那些遇到过的问题

如何访问SHA内在函数？

jsj*_*jsj 5 c hash sha intrinsics

Gprof告诉我,我计算量很大的程序花费大部分时间(36%)使用AP-Hash进行散列.

我无法减少通话次数,但我仍然想让它更快,我可以从ac程序中调用内部SHA吗？

我需要intel编译器还是可以坚持使用gcc？

jww*_*jww 7

SHA指令现在可在Goldmont架构中使用.它于2016年9月左右发布.根据英特尔内在指南,这些是感兴趣的内在因素:

  • __m128i _mm_sha1msg1_epu32 (__m128i a, __m128i b)
  • __m128i _mm_sha1msg2_epu32 (__m128i a, __m128i b)
  • __m128i _mm_sha1nexte_epu32 (__m128i a, __m128i b)
  • __m128i _mm_sha1rnds4_epu32 (__m128i a, __m128i b, const int func)
  • __m128i _mm_sha256msg1_epu32 (__m128i a, __m128i b)
  • __m128i _mm_sha256msg2_epu32 (__m128i a, __m128i b)
  • __m128i _mm_sha256rnds2_epu32 (__m128i a, __m128i b, __m128i k)

GCC 5.0及更高版本使功能特定选项Pragma始终可用内在函数.但是,你需要Binutils 2.24.测试还表明Clang 3.7和3.8支持内在函数.测试还显示Visual Studio 2015可以使用它们,但VS2013无法编译它们.

您可以通过查找宏来检测Linux上预处理器中SHA的可用性__SHA__.-march=native如果它原生于处理器,它将可用.如果没有,您可以启用它-msha.

$ gcc -march=native -dM -E - </dev/null | egrep -i '(aes|rdrnd|rdseed|sha)'
#define __RDRND__ 1
#define __SHA__ 1
#define __RDSEED__ 1
#define __AES__ 1
Run Code Online (Sandbox Code Playgroud)

使用SHA1的代码如下所示.它基于英特尔的博客标题为英特尔®SHA扩展.miTLS项目提供了另一个参考实现.

以下代码基于英特尔®SHA扩展博客.该代码适用于完整的SHA1块,因此const uint32_t *data是64字节.您必须为最终块添加填充并设置位长度.

它在Celeron J3455上以大约1.7个周期的每字节(cpb)运行.我相信Andy Polyakov 的OpenSSL的 SHA1运行速度约为1.5 cpb.作为参考,优化的C/C++实现将在大约9到10 cpb的范围内运行.

static void SHA1_SHAEXT_Transform(uint32_t *state, const uint32_t *data)
{
    __m128i ABCD, ABCD_SAVE, E0, E0_SAVE, E1;
    __m128i MASK, MSG0, MSG1, MSG2, MSG3;

    // Load initial values
    ABCD = _mm_loadu_si128((__m128i*) state);
    E0 = _mm_set_epi32(state[4], 0, 0, 0);
    ABCD = _mm_shuffle_epi32(ABCD, 0x1B);
    MASK = _mm_set_epi64x(0x0001020304050607ULL, 0x08090a0b0c0d0e0fULL);

    // Save current hash
    ABCD_SAVE = ABCD;
    E0_SAVE = E0;

    // Rounds 0-3
    MSG0 = _mm_loadu_si128((__m128i*) data+0);
    MSG0 = _mm_shuffle_epi8(MSG0, MASK);
    E0 = _mm_add_epi32(E0, MSG0);
    E1 = ABCD;
    ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 0);

    // Rounds 4-7
    MSG1 = _mm_loadu_si128((__m128i*) (data+4));
    MSG1 = _mm_shuffle_epi8(MSG1, MASK);
    E1 = _mm_sha1nexte_epu32(E1, MSG1);
    E0 = ABCD;
    ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 0);
    MSG0 = _mm_sha1msg1_epu32(MSG0, MSG1);

    // Rounds 8-11
    MSG2 = _mm_loadu_si128((__m128i*) (data+8));
    MSG2 = _mm_shuffle_epi8(MSG2, MASK);
    E0 = _mm_sha1nexte_epu32(E0, MSG2);
    E1 = ABCD;
    ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 0);
    MSG1 = _mm_sha1msg1_epu32(MSG1, MSG2);
    MSG0 = _mm_xor_si128(MSG0, MSG2);

    // Rounds 12-15
    MSG3 = _mm_loadu_si128((__m128i*) (data+12));
    MSG3 = _mm_shuffle_epi8(MSG3, MASK);
    E1 = _mm_sha1nexte_epu32(E1, MSG3);
    E0 = ABCD;
    MSG0 = _mm_sha1msg2_epu32(MSG0, MSG3);
    ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 0);
    MSG2 = _mm_sha1msg1_epu32(MSG2, MSG3);
    MSG1 = _mm_xor_si128(MSG1, MSG3);

