1 /* { dg-do link } */
2 /* { dg-require-effective-target sync_int_128_runtime } */
3 /* { dg-options "-mcx16" { target { x86_64-*-* i?86-*-* } } } */
4 /* { dg-final { simulate-thread } } */
5
6 #include <stdio.h>
7 #include "simulate-thread.h"
8
9
10 /* Testing load for atomicity is a little trickier.
11
12 Set up the atomic value so that it changes value after every instruction
13 is executed.
14
15 Simply alternating between 2 values wouldn't be sufficient since a load of
16 one part, followed by the load of the second part 2 instructions later would
17 appear to be valid.
18
19 set up a table of 16 values which change a bit in every byte of the value
20 each time, this will give us a 16 instruction cycle before repetition
21 kicks in, which should be sufficient to detect any issues. Just to be sure,
22 we also change the table cycle size during execution.
23
24 The end result is that all loads should always get one of the values from
25 the table. Any other pattern means the load failed. */
26
27 __int128_t ret;
28 __int128_t value = 0;
29 __int128_t result = 0;
30 __int128_t table[16] = {
31 0x0000000000000000,
32 0x1111111111111111,
33 0x2222222222222222,
34 0x3333333333333333,
35 0x4444444444444444,
36 0x5555555555555555,
37 0x6666666666666666,
38 0x7777777777777777,
39 0x8888888888888888,
40 0x9999999999999999,
41 0xAAAAAAAAAAAAAAAA,
42 0xBBBBBBBBBBBBBBBB,
43 0xCCCCCCCCCCCCCCCC,
44 0xDDDDDDDDDDDDDDDD,
45 0xEEEEEEEEEEEEEEEE,
46 0xFFFFFFFFFFFFFFFF
47 };
48
49 int table_cycle_size = 16;
50
51 /* Since we don't have 128 bit constants, we have to properly pad the table. */
fill_table()52 void fill_table()
53 {
54 int x;
55 for (x = 0; x < 16; x++)
56 {
57 ret = table[x];
58 ret = (ret << 64) | ret;
59 table[x] = ret;
60 }
61 }
62
63 /* Return 0 if 'result' is a valid value to have loaded. */
verify_result()64 int verify_result ()
65 {
66 int x;
67 int found = 0;
68
69 /* Check entire table for valid values. */
70 for (x = 0; x < 16; x++)
71 if (result == table[x])
72 {
73 found = 1;
74 break;
75 }
76
77 if (!found)
78 printf("FAIL: Invalid result returned from fetch\n");
79
80 return !found;
81 }
82
83 /* Iterate VALUE through the different valid values. */
simulate_thread_other_threads()84 void simulate_thread_other_threads ()
85 {
86 static int current = 0;
87
88 if (++current >= table_cycle_size)
89 current = 0;
90 value = table[current];
91 }
92
simulate_thread_step_verify()93 int simulate_thread_step_verify ()
94 {
95 return verify_result ();
96 }
97
simulate_thread_final_verify()98 int simulate_thread_final_verify ()
99 {
100 return verify_result ();
101 }
102
103 __attribute__((noinline))
simulate_thread_main()104 void simulate_thread_main()
105 {
106 int x;
107
108 /* Execute loads with value changing at various cyclic values. */
109 for (table_cycle_size = 16; table_cycle_size > 4 ; table_cycle_size--)
110 {
111 ret = __atomic_load_n (&value, __ATOMIC_SEQ_CST);
112 /* In order to verify the returned value (which is not atomic), it needs
113 to be atomically stored into another variable and check that. */
114 __atomic_store_n (&result, ret, __ATOMIC_SEQ_CST);
115
116 /* Execute the fetch/store a couple of times just to ensure the cycles
117 have a chance to be interesting. */
118 ret = __atomic_load_n (&value, __ATOMIC_SEQ_CST);
119 __atomic_store_n (&result, ret, __ATOMIC_SEQ_CST);
120 }
121 }
122
123 int
main()124 main()
125 {
126 fill_table ();
127
128 /* Make sure value starts with an atomic value from the table. */
129 __atomic_store_n (&value, table[0], __ATOMIC_SEQ_CST);
130
131 simulate_thread_main ();
132 simulate_thread_done ();
133 return 0;
134 }
135