none/tests/s390x/stmg.c

   1 #include <stdio.h>
   2
   3 static const union words {
   4    char c[5 * 8];
   5    unsigned long i[5];
   6 }  base = { .c = "0123456789abcdefghijklmnopqrstuvwxyzABCD" },
   7    init = { .c = "._,-'-._,-'-._,-'-._,-'-._,-'-._,-'-._,-" };
   8
   9 static void stmg_no_wrap(void)
  10 {
  11    union words buf = init;
  12    register unsigned long a asm("5") = base.i[0];
  13    register unsigned long b asm("6") = base.i[1];
  14    register unsigned long c asm("7") = base.i[2];
  15
  16    /* No-wrap around case; copies 24 bytes from BASE to BUF */
  17    asm ("stmg %[a], %[c], %[buf]"
  18         : [buf] "=S"(buf)
  19         : [a] "d"(a), "d"(b), [c] "d"(c)
  20         : );
  21
  22    /* Write out BUF */
  23    fwrite(buf.c, sizeof(buf), 1, stdout);
  24 }
  25
  26 static void stmg_wrap(void)
  27 {
  28    union words buf = init;
  29    register unsigned long sp asm("15");
  30    register unsigned long a asm("0") = base.i[2];
  31    register unsigned long b asm("1") = base.i[3];
  32    register unsigned long c asm("2") = base.i[4];
  33
  34    /* Wrap around case: avoid changing r15, but ensure it's stored */
  35    asm ("stmg 15, %[c], %[buf]"
  36         : [buf] "=S"(buf), "=d"(sp)
  37         : "d"(a), "d"(b), [c] "d"(c)
  38         : );
  39    buf.i[0] ^= sp ^ base.i[1];
  40
  41    /* Write out BUF */
  42    fwrite(buf.c, sizeof(buf), 1, stdout);
  43 }
  44
  45
  46 int main(void)
  47 {
  48    stmg_no_wrap();
  49    putchar('\n');
  50    stmg_wrap();
  51    putchar('\n');
  52
  53    return 0;
  54 }