    // Rounds 16-19
    E0 = _mm_sha1nexte_epu32(E0, MSG0);
    E1 = ABCD;
    MSG1 = _mm_sha1msg2_epu32(MSG1, MSG0);
    ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 0);
    MSG3 = _mm_sha1msg1_epu32(MSG3, MSG0);
    MSG2 = _mm_xor_si128(MSG2, MSG0);

    // Rounds 20-23
    E1 = _mm_sha1nexte_epu32(E1, MSG1);
    E0 = ABCD;
    MSG2 = _mm_sha1msg2_epu32(MSG2, MSG1);
    ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 1);
    MSG0 = _mm_sha1msg1_epu32(MSG0, MSG1);
    MSG3 = _mm_xor_si128(MSG3, MSG1);

    // Rounds 24-27
    E0 = _mm_sha1nexte_epu32(E0, MSG2);
    E1 = ABCD;
    MSG3 = _mm_sha1msg2_epu32(MSG3, MSG2);
    ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 1);
    MSG1 = _mm_sha1msg1_epu32(MSG1, MSG2);
    MSG0 = _mm_xor_si128(MSG0, MSG2);

    // Rounds 28-31
    E1 = _mm_sha1nexte_epu32(E1, MSG3);
    E0 = ABCD;
    MSG0 = _mm_sha1msg2_epu32(MSG0, MSG3);
    ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 1);
    MSG2 = _mm_sha1msg1_epu32(MSG2, MSG3);
    MSG1 = _mm_xor_si128(MSG1, MSG3);

    // Rounds 32-35
    E0 = _mm_sha1nexte_epu32(E0, MSG0);
    E1 = ABCD;
    MSG1 = _mm_sha1msg2_epu32(MSG1, MSG0);
    ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 1);
    MSG3 = _mm_sha1msg1_epu32(MSG3, MSG0);
    MSG2 = _mm_xor_si128(MSG2, MSG0);

    // Rounds 36-39
    E1 = _mm_sha1nexte_epu32(E1, MSG1);
    E0 = ABCD;
    MSG2 = _mm_sha1msg2_epu32(MSG2, MSG1);
    ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 1);
    MSG0 = _mm_sha1msg1_epu32(MSG0, MSG1);
    MSG3 = _mm_xor_si128(MSG3, MSG1);

    // Rounds 40-43
    E0 = _mm_sha1nexte_epu32(E0, MSG2);
    E1 = ABCD;
    MSG3 = _mm_sha1msg2_epu32(MSG3, MSG2);
    ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 2);
    MSG1 = _mm_sha1msg1_epu32(MSG1, MSG2);
    MSG0 = _mm_xor_si128(MSG0, MSG2);

    // Rounds 44-47
    E1 = _mm_sha1nexte_epu32(E1, MSG3);
    E0 = ABCD;
    MSG0 = _mm_sha1msg2_epu32(MSG0, MSG3);
    ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 2);
    MSG2 = _mm_sha1msg1_epu32(MSG2, MSG3);
    MSG1 = _mm_xor_si128(MSG1, MSG3);

    // Rounds 48-51
    E0 = _mm_sha1nexte_epu32(E0, MSG0);
    E1 = ABCD;
    MSG1 = _mm_sha1msg2_epu32(MSG1, MSG0);
    ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 2);
    MSG3 = _mm_sha1msg1_epu32(MSG3, MSG0);
    MSG2 = _mm_xor_si128(MSG2, MSG0);

    // Rounds 52-55
    E1 = _mm_sha1nexte_epu32(E1, MSG1);
    E0 = ABCD;
    MSG2 = _mm_sha1msg2_epu32(MSG2, MSG1);
    ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 2);
    MSG0 = _mm_sha1msg1_epu32(MSG0, MSG1);
    MSG3 = _mm_xor_si128(MSG3, MSG1);

    // Rounds 56-59
    E0 = _mm_sha1nexte_epu32(E0, MSG2);
    E1 = ABCD;
    MSG3 = _mm_sha1msg2_epu32(MSG3, MSG2);
    ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 2);
    MSG1 = _mm_sha1msg1_epu32(MSG1, MSG2);
    MSG0 = _mm_xor_si128(MSG0, MSG2);

    // Rounds 60-63
    E1 = _mm_sha1nexte_epu32(E1, MSG3);
    E0 = ABCD;
    MSG0 = _mm_sha1msg2_epu32(MSG0, MSG3);
    ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 3);
    MSG2 = _mm_sha1msg1_epu32(MSG2, MSG3);
    MSG1 = _mm_xor_si128(MSG1, MSG3);

