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tuklib_integer: Rename bswapXX to byteswapXX

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The __builtin_bswapXX from GCC and Clang are preferred when
they are available. This can allow compilers to emit the x86 MOVBE
instruction instead of doing a load + byteswap as two instructions
(which would happen if the byteswapping is done in inline asm).

bswap16, bswap32, and bswap64 exist in system headers on *BSDs
and Darwin. #defining bswap16 on NetBSD results in a warning about
macro redefinition. It's safest to avoid this namespace conflict
completely.

No OS supported by tuklib_integer.h uses byteswapXX names and
a web search doesn't immediately find any obvious danger of
namespace conflicts. So let's try these still-pretty-short names
for the macros.

Thanks to Sam James for pointing out the compiler warning on
NetBSD 10.0.

(cherry picked from commit 4ffc60f32397371769b7d6b5e3ed8626292d58df)
This commit is contained in:
Lasse Collin 2024-04-25 14:00:57 +03:00
parent 0ca14871f3
commit 6e76a25df2
5 changed files with 31 additions and 28 deletions
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47
src/common/tuklib_integer.h
View File

@ -16,7 +16,7 @@
///
/// Endianness-converting integer operations (these can be macros!)
/// (XX = 16, 32, or 64; Y = b or l):
/// - Byte swapping: bswapXX(num)
/// - Byte swapping: byteswapXX(num)
/// - Byte order conversions to/from native (byteswaps if Y isn't
/// the native endianness): convXXYe(num)
/// - Unaligned reads: readXXYe(ptr)
@ -66,38 +66,41 @@
#if defined(HAVE___BUILTIN_BSWAPXX)
// GCC >= 4.8 and Clang
# define bswap16(n) __builtin_bswap16(n)
# define bswap32(n) __builtin_bswap32(n)
# define bswap64(n) __builtin_bswap64(n)
# define byteswap16(num) __builtin_bswap16(num)
# define byteswap32(num) __builtin_bswap32(num)
# define byteswap64(num) __builtin_bswap64(num)
#elif defined(HAVE_BYTESWAP_H)
// glibc, uClibc, dietlibc
# include <byteswap.h>
# ifdef HAVE_BSWAP_16
# define bswap16(num) bswap_16(num)
# define byteswap16(num) bswap_16(num)
# endif
# ifdef HAVE_BSWAP_32
# define bswap32(num) bswap_32(num)
# define byteswap32(num) bswap_32(num)
# endif
# ifdef HAVE_BSWAP_64
# define bswap64(num) bswap_64(num)
# define byteswap64(num) bswap_64(num)
# endif
#elif defined(HAVE_SYS_ENDIAN_H)
// *BSDs and Darwin
# include <sys/endian.h>
# define byteswap16(num) bswap16(num)
# define byteswap32(num) bswap32(num)
# define byteswap64(num) bswap64(num)
#elif defined(HAVE_SYS_BYTEORDER_H)
// Solaris
# include <sys/byteorder.h>
# ifdef BSWAP_16
# define bswap16(num) BSWAP_16(num)
# define byteswap16(num) BSWAP_16(num)
# endif
# ifdef BSWAP_32
# define bswap32(num) BSWAP_32(num)
# define byteswap32(num) BSWAP_32(num)
# endif
# ifdef BSWAP_64
# define bswap64(num) BSWAP_64(num)
# define byteswap64(num) BSWAP_64(num)
# endif
# ifdef BE_16
# define conv16be(num) BE_16(num)
@ -119,15 +122,15 @@
# endif
#endif
#ifndef bswap16
# define bswap16(n) (uint16_t)( \
#ifndef byteswap16
# define byteswap16(n) (uint16_t)( \
(((n) & 0x00FFU) << 8) \
| (((n) & 0xFF00U) >> 8) \
)
#endif
#ifndef bswap32
# define bswap32(n) (uint32_t)( \
#ifndef byteswap32
# define byteswap32(n) (uint32_t)( \
(((n) & UINT32_C(0x000000FF)) << 24) \
| (((n) & UINT32_C(0x0000FF00)) << 8) \
| (((n) & UINT32_C(0x00FF0000)) >> 8) \
@ -135,8 +138,8 @@
)
#endif
#ifndef bswap64
# define bswap64(n) (uint64_t)( \
#ifndef byteswap64
# define byteswap64(n) (uint64_t)( \
(((n) & UINT64_C(0x00000000000000FF)) << 56) \
| (((n) & UINT64_C(0x000000000000FF00)) << 40) \
| (((n) & UINT64_C(0x0000000000FF0000)) << 24) \
@ -160,23 +163,23 @@
# define conv64be(num) ((uint64_t)(num))
# endif
# ifndef conv16le
# define conv16le(num) bswap16(num)
# define conv16le(num) byteswap16(num)
# endif
# ifndef conv32le
# define conv32le(num) bswap32(num)
# define conv32le(num) byteswap32(num)
# endif
# ifndef conv64le
# define conv64le(num) bswap64(num)
# define conv64le(num) byteswap64(num)
# endif
#else
# ifndef conv16be
# define conv16be(num) bswap16(num)
# define conv16be(num) byteswap16(num)
# endif
# ifndef conv32be
# define conv32be(num) bswap32(num)
# define conv32be(num) byteswap32(num)
# endif
# ifndef conv64be
# define conv64be(num) bswap64(num)
# define conv64be(num) byteswap64(num)
# endif
# ifndef conv16le
# define conv16le(num) ((uint16_t)(num))

