__cpuid.c

// Queries the computer for the cpuid bits and tries detailing the results.
//# vcvars32 & cl __cpuid.c
// See http://msdn.microsoft.com/en-us/library/hskdteyh(v=vs.90).aspx
// Not sure what to do for Linux.

#include <stdio.h>
#include <intrin.h>

int main(int argc, char *argv[]) {

  int cpuinfo[4];
  printf("CPU identification thing\n"
        "prints out various data the cpuid instruction returns\n" 
        "instructions marked with an asterisk (*) are Intel-only\n"
        "approximated from http://msdn.microsoft.com/en-us/library/hskdteyh(v=vs.90).aspx\n\n");
  // 
  // 0 - Ident string
  // 
  __cpuid(cpuinfo, 0);

  printf("- __cpuid(0) -\n  ident string: %c%c%c%c%c%c%c%c%c%c%c%c\n",
    
    cpuinfo[1]       &0xff, 
    cpuinfo[1] >> 8  &0xff, 
    cpuinfo[1] >> 16 &0xff, 
    cpuinfo[1] >> 24 &0xff,

    cpuinfo[3]       &0xff,
    cpuinfo[3] >> 8  &0xff,
    cpuinfo[3] >> 16 &0xff,
    cpuinfo[3] >> 24 &0xff,

    cpuinfo[2]       &0xff,
    cpuinfo[2] >> 8  &0xff,
    cpuinfo[2] >> 16 &0xff,
    cpuinfo[2] >> 24 &0xff);

  // 
  // 1 - Tons of crap
  // 
  __cpuid(cpuinfo, 1);

  // all the names here are copied off the msdn article anyway
  // ...but basically they describe the CPU in ...detail
  printf("\n- __cpuid(1) eax -\n");
  printf("  stepping id: %d\n",            cpuinfo[0]       &0xf );
  printf("  model: %d\n",                  cpuinfo[0] >> 4  &0xf );
  printf("  family: %d\n",                 cpuinfo[0] >> 8  &0xf );
  printf("* processor type: %d\n",         cpuinfo[0] >> 12 &0x3 );
  printf("  reserved bits 14-15: %d\n",    cpuinfo[0] >> 14 &0x3 );
  printf("  extended model: %d\n",         cpuinfo[0] >> 16 &0xf );
  printf("  extended family: %d\n",        cpuinfo[0] >> 20 &0xff);
  printf("  reserved bits 28-31: %d\n",    cpuinfo[0] >> 28 &0xf );

  printf("\n- __cpuid(1) ebx -\n");
  printf("  brand index: %d\n",                         cpuinfo[1]       &0xff);
  printf("  clflush cache line size: %d (quadwords)\n", cpuinfo[1] >> 8  &0xff);
  printf("  logical processors: %d\n",                  cpuinfo[1] >> 16 &0xff);
  printf("  initial apic id: %d\n",                     cpuinfo[1] >> 24 &0xff); 

  printf("\n- __cpuid(1) ecx -\n");
  printf("  SSE3 instructions: %d\n", cpuinfo[2]  &1);
  printf("  reserved 1-2: %d\n", cpuinfo[2] >> 1  &3);
  printf("  monitor/mwait: %d\n", cpuinfo[2] >> 3 &1);
  printf("* cpl qualified debug store: %d\n", cpuinfo[2] >> 4 &1);
  printf("* virtual machine extensions: %d\n", cpuinfo[2] >> 5 &1);
  printf("* safer-mode extensions: %d\n", cpuinfo[2] >> 6 &1);
  printf("* enhanced intel speedstep extensions: %d\n", cpuinfo[2] >> 7 &1);
  printf("* thermal monitor: %d\n", cpuinfo[2] >> 8 &1); 
  printf("  supplemental SSE3: %d\n", cpuinfo[2] >> 9 &1);
  printf("* L1 context id: %d\n", cpuinfo[2] >> 10 &1);  
  printf("  reserved bit 11: %d\n", cpuinfo[2] >> 11 &1);
  printf("* 256-bit fma extensions: %d\n", cpuinfo[2] >> 12 &1);
  printf("  CMPXCHG16B (compare-exchange-16bytes) support: %d\n", cpuinfo[2] >> 13 &1);
  printf("  xTPR update control: %d\n", cpuinfo[2] >> 14 &1); 
  printf("  performance/debug capability MSR: %d\n", cpuinfo[2] >> 15 &1);
  printf("  reserved bits 16-17: %d\n", cpuinfo[2] >> 16 &3); 
  printf("* direct cache access (DCA): %d\n", cpuinfo[2] >> 18 &1); 
  printf("  SSE 4.1 extensions: %d\n", cpuinfo[2] >> 19 &1); 
  printf("  SSE 4.2 extensions: %d\n", cpuinfo[2] >> 20 &1); 
  printf("* x2APIC support: %d\n", cpuinfo[2] >> 21 &1);
  printf("* MOVBE instruction support: %d\n", cpuinfo[2] >> 22 &1); 
  printf("  POPCNT instruction support: %d\n", cpuinfo[2] >> 23 &1);
  printf("  reserved bit 24: %d\n", cpuinfo[2] >> 24 &1);
  printf("* AES instruction support: %d\n", cpuinfo[2] >> 25 &1);
  printf("* XSAVE instruction support: %d\n", cpuinfo[2] >> 26&1);
  printf("* OSXSAVE instruction support: %d\n", cpuinfo[2] >> 27 &1);
  printf("* 256bit advanced vector extensions: %d\n", cpuinfo[2] >> 28 &1);
  printf("  reserved bits 29-31: %d\n", cpuinfo[2] >> 29 &0xf);

