diff options
Diffstat (limited to 'src/third-party/base64/lib/codec_choose.c')
| -rw-r--r-- | src/third-party/base64/lib/codec_choose.c | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/src/third-party/base64/lib/codec_choose.c b/src/third-party/base64/lib/codec_choose.c new file mode 100644 index 0000000..6a07d6a --- /dev/null +++ b/src/third-party/base64/lib/codec_choose.c @@ -0,0 +1,281 @@ +#include <stdbool.h> +#include <stdint.h> +#include <stddef.h> +#include <stdint.h> + +#include "../include/libbase64.h" +#include "codecs.h" +#include "config.h" +#include "env.h" + +#if (__x86_64__ || __i386__ || _M_X86 || _M_X64) + #define BASE64_X86 + #if (HAVE_SSSE3 || HAVE_SSE41 || HAVE_SSE42 || HAVE_AVX || HAVE_AVX2) + #define BASE64_X86_SIMD + #endif +#endif + +#ifdef BASE64_X86 +#ifdef _MSC_VER + #include <intrin.h> + #define __cpuid_count(__level, __count, __eax, __ebx, __ecx, __edx) \ + { \ + int info[4]; \ + __cpuidex(info, __level, __count); \ + __eax = info[0]; \ + __ebx = info[1]; \ + __ecx = info[2]; \ + __edx = info[3]; \ + } + #define __cpuid(__level, __eax, __ebx, __ecx, __edx) \ + __cpuid_count(__level, 0, __eax, __ebx, __ecx, __edx) +#else + #include <cpuid.h> + #if HAVE_AVX2 || HAVE_AVX + #if ((__GNUC__ > 4 || __GNUC__ == 4 && __GNUC_MINOR__ >= 2) || (__clang_major__ >= 3)) + static inline uint64_t _xgetbv (uint32_t index) + { + uint32_t eax, edx; + __asm__ __volatile__("xgetbv" : "=a"(eax), "=d"(edx) : "c"(index)); + return ((uint64_t)edx << 32) | eax; + } + #else + #error "Platform not supported" + #endif + #endif +#endif + +#ifndef bit_AVX2 +#define bit_AVX2 (1 << 5) +#endif +#ifndef bit_SSSE3 +#define bit_SSSE3 (1 << 9) +#endif +#ifndef bit_SSE41 +#define bit_SSE41 (1 << 19) +#endif +#ifndef bit_SSE42 +#define bit_SSE42 (1 << 20) +#endif +#ifndef bit_AVX +#define bit_AVX (1 << 28) +#endif + +#define bit_XSAVE_XRSTORE (1 << 27) + +#ifndef _XCR_XFEATURE_ENABLED_MASK +#define _XCR_XFEATURE_ENABLED_MASK 0 +#endif + +#define _XCR_XMM_AND_YMM_STATE_ENABLED_BY_OS 0x6 +#endif + +// Function declarations: +#define BASE64_CODEC_FUNCS(arch) \ + BASE64_ENC_FUNCTION(arch); \ + BASE64_DEC_FUNCTION(arch); \ + +BASE64_CODEC_FUNCS(avx2) +BASE64_CODEC_FUNCS(neon32) +BASE64_CODEC_FUNCS(neon64) +BASE64_CODEC_FUNCS(plain) +BASE64_CODEC_FUNCS(ssse3) +BASE64_CODEC_FUNCS(sse41) +BASE64_CODEC_FUNCS(sse42) +BASE64_CODEC_FUNCS(avx) + +static bool +codec_choose_forced (struct codec *codec, int flags) +{ + // If the user wants to use a certain codec, + // always allow it, even if the codec is a no-op. + // For testing purposes. + + if (!(flags & 0xFF)) { + return false; + } + if (flags & BASE64_FORCE_AVX2) { + codec->enc = base64_stream_encode_avx2; + codec->dec = base64_stream_decode_avx2; + return true; + } + if (flags & BASE64_FORCE_NEON32) { + codec->enc = base64_stream_encode_neon32; + codec->dec = base64_stream_decode_neon32; + return true; + } + if (flags & BASE64_FORCE_NEON64) { + codec->enc = base64_stream_encode_neon64; + codec->dec = base64_stream_decode_neon64; + return true; + } + if (flags & BASE64_FORCE_PLAIN) { + codec->enc = base64_stream_encode_plain; + codec->dec = base64_stream_decode_plain; + return true; + } + if (flags & BASE64_FORCE_SSSE3) { + codec->enc = base64_stream_encode_ssse3; + codec->dec = base64_stream_decode_ssse3; + return true; + } + if (flags & BASE64_FORCE_SSE41) { + codec->enc = base64_stream_encode_sse41; + codec->dec = base64_stream_decode_sse41; + return true; + } + if (flags & BASE64_FORCE_SSE42) { + codec->enc = base64_stream_encode_sse42; + codec->dec = base64_stream_decode_sse42; + return true; + } + if (flags & BASE64_FORCE_AVX) { + codec->enc = base64_stream_encode_avx; + codec->dec = base64_stream_decode_avx; + return true; + } + return false; +} + +static bool +codec_choose_arm (struct codec *codec) +{ +#if (defined(__ARM_NEON__) || defined(__ARM_NEON)) && ((defined(__aarch64__) && HAVE_NEON64) || HAVE_NEON32) + + // Unfortunately there is no portable way to check for NEON + // support at runtime from userland in the same way that x86 + // has cpuid, so just stick to the compile-time configuration: + + #if defined(__aarch64__) && HAVE_NEON64 + codec->enc = base64_stream_encode_neon64; + codec->dec = base64_stream_decode_neon64; + #else + codec->enc = base64_stream_encode_neon32; + codec->dec = base64_stream_decode_neon32; + #endif + + return true; + +#else + (void)codec; + return false; +#endif +} + +static bool +codec_choose_x86 (struct codec *codec) +{ +#ifdef BASE64_X86_SIMD + + unsigned int eax, ebx = 0, ecx = 0, edx; + unsigned int max_level; + + #ifdef _MSC_VER + int info[4]; + __cpuidex(info, 0, 0); + max_level = info[0]; + #else + max_level = __get_cpuid_max(0, NULL); + #endif + + #if HAVE_AVX2 || HAVE_AVX + // Check for AVX/AVX2 support: + // Checking for AVX requires 3 things: + // 1) CPUID indicates that the OS uses XSAVE and XRSTORE instructions + // (allowing saving YMM registers on context switch) + // 2) CPUID indicates support for AVX + // 3) XGETBV indicates the AVX registers will be saved and restored on + // context switch + // + // Note that XGETBV is only available on 686 or later CPUs, so the + // instruction needs to be conditionally run. + if (max_level >= 1) { + __cpuid_count(1, 0, eax, ebx, ecx, edx); + if (ecx & bit_XSAVE_XRSTORE) { + uint64_t xcr_mask; + xcr_mask = _xgetbv(_XCR_XFEATURE_ENABLED_MASK); + if (xcr_mask & _XCR_XMM_AND_YMM_STATE_ENABLED_BY_OS) { + #if HAVE_AVX2 + if (max_level >= 7) { + __cpuid_count(7, 0, eax, ebx, ecx, edx); + if (ebx & bit_AVX2) { + codec->enc = base64_stream_encode_avx2; + codec->dec = base64_stream_decode_avx2; + return true; + } + } + #endif + #if HAVE_AVX + __cpuid_count(1, 0, eax, ebx, ecx, edx); + if (ecx & bit_AVX) { + codec->enc = base64_stream_encode_avx; + codec->dec = base64_stream_decode_avx; + return true; + } + #endif + } + } + } + #endif + + #if HAVE_SSE42 + // Check for SSE42 support: + if (max_level >= 1) { + __cpuid(1, eax, ebx, ecx, edx); + if (ecx & bit_SSE42) { + codec->enc = base64_stream_encode_sse42; + codec->dec = base64_stream_decode_sse42; + return true; + } + } + #endif + + #if HAVE_SSE41 + // Check for SSE41 support: + if (max_level >= 1) { + __cpuid(1, eax, ebx, ecx, edx); + if (ecx & bit_SSE41) { + codec->enc = base64_stream_encode_sse41; + codec->dec = base64_stream_decode_sse41; + return true; + } + } + #endif + + #if HAVE_SSSE3 + // Check for SSSE3 support: + if (max_level >= 1) { + __cpuid(1, eax, ebx, ecx, edx); + if (ecx & bit_SSSE3) { + codec->enc = base64_stream_encode_ssse3; + codec->dec = base64_stream_decode_ssse3; + return true; + } + } + #endif + +#else + (void)codec; +#endif + + return false; +} + +void +codec_choose (struct codec *codec, int flags) +{ + // User forced a codec: + if (codec_choose_forced(codec, flags)) { + return; + } + + // Runtime feature detection: + if (codec_choose_arm(codec)) { + return; + } + if (codec_choose_x86(codec)) { + return; + } + codec->enc = base64_stream_encode_plain; + codec->dec = base64_stream_decode_plain; +} |