NAME

decimal_to_single, decimal_to_double, decimal_to_extended − convert decimal record to floating-point value

SYNOPSIS

#include <floatingpoint.h>

void decimal_to_single(px, pm, pd, ps)
single ∗px ;
decimal_mode ∗pm;
decimal_record ∗pd;
fp_exception_field_type ∗ps;

void decimal_to_double(px, pm, pd, ps)
double ∗px ;
decimal_mode ∗pm;
decimal_record ∗pd;
fp_exception_field_type ∗ps;

void decimal_to_extended(px, pm, pd, ps)
extended ∗px ;
decimal_mode ∗pm;
decimal_record ∗pd;
fp_exception_field_type ∗ps;

DESCRIPTION

The decimal_to_floating() functions convert the decimal record at ∗pd into a floating-point value at ∗px, observing the modes specified in ∗pm and setting exceptions in ∗ps. If there are no IEEE exceptions, ∗ps will be zero. 

pd->sign and pd->fpclass are always taken into account.  pd->exponent and pd->ds are used when pd->fpclass is fp_normal or fp_subnormal. In these cases pd->ds must contain one or more ascii digits followed by a NULL.  ∗px is set to a correctly rounded approximation to

(pd->sign)∗(pd->ds)∗10∗∗(pd->exponent)

Thus if pd->exponent == −2 and pd->ds == "1234", ∗px will get 12.34 rounded to storage precision.  pd->ds cannot have more than DECIMAL_STRING_LENGTH-1 significant digits because one character is used to terminate the string with a NULL.  If pd->more != 0 on input then additional nonzero digits follow those in pd->ds; fp_inexact is set accordingly on output in ∗ps.

∗px is correctly rounded according to the IEEE rounding modes in pm->rd. ∗ps is set to contain fp_inexact, fp_underflow, or fp_overflow if any of these arise. 

pd->ndigits, pm->df, and pm->ndigits are not used. 

strtod(3), scanf(3), fscanf(3), and sscanf(3) all use decimal_to_double. 

SEE ALSO

scanf(3S), scanf(3V), strtod(3)

Sun Release 4.0  —  Last change: 23 October 1987