root/arm/filter_neon_intrinsics.c
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DEFINITIONS
This source file includes following definitions.
- png_read_filter_row_up_neon
- png_read_filter_row_sub3_neon
- png_read_filter_row_sub4_neon
- png_read_filter_row_avg3_neon
- png_read_filter_row_avg4_neon
- paeth
- png_read_filter_row_paeth3_neon
- png_read_filter_row_paeth4_neon
/* filter_neon_intrinsics.c - NEON optimised filter functions
*
* Copyright (c) 2013 Glenn Randers-Pehrson
* Written by James Yu <james.yu at linaro.org>, October 2013.
* Based on filter_neon.S, written by Mans Rullgard, 2011.
*
* Last changed in libpng 1.6.8 [December 19, 2013]
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
* and license in png.h
*/
#include "../pngpriv.h"
/* This code requires -mfpu=neon on the command line: */
#if PNG_ARM_NEON_IMPLEMENTATION == 1 /* intrinsics code from pngpriv.h */
#include <arm_neon.h>
/* libpng row pointers are not necessarily aligned to any particular boundary,
* however this code will only work with appropriate alignment. arm/arm_init.c
* checks for this (and will not compile unless it is done). This code uses
* variants of png_aligncast to avoid compiler warnings.
*/
#define png_ptr(type,pointer) png_aligncast(type *,pointer)
#define png_ptrc(type,pointer) png_aligncastconst(const type *,pointer)
/* The following relies on a variable 'temp_pointer' being declared with type
* 'type'. This is written this way just to hide the GCC strict aliasing
* warning; note that the code is safe because there never is an alias between
* the input and output pointers.
*/
#define png_ldr(type,pointer)\
(temp_pointer = png_ptr(type,pointer), *temp_pointer)
#ifdef PNG_READ_SUPPORTED
#if PNG_ARM_NEON_OPT > 0
void
png_read_filter_row_up_neon(png_row_infop row_info, png_bytep row,
png_const_bytep prev_row)
{
png_bytep rp = row;
png_bytep rp_stop = row + row_info->rowbytes;
png_const_bytep pp = prev_row;
for (; rp < rp_stop; rp += 16, pp += 16)
{
uint8x16_t qrp, qpp;
qrp = vld1q_u8(rp);
qpp = vld1q_u8(pp);
qrp = vaddq_u8(qrp, qpp);
vst1q_u8(rp, qrp);
}
}
void
png_read_filter_row_sub3_neon(png_row_infop row_info, png_bytep row,
png_const_bytep prev_row)
{
png_bytep rp = row;
png_bytep rp_stop = row + row_info->rowbytes;
uint8x16_t vtmp = vld1q_u8(rp);
uint8x8x2_t *vrpt = png_ptr(uint8x8x2_t, &vtmp);
uint8x8x2_t vrp = *vrpt;
uint8x8x4_t vdest;
vdest.val[3] = vdup_n_u8(0);
for (; rp < rp_stop;)
{
uint8x8_t vtmp1, vtmp2;
uint32x2_t *temp_pointer;
vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]);
vtmp2 = vext_u8(vrp.val[0], vrp.val[1], 6);
vdest.val[1] = vadd_u8(vdest.val[0], vtmp1);
vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
vdest.val[2] = vadd_u8(vdest.val[1], vtmp2);
vdest.val[3] = vadd_u8(vdest.val[2], vtmp1);
vtmp = vld1q_u8(rp + 12);
vrpt = png_ptr(uint8x8x2_t, &vtmp);
vrp = *vrpt;
vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0);
rp += 3;
vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0);
rp += 3;
vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0);
rp += 3;
vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
rp += 3;
}
PNG_UNUSED(prev_row)
}
void
png_read_filter_row_sub4_neon(png_row_infop row_info, png_bytep row,
png_const_bytep prev_row)
{
png_bytep rp = row;
