KB145821 - BUG: Format Specifications Give Incorrect Output

Article ID: 145821

Article Last Modified on 10/2/2003

Microsoft Visual C++ 4.0 Cross Development Edition for Macintosh

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);

Additional query words: 4.00 Windows 95 NT

Keywords: kbcrt KB145821