Function evlSqrt

src/jrd/SysFunction.cpp:6616–6656

dsc* evlSqrt(thread_db* tdbb, const SysFunction* function, const NestValueArray& args,
	impure_value* impure)
{
	fb_assert(args.getCount() == 1);

	Request* request = tdbb->getRequest();

	const dsc* value = EVL_expr(tdbb, request, args[0]);
	if (request->req_flags & req_null)	// return NULL if value is NULL
		return NULL;

	if (value->isDecOrInt128())
	{
		DecimalStatus decSt = tdbb->getAttachment()->att_dec_status;
		impure->vlu_misc.vlu_dec128 = MOV_get_dec128(tdbb, value);

		if (impure->vlu_misc.vlu_dec128.compare(decSt, CDecimal128(0)) < 0)
		{
			status_exception::raise(Arg::Gds(isc_expression_eval_err) <<
									Arg::Gds(isc_sysf_argmustbe_nonneg) << Arg::Str(function->name));
		}

		impure->vlu_misc.vlu_dec128 = impure->vlu_misc.vlu_dec128.sqrt(decSt);
		impure->vlu_desc.makeDecimal128(&impure->vlu_misc.vlu_dec128);
	}
	else
	{
		impure->vlu_misc.vlu_double = MOV_get_double(tdbb, value);

		if (impure->vlu_misc.vlu_double < 0)
		{
			status_exception::raise(Arg::Gds(isc_expression_eval_err) <<
									Arg::Gds(isc_sysf_argmustbe_nonneg) << Arg::Str(function->name));
		}

		impure->vlu_misc.vlu_double = sqrt(impure->vlu_misc.vlu_double);
		impure->vlu_desc.makeDouble(&impure->vlu_misc.vlu_double);
	}

	return &impure->vlu_desc;
}


dsc* evlTrunc(thread_db* tdbb, const SysFunction* function, const NestValueArray& args,