png_bytep rp_stop = row + row_info->rowbytes;
uint8x8x4_t vdest;
vdest.val[3] = vdup_n_u8(0);
for (; rp < rp_stop; rp += 16)
{
uint32x2x4_t vtmp = vld4_u32(png_ptr(uint32_t,rp));
uint8x8x4_t *vrpt = png_ptr(uint8x8x4_t,&vtmp);
uint8x8x4_t vrp = *vrpt;
uint32x2x4_t *temp_pointer;
vdest.val[0] = vadd_u8(vdest.val[3], vrp.val[0]);
vdest.val[1] = vadd_u8(vdest.val[0], vrp.val[1]);
vdest.val[2] = vadd_u8(vdest.val[1], vrp.val[2]);
vdest.val[3] = vadd_u8(vdest.val[2], vrp.val[3]);
vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
}
PNG_UNUSED(prev_row)
}
void
png_read_filter_row_avg3_neon(png_row_infop row_info, png_bytep row,
png_const_bytep prev_row)
{
png_bytep rp = row;
png_const_bytep pp = prev_row;
png_bytep rp_stop = row + row_info->rowbytes;
uint8x16_t vtmp;
uint8x8x2_t *vrpt;
uint8x8x2_t vrp;
uint8x8x4_t vdest;
vdest.val[3] = vdup_n_u8(0);
vtmp = vld1q_u8(rp);
vrpt = png_ptr(uint8x8x2_t,&vtmp);
vrp = *vrpt;
for (; rp < rp_stop; pp += 12)
{
uint8x8_t vtmp1, vtmp2, vtmp3;
uint8x8x2_t *vppt;
uint8x8x2_t vpp;
uint32x2_t *temp_pointer;
vtmp = vld1q_u8(pp);
vppt = png_ptr(uint8x8x2_t,&vtmp);
vpp = *vppt;
vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]);
vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3);
vtmp3 = vext_u8(vrp.val[0], vrp.val[1], 6);
vdest.val[1] = vhadd_u8(vdest.val[0], vtmp2);
vdest.val[1] = vadd_u8(vdest.val[1], vtmp1);
vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 6);
vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
vtmp = vld1q_u8(rp + 12);
vrpt = png_ptr(uint8x8x2_t,&vtmp);
vrp = *vrpt;
vdest.val[2] = vhadd_u8(vdest.val[1], vtmp2);
vdest.val[2] = vadd_u8(vdest.val[2], vtmp3);
vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1);
vdest.val[3] = vhadd_u8(vdest.val[2], vtmp2);
vdest.val[3] = vadd_u8(vdest.val[3], vtmp1);
vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0);
rp += 3;
vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0);
rp += 3;
vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0);
rp += 3;
vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
rp += 3;
}
}
void
png_read_filter_row_avg4_neon(png_row_infop row_info, png_bytep row,
png_const_bytep prev_row)
{
png_bytep rp = row;
png_bytep rp_stop = row + row_info->rowbytes;
png_const_bytep pp = prev_row;
uint8x8x4_t vdest;
vdest.val[3] = vdup_n_u8(0);
for (; rp < rp_stop; rp += 16, pp += 16)
{
uint32x2x4_t vtmp;
uint8x8x4_t *vrpt, *vppt;
uint8x8x4_t vrp, vpp;
uint32x2x4_t *temp_pointer;
vtmp = vld4_u32(png_ptr(uint32_t,rp));
vrpt = png_ptr(uint8x8x4_t,&vtmp);
vrp = *vrpt;
vtmp = vld4_u32(png_ptrc(uint32_t,pp));
vppt = png_ptr(uint8x8x4_t,&vtmp);
vpp = *vppt;
vdest.val[0] = vhadd_u8(vdest.val[3], vpp.val[0]);
vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
vdest.val[1] = vhadd_u8(vdest.val[0], vpp.val[1]);
vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]);
vdest.val[2] = vhadd_u8(vdest.val[1], vpp.val[2]);
vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]);
vdest.val[3] = vhadd_u8(vdest.val[2], vpp.val[3]);
vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]);
vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
}
}
static uint8x8_t
paeth(uint8x8_t a, uint8x8_t b, uint8x8_t c)
{
uint8x8_t d, e;
uint16x8_t p1, pa, pb, pc;
p1 = vaddl_u8(a, b); /* a + b */
