cdsg.c revision 663860b1408516d02ebfcb3a9999a134e6cfb223 
1#include <stdint.h>
2#include <stdio.h>
3
4typedef struct {
5   uint64_t high;
6   uint64_t low;
7} __attribute__((aligned(16))) quad_word;
8
9
10/* CDSG needs quad-word alignment */
11quad_word _op1, _op2, _op3;
12
13void
14test(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
82int 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}
111