diff options
Diffstat (limited to 'src/liblzma/check/crc32_fast.c')
| -rw-r--r-- | src/liblzma/check/crc32_fast.c | 47 |
1 files changed, 7 insertions, 40 deletions
diff --git a/src/liblzma/check/crc32_fast.c b/src/liblzma/check/crc32_fast.c index 5e26914a4d1b..16dbb7467513 100644 --- a/src/liblzma/check/crc32_fast.c +++ b/src/liblzma/check/crc32_fast.c @@ -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; @@ -97,24 +97,14 @@ crc32_generic(const uint8_t *buf, size_t size, uint32_t crc) // If both the generic and arch-optimized implementations are built, then // the function to use is selected at runtime because the system running // the binary might not have the arch-specific instruction set extension(s) -// available. The three dispatch methods in order of priority: +// available. The dispatch methods in order of priority: // -// 1. Indirect function (ifunc). This method is slightly more efficient -// than the constructor method because it will change the entry in the -// Procedure Linkage Table (PLT) for the function either at load time or -// at the first call. This avoids having to call the function through a -// function pointer and will treat the function call like a regular call -// through the PLT. ifuncs are created by using -// __attribute__((__ifunc__("resolver"))) on a function which has no -// body. The "resolver" is the name of the function that chooses at -// runtime which implementation to use. -// -// 2. Constructor. This method uses __attribute__((__constructor__)) to +// 1. Constructor. This method uses __attribute__((__constructor__)) to // set crc32_func at load time. This avoids extra computation (and any // unlikely threading bugs) on the first call to lzma_crc32() to decide // which implementation should be used. // -// 3. First Call Resolution. On the very first call to lzma_crc32(), the +// 2. First Call Resolution. On the very first call to lzma_crc32(), the // call will be directed to crc32_dispatch() instead. This will set the // appropriate implementation function and will not be called again. // This method does not use any kind of locking but is safe because if @@ -124,17 +114,7 @@ crc32_generic(const uint8_t *buf, size_t size, uint32_t crc) typedef uint32_t (*crc32_func_type)( const uint8_t *buf, size_t size, uint32_t crc); -// Clang 16.0.0 and older has a bug where it marks the ifunc resolver -// function as unused since it is static and never used outside of -// __attribute__((__ifunc__())). -#if defined(CRC_USE_IFUNC) && defined(__clang__) -# pragma GCC diagnostic push -# pragma GCC diagnostic ignored "-Wunused-function" -#endif - -// This resolver is shared between all three dispatch methods. It serves as -// the ifunc resolver if ifunc is supported, otherwise it is called as a -// regular function by the constructor or first call resolution methods. +// This resolver is shared between all dispatch methods. static crc32_func_type crc32_resolve(void) { @@ -142,11 +122,6 @@ crc32_resolve(void) ? &crc32_arch_optimized : &crc32_generic; } -#if defined(CRC_USE_IFUNC) && defined(__clang__) -# pragma GCC diagnostic pop -#endif - -#ifndef CRC_USE_IFUNC #ifdef HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR // Constructor method. @@ -171,8 +146,7 @@ crc32_set_func(void) static uint32_t crc32_dispatch(const uint8_t *buf, size_t size, uint32_t crc) { - // When __attribute__((__ifunc__(...))) and - // __attribute__((__constructor__)) isn't supported, set the + // When __attribute__((__constructor__)) isn't supported, set the // function pointer without any locking. If multiple threads run // the detection code in parallel, they will all end up setting // the pointer to the same value. This avoids the use of @@ -184,14 +158,8 @@ crc32_dispatch(const uint8_t *buf, size_t size, uint32_t crc) #endif #endif -#endif -#ifdef CRC_USE_IFUNC -extern LZMA_API(uint32_t) -lzma_crc32(const uint8_t *buf, size_t size, uint32_t crc) - __attribute__((__ifunc__("crc32_resolve"))); -#else extern LZMA_API(uint32_t) lzma_crc32(const uint8_t *buf, size_t size, uint32_t crc) { @@ -234,4 +202,3 @@ lzma_crc32(const uint8_t *buf, size_t size, uint32_t crc) return crc32_generic(buf, size, crc); #endif } -#endif |