[thirdparty/gcc.git] / gcc / testsuite / gcc.dg / tree-ssa / ssa-thread-backedge.c

// { dg-do compile }
// { dg-options "-O2 -fdisable-tree-ethread -fdisable-tree-thread1 -fdisable-tree-thread2 -fno-tree-dominator-opts -fdump-tree-threadfull2-details" }

// Test that we can thread jumps across the backedge of a loop through
// the switch statement to a particular case.
//
// Just in case, we disable all the jump threaders before loop
// optimizations to make sure we get a clean stab at this.

int foo (unsigned int x, int s)
{
  while (s != 999)
    {
      switch (s)
	{
	case 0:
	  if (x)
	    s = 1;
	  break;
	case 1:
	  if (x)
	    s = 999;
	  break;
	default:
	  break;
	}
      x++;
    }
  return s;
}

// { dg-final { scan-tree-dump "Registering jump thread:.*normal \\(back\\)" "threadfull2" } }
Commit	Line	Data
f6d01233	1	// { dg-do compile }
4b3a325f	2	// { dg-options "-O2 -fdisable-tree-ethread -fdisable-tree-thread1 -fdisable-tree-thread2 -fno-tree-dominator-opts -fdump-tree-threadfull2-details" }
f6d01233 AH	3
	4	// Test that we can thread jumps across the backedge of a loop through
	5	// the switch statement to a particular case.
	6	//
	7	// Just in case, we disable all the jump threaders before loop
	8	// optimizations to make sure we get a clean stab at this.
	9
	10	int foo (unsigned int x, int s)
	11	{
	12	while (s != 999)
	13	{
	14	switch (s)
	15	{
	16	case 0:
	17	if (x)
	18	s = 1;
	19	break;
	20	case 1:
	21	if (x)
	22	s = 999;
	23	break;
	24	default:
	25	break;
	26	}
	27	x++;
	28	}
	29	return s;
	30	}
	31
4b3a325f	32	// { dg-final { scan-tree-dump "Registering jump thread:.*normal \\(back\\)" "threadfull2" } }