VEX/test/frstor.c

   1
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4
   5 void do_fsave_interesting_stuff ( void* p )
   6 {
   7    asm __volatile__("fninit");
   8    asm __volatile__("fldpi");
   9    asm __volatile__("fld1");
  10    asm __volatile__("fldln2");
  11    asm __volatile__("fsave (%0)" : : "r" (p) : "memory" );
  12 }
  13
  14 void do_fsave ( void* p )
  15 {
  16    asm __volatile__("fsave (%0)" : : "r" (p) : "memory" );
  17 }
  18
  19 void do_frstor ( void* p )
  20 {
  21    asm __volatile__("frstor (%0)" : : "r" (p) : "memory" );
  22 }
  23
  24
  25 int isFPLsbs ( int i )
  26 {
  27    int q;
  28    q = 0; if (i == q || i == q+1) return 1;
  29    q = 10; if (i == q || i == q+1) return 1;
  30    q = 20; if (i == q || i == q+1) return 1;
  31    q = 30; if (i == q || i == q+1) return 1;
  32    q = 40; if (i == q || i == q+1) return 1;
  33    q = 50; if (i == q || i == q+1) return 1;
  34    q = 60; if (i == q || i == q+1) return 1;
  35    q = 70; if (i == q || i == q+1) return 1;
  36    return 0;
  37 }
  38
  39 void show_fpustate ( unsigned char* buf, int hide64to80 )
  40 {
  41    int i;
  42    printf("  0   ");
  43    for (i = 0; i < 14; i++)
  44       printf("%02x ", buf[i]);
  45    printf("\n");
  46
  47    printf(" 14   ");
  48    for (i = 14; i < 28; i++)
  49       printf("%02x ", buf[i]);
  50    printf("\n");
  51
  52    for (i = 0; i < 80; i++) {
  53       if ((i % 10) == 0)
  54          printf("%3d   ", i+28);
  55       if (hide64to80 && isFPLsbs(i))
  56          printf("xx ");
  57       else
  58          printf("%02x ", buf[i+28]);
  59       if (i > 0 && ((i % 10) == 9))
  60           printf("\n");
  61    }
  62 }
  63
  64 int main ( int argc, char** argv )
  65 {
  66    unsigned short* buf1 = malloc(54*sizeof(short));
  67    unsigned short* buf2 = malloc(54*sizeof(short));
  68    int xx = argc > 1;
  69    printf("Re-run with any arg to suppress least-significant\n"
  70           "   16 bits of FP numbers\n");
  71
  72    /* Create an initial image. */
  73    do_fsave_interesting_stuff(buf1);
  74    show_fpustate( (unsigned char*)buf1, xx );
  75
  76    /* Reload it into buf2. */
  77    do_frstor(buf1);
  78    do_fsave(buf2);
  79    show_fpustate( (unsigned char*)buf2, xx );
  80
  81    return 0;
  82 }