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#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;
}
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