec_abs(pb_vec);
pc_vec = vec_abs(pc_vec);
smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec));
nearest_vec = if_then_else(
vec_cmpeq(pa_vec,smallest_vec),
a_vec,
if_then_else(
vec_cmpeq(pb_vec,smallest_vec),
b_vec,
c_vec
)
);
rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,3,4)));
vec_st(rp_vec,0,rp);
rp += 16;
pp += 16;
istop -= 16;
}
if(istop > 0)
for (i = 0; i < istop % 16; i++)
{
vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp)
}
}
void png_read_filter_row_paeth3_vsx(png_row_infop row_info, png_bytep row,
png_const_bytep prev_row)
{
png_byte bpp = 3;
int a, b, c, pa, pb, pc, p;
vector unsigned char rp_vec;
vector unsigned char pp_vec;
vector unsigned short a_vec,b_vec,c_vec,nearest_vec;
vector signed short pa_vec,pb_vec,pc_vec,smallest_vec;
vsx_declare_common_vars(row_info,row,prev_row,bpp)
rp -= bpp;
if(istop >= bpp)
istop -= bpp;
/* Process the first pixel in the row completely (this is the same as 'up'
* because there is only one candidate predictor for the first row).
*/
for(i = 0; i < bpp ; i++)
{
*rp = (png_byte)( *rp + *pp);
rp++;
pp++;
}
for(i = 0; i < unaligned_top ; i++)
{
vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp)
}
while( istop >= 16)
{
for(i = 0; i < bpp ; i++)
{
vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp)
}
rp -= bpp;
pp -= bpp;
rp_vec = vec_ld(0,rp);
vec_ld_unaligned(pp_vec,pp);
a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED1_3),1,3);
b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED1_3),1,3);
c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED1_3),1,3);
pa_vec = (vector signed short) vec_sub(b_vec,c_vec);
pb_vec = (vector signed short) vec_sub(a_vec , c_vec);
pc_vec = vec_add(pa_vec,pb_vec);
pa_vec = vec_abs(pa_vec);
pb_vec = vec_abs(pb_vec);
pc_vec = vec_abs(pc_vec);
smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec));
nearest_vec = if_then_else(
vec_cmpeq(pa_vec,smallest_vec),
a_vec,
if_then_else(
vec_cmpeq(pb_vec,smallest_vec),
b_vec,
c_vec
)
);
rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,1,3)));
a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED2_3),2,3);
b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED2_3),2,3);
c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED2_3),2,3);
pa_vec = (vector signed short) vec_sub(b_vec,c_vec);
pb_vec = (vector signed short) vec_sub(a_vec , c_vec);
pc_vec = vec_add(pa_vec,pb_vec);
pa_vec = vec_abs(pa_vec);
pb_vec = vec_abs(pb_vec);
pc_vec = vec_abs(pc_vec);
smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec));
nearest_vec = if_then_else(
vec_cmpeq(pa_vec,smallest_vec),
a_vec,
if_then_else(
vec_cmpeq(pb_vec,smallest_vec),
b_vec,
c_vec
)
);
rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,2,3)));
a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED3_3),3,3);
b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED3_3),3,3);
c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED3_3),3,3);
pa_vec = (vector signed short) vec_sub(b_vec,c_vec);
pb_vec = (vector signed short) vec_sub(a_vec , c_vec);
pc_vec = vec_add(pa_vec,pb_vec);
pa_vec = vec_abs(pa_vec);
pb_vec = vec_abs(pb_vec);
pc_vec = vec_abs(pc_vec);
smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec));
nearest_vec = if_then_else(
vec_cmpeq(pa_vec,smallest_vec),
a_vec,
if_then_else(
vec_cmpeq(pb_vec,smallest_vec),
b_vec,
c_vec
)
);
rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,3,3)));
a_vec = vsx_char_to_short(vec_perm(rp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED4_3),4,3);
b_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_NOT_SHIFTED4_3),4,3);
c_vec = vsx_char_to_short(vec_perm(pp_vec , VSX_CHAR_ZERO , VSX_LEFTSHIFTED4_3),4,3);
pa_vec = (vector signed short) vec_sub(b_vec,c_vec);
pb_vec = (vector signed short) vec_sub(a_vec , c_vec);
pc_vec = vec_add(pa_vec,pb_vec);
pa_vec = vec_abs(pa_vec);
pb_vec = vec_abs(pb_vec);
pc_vec = vec_abs(pc_vec);
smallest_vec = vec_min(pc_vec, vec_min(pa_vec,pb_vec));
nearest_vec = if_then_else(
vec_cmpeq(pa_vec,smallest_vec),
a_vec,
if_then_else(
vec_cmpeq(pb_vec,smallest_vec),
b_vec,
c_vec
)
);
rp_vec = vec_add(rp_vec,(vsx_short_to_char(nearest_vec,4,3)));
vec_st(rp_vec,0,rp);
rp += 15;
pp += 15;
istop -= 16;
/* Since 16 % bpp = 16 % 3 = 1, last element of array must
* be proceeded manually
*/
vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp)
}
if(istop > 0)
for (i = 0; i < istop % 16; i++)
{
vsx_paeth_process(rp,pp,a,b,c,pa,pb,pc,bpp)
}
}
#endif /* PNG_POWERPC_VSX_OPT > 0 */
#endif /* PNG_POWERPC_VSX_IMPLEMENTATION == 1 (intrinsics) */
#endif /* READ */