Update libpng from 1.6.3 to 1.6.10
Change-Id: I76e81e7fd267d15991cd342c5caeb2fe77964ebf
diff --git a/arm/arm_init.c b/arm/arm_init.c
index 15f5162..952b802 100644
--- a/arm/arm_init.c
+++ b/arm/arm_init.c
@@ -1,9 +1,9 @@
/* arm_init.c - NEON optimised filter functions
*
- * Copyright (c) 2013 Glenn Randers-Pehrson
+ * Copyright (c) 2014 Glenn Randers-Pehrson
* Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.5.17 [July 18, 2013]
+ * 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
@@ -19,132 +19,33 @@
#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.
+/* WARNING: it is strongly recommended that you do not build libpng with
+ * run-time checks for CPU features if at all possible. In the case of the ARM
+ * NEON instructions there is no processor-specific way of detecting the
+ * presense of the required support, therefore run-time detectioon is extremely
+ * OS specific.
*
- * Documentation: http://www.kandroid.org/ndk/docs/CPU-ARM-NEON.html
+ * You may set the macro PNG_ARM_NEON_FILE to the file name of file containing
+ * a fragment of C source code which defines the png_have_neon function. There
+ * are a number of implementations in contrib/arm-neon, but the only one that
+ * has partial support is contrib/arm-neon/linux.c - a generic Linux
+ * implementation which reads /proc/cpufino.
*/
-#include <cpu-features.h>
+#ifndef PNG_ARM_NEON_FILE
+# ifdef __linux__
+# define PNG_ARM_NEON_FILE "contrib/arm-neon/linux.c"
+# endif
+#endif
-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 */
+#ifdef PNG_ARM_NEON_FILE
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <elf.h>
-#include <asm/hwcap.h>
+#include <signal.h> /* for sig_atomic_t */
+static int png_have_neon(png_structp png_ptr);
+#include PNG_ARM_NEON_FILE
-/* 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 */
+#else /* PNG_ARM_NEON_FILE */
+# error "PNG_ARM_NEON_FILE undefined: no support for run-time ARM NEON checks"
+#endif /* PNG_ARM_NEON_FILE */
#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */
#ifndef PNG_ALIGNED_MEMORY_SUPPORTED
@@ -154,6 +55,16 @@
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)
{
@@ -178,13 +89,14 @@
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;
-
- default: /* OFF or INVALID */
- return;
}
#endif