gcc/testsuite/gcc.dg/torture/pr33848.c

   1 /* &&foo should be hoisted, but on most targets, excess register pressure
   2    forces it to be rematerialized before "data != &&foo".  On targets that
   3    have a "branch if registers are equal" instruction, this leads to the
   4    branch having two LABEL_REFs: one for the branch target and one for
   5    &&foo.  When reloading &&foo into a register, reload would wrongly
   6    say that &&foo was the target of the branch, and the real target would
   7    then be removed as dead.  */
   8 /* { dg-do link } */
   9 #define NVARS 30
  10 #define MULTI(X) \
  11   X( 0), X( 1), X( 2), X( 3), X( 4), X( 5), X( 6), X( 7), X( 8), X( 9), \
  12   X(10), X(11), X(12), X(13), X(14), X(15), X(16), X(17), X(18), X(19), \
  13   X(20), X(21), X(22), X(23), X(24), X(25), X(26), X(27), X(28), X(29)
  14
  15 #define DECLARE(INDEX) i##INDEX = gv[INDEX]
  16 #define COPY(INDEX) gv[INDEX] = i##INDEX
  17
  18 volatile int gv[NVARS];
  19 void *volatile data;
  20
  21 int
  22 main (void)
  23 {
  24   __label__ foo;
  25
  26   if (gv[0] == 1)
  27     goto foo;
  28   data = &&foo;
  29   do
  30     {
  31       int MULTI (DECLARE);
  32       MULTI (COPY);
  33       MULTI (COPY);
  34       MULTI (COPY);
  35       if (data != &&foo)
  36         gv[0] = 1;
  37       else
  38         gv[1] = 2;
  39     }
  40   while (gv[0] > 0);
  41  foo:
  42   return 0;
  43 }