WIP: printing a double-double in fixed form destroys a leading zero

Author: Ravenwater

include/universal/number/dd/dd_impl.hpp

@@ -533,13 +533,13 @@ class dd {
 
 			// trap for improper offset with large values
 			// without this trap, output of values of the for 10^j - 1 fail for j > 28
-			// and are output with the point in the wrong place, leading to a dramatically off value
+			// and are output with the point in the wrong place, leading to a significant error
 			if (fixed && (precision > 0)) {
 				// make sure that the value isn't dramatically larger
 				double from_string = atof(s.c_str());
 
 				// if this ratio is large, then we've got problems
-				if (std::fabs(from_string / this->hi) > 3.0) {
+				if (std::fabs(from_string / hi) > 3.0) {
 
 					// loop on the string, find the point, move it up one
 					// don't act on the first character
@@ -550,11 +550,13 @@ class dd {
 							break;
 						}
 					}
+					// BUG: the loop above, in particular s[i-1] = '.', destroys the leading 0
+					// in the fixed point representation if the point is located at i = 1;
 
 					from_string = atof(s.c_str());
 					// if this ratio is large, then the string has not been fixed
-					if (std::fabs(from_string / this->hi) > 3.0) {
-						//error("Re-rounding unsuccessful in large number fixed point trap.");
+					if (std::fabs(from_string / hi) > 3.0) {
+						std::cerr << "re-rounding unsuccessful in large number fixed point trap\n";
 					}
 				}
 			}

static/dd/api/api.cpp

@@ -114,8 +114,8 @@ namespace sw {
 				from *= 10.0) {
 				dd u = ulp(from);
 				std::cout << "ulp(" << std::scientific << std::setprecision(0) << from
-					<< ") gives " //<< to_binary(u) << " : "
-					<< std::fixed << std::setprecision(6) << u 
+					<< ") gives "
+					<< std::fixed << std::setprecision(6) << u
 					<< '\n';
 			}
 		}
@@ -447,8 +447,6 @@ try {
 		std::cout << std::setprecision(defaultPrecision);
 	}
 
-
-
 	std::cout << "+---------    double-double subnormal behavior   --------+\n";
 	{
 		constexpr double minpos = std::numeric_limits<double>::min();