pc = vaddl_u8(c, c); /* c * 2 */
pa = vabdl_u8(b, c); /* pa */
pb = vabdl_u8(a, c); /* pb */
pc = vabdq_u16(p1, pc); /* pc */
p1 = vcleq_u16(pa, pb); /* pa <= pb */
pa = vcleq_u16(pa, pc); /* pa <= pc */
pb = vcleq_u16(pb, pc); /* pb <= pc */
p1 = vandq_u16(p1, pa); /* pa <= pb && pa <= pc */
d = vmovn_u16(pb);
e = vmovn_u16(p1);
d = vbsl_u8(d, b, c);
e = vbsl_u8(e, a, d);
return e;
}
void
png_read_filter_row_paeth3_neon(png_row_infop row_info, png_bytep row,
png_const_bytep prev_row)
{
png_bytep rp = row;
png_const_bytep pp = prev_row;
png_bytep rp_stop = row + row_info->rowbytes;
uint8x16_t vtmp;
uint8x8x2_t *vrpt;
uint8x8x2_t vrp;
uint8x8_t vlast = vdup_n_u8(0);
uint8x8x4_t vdest;
vdest.val[3] = vdup_n_u8(0);
vtmp = vld1q_u8(rp);
vrpt = png_ptr(uint8x8x2_t,&vtmp);
vrp = *vrpt;
for (; rp < rp_stop; pp += 12)
{
uint8x8x2_t *vppt;
uint8x8x2_t vpp;
uint8x8_t vtmp1, vtmp2, vtmp3;
uint32x2_t *temp_pointer;
vtmp = vld1q_u8(pp);
vppt = png_ptr(uint8x8x2_t,&vtmp);
vpp = *vppt;
vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast);
vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 3);
vtmp2 = vext_u8(vpp.val[0], vpp.val[1], 3);
vdest.val[1] = paeth(vdest.val[0], vtmp2, vpp.val[0]);
vdest.val[1] = vadd_u8(vdest.val[1], vtmp1);
vtmp1 = vext_u8(vrp.val[0], vrp.val[1], 6);
vtmp3 = vext_u8(vpp.val[0], vpp.val[1], 6);
vdest.val[2] = paeth(vdest.val[1], vtmp3, vtmp2);
vdest.val[2] = vadd_u8(vdest.val[2], vtmp1);
vtmp1 = vext_u8(vrp.val[1], vrp.val[1], 1);
vtmp2 = vext_u8(vpp.val[1], vpp.val[1], 1);
vtmp = vld1q_u8(rp + 12);
vrpt = png_ptr(uint8x8x2_t,&vtmp);
vrp = *vrpt;
vdest.val[3] = paeth(vdest.val[2], vtmp2, vtmp3);
vdest.val[3] = vadd_u8(vdest.val[3], vtmp1);
vlast = vtmp2;
vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[0]), 0);
rp += 3;
vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[1]), 0);
rp += 3;
vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[2]), 0);
rp += 3;
vst1_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2_t,&vdest.val[3]), 0);
rp += 3;
}
}
void
png_read_filter_row_paeth4_neon(png_row_infop row_info, png_bytep row,
png_const_bytep prev_row)
{
png_bytep rp = row;
png_bytep rp_stop = row + row_info->rowbytes;
png_const_bytep pp = prev_row;
uint8x8_t vlast = vdup_n_u8(0);
uint8x8x4_t vdest;
vdest.val[3] = vdup_n_u8(0);
for (; rp < rp_stop; rp += 16, pp += 16)
{
uint32x2x4_t vtmp;
uint8x8x4_t *vrpt, *vppt;
uint8x8x4_t vrp, vpp;
uint32x2x4_t *temp_pointer;
vtmp = vld4_u32(png_ptr(uint32_t,rp));
vrpt = png_ptr(uint8x8x4_t,&vtmp);
vrp = *vrpt;
vtmp = vld4_u32(png_ptrc(uint32_t,pp));
vppt = png_ptr(uint8x8x4_t,&vtmp);
vpp = *vppt;
vdest.val[0] = paeth(vdest.val[3], vpp.val[0], vlast);
vdest.val[0] = vadd_u8(vdest.val[0], vrp.val[0]);
vdest.val[1] = paeth(vdest.val[0], vpp.val[1], vpp.val[0]);
vdest.val[1] = vadd_u8(vdest.val[1], vrp.val[1]);
vdest.val[2] = paeth(vdest.val[1], vpp.val[2], vpp.val[1]);
vdest.val[2] = vadd_u8(vdest.val[2], vrp.val[2]);
vdest.val[3] = paeth(vdest.val[2], vpp.val[3], vpp.val[2]);
vdest.val[3] = vadd_u8(vdest.val[3], vrp.val[3]);
vlast = vpp.val[3];
vst4_lane_u32(png_ptr(uint32_t,rp), png_ldr(uint32x2x4_t,&vdest), 0);
}
}
#endif /* PNG_ARM_NEON_OPT > 0 */
#endif /* PNG_READ_SUPPORTED */
#endif /* PNG_ARM_NEON_IMPLEMENTATION == 1 (intrinsics) */