233 lines
6.8 KiB
C
233 lines
6.8 KiB
C
|
|
||
|
|
/* arm_init.c - NEON optimised filter functions
|
||
|
|
*
|
||
|
|
* Copyright (c) 2013 Glenn Randers-Pehrson
|
||
|
|
* 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
|
||
|
|
*/
|
||
|
|
/* Below, after checking __linux__, various non-C90 POSIX 1003.1 functions are
|
||
|
|
* called.
|
||
|
|
*/
|
||
|
|
#define _POSIX_SOURCE 1
|
||
|
|
|
||
|
|
#include "../pngpriv.h"
|
||
|
|
|
||
|
|
#ifdef PNG_READ_SUPPORTED
|
||
|
|
#if PNG_ARM_NEON_OPT > 0
|
||
|
|
#ifdef PNG_ARM_NEON_CHECK_SUPPORTED /* Do run-time checks */
|
||
|
|
#include <signal.h> /* for sig_atomic_t */
|
||
|
|
|
||
|
|
#ifdef __ANDROID__
|
||
|
|
/* Linux provides access to information about CPU capabilites via
|
||
|
|
* /proc/self/auxv, however Android blocks this while still claiming to be
|
||
|
|
* Linux. The Andoid NDK, however, provides appropriate support.
|
||
|
|
*
|
||
|
|
* Documentation: http://www.kandroid.org/ndk/docs/CPU-ARM-NEON.html
|
||
|
|
*/
|
||
|
|
#include <cpu-features.h>
|
||
|
|
|
||
|
|
static int
|
||
|
|
png_have_neon(png_structp png_ptr)
|
||
|
|
{
|
||
|
|
/* This is a whole lot easier than the mess below, however it is probably
|
||
|
|
* implemented as below, therefore it is better to cache the result (these
|
||
|
|
* function calls may be slow!)
|
||
|
|
*/
|
||
|
|
PNG_UNUSED(png_ptr)
|
||
|
|
return android_getCpuFamily() == ANDROID_CPU_FAMILY_ARM &&
|
||
|
|
(android_getCpuFeatures() & ANDROID_CPU_ARM_FEATURE_NEON) != 0;
|
||
|
|
}
|
||
|
|
#elif defined(__linux__)
|
||
|
|
/* The generic __linux__ implementation requires reading /proc/self/auxv and
|
||
|
|
* looking at each element for one that records NEON capabilities.
|
||
|
|
*/
|
||
|
|
#include <unistd.h> /* for POSIX 1003.1 */
|
||
|
|
#include <errno.h> /* for EINTR */
|
||
|
|
|
||
|
|
#include <sys/types.h>
|
||
|
|
#include <sys/stat.h>
|
||
|
|
#include <fcntl.h>
|
||
|
|
#include <elf.h>
|
||
|
|
#include <asm/hwcap.h>
|
||
|
|
|
||
|
|
/* A read call may be interrupted, in which case it returns -1 and sets errno to
|
||
|
|
* EINTR if nothing was done, otherwise (if something was done) a partial read
|
||
|
|
* may result.
|
||
|
|
*/
|
||
|
|
static size_t
|
||
|
|
safe_read(png_structp png_ptr, int fd, void *buffer_in, size_t nbytes)
|
||
|
|
{
|
||
|
|
size_t ntotal = 0;
|
||
|
|
char *buffer = png_voidcast(char*, buffer_in);
|
||
|
|
|
||
|
|
while (nbytes > 0)
|
||
|
|
{
|
||
|
|
unsigned int nread;
|
||
|
|
int iread;
|
||
|
|
|
||
|
|
/* Passing nread > INT_MAX to read is implementation defined in POSIX
|
||
|
|
* 1003.1, therefore despite the unsigned argument portable code must
|
||
|
|
* limit the value to INT_MAX!
|
||
|
|
*/
|
||
|
|
if (nbytes > INT_MAX)
|
||
|
|
nread = INT_MAX;
|
||
|
|
|
||
|
|
else
|
||
|
|
nread = (unsigned int)/*SAFE*/nbytes;
|
||
|
|
|
||
|
|
iread = read(fd, buffer, nread);
|
||
|
|
|
||
|
|
if (iread == -1)
|
||
|
|
{
|
||
|
|
/* This is the devil in the details, a read can terminate early with 0
|
||
|
|
* bytes read because of EINTR, yet it still returns -1 otherwise end
|
||
|
|
* of file cannot be distinguished.
