std::uint64_t popcnt_cpu_64bit(const uint8_t* data, const size_t n) { uint64_t result = 0; uint64_t v, i = 0; #define ITER { \ v = *reinterpret_cast<const uint64_t*>(data + i); \ result += _popcnt64(v); \ i += 8; \ } while (i + 4*8 <= n) { ITER ...
Before an application attempts to use the POPCNT instruction, it must check that the processor supports SSE4.2 (if CPUID.01H:ECX.SSE4_2[bit 20] = 1) and POPCNT (if CPUID.01H:ECX.POPCNT[bit 23] = 1). asm 可以用来在 C/C++ 代码中插入汇编指令,然后 asm 本来是 C++ 的关键字的,编译...
uint32_t cyc_high, cyc_low; \ __asm volatile("cpuid\n" \ "rdtsc\n" \ "mov %%edx, %0\n" \ "mov %%eax, %1" : \ "=r" (cyc_high), \ "=r"(cyc_low) : \ : /* no read only */ \ "%rax", "%rbx", "%rcx", "%rdx" /* clobbers */ \ ...
如何检测您的浏览器是否支持HTML5视频，看下面代码： function checkVideo() { if(!!document....
_mm_popcnt_u64可移植到非GNU编译器，__builtin_popcountll可移植到非SSE-4.2 CPU。但是在两者都...
ATOM CPU feature captures exactly // the right set of processors. __ xorps(tmp, tmp); __ pavgb(tmp, src); if (dst != src) { __ movaps(dst, src); } __ andps(tmp, __ ExternalReferenceAsOperand( ExternalReference::address_of_wasm_i8x16_splat_0x55(), scratch)); __ psubb(...
uint32_t cyc_high, cyc_low; \ __asm volatile("rdtscp\n" \ "mov %%edx, %0\n" \ "mov %%eax, %1\n" \ "cpuid" : \ "=r"(cyc_high), \ "=r"(cyc_low) : \ /* no read only registers */ : \ "%rax", "%rbx", "%rcx", "%rdx" /* clobbers ...
uint32_t cyc_high, cyc_low; \ __asm volatile("rdtscp\n" \ "mov %%edx, %0\n" \ "mov %%eax, %1\n" \ "cpuid" : \ "=r"(cyc_high), \ "=r"(cyc_low) : \ /* no read only registers */ : \ "%rax", "%rbx", "%rcx", "%rdx" /* clobbers *...
uint32_t cyc_high, cyc_low; \ __asm volatile("cpuid\n" \ "rdtsc\n" \ "mov %%edx, %0\n" \ "mov %%eax, %1" : \ "=r" (cyc_high), \ "=r"(cyc_low) : \ : /* no read only */ \ "%rax", "%rbx", "%rcx", "%rdx" /* clobbers */ \ ); \...
uint32_t cyc_high, cyc_low; \ __asm volatile("cpuid\n" \ "rdtsc\n" \ "mov %%edx, %0\n" \ "mov %%eax, %1" : \ "=r" (cyc_high), \ "=r"(cyc_low) : \ : /* no read only */ \ "%rax", "%rbx", "%rcx", "%rdx" /* clobbers */ \ );...