Runtime Exceptions Issued by the Compiler for _DecimalT Class Templates

The runtime exceptions issued by the compiler for _DecimalT class templates are shown in the following figure.

Figure 1. Runtime Exceptions Issued by the Compiler for _DecimalT Class Templates

#include <bcd.h>

static _DecimalT<5,2>   s1 =   __D("12345678.0");

static _DecimalT<10,2>  s2 =   __D("1234567891234567891234567.12345")
                                               + __D("12345.1234567891");

                                           // s2 = (31,5) + (15,10)

static _DecimalT<10,2>  s3 =  __D("1234567891234562345")
                                               * __D("1234567891234.12");

                                           // s3 = (19,0) * (15,2)

static _DecimalT<10,2>  s4 =  __D("12345678912345678912") /
                                            __D("12345.123456789123456");

                                           // s4 = (20,0) / (20,15)

int main(void)

{
    _DecimalT<5,2> a1 = __D("12345678.0");

    _DecimalT<10,2> a2, a3, a4;

    _DecimalT<5,2> a5 = (_DecimalT<5,2>) __D("123456.78");




    a2 = __D("1234567891234567891234567.12345") + __D("12345.1234567891");

                                           // a2 = (31,5) + (15,10)

    a3 = __D("123456789123456.12345") * __D("1234567891234.12");

                                           // a3 = (20,5) * (15,2)
                                           // expression.
                                           // Note: Need (35,7) but
                                           // use (31,2), for example,
                                           // keep the integral part.

    a4 = __D("12345678912345678912") / __D("12345.123456789123456");

                                           // a4 = (20,0) / (20,15)
                                           // Note: Need 35 digits to
                                           // calculate integral part
                                           // and the result becomes
                                           // (31,0).
}

Note:

For assignments to a target field too small to hold the _DecimalT class template object, there is a runtime exception issued for static, external, or automatic initialization.
For expressions requiring decimal-point alignment, namely addition, subtraction, or comparison, there is a runtime exception issued for static, external, and automatic initialization if, during alignment, the maximum number of allowed digits is exceeded.
For multiplication, if the evaluation of the expression results in a value larger than the maximum number of allowed digits (DEC_DIG):
- A runtime exception is issued either for static or external initialization, or if the expression is within a function.
- Truncation occurs on the fractional part, preserving as much of the integral part as possible.
For division, a runtime exception is generated when ((n[1]- p[1]) + p[2]) >31.