5 Commits

Author	SHA1	Message	Date
Lasse Collin	524c2f12c7	tuklib_integer.m4: Optimize the check order. ... The __builtin byteswapping is the preferred one so check for it first.	2020-02-21 01:24:18 +02:00
Lasse Collin	77bc5bc6dd	Revise tuklib_integer.h and .m4. ... Add a configure option --enable-unsafe-type-punning to get the old non-conforming memory access methods. It can be useful with old compilers or in some other less typical situations but shouldn't normally be used. Omit the packed struct trick for unaligned access. While it's best in some cases, this is simpler. If the memcpy trick doesn't work, one can request unsafe type punning from configure. Because CRC32/CRC64 code needs fast aligned reads, if no very safe way to do it is found, type punning is used as a fallback. This sucks but since it currently works in practice, it seems to be the least bad option. It's never needed with GCC >= 4.7 or Clang >= 3.6 since these support __builtin_assume_aligned and thus fast aligned access can be done with the memcpy trick. Other things: - Support GCC/Clang __builtin_bswapXX - Cleaner bswap fallback macros - Minor cleanups	2019-12-31 00:18:24 +02:00
Lasse Collin	e5f13a6656	tuklib_integer: Autodetect support for unaligned access on ARM. ... The result is used as the default for --enable-unaligned-access. The test should work with GCC and Clang.	2019-06-01 18:46:54 +03:00
Lasse Collin	b13a781833	Build: Replace obsolete AC_HELP_STRING with AS_HELP_STRING.	2014-11-17 18:52:21 +02:00
Lasse Collin	ebfb2c5e1f	Use a tuklib module for integer handling. ... This replaces bswap.h and integer.h. The tuklib module uses <byteswap.h> on GNU, <sys/endian.h> on *BSDs and <sys/byteorder.h> on Solaris, which may contain optimized code like inline assembly.	2009-10-04 22:57:12 +03:00