gstconfig.h: Detect unaligned access support at compile-time

This makes gstconfig.h completely arch-independent. Should cover all
compilers that gstreamer is known to build on, and all architectures
that I could find information on. People are encouraged to file bugs if
their platform/arch is missing.
This commit is contained in:
Nirbheek Chauhan 2016-06-21 18:59:49 +05:30 committed by Tim-Philipp Müller
parent e2cd6ffafc
commit 6ef601367e
2 changed files with 16 additions and 13 deletions

View file

@ -411,17 +411,6 @@ dnl substitution for win32/common/config.h
HOST_CPU=$host_cpu
AC_SUBST(HOST_CPU)
dnl common/m4/gst-arch.m4
dnl check for unaligned access
AG_GST_UNALIGNED_ACCESS
dnl create a configure variable for gst/gstconfig.h
if test x${as_cv_unaligned_access} = xyes ; then
GST_HAVE_UNALIGNED_ACCESS_DEFINE="#define GST_HAVE_UNALIGNED_ACCESS 1"
else
GST_HAVE_UNALIGNED_ACCESS_DEFINE="#define GST_HAVE_UNALIGNED_ACCESS 0"
fi
AC_SUBST(GST_HAVE_UNALIGNED_ACCESS_DEFINE)
dnl check for platform specific settings
AG_GST_PLATFORM

View file

@ -95,8 +95,22 @@
/* Configures the use of external plugins */
@GST_DISABLE_PLUGIN_DEFINE@
/* whether or not the CPU supports unaligned access */
@GST_HAVE_UNALIGNED_ACCESS_DEFINE@
/* Whether or not the CPU supports unaligned access
* The macros used are defined consistently by GCC, Clang, MSVC, Sun, and ICC
*
* References:
* https://sourceforge.net/p/predef/wiki/Architectures/
* https://msdn.microsoft.com/en-us/library/b0084kay.aspx
* http://docs.oracle.com/cd/E19205-01/820-4155/c++_faq.html#Vers6
* https://software.intel.com/en-us/node/583402
*/
#if defined(__alpha__) || defined(__arm__) || defined(__aarch64__) || defined(__bfin) || defined(__hppa__) || defined(__mips__) || defined(__sh__) || defined(__sparc__) || defined(__sparc) || defined(__ia64__) || defined(_M_ALPHA) || defined(_M_ARM) || defined(_M_IA64)
# define GST_HAVE_UNALIGNED_ACCESS 0
#elif defined(__i386__) || defined(__i386) || defined(__amd64__) || defined(__amd64) || defined(__x86_64__) || defined(__ppc__) || defined(__ppc64__) || defined(__m68k__) || defined(_M_IX86) || defined(_M_AMD64) || defined(_M_X64)
# define GST_HAVE_UNALIGNED_ACCESS 1
#else
# error "Could not detect architecture; don't know whether it supports unaligned access! Please file a bug."
#endif
/**
* GST_EXPORT: