diff options
Diffstat (limited to 'absl/base')
| -rw-r--r-- | absl/base/config.h | 32 | ||||
| -rw-r--r-- | absl/base/internal/endian.h | 79 |
2 files changed, 49 insertions, 62 deletions
diff --git a/absl/base/config.h b/absl/base/config.h index 78de4d1c..429dd353 100644 --- a/absl/base/config.h +++ b/absl/base/config.h @@ -269,6 +269,8 @@ static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' || #define ABSL_HAVE_SOURCE_LOCATION_CURRENT 1 #elif ABSL_INTERNAL_HAVE_MIN_GNUC_VERSION(5, 0) #define ABSL_HAVE_SOURCE_LOCATION_CURRENT 1 +#elif defined(_MSC_VER) && _MSC_VER >= 1926 +#define ABSL_HAVE_SOURCE_LOCATION_CURRENT 1 #endif #endif @@ -818,4 +820,34 @@ static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' || #define ABSL_INTERNAL_HAS_RTTI 1 #endif // !defined(__GNUC__) || defined(__GXX_RTTI) +// ABSL_INTERNAL_HAVE_SSE2 is used for compile-time detection of SSE2 support. +// See https://gcc.gnu.org/onlinedocs/gcc/x86-Options.html for an overview of +// which architectures support the various x86 instruction sets. +#ifdef ABSL_INTERNAL_HAVE_SSE2 +#error ABSL_INTERNAL_HAVE_SSE2 cannot be directly set +#elif defined(__SSE2__) +#define ABSL_INTERNAL_HAVE_SSE2 1 +#elif defined(_M_X64) || (defined(_M_IX86_FP) && _M_IX86_FP >= 2) +// MSVC only defines _M_IX86_FP for x86 32-bit code, and _M_IX86_FP >= 2 +// indicates that at least SSE2 was targeted with the /arch:SSE2 option. +// All x86-64 processors support SSE2, so support can be assumed. +// https://docs.microsoft.com/en-us/cpp/preprocessor/predefined-macros +#define ABSL_INTERNAL_HAVE_SSE2 1 +#endif + +// ABSL_INTERNAL_HAVE_SSSE3 is used for compile-time detection of SSSE3 support. +// See https://gcc.gnu.org/onlinedocs/gcc/x86-Options.html for an overview of +// which architectures support the various x86 instruction sets. +// +// MSVC does not have a mode that targets SSSE3 at compile-time. To use SSSE3 +// with MSVC requires either assuming that the code will only every run on CPUs +// that support SSSE3, otherwise __cpuid() can be used to detect support at +// runtime and fallback to a non-SSSE3 implementation when SSSE3 is unsupported +// by the CPU. +#ifdef ABSL_INTERNAL_HAVE_SSSE3 +#error ABSL_INTERNAL_HAVE_SSSE3 cannot be directly set +#elif defined(__SSSE3__) +#define ABSL_INTERNAL_HAVE_SSSE3 1 +#endif + #endif // ABSL_BASE_CONFIG_H_ diff --git a/absl/base/internal/endian.h b/absl/base/internal/endian.h index dad0e9ae..50747d75 100644 --- a/absl/base/internal/endian.h +++ b/absl/base/internal/endian.h @@ -16,16 +16,9 @@ #ifndef ABSL_BASE_INTERNAL_ENDIAN_H_ #define ABSL_BASE_INTERNAL_ENDIAN_H_ -// The following guarantees declaration of the byte swap functions -#ifdef _MSC_VER -#include <stdlib.h> // NOLINT(build/include) -#elif defined(__FreeBSD__) -#include <sys/endian.h> -#elif defined(__GLIBC__) -#include <byteswap.h> // IWYU pragma: export -#endif - #include <cstdint> +#include <cstdlib> + #include "absl/base/casts.h" #include "absl/base/config.h" #include "absl/base/internal/unaligned_access.h" @@ -34,47 +27,11 @@ namespace absl { ABSL_NAMESPACE_BEGIN -// Use compiler byte-swapping intrinsics if they are available. 32-bit -// and 64-bit versions are available in Clang and GCC as of GCC 4.3.0. -// The 16-bit version is available in Clang and GCC only as of GCC 4.8.0. -// For simplicity, we enable them all only for GCC 4.8.0 or later. -#if defined(__clang__) || \ - (defined(__GNUC__) && \ - ((__GNUC__ == 4 && __GNUC_MINOR__ >= 8) || __GNUC__ >= 5)) inline uint64_t gbswap_64(uint64_t host_int) { +#if ABSL_HAVE_BUILTIN(__builtin_bswap64) || defined(__GNUC__) return __builtin_bswap64(host_int); -} -inline uint32_t gbswap_32(uint32_t host_int) { - return __builtin_bswap32(host_int); -} -inline uint16_t gbswap_16(uint16_t host_int) { - return __builtin_bswap16(host_int); -} - #elif defined(_MSC_VER) -inline uint64_t gbswap_64(uint64_t host_int) { return _byteswap_uint64(host_int); -} -inline uint32_t gbswap_32(uint32_t host_int) { - return _byteswap_ulong(host_int); -} -inline uint16_t gbswap_16(uint16_t host_int) { - return _byteswap_ushort(host_int); -} - -#else -inline uint64_t gbswap_64(uint64_t host_int) { -#if defined(__GNUC__) && defined(__x86_64__) && !defined(__APPLE__) - // Adapted from /usr/include/byteswap.h. Not available on Mac. - if (__builtin_constant_p(host_int)) { - return __bswap_constant_64(host_int); - } else { - uint64_t result; - __asm__("bswap %0" : "=r"(result) : "0"(host_int)); - return result; - } -#elif defined(__GLIBC__) - return bswap_64(host_int); #else return (((host_int & uint64_t{0xFF}) << 56) | ((host_int & uint64_t{0xFF00}) << 40) | @@ -84,12 +41,14 @@ inline uint64_t gbswap_64(uint64_t host_int) { ((host_int & uint64_t{0xFF0000000000}) >> 24) | ((host_int & uint64_t{0xFF000000000000}) >> 40) | ((host_int & uint64_t{0xFF00000000000000}) >> 56)); -#endif // bswap_64 +#endif } inline uint32_t gbswap_32(uint32_t host_int) { -#if defined(__GLIBC__) - return bswap_32(host_int); +#if ABSL_HAVE_BUILTIN(__builtin_bswap32) || defined(__GNUC__) + return __builtin_bswap32(host_int); +#elif defined(_MSC_VER) + return _byteswap_ulong(host_int); #else return (((host_int & uint32_t{0xFF}) << 24) | ((host_int & uint32_t{0xFF00}) << 8) | @@ -99,33 +58,29 @@ inline uint32_t gbswap_32(uint32_t host_int) { } inline uint16_t gbswap_16(uint16_t host_int) { -#if defined(__GLIBC__) - return bswap_16(host_int); +#if ABSL_HAVE_BUILTIN(__builtin_bswap16) || defined(__GNUC__) + return __builtin_bswap16(host_int); +#elif defined(_MSC_VER) + return _byteswap_ushort(host_int); #else return (((host_int & uint16_t{0xFF}) << 8) | ((host_int & uint16_t{0xFF00}) >> 8)); #endif } -#endif // intrinsics available - #ifdef ABSL_IS_LITTLE_ENDIAN -// Definitions for ntohl etc. that don't require us to include -// netinet/in.h. We wrap gbswap_32 and gbswap_16 in functions rather -// than just #defining them because in debug mode, gcc doesn't -// correctly handle the (rather involved) definitions of bswap_32. -// gcc guarantees that inline functions are as fast as macros, so -// this isn't a performance hit. +// Portable definitions for htonl (host-to-network) and friends on little-endian +// architectures. inline uint16_t ghtons(uint16_t x) { return gbswap_16(x); } inline uint32_t ghtonl(uint32_t x) { return gbswap_32(x); } inline uint64_t ghtonll(uint64_t x) { return gbswap_64(x); } #elif defined ABSL_IS_BIG_ENDIAN -// These definitions are simpler on big-endian machines -// These are functions instead of macros to avoid self-assignment warnings -// on calls such as "i = ghtnol(i);". This also provides type checking. +// Portable definitions for htonl (host-to-network) etc on big-endian +// architectures. These definitions are simpler since the host byte order is the +// same as network byte order. inline uint16_t ghtons(uint16_t x) { return x; } inline uint32_t ghtonl(uint32_t x) { return x; } inline uint64_t ghtonll(uint64_t x) { return x; } |