none/tests/s390x/rounding-5.c

   1 #include <stdio.h>
   2 #include <assert.h>
   3 #include <stdint.h>
   4 #include <inttypes.h>
   5 #include "opcodes.h"
   6
   7 /* Test "convert from fixed" with universally available rounding modes.
   8    Rounding mode is provided via FPC. */
   9
  10 volatile int32_t i32;
  11 volatile int64_t i64;
  12
  13 const char *
  14 rtext(unsigned fpc_round)
  15 {
  16    switch (fpc_round) {
  17    case 0: return "[-> near]";
  18    case 1: return "[-> zero]";
  19    case 2: return "[-> +inf]";
  20    case 3: return "[-> -inf]";
  21    }
  22    assert(0);
  23 }
  24
  25 void
  26 set_rounding_mode(unsigned mode)
  27 {
  28    printf("setting FPC rounding mode to %s\n", rtext(mode));
  29    register unsigned r asm("1") = mode;
  30    __asm__ volatile ( SFPC(1) : : "d"(r) );
  31 }
  32
  33 void cefbr(unsigned mode)
  34 {
  35    set_rounding_mode(mode);
  36
  37    float out;
  38
  39    __asm__ volatile("cefbr %[r1],%[r2]" : [r1] "=f"(out) : [r2] "d"(i32));
  40    printf("cefbr:  %"PRId32" -> %f\n", i32, out);
  41 }
  42
  43 void cegbr(unsigned mode)
  44 {
  45    set_rounding_mode(mode);
  46
  47    float out;
  48
  49    __asm__ volatile("cegbr %[r1],%[r2]" : [r1] "=f"(out) : [r2] "d"(i64));
  50    printf("cegbr:  %"PRId64" -> %f\n", i64, out);
  51 }
  52
  53 void cdgbr(unsigned mode)
  54 {
  55    set_rounding_mode(mode);
  56
  57    double out;
  58
  59    __asm__ volatile("cdgbr %[r1],%[r2]" : [r1] "=f"(out) : [r2] "d"(i64));
  60    printf("cegbr:  %"PRId64" -> %f\n", i64, out);
  61 }
  62
  63
  64 int main()
  65 {
  66    int mode;
  67
  68    /* i32 -> f32 */
  69    i32 = INT32_MAX;
  70    for (mode = 0; mode <= 3; ++mode) cefbr(mode);
  71    printf("\n");
  72    i32 = INT32_MIN;
  73    for (mode = 0; mode <= 3; ++mode) cefbr(mode);
  74    printf("\n");
  75
  76    /* i64 -> f32 */
  77    i64 = INT64_MAX;
  78    for (mode = 0; mode <= 3; ++mode) cegbr(mode);
  79    printf("\n");
  80    i64 = INT64_MIN;
  81    for (mode = 0; mode <= 3; ++mode) cegbr(mode);
  82    printf("\n");
  83
  84    /* i64 -> f64 */
  85    i64 = INT64_MAX;
  86    for (mode = 0; mode <= 3; ++mode) cdgbr(mode);
  87    printf("\n");
  88    i64 = INT64_MIN;
  89    for (mode = 0; mode <= 3; ++mode) cdgbr(mode);
  90    printf("\n");
  91
  92    return 0;
  93 }