4
src/liblzma/check/crc32_fast.c
View File

@ -34,7 +34,7 @@ crc32_generic(const uint8_t *buf, size_t size, uint32_t crc)
crc = ~crc;
#ifdef WORDS_BIGENDIAN
crc = bswap32(crc);
crc = byteswap32(crc);
#endif
if (size > 8) {
@ -80,7 +80,7 @@ crc32_generic(const uint8_t *buf, size_t size, uint32_t crc)
crc = lzma_crc32_table[0][*buf++ ^ A(crc)] ^ S8(crc);
#ifdef WORDS_BIGENDIAN
crc = bswap32(crc);
crc = byteswap32(crc);
#endif
return ~crc;

2
src/liblzma/check/crc32_tablegen.c
View File

@ -43,7 +43,7 @@ init_crc32_table(void)
#ifdef WORDS_BIGENDIAN
for (size_t s = 0; s < 8; ++s)
for (size_t b = 0; b < 256; ++b)
crc32_table[s][b] = bswap32(crc32_table[s][b]);
crc32_table[s][b] = byteswap32(crc32_table[s][b]);
#endif
return;

4
src/liblzma/check/crc64_fast.c
View File

@ -39,7 +39,7 @@ crc64_generic(const uint8_t *buf, size_t size, uint64_t crc)
crc = ~crc;
#ifdef WORDS_BIGENDIAN
crc = bswap64(crc);
crc = byteswap64(crc);
#endif
if (size > 4) {
@ -73,7 +73,7 @@ crc64_generic(const uint8_t *buf, size_t size, uint64_t crc)
crc = lzma_crc64_table[0][*buf++ ^ A1(crc)] ^ S8(crc);
#ifdef WORDS_BIGENDIAN
crc = bswap64(crc);
crc = byteswap64(crc);
#endif
return ~crc;

2
src/liblzma/check/crc64_tablegen.c
View File

@ -42,7 +42,7 @@ init_crc64_table(void)
#ifdef WORDS_BIGENDIAN
for (size_t s = 0; s < 4; ++s)
for (size_t b = 0; b < 256; ++b)
crc64_table[s][b] = bswap64(crc64_table[s][b]);
crc64_table[s][b] = byteswap64(crc64_table[s][b]);
#endif
return;