INT_TYPE
DFP_TO_INT (DFP_C_TYPE x)
{
/* decNumber's decimal* types have the same format as C's _Decimal*
types, but they have different calling conventions. */
IEEE_TYPE s;
char buf[BUFMAX];
char *pos;
decNumber qval, n1, n2;
decContext context;
decContextDefault (&context, CONTEXT_INIT);
/* Need non-default rounding mode here. */
context.round = DEC_ROUND_DOWN;
HOST_TO_IEEE (x, &s);
TO_INTERNAL (&s, &n1);
/* Rescale if the exponent is less than zero. */
decNumberToIntegralValue (&n2, &n1, &context);
/* Get a value to use for the quantize call. */
decNumberFromString (&qval, (char *) "1.0", &context);
/* Force the exponent to zero. */
decNumberQuantize (&n1, &n2, &qval, &context);
/* This is based on text in N1107 section 5.1; it might turn out to be
undefined behavior instead. */
if (context.status & DEC_Invalid_operation)
{
#if defined (L_sd_to_si) || defined (L_dd_to_si) || defined (L_td_to_si)
if (decNumberIsNegative(&n2))
return INT_MIN;
else
return INT_MAX;
#elif defined (L_sd_to_di) || defined (L_dd_to_di) || defined (L_td_to_di)
if (decNumberIsNegative(&n2))
/* Find a defined constant that will work here. */
return (-9223372036854775807LL - 1LL);
else
/* Find a defined constant that will work here. */
return 9223372036854775807LL;
#elif defined (L_sd_to_usi) || defined (L_dd_to_usi) || defined (L_td_to_usi)
return UINT_MAX;
#elif defined (L_sd_to_udi) || defined (L_dd_to_udi) || defined (L_td_to_udi)
/* Find a defined constant that will work here. */
return 18446744073709551615ULL;
#endif
}
/* Get a string, which at this point will not include an exponent. */
decNumberToString (&n1, buf);
/* Ignore the fractional part. */
pos = strchr (buf, '.');
if (pos)
*pos = 0;
/* Use a C library function to convert to the integral type. */
return STR_TO_INT (buf, NULL, 10);
}
/* decNumber doesn't provide support for conversions to 64-bit integer
types, so do it the hard way. */
INT_TYPE
DFP_TO_INT (DFP_C_TYPE x)
{
/* decNumber's decimal* types have the same format as C's _Decimal*
types, but they have different calling conventions. */
/* TODO: Decimal float to integer conversions should raise FE_INVALID
if the result value does not fit into the result type. */
IEEE_TYPE s;
char buf[BUFMAX];
char *pos;
decNumber qval, n1, n2;
decContext context;
/* Use a large context to avoid losing precision. */
decContextDefault (&context, DEC_INIT_DECIMAL128);
/* Need non-default rounding mode here. */
context.round = DEC_ROUND_DOWN;
HOST_TO_IEEE (x, &s);
TO_INTERNAL (&s, &n1);
/* Rescale if the exponent is less than zero. */
decNumberToIntegralValue (&n2, &n1, &context);
/* Get a value to use for the quantize call. */
decNumberFromString (&qval, (char *) "1.", &context);
/* Force the exponent to zero. */
decNumberQuantize (&n1, &n2, &qval, &context);
/* Get a string, which at this point will not include an exponent. */
decNumberToString (&n1, buf);
/* Ignore the fractional part. */
pos = strchr (buf, '.');
if (pos)
*pos = 0;
/* Use a C library function to convert to the integral type. */
return STR_TO_INT (buf, NULL, 10);
}
static int_t value_from_string(const char *s)
{
return strcmp(s,".") ? STR_TO_INT(s,0) : NOT_A_NUMBER;
}
