blob: 02df812e775fafcd10b3dc7c514275c6b5565405 [file] [log] [blame]
Glenn Randers-Pehrson871b1d02013-03-02 14:58:22 -06001
2/* arm_init.c - NEON optimised filter functions
3 *
Glenn Randers-Pehrsonda9d1d72016-02-19 14:58:59 -06004 * Copyright (c) 2014,2016 Glenn Randers-Pehrson
Glenn Randers-Pehrson871b1d02013-03-02 14:58:22 -06005 * Written by Mans Rullgard, 2011.
Glenn Randers-Pehrson428f5dd2016-06-11 13:59:40 -05006 * Last changed in libpng 1.6.22 [May 26, 2016]
Glenn Randers-Pehrson871b1d02013-03-02 14:58:22 -06007 *
8 * This code is released under the libpng license.
9 * For conditions of distribution and use, see the disclaimer
10 * and license in png.h
11 */
12/* Below, after checking __linux__, various non-C90 POSIX 1003.1 functions are
13 * called.
14 */
15#define _POSIX_SOURCE 1
16
17#include "../pngpriv.h"
18
John Bowler497e7312013-07-02 22:57:40 -050019#ifdef PNG_READ_SUPPORTED
Glenn Randers-Pehrson7c5d0372014-11-29 17:04:35 -060020
John Bowler18dd07e2013-06-08 13:07:13 -050021#if PNG_ARM_NEON_OPT > 0
Glenn Randers-Pehrson871b1d02013-03-02 14:58:22 -060022#ifdef PNG_ARM_NEON_CHECK_SUPPORTED /* Do run-time checks */
John Bowlerdba54b82014-02-16 14:00:06 -060023/* WARNING: it is strongly recommended that you do not build libpng with
24 * run-time checks for CPU features if at all possible. In the case of the ARM
25 * NEON instructions there is no processor-specific way of detecting the
Glenn Randers-Pehrson149eea22014-03-17 10:58:02 -050026 * presence of the required support, therefore run-time detection is extremely
John Bowlerdba54b82014-02-16 14:00:06 -060027 * OS specific.
Glenn Randers-Pehrson871b1d02013-03-02 14:58:22 -060028 *
John Bowlerdba54b82014-02-16 14:00:06 -060029 * You may set the macro PNG_ARM_NEON_FILE to the file name of file containing
30 * a fragment of C source code which defines the png_have_neon function. There
31 * are a number of implementations in contrib/arm-neon, but the only one that
32 * has partial support is contrib/arm-neon/linux.c - a generic Linux
33 * implementation which reads /proc/cpufino.
Glenn Randers-Pehrson871b1d02013-03-02 14:58:22 -060034 */
John Bowlerdba54b82014-02-16 14:00:06 -060035#ifndef PNG_ARM_NEON_FILE
36# ifdef __linux__
37# define PNG_ARM_NEON_FILE "contrib/arm-neon/linux.c"
38# endif
39#endif
Glenn Randers-Pehrson871b1d02013-03-02 14:58:22 -060040
John Bowlerdba54b82014-02-16 14:00:06 -060041#ifdef PNG_ARM_NEON_FILE
Glenn Randers-Pehrson871b1d02013-03-02 14:58:22 -060042
John Bowlerdba54b82014-02-16 14:00:06 -060043#include <signal.h> /* for sig_atomic_t */
44static int png_have_neon(png_structp png_ptr);
45#include PNG_ARM_NEON_FILE
Glenn Randers-Pehrson871b1d02013-03-02 14:58:22 -060046
John Bowlerdba54b82014-02-16 14:00:06 -060047#else /* PNG_ARM_NEON_FILE */
48# error "PNG_ARM_NEON_FILE undefined: no support for run-time ARM NEON checks"
49#endif /* PNG_ARM_NEON_FILE */
Glenn Randers-Pehrson871b1d02013-03-02 14:58:22 -060050#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
51
52#ifndef PNG_ALIGNED_MEMORY_SUPPORTED
53# error "ALIGNED_MEMORY is required; set: -DPNG_ALIGNED_MEMORY_SUPPORTED"
54#endif
55
56void
57png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
58{
John Bowler8f381902013-09-30 11:24:17 -050059 /* The switch statement is compiled in for ARM_NEON_API, the call to
60 * png_have_neon is compiled in for ARM_NEON_CHECK. If both are defined
61 * the check is only performed if the API has not set the NEON option on
62 * or off explicitly. In this case the check controls what happens.
