diff options
Diffstat (limited to 'Build/source/libs/libpng/libpng-1.6.16/contrib/arm-neon/linux-auxv.c')
-rw-r--r-- | Build/source/libs/libpng/libpng-1.6.16/contrib/arm-neon/linux-auxv.c | 120 |
1 files changed, 0 insertions, 120 deletions
diff --git a/Build/source/libs/libpng/libpng-1.6.16/contrib/arm-neon/linux-auxv.c b/Build/source/libs/libpng/libpng-1.6.16/contrib/arm-neon/linux-auxv.c deleted file mode 100644 index 696e297ef4c..00000000000 --- a/Build/source/libs/libpng/libpng-1.6.16/contrib/arm-neon/linux-auxv.c +++ /dev/null @@ -1,120 +0,0 @@ -/* contrib/arm-neon/linux-auxv.c - * - * Copyright (c) 2014 Glenn Randers-Pehrson - * Written by Mans Rullgard, 2011. - * Last changed in libpng 1.6.10 [March 6, 2014] - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - * - * SEE contrib/arm-neon/README before reporting bugs - * - * STATUS: COMPILED, TESTED - * BUG REPORTS: png-mng-implement@sourceforge.net - * - * png_have_neon implemented for Linux versions which allow access to - * /proc/self/auxv. This is probably faster, cleaner and safer than the code to - * read /proc/cpuinfo in contrib/arm-neon/linux, however it is yet another piece - * of potentially untested code and has more complex dependencies than the code - * to read cpuinfo. - * - * This 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; -} |