gcc/testsuite/gcc.dg/combine-subregs.c

   1 /* { dg-do run { target { stdint_types } } } */
   2 /* { dg-options "-O2" } */
   3
   4 #include <stdint.h>
   5 #include <stdlib.h>
   6
   7 void __attribute__ ((noinline))
   8 foo (uint64_t state, uint32_t last)
   9 {
  10   if (state == last) abort ();
  11 }
  12
  13 /* This function may do a bad comparision by trying to
  14    use SUBREGS during the compare on machines where comparing
  15    two registers always compares the entire register regardless
  16    of mode.  */
  17
  18 int __attribute__ ((noinline))
  19 compare (uint64_t state, uint32_t *last, uint8_t buf)
  20 {
  21     if (*last == ((state | buf) & 0xFFFFFFFF)) {
  22         foo (state, *last);
  23         return 0;
  24     }
  25     return 1;
  26 }
  27
  28 int
  29 main(int argc, char **argv) {
  30     uint64_t state = 0xF00000100U;
  31     uint32_t last  = 0x101U;
  32     int ret        = compare(state, &last, 0x01);
  33     if (ret != 0)
  34         abort ();
  35     exit (0);
  36 }