Check in patch/merge from cxx-mem-model Branch

From-SVN: r181031

1 files changed, 132 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.dg/simulate-thread/atomic-load-int128.c b/gcc/testsuite/gcc.dg/simulate-thread/atomic-load-int128.c
new file mode 100644
index 0000000..3ade0d6
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/simulate-thread/atomic-load-int128.c
@@ -0,0 +1,132 @@
+/* { dg-do link } */
+/* { dg-require-effective-target sync_int_128 } */
+/* { dg-options "-mcx16" { target { x86_64-*-* i?86-*-* } } } */
+/* { dg-final { simulate-thread } } */
+
+#include <stdio.h>
+#include "simulate-thread.h"
+
+
+/* Testing load for atomicity is a little trickier.  
+
+   Set up the atomic value so that it changes value after every instruction 
+   is executed.
+
+   Simply alternating between 2 values wouldn't be sufficient since a load of
+   one part, followed by the load of the second part 2 instructions later would
+   appear to be valid.
+
+   set up a table of 16 values which change a bit in every byte of the value 
+   each time, this will give us a 16 instruction cycle before repetition
+   kicks in, which should be sufficient to detect any issues.  Just to be sure,
+   we also change the table cycle size during execution. 
+   
+   The end result is that all loads should always get one of the values from
+   the table. Any other pattern means the load failed.  */
+
+__int128_t ret;
+__int128_t value = 0;
+__int128_t result = 0;
+__int128_t table[16] = {
+0x0000000000000000, 
+0x1111111111111111, 
+0x2222222222222222, 
+0x3333333333333333,
+0x4444444444444444,
+0x5555555555555555,
+0x6666666666666666,
+0x7777777777777777,
+0x8888888888888888,
+0x9999999999999999,
+0xAAAAAAAAAAAAAAAA,
+0xBBBBBBBBBBBBBBBB,
+0xCCCCCCCCCCCCCCCC,
+0xDDDDDDDDDDDDDDDD,
+0xEEEEEEEEEEEEEEEE,
+0xFFFFFFFFFFFFFFFF
+};
+
+int table_cycle_size = 16;
+
+/* Since we don't have 128 bit constants, we have to properly pad the table.  */
+void fill_table()
+{
+  int x;
+  for (x = 0; x < 16; x++)
+    {
+      ret = table[x];
+      ret = (ret << 64) | ret;
+      table[x] = ret;
+    }
+}
+
+/* Return 0 if 'result' is a valid value to have loaded.  */
+int verify_result ()
+{
+  int x;
+  int found = 0;
+
+  /* Check entire table for valid values.  */
+  for (x = 0; x < 16; x++)
+    if (result == table[x])
+      {
+	found = 1;
+	break;
+      }
+
+  if (!found)
+    printf("FAIL: Invalid result returned from fetch\n");
+
+  return !found;
+}
+
+/* Iterate VALUE through the different valid values. */
+void simulate_thread_other_threads ()
+{
+  static int current = 0;
+
+  if (++current >= table_cycle_size)
+    current = 0;
+  value = table[current];
+}
+
+int simulate_thread_step_verify ()
+{
+  return verify_result ();
+}
+
+int simulate_thread_final_verify ()
+{
+  return verify_result ();
+}
+
+__attribute__((noinline))
+void simulate_thread_main()
+{
+  int x;
+
+  /* Make sure value starts with an atomic value now.  */
+  __atomic_store_n (&value, ret, __ATOMIC_SEQ_CST);
+
+  /* Execute loads with value changing at various cyclic values.  */
+  for (table_cycle_size = 16; table_cycle_size > 4 ; table_cycle_size--)
+    {
+      ret = __atomic_load_n (&value, __ATOMIC_SEQ_CST);
+      /* In order to verify the returned value (which is not atomic), it needs
+	 to be atomically stored into another variable and check that.  */
+      __atomic_store_n (&result, ret, __ATOMIC_SEQ_CST);
+
+      /* Execute the fetch/store a couple of times just to ensure the cycles
+         have a chance to be interesting.  */
+      ret = __atomic_load_n (&value, __ATOMIC_SEQ_CST);
+      __atomic_store_n (&result, ret, __ATOMIC_SEQ_CST);
+    }
+}
+
+main()
+{
+  fill_table ();
+  simulate_thread_main ();
+  simulate_thread_done ();
+  return 0;
+}