BUG: Format Specifications Give Incorrect Output (145821)

The information in this article applies to:

Microsoft Visual C++, Macintosh Cross-Development Addon 4.0

This article was previously published under Q145821

SYMPTOMS

When you use the C run-time functions such as sprintf when building a 68K Macintosh target, the format specification for long double (%ld, %le, %lg) yields incorrect output. This is not a problem with a Power Macintosh target.

RESOLUTION

Use other format specifications. Internally, do your calculations using long doubles. However, when it comes time to output final results, convert the result to a double, and use the corresponding format specification.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Code to Reproduce Problem

/* Compile options needed: default
*/ 

char buf[1000];
long double ldReturn  = 7.9718893639526417;

sprintf(buf,"ldReturn(%%ld)=%ld\n", ldReturn);

/* Instead, do the following
*/ 

char buf[1000];
long double ldReturn  = 7.9718893639526417;

sprintf(buf,"ldReturn(%%d)=%ld\n", (double)ldReturn);

Modification Type:	Major	Last Reviewed:	10/2/2003
Keywords:	kbCRT KB145821