cpu_mode_ppc.c

来自「FEC Optimized viterbi code」· C语言 代码 · 共 41 行

/* Determine CPU support for SIMD on Power PC
 * Copyright 2004 Phil Karn, KA9Q
 */
#include <stdio.h>
#include "fec.h"
#ifdef __VEC__
#include <sys/sysctl.h>
#endif

/* Various SIMD instruction set names */
char *Cpu_modes[] = {"Unknown","Portable C","x86 Multi Media Extensions (MMX)",
		   "x86 Streaming SIMD Extensions (SSE)",
		   "x86 Streaming SIMD Extensions 2 (SSE2)",
		   "PowerPC G4/G5 Altivec/Velocity Engine"};

enum cpu_mode Cpu_mode;

void find_cpu_mode(void){

  if(Cpu_mode != UNKNOWN)
    return;

#ifdef __VEC__
  {
  /* Ask the OS if we have Altivec support */
  int selectors[2] = { CTL_HW, HW_VECTORUNIT };
  int hasVectorUnit = 0;
  size_t length = sizeof(hasVectorUnit);
  int error = sysctl(selectors, 2, &hasVectorUnit, &length, NULL, 0);
  if(0 == error && hasVectorUnit)
    Cpu_mode = ALTIVEC;
  else
    Cpu_mode = PORT;
  }
#else
  Cpu_mode = PORT;
#endif

  fprintf(stderr,"SIMD CPU detect: %s\n",Cpu_modes[Cpu_mode]);
}