none/tests/s390x/cdsg.c

   1 #include <stdint.h>
   2 #include <stdio.h>
   3
   4 typedef struct {
   5    uint64_t high;
   6    uint64_t low;
   7 } __attribute__((aligned(16))) quad_word;
   8
   9
  10 /* CDSG needs quad-word alignment */
  11 quad_word _op1, _op2, _op3;
  12
  13 void
  14 test(quad_word op1_init, quad_word op2_init, quad_word op3_init,
  15      int expected_cc)
  16 {
  17    quad_word op1_before, op2_before, op3_before;
  18    int cc = 1 - expected_cc;
  19
  20    _op1 = op1_init;
  21    _op2 = op2_init;
  22    _op3 = op3_init;
  23
  24    op1_before = _op1;
  25    op2_before = _op2;
  26    op3_before = _op3;
  27
  28    printf("before op1 = (%#lx, %#lx)\n", _op1.high, _op1.low);
  29    printf("before op2 = (%#lx, %#lx)\n", _op2.high, _op2.low);
  30    printf("before op3 = (%#lx, %#lx)\n", _op3.high, _op3.low);
  31
  32    __asm__ volatile (
  33                      "lmg     %%r0,%%r1,%1\n\t"
  34                      "lmg     %%r2,%%r3,%3\n\t"
  35                      "cdsg    %%r0,%%r2,%2\n\t"  //  cdsg 1st,3rd,2nd
  36                      "stmg    %%r0,%%r1,%1\n"    // store r0,r1 to _op1
  37                      "stmg    %%r2,%%r3,%3\n"    // store r2,r3 to _op3
  38                      "ipm     %0\n\t"
  39                      "srl     %0,28\n\t"
  40                      : "=d" (cc), "+QS" (_op1), "+QS" (_op2), "+QS" (_op3)
  41                      :
  42                      : "r0", "r1", "r2", "r3", "cc");
  43
  44    printf("after  op1 = (%#lx, %#lx)\n", _op1.high, _op1.low);
  45    printf("after  op2 = (%#lx, %#lx)\n", _op2.high, _op2.low);
  46    printf("after  op3 = (%#lx, %#lx)\n", _op3.high, _op3.low);
  47    printf("cc = %d\n", cc);
  48
  49    if (cc != expected_cc) {
  50       printf("condition code is incorrect\n");
  51    }
  52
  53    // _op3 never changes
  54    if (_op3.low != op3_before.low || _op3.high != op3_before.high) {
  55       printf("operand #3 modified\n");
  56    }
  57
  58    if (expected_cc == 0) {
  59       // 3rd operand stored at 2nd operand location
  60
  61       // _op1 did not change
  62       if (_op1.low != op1_before.low || _op1.high != op1_before.high) {
  63          printf("operand #1 modified\n");
  64       }
  65       if (_op2.high != _op3.high || _op2.low != _op3.low) {
  66          printf("operand #2 incorrect\n");
  67       }
  68    } else {
  69       // 2nd operand stored at 1st operand location
  70
  71       // _op2 did not change
  72       if (_op2.low != op2_before.low || _op2.high != op2_before.high) {
  73          printf("operand #2 modified\n");
  74       }
  75
  76       if (_op1.high != _op2.high || _op1.low != _op2.low) {
  77          printf("operand #1 incorrect\n");
  78       }
  79    }
  80 }
  81
  82 int main ()
  83 {
  84    quad_word op1, op2, op3;
  85
  86    // op1 == op2
  87    op1.high = 0x0011223344556677ull;
  88    op1.low  = 0x8899aabbccddeeffull;
  89    op2 = op1;
  90    op3.high = op3.low = 0xdeadbeefdeadbabeull;
  91    test(op1, op2, op3, 0);
  92
  93    // op1 != op2 (only MSB differs)
  94    op1.high = 0x8000000000000000ull;
  95    op1.low  = 0x0000000000000000ull;
  96    op2.high = 0;
  97    op2.low  = 1;
  98    op3.high = op3.low = 0xdeadbeefdeadbabeull;
  99    test(op1, op2, op3, 1);
 100
 101    // op1 != op2 (only LSB differs)
 102    op1.high = 0x0000000000000000ull;
 103    op1.low  = 0x0000000000000001ull;
 104    op2.high = 1;
 105    op2.low  = 0;
 106    op3.high = op3.low = 0xdeadbeefdeadbabeull;
 107    test(op1, op2, op3, 1);
 108
 109    return 0;
 110 }