gcc/testsuite/gcc.dg/hoist-register-pressure-1.c

   1 /* { dg-options "-Os -fdump-rtl-hoist" }  */
   2 /* The rtl hoist pass requires that the expression to be hoisted can
   3    be assigned without clobbering cc.  For a PLUS rtx on S/390 this
   4    requires a load address instruction which is fine on 64 bit but
   5    cannot be used on 31 bit since it does a 31 bit add only.  */
   6 /* { dg-final { scan-rtl-dump "PRE/HOIST: end of bb .* copying expression" "hoist" { target { { ! s390-*-* } && nonpic } } } } */
   7 /* { dg-final { cleanup-rtl-dump "hoist" } } */
   8
   9 #define BUF 100
  10 long a[BUF];
  11
  12 void com (long);
  13 void bar (long);
  14
  15 long foo (long x, long y, long z)
  16 {
  17   /* "x+y" won't be hoisted if "-fira-hoist-pressure" is disabled,
  18      because its rtx_cost is too small.  */
  19   if (z)
  20     {
  21       a[1] = a[0] + a[2];
  22       a[2] = a[1] + a[3];
  23       a[3] = a[2] + a[4];
  24       a[4] = a[3] + a[5];
  25       a[5] = a[4] + a[6];
  26       a[6] = a[5] + a[7];
  27       a[7] = a[6] + a[8];
  28       com (x+y);
  29     }
  30   else
  31     {
  32       bar (x+y);
  33     }
  34
  35   return 0;
  36 }