63 *
64 * If the CHECK is not compiled in and the option is UNSET the behavior prior
65 * to 1.6.7 was to use the NEON code - this was a bug caused by having the
66 * wrong order of the 'ON' and 'default' cases. UNSET now defaults to OFF,
67 * as documented in png.h
68 */
Glenn Randers-Pehrsonda9d1d72016-02-19 14:58:59 -060069 png_debug(1, "in png_init_filter_functions_neon");
John Bowlerf3728102013-03-04 16:26:31 -060070#ifdef PNG_ARM_NEON_API_SUPPORTED
71 switch ((pp->options >> PNG_ARM_NEON) & 3)
72 {
73 case PNG_OPTION_UNSET:
74 /* Allow the run-time check to execute if it has been enabled -
75 * thus both API and CHECK can be turned on. If it isn't supported
76 * this case will fall through to the 'default' below, which just
77 * returns.
78 */
79#endif /* PNG_ARM_NEON_API_SUPPORTED */
Glenn Randers-Pehrson871b1d02013-03-02 14:58:22 -060080#ifdef PNG_ARM_NEON_CHECK_SUPPORTED
John Bowlerf3728102013-03-04 16:26:31 -060081 {
82 static volatile sig_atomic_t no_neon = -1; /* not checked */
Glenn Randers-Pehrson871b1d02013-03-02 14:58:22 -060083
John Bowlerf3728102013-03-04 16:26:31 -060084 if (no_neon < 0)
85 no_neon = !png_have_neon(pp);
Glenn Randers-Pehrson871b1d02013-03-02 14:58:22 -060086
John Bowlerf3728102013-03-04 16:26:31 -060087 if (no_neon)
88 return;
89 }
90#ifdef PNG_ARM_NEON_API_SUPPORTED
91 break;
92#endif
Glenn Randers-Pehrson871b1d02013-03-02 14:58:22 -060093#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
John Bowler8f381902013-09-30 11:24:17 -050094
John Bowlerf3728102013-03-04 16:26:31 -060095#ifdef PNG_ARM_NEON_API_SUPPORTED
John Bowler8f381902013-09-30 11:24:17 -050096 default: /* OFF or INVALID */
97 return;
98
John Bowlerf3728102013-03-04 16:26:31 -060099 case PNG_OPTION_ON:
100 /* Option turned on */
101 break;
John Bowlerf3728102013-03-04 16:26:31 -0600102 }
103#endif
Glenn Randers-Pehrson871b1d02013-03-02 14:58:22 -0600104
105 /* IMPORTANT: any new external functions used here must be declared using
106 * PNG_INTERNAL_FUNCTION in ../pngpriv.h. This is required so that the
107 * 'prefix' option to configure works:
108 *
109 * ./configure --with-libpng-prefix=foobar_
110 *
111 * Verify you have got this right by running the above command, doing a build
112 * and examining pngprefix.h; it must contain a #define for every external
113 * function you add. (Notice that this happens automatically for the
114 * initialization function.)
115 */
116 pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon;
117
118 if (bpp == 3)
119 {
120 pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon;
121 pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon;
122 pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
123 png_read_filter_row_paeth3_neon;
124 }
125
126 else if (bpp == 4)
127 {
128 pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon;
129 pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon;
130 pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
131 png_read_filter_row_paeth4_neon;
132 }
133}
John Bowler18dd07e2013-06-08 13:07:13 -0500134#endif /* PNG_ARM_NEON_OPT > 0 */
Glenn Randers-Pehrsonee16fc42014-11-29 16:27:27 -0600135#endif /* READ */