PRB: "Floating-point Support Not Loaded" Error with scanf() (37507)

The information in this article applies to:

The C Run-Time (CRT), when used with:
- Microsoft C for MS-DOS 6.0
- Microsoft C for MS-DOS 6.0a
- Microsoft C for MS-DOS 6.0ax
- Microsoft C for OS/2 6.0
- Microsoft C for OS/2 6.0a
- Microsoft C/C++ for MS-DOS 7.0
- Microsoft Visual C++ 1.0
- Microsoft Visual C++ 1.5
- Microsoft Visual C++, 32-bit Learning Edition 4.0
- Microsoft Visual C++, 32-bit Professional Edition 2.0
- Microsoft Visual C++, 32-bit Professional Edition 4.0
- Microsoft Visual C++, 32-bit Professional Edition 5.0
- Microsoft Visual C++, 32-bit Professional Edition 6.0

This article was previously published under Q37507

SYMPTOMS

When an application uses the scanf() function to read a floating-point value from the console into an uninitialized "float" type global variable, an R6002 "floating-point format support not loaded" error occurs. This error also occurs when any formatted input routine is used to read a value.

CAUSE

The compiler does not generate a reference to the __fltused variable that instructs the linker to load the floating-point support module.

RESOLUTION

To work around this problem, initialize the floating-point variable or use the variable in an expression in the routine that contains the scanf() call.

STATUS

This behavior is expected. To minimize the size of the executable file, the compiler loads floating-point support only when it is required.

MORE INFORMATION

When a module uses only one of the formatted input routines and does not also initialize a floating-point variable, the compiler does not load floating-point support.

Remove the comment indication from either or both of the two lines in the sample code below to eliminate the R6002 error.

Sample Code

   /*
    * Compile options needed: none
    */ 

   #include <stdio.h>
   float x ;

   main()
   {
   // Remove the comment from the next line to eliminate the error.
   // x = 2.3 ;

      scanf ("%f", &x) ;

   // Remove the comment from the next line to eliminate the error.
   // printf ("%f\n", x) ;
   }

Modification Type:	Major	Last Reviewed:	9/17/2