intrinsics - 确定 Intel Intrinsics Guide 中列出的 CPUID

Question

在 Intel Intrinsics Guide 中，在几个 Intrinsics 的底部有“延迟和吞吐量信息”，列出了几个 CPUID 的性能。

例如，Intrinsics Guide 中的表格对于 Intrinsic _mm_hadd_pd 如下所示。 :

CPUID(s)               Parameters   Latency   Throughput
0F_03                                    13            4
06_2A                  xmm1, xmm2         5            2
06_25/2C/1A/1E/1F/2E   xmm1, xmm2         5            2
06_17/1D               xmm1, xmm2         6            1
06_0F                  xmm1, xmm2         5            2

现在:我如何确定我的 CPU 有什么 ID？

我正在使用 Kubuntu 12.04 并尝试使用 sudo dmidecode -t 4还有小程序 cpuid来自 Ubuntu 软件包，但它们的输出并不是很有用。

我在上述命令的输出中的任何地方都找不到 Intrinsics Guide 中列出的任何字符串。

Answer 1

您可以使用 CPUID 指令获取该信息，其中

The extended family, bit positions 20 through 27 are used in conjunction with the family code, specified in bit positions 8 through 11, to indicate whether the processor belongs to the Intel386, Intel486, Pentium, Pentium Pro or Pentium 4 family of processors. P6 family processors include all processors based on the Pentium Pro processor architecture and have an extended family equal to 00h and a family code equal to 06h. Pentium 4 family processors include all processors based on the Intel NetBurst® microarchitecture and have an extended family equal to 00h and a family code equal to 0Fh.

The extended model specified in bit positi ons 16 through 19, in conjunction with the model number specified in bits 4 though 7 are used to identify the model of the processor within the processor’s family.

参见 Intel Processor Identification and the CPUID Instruction 中的第 22 页了解更多详情。

实际的 CPUID 是“family_model”。
以下代码应该可以完成这项工作:

#include "stdio.h"

int main () {

  int ebx = 0, ecx = 0, edx = 0, eax = 1;
  __asm__ ("cpuid": "=b" (ebx), "=c" (ecx), "=d" (edx), "=a" (eax):"a" (eax));

  int model = (eax & 0x0FF) >> 4;
  int extended_model = (eax & 0xF0000) >> 12;
  int family_code = (eax & 0xF00) >> 8;
  int extended_family_code = (eax & 0xFF00000) >> 16;

  printf ("%x %x %x %x \n", eax, ebx, ecx, edx);
  printf ("CPUID: %02x %x\n", extended_family_code | family_code, extended_model | model);
  return 0;
}

对于我的电脑，我得到:

CPUID: 06_25

希望能帮助到你。