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* Fix an issue introduced in sys/x86/include/endian.h with r232721. Indim2012-03-291-2/+2
| | | | | | | | | | | | | | | | | | | that revision, the bswapXX_const() macros were renamed to bswapXX_gen(). Also, bswap64_gen() was implemented as two calls to bswap32(), and similarly, bswap32_gen() as two calls to bswap16(). This mainly helps our base gcc to produce more efficient assembly. However, the arguments are not properly masked, which results in the wrong value being calculated in some instances. For example, bswap32(0x12345678) returns 0x7c563412, and bswap64(0x123456789abcdef0) returns 0xfcdefc9a7c563412. Fix this by appropriately masking the arguments to bswap16() in bswap32_gen(), and to bswap32() in bswap64_gen(). This should also silence warnings from clang. Submitted by: jh
* Revert sys/x86/include/endian.h to what it was before r233419, as thatdim2012-03-291-3/+3
| | | | | | | | | | revision has two problems: - It can produce worse code with both clang and gcc. - It doesn't fix the actual issue introduced in r232721, which will be fixed in the next commit. Submitted by: bde, tijl and jh Pointy hat to: dim
* Fix the following clang warning in sys/dev/dcons/dcons.c, caused by thedim2012-03-241-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | recent changes in sys/x86/include/endian.h: sys/dev/dcons/dcons.c:190:15: error: implicit conversion from '__uint32_t' (aka 'unsigned int') to '__uint16_t' (aka 'unsigned short') changes value from 1684238190 to 28526 [-Werror,-Wconstant-conversion] buf->magic = ntohl(DCONS_MAGIC); ^~~~~~~~~~~~~~~~~~ sys/sys/param.h:306:18: note: expanded from: #define ntohl(x) __ntohl(x) ^ ./x86/endian.h:128:20: note: expanded from: #define __ntohl(x) __bswap32(x) ^ ./x86/endian.h:78:20: note: expanded from: __bswap32_gen((__uint32_t)(x)) : __bswap32_var(x)) ^ ./x86/endian.h:68:26: note: expanded from: (((__uint32_t)__bswap16(x) << 16) | __bswap16((x) >> 16)) ^ ./x86/endian.h:75:53: note: expanded from: __bswap16_gen((__uint16_t)(x)) : __bswap16_var(x))) ~~~~~~~~~~~~~ ^ This is because the __bswapXX_gen() macros (for x86) call the regular __bswapXX() macros. Since the __bswapXX_gen() variants are only called when their arguments are constant, there is no need to do that constancy check recursively. Also, it causes the above error with clang. Fix it by calling __bswap16_gen() from __bswap32_gen(), and similarly, __bswap32_gen() from __bswap64_gen(). While here, add extra parentheses around the __bswap16_gen() macro expansion, to prevent unexpected side effects.
* Add casts to __uint16_t to the __bswap16() macros on all arches whichdim2012-03-091-2/+2
| | | | | | | | | | | didn't already have them. This is because the ternary expression will return int, due to the Usual Arithmetic Conversions. Such casts are not needed for the 32 and 64 bit variants. While here, add additional parentheses around the x86 variant, to protect against unintended consequences. MFC after: 2 weeks
* Cast the expression in __bswap16(x) to __uint16_t because it is promotedtijl2012-03-091-2/+2
| | | | | | to int. Reviewed by: dim
* Clean up x86 endian.h:tijl2012-03-091-44/+37
| | | | | | | | | | | | | - Remove extern "C". There are no functions with external linkage here. [1] - Rename bswapNN_const(x) to bswapNN_gen(x) to indicate that these macros are generic implementations that can take non-constant arguments. [1] - Split up __GNUCLIKE_ASM && __GNUCLIKE_BUILTIN_CONSTANT_P and deal with each separately. - Replace _LP64 with __amd64__ because asm instructions are machine dependent, not ABI dependent. Submitted by: bde [1] Reviewed by: bde
* Copy amd64 endian.h to x86 and merge with i386 endian.h. Replacetijl2012-02-281-0/+138
amd64/i386/pc98 endian.h with stubs. In __bswap64_const(x) the conflict between 0xffUL and 0xffULL has been resolved by reimplementing the macro in terms of __bswap32(x). As a side effect __bswap64_var(x) is now implemented using two bswap instructions on i386 and should be much faster. __bswap32_const(x) has been reimplemented in terms of __bswap16(x) for consistency.
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