  printf("\n- __cpuid(1) edx -\n");
  printf("  FPU - x87 FPU on chip: %d\n", cpuinfo[3] >> 0 &1);
  printf("  VME - Virtual-8086 mode enhancement: %d\n", cpuinfo[3] >> 1 &1);
  printf("  DE - Debugging extensions: %d\n", cpuinfo[3] >> 2 &1);
  printf("  PSE - Page size extensions: %d\n", cpuinfo[3] >> 3 &1);
  printf("  TSC - Time stamp counter: %d\n", cpuinfo[3] >> 4 &1);
  printf("  MSR - RDMSR and WRMSR support: %d\n", cpuinfo[3] >> 5 &1);
  printf("  PAE - Physical address extensions: %d\n", cpuinfo[3] >> 6 &1);
  printf("  MCE - Machine check exception: %d\n", cpuinfo[3] >> 7 &1);
  printf("  CX8 - CMPXCHG8B instruction: %d\n", cpuinfo[3] >> 8 &1);
  printf("  APIC - APIC on chip: %d\n", cpuinfo[3] >> 9 &1);
  printf("  n/a - Reserved: %d\n", cpuinfo[3] >> 10 &1);
  printf("  SEP - SYSENTER and SYSEXIT: %d\n", cpuinfo[3] >> 11 &1);
  printf("  MTRR - Memory type range registers: %d\n", cpuinfo[3] >> 12 &1);
  printf("  PGE - PTE global bit: %d\n", cpuinfo[3] >> 13 &1);
  printf("  MCA - Machine check architecture: %d\n", cpuinfo[3] >> 14 &1);
  printf("  CMOV - Conditional move/compare instruction: %d\n", cpuinfo[3] >> 15 &1);
  printf("  PAT - Page Attribute Table: %d\n", cpuinfo[3] >> 16 &1);
  printf("  PSE-36 - 36-bit page size extension: %d\n", cpuinfo[3] >> 17 &1);
  printf("  PSN - Processor serial number: %d\n", cpuinfo[3] >> 18 &1);
  printf("  CLFSH - CFLUSH instruction: %d\n", cpuinfo[3] >> 19 &1);
  printf("  n -/a Reserved: %d\n", cpuinfo[3] >> 20 &1);
  printf("  DS - Debug store: %d\n", cpuinfo[3] >> 21 &1);
  printf("  ACPI - Thermal monitor and clock control: %d\n", cpuinfo[3] >> 22 &1);
  printf("  MMX - MMX technology: %d\n", cpuinfo[3] >> 23 &1);
  printf("  FXSR - FXSAVE/FXRSTOR: %d\n", cpuinfo[3] >> 24 &1);
  printf("  SSE - SSE extensions: %d\n", cpuinfo[3] >> 25 &1);
  printf("  SSE2 - SSE2 extensions: %d\n", cpuinfo[3] >> 26 &1);
  printf("  SS - Self snoop: %d\n", cpuinfo[3] >> 27 &1);
  printf("  HTT - Multithreading: %d\n", cpuinfo[3] >> 28 &1);
  printf("  TM - Thermal monitor: %d\n", cpuinfo[3] >> 29 &1);
  printf("  n/a - Reserved: %d\n", cpuinfo[3] >> 30 &1);
  printf("  PBE - Pending break enable: %d\n", cpuinfo[3] >> 31 &1);

  //
  // 2 - 
}