    // Rounds 64-67
    E0 = _mm_sha1nexte_epu32(E0, MSG0);
    E1 = ABCD;
    MSG1 = _mm_sha1msg2_epu32(MSG1, MSG0);
    ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 3);
    MSG3 = _mm_sha1msg1_epu32(MSG3, MSG0);
    MSG2 = _mm_xor_si128(MSG2, MSG0);

    // Rounds 68-71
    E1 = _mm_sha1nexte_epu32(E1, MSG1);
    E0 = ABCD;
    MSG2 = _mm_sha1msg2_epu32(MSG2, MSG1);
    ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 3);
    MSG3 = _mm_xor_si128(MSG3, MSG1);

    // Rounds 72-75
    E0 = _mm_sha1nexte_epu32(E0, MSG2);
    E1 = ABCD;
    MSG3 = _mm_sha1msg2_epu32(MSG3, MSG2);
    ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 3);

    // Rounds 76-79
    E1 = _mm_sha1nexte_epu32(E1, MSG3);
    E0 = ABCD;
    ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 3);

    // Add values back to state
    E0 = _mm_sha1nexte_epu32(E0, E0_SAVE);
    ABCD = _mm_add_epi32(ABCD, ABCD_SAVE);

    // Save state
    ABCD = _mm_shuffle_epi32(ABCD, 0x1B);
    _mm_storeu_si128((__m128i*) state, ABCD);
    *(state+4) = _mm_extract_epi32(E0, 3);
}
Run Code Online (Sandbox Code Playgroud)

您可以通过查找sha_ni标志来判断您的处理器是否支持Linux下的SHA扩展:

$ cat /proc/cpuinfo
processor   : 0
vendor_id   : GenuineIntel
cpu family  : 6
model       : 92
model name  : Intel(R) Celeron(R) CPU J3455 @ 1.50GHz
stepping    : 9
microcode   : 0x1a
cpu MHz     : 799.987
cache size  : 1024 KB
physical id : 0
siblings    : 4
core id     : 0
cpu cores   : 4
apicid      : 0
initial apicid  : 0
fpu     : yes
fpu_exception   : yes
cpuid level : 21
wp      : yes
flags       : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 
clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc 
art arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclm
ulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 sdbg cx16 xtpr pdcm sse4_1 sse4_2 x2apic mov
be popcnt tsc_deadline_timer aes xsave rdrand lahf_lm 3dnowprefetch intel_pt tpr_shadow vn
mi flexpriority ept vpid fsgsbase tsc_adjust smep erms mpx rdseed smap clflushopt sha_ni x
saveopt xsavec xgetbv1 xsaves dtherm ida arat pln pts
bugs        : monitor
bogomips    : 2995.20
clflush size    : 64
cache_alignment : 64
address sizes   : 39 bits physical, 48 bits virtual
power management:
...
Run Code Online (Sandbox Code Playgroud)

另请参阅x86中是否有任何加速SHA(SHA1/2/256/512)编码的指令？

您可以在Noloader GitHub上找到Intel SHA内在函数和ARMv8 SHA内在函数的源代码 SHA-Intrinsics.它们是C源文件,并为SHA-1,SHA-224和SHA-256提供压缩功能.基于内在的实现为SHA-1增加了大约3x到4x的吞吐量,为SHA-224和SHA-256增加了大约6x到12x的吞吐量.

归档时间：

查看次数：

1932 次

最近记录：

7 年，10 月 前
在x86中有加速SHA(SHA1/2/256/512)编码的任何指令吗？ 17
更多相关链接
相关归档
'int main(){return(0);上的浮点异常(SIGFPE); }" 70
如何在C预处理器中使用#if在#define中？ 46
const指针到指针在C和C++中意味着什么？ 42
向Eclipse项目添加C/C++特性 41
C中的标准数据结构库？ 17
安全密码哈希 17
从C中的变量构建字符串 16
C编译器是否重复(合并)代码？ 14
C未定义的行为.严格别名规则或错误对齐？ 13
在"abcdefgh"中搜索md5("cdef") 1
难疑归档
比较Git中的两个分支？ 2149
什么是JavaBean？ 1677
'real','user'和'sys'在time(1)的输出中意味着什么？ 1622
如何在Git中完全替换另一个分支中的master分支？ 1549
是否有快速Git命令来查看旧版本的文件？ 1438
关闭特定行的eslint规则 1214
如何从JavaScript对象中删除密钥？ 1171
迭代集合,在循环中删除对象时避免使用ConcurrentModificationException 1158
什么是Python 3相当于"python -m SimpleHTTPServer" 1124
有哪些常用的命名git分支实例的例子？ 1034