Re: [Qemu-devel] [RFC] alpha qemu arithmetic exceptions

[Richard Henderson <rth@twiddle.net>]

[-- Attachment #1: Type: text/plain, Size: 466 bytes --]

On 07/01/2014 09:05 PM, Al Viro wrote:
> Which glibc version it is?  I don't see such failures with your
> axp/axp-next (head at 6b38f4e7f); could you post the details on your
> reproducer?  I've tried to guess the likely version by glibc.git, but
> I don't see nearbyint tests with such argument in any version there,
> so I couldn't find it that way...

Glibc mainline, then look at math/test-double.out.

I'm interested in the results of the following test.


r~

[-- Attachment #2: test.c --]
[-- Type: text/x-csrc, Size: 1981 bytes --]

#include <stdio.h>
#include <fenv.h>
#include <math.h>
#include <float.h>

static void div_su(void)
{
  asm("divt/su %0,%1,$f0; trapb" : : "f"(1.0), "f"(3.0) : "$f0");
}

static void div_sui(void)
{
  asm("divt/su %0,%1,$f0; trapb" : : "f"(1.0), "f"(3.0) : "$f0");
}

static void mul_su(void)
{
  asm("mult/su %0,%0,$f0; trapb" : : "f"(DBL_MIN) : "$f0");
}

static void mul_sui(void)
{
  asm("mult/sui %0,%0,$f0; trapb" : : "f"(DBL_MIN) : "$f0");
}

static void cvttq_45(void)
{
  asm("cvttq/c %0,$f0; trapb" : : "f"(4.5) : "$f0");
}

static void cvttq_sv_45(void)
{
  asm("cvttq/svc %0,$f0; trapb" : : "f"(4.5) : "$f0");
}

static void cvttq_svi_45(void)
{
  asm("cvttq/svic %0,$f0; trapb" : : "f"(4.5) : "$f0");
}

static void cvttq_max(void)
{
  asm("cvttq/c %0,$f0; trapb" : : "f"(DBL_MAX) : "$f0");
}

static void cvttq_sv_max(void)
{
  asm("cvttq/svc %0,$f0; trapb" : : "f"(DBL_MAX) : "$f0");
}

static void cvttq_svi_max(void)
{
  asm("cvttq/svic %0,$f0; trapb" : : "f"(DBL_MAX) : "$f0");
}

static struct test {
  void (*fn)(void);
  const char *name;
} const tests[] = {
  { div_su,		"/su  : 1/3" },
  { div_sui,		"/sui : 1/3" },
  { mul_su,		"/su  : min*min" },
  { mul_sui,		"/sui : min*min" },
  { cvttq_45,		"/    : (long)4.5" },
  { cvttq_sv_45,	"/sv  : (long)4.5" },
  { cvttq_svi_45,	"/svi : (long)4.5" },
  { cvttq_max,		"/    : (long)max" },
  { cvttq_sv_max,	"/sv  : (long)max" },
  { cvttq_svi_max,	"/svi : (long)max" },
};

int main()
{
  char result[8];
  int i, e;

  for (i = 0; i < sizeof(tests)/sizeof(struct test); ++i)
    {
      feclearexcept(FE_ALL_EXCEPT);
      tests[i].fn();

      e = fetestexcept(FE_ALL_EXCEPT);
      result[0] = e & FE_DIVBYZERO ? 'd' : '-';
      result[1] = e & FE_INEXACT ? 'i' : '-';
      result[2] = e & FE_INVALID ? 'I' : '-';
      result[3] = e & FE_OVERFLOW ? 'o' : '-';
      result[4] = e & FE_UNDERFLOW ? 'u' : '-';
      result[5] = '\0';
      printf("%-20s %s\n", tests[i].name, result);
    }

  return 0;
}