none/tests/amd64/bt_flags.c

   1
   2 #include <stdio.h>
   3 #include <string.h>
   4
   5 typedef  unsigned long long int  ULong;
   6 typedef  unsigned int  UInt;
   7
   8 #define CC_SHIFT_O   11
   9 #define CC_SHIFT_S   7
  10 #define CC_SHIFT_Z   6
  11 #define CC_SHIFT_A   4
  12 #define CC_SHIFT_C   0
  13 #define CC_SHIFT_P   2
  14
  15 #define CC_MASK_O    (1ULL << CC_SHIFT_O)
  16 #define CC_MASK_S    (1ULL << CC_SHIFT_S)
  17 #define CC_MASK_Z    (1ULL << CC_SHIFT_Z)
  18 #define CC_MASK_A    (1ULL << CC_SHIFT_A)
  19 #define CC_MASK_C    (1ULL << CC_SHIFT_C)
  20 #define CC_MASK_P    (1ULL << CC_SHIFT_P)
  21
  22 #define CC_MASK_OSZACP \
  23    (CC_MASK_O | CC_MASK_S | CC_MASK_Z | CC_MASK_A | CC_MASK_C | CC_MASK_P)
  24
  25
  26 void showFlags(/*OUT*/char* str, int nStr, ULong flags)
  27 {
  28    // Ignore everything except OSZACP, because V differs from real h/w in
  29    // flags other than OSZACP, and we don't want that to confuse the
  30    // results here
  31    memset(str, 0, nStr);
  32    sprintf(str, "%c%c%c%c%c%c",
  33            (flags & CC_MASK_O) ? 'o' : '-',
  34            (flags & CC_MASK_S) ? 's' : '-',
  35            (flags & CC_MASK_Z) ? 'z' : '-',
  36            (flags & CC_MASK_A) ? 'a' : '-',
  37            (flags & CC_MASK_C) ? 'c' : '-',
  38            (flags & CC_MASK_P) ? 'p' : '-');
  39 }
  40
  41 __attribute__((noinline))
  42 void do_test ( ULong val, UInt ix )
  43 {
  44   ULong o, s, z, a, c, p, flags_before;
  45   for (o = 0; o < 2; o++) {
  46   for (s = 0; s < 2; s++) {
  47   for (z = 0; z < 2; z++) {
  48   for (a = 0; a < 2; a++) {
  49   for (c = 0; c < 2; c++) {
  50   for (p = 0; p < 2; p++) {
  51     flags_before = (o ? CC_MASK_O : 0)
  52                  | (s ? CC_MASK_S : 0)
  53                  | (z ? CC_MASK_Z : 0)
  54                  | (a ? CC_MASK_A : 0)
  55                  | (c ? CC_MASK_C : 0)
  56                  | (p ? CC_MASK_P : 0);
  57     ULong block[4] = { flags_before, val, ix, 0 };
  58     __asm__ __volatile__(
  59       "movq  0(%0),  %%r15"    "\n\t" // flags_before
  60       "pushq %%r15"            "\n\t"
  61       "popfq"                  "\n\t"
  62       "movq  8(%0),  %%r14"    "\n\t" // val
  63       "movq  16(%0), %%r13"    "\n\t" // ix
  64       "bt    %%r13,  %%r14"    "\n\t"
  65       "pushfq"                 "\n\t"
  66       "popq %%r15"             "\n\t"
  67       "movq %%r15,   24(%0)"   "\n" // block[3]
  68       : : "r"(&block[0]) : "cc","memory","r13","r14","r15"
  69     );
  70     ULong flags_after = block[3];
  71     flags_after &= CC_MASK_OSZACP;
  72     char flags_after_str[100];
  73     char flags_before_str[100];
  74     showFlags(flags_before_str, 100, flags_before);
  75     showFlags(flags_after_str, 100, flags_after);
  76     printf("flags 0x%03llx(%s)  val 0x%llx  ix %d  ->  flags 0x%03llx(%s)\n",
  77            flags_before, flags_before_str, val, ix,
  78            flags_after, flags_after_str);
  79   }}}}}}
  80 }
  81
  82 int main ( void )
  83 {
  84    do_test(0x8000, 14); // should always return C == 0
  85    printf("\n");
  86    do_test(0x8000, 15); // should always return C == 1
  87    return 0;
  88 }