|
||
|
|
*/
|
||
|
|
if (errno != EINTR)
|
||
|
|
{
|
||
|
|
png_warning(png_ptr, "/proc read failed");
|
||
|
|
return 0; /* I.e., a permanent failure */
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
else if (iread < 0)
|
||
|
|
{
|
||
|
|
/* Not a valid 'read' result: */
|
||
|
|
png_warning(png_ptr, "OS /proc read bug");
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
else if (iread > 0)
|
||
|
|
{
|
||
|
|
/* Continue reading until a permanent failure, or EOF */
|
||
|
|
buffer += iread;
|
||
|
|
nbytes -= (unsigned int)/*SAFE*/iread;
|
||
|
|
ntotal += (unsigned int)/*SAFE*/iread;
|
||
|
|
}
|
||
|
|
|
||
|
|
else
|
||
|
|
return ntotal;
|
||
|
|
}
|
||
|
|
|
||
|
|
return ntotal; /* nbytes == 0 */
|
||
|
|
}
|
||
|
|
|
||
|
|
static int
|
||
|
|
png_have_neon(png_structp png_ptr)
|
||
|
|
{
|
||
|
|
int fd = open("/proc/self/auxv", O_RDONLY);
|
||
|
|
Elf32_auxv_t aux;
|
||
|
|
|
||
|
|
/* Failsafe: failure to open means no NEON */
|
||
|
|
if (fd == -1)
|
||
|
|
{
|
||
|
|
png_warning(png_ptr, "/proc/self/auxv open failed");
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
while (safe_read(png_ptr, fd, &aux, sizeof aux) == sizeof aux)
|
||
|
|
{
|
||
|
|
if (aux.a_type == AT_HWCAP && (aux.a_un.a_val & HWCAP_NEON) != 0)
|
||
|
|
{
|
||
|
|
close(fd);
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
close(fd);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
#else
|
||
|
|
/* We don't know how to do a run-time check on this system */
|
||
|
|
# error "no support for run-time ARM NEON checks"
|
||
|
|
#endif /* OS checks */
|
||
|
|
#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
|
||
|
|
|
||
|
|
#ifndef PNG_ALIGNED_MEMORY_SUPPORTED
|
||
|
|
# error "ALIGNED_MEMORY is required; set: -DPNG_ALIGNED_MEMORY_SUPPORTED"
|
||
|
|
#endif
|
||
|
|
|
||
|
|
void
|
||
|
|
png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
|
||
|
|
{
|
||
|
|
/* The switch statement is compiled in for ARM_NEON_API, the call to
|
||
|
|
* png_have_neon is compiled in for ARM_NEON_CHECK. If both are defined
|
||
|
|
* the check is only performed if the API has not set the NEON option on
|
||
|
|
* or off explicitly. In this case the check controls what happens.
|
||
|
|
*
|
||
|
|
* If the CHECK is not compiled in and the option is UNSET the behavior prior
|
||
|
|
* to 1.6.7 was to use the NEON code - this was a bug caused by having the
|
||
|
|
* wrong order of the 'ON' and 'default' cases. UNSET now defaults to OFF,
|
||
|
|
* as documented in png.h
|
||
|
|
*/
|
||
|
|
#ifdef PNG_ARM_NEON_API_SUPPORTED
|
||
|
|
switch ((pp->options >> PNG_ARM_NEON) & 3)
|
||
|
|
{
|
||
|
|
case PNG_OPTION_UNSET:
|
||
|
|
/* Allow the run-time check to execute if it has been enabled -
|
||
|
|
* thus both API and CHECK can be turned on. If it isn't supported
|
||
|
|
* this case will fall through to the 'default' below, which just
|
||
|
|
* returns.
|
||
|
|
*/
|
||
|
|
#endif /* PNG_ARM_NEON_API_SUPPORTED */
|
||
|
|
#ifdef PNG_ARM_NEON_CHECK_SUPPORTED
|
||
|
|
{
|
||
|
|
static volatile sig_atomic_t no_neon = -1; /* not checked */
|
||
|
|
|
||
|
|
if (no_neon < 0)
|
||
|
|
no_neon = !png_have_neon(pp);
|
||
|
|
|
||
|
|
if (no_neon)
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
#ifdef PNG_ARM_NEON_API_SUPPORTED
|
||
|
|
break;
|
||
|
|
#endif
|
||
|
|
#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
|
||
|
|
|
||
|
|
#ifdef PNG_ARM_NEON_API_SUPPORTED
|
||
|
|
default: /* OFF or INVALID */
|
||
|
|
return;
|
||
|
|
|
||
|
|
case PNG_OPTION_ON:
|
||
|
|
/* Option turned on */
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/* IMPORTANT: any new external functions used here must be declared using
|
||
|
|
* PNG_INTERNAL_FUNCTION in ../pngpriv.h. This is required so that the
|
||
|
|
* 'prefix' option to configure works:
|
||
|
|
*
|
||
|
|
* ./configure --with-libpng-prefix=foobar_
|
||
|
|
*
|
||
|
|
* Verify you have got this right by running the above command, doing a build
|
||
|
|
* and examining pngprefix.h; it must contain a #define for every external
|
||
|
|
* function you add. (Notice that this happens automatically for the
|
||
|
|
* initialization function.)
|
||
|
|
*/
|
||
|
|
pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon;
|
||
|
|
|
||
|
|
if (bpp == 3)
|
||
|
|
{
|
||
|
|
pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon;
|
||
|
|
pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon;
|
||
|
|
pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
|
||
|
|
png_read_filter_row_paeth3_neon;
|
||
|
|
}
|
||
|
|
|
||
|
|
else if (bpp == 4)
|
||
|
|
{
|
||
|
|
pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon;
|
||
|
|
pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon;
|
||
|
|
pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
|
||
|
|
png_read_filter_row_paeth4_neon;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
#endif /* PNG_ARM_NEON_OPT > 0 */
|
||
|
|
#endif /* PNG_READ_SUPPORTED */
|