none/tests/s390x/srnmb.c

   1 #include <assert.h>
   2 #include <stdlib.h>
   3 #include <stdio.h>
   4 #include "opcodes.h"
   5
   6 #define srnmb(b,d) \
   7    ({ \
   8       __asm__ volatile ( "lghi 8," #b "\n\t" \
   9                          SRNMB(8,d) \
  10                          ::: "8"); \
  11    })
  12
  13
  14 /* Like srnm above, except it uses r0 as a base register */
  15 #define srnmb0(d) \
  16    ({ \
  17       __asm__ volatile ( SRNMB(0,d) \
  18                          ::: "0"); \
  19    })
  20
  21 #define get_rounding_mode() \
  22    ({ \
  23       unsigned fpc; \
  24       __asm__ volatile ("stfpc  %0" : "=Q"(fpc)); \
  25       fpc & 0x7; \
  26    })
  27
  28 int main(void)
  29 {
  30    printf("initial rounding mode = %u\n", get_rounding_mode());
  31
  32    /* Set basic rounding modes in various ways */
  33    srnmb(1,002);  // 1 + 2 = 3
  34    printf("rounding mode = %u\n", get_rounding_mode());
  35
  36    srnmb(2,000);
  37    printf("rounding mode = %u\n", get_rounding_mode());
  38
  39    srnmb(0,001);
  40    printf("rounding mode = %u\n", get_rounding_mode());
  41
  42    srnmb(0,000);
  43    printf("rounding mode = %u\n", get_rounding_mode());
  44
  45 #if 0
  46    // fpext
  47    srnmb(7,000);  // -> 7
  48    printf("rounding mode = %u\n", get_rounding_mode());
  49
  50    srnmb(0,000);  // -> 0
  51    printf("rounding mode = %u\n", get_rounding_mode());
  52
  53    srnmb(0,007);  // -> 7
  54    printf("rounding mode = %u\n", get_rounding_mode());
  55 #endif
  56
  57    srnmb(0,001);
  58    printf("rounding mode = %u\n", get_rounding_mode());
  59
  60    srnmb0(004);    // -> emul warning invalid rounding mode
  61    printf("rounding mode = %u\n", get_rounding_mode());
  62
  63    return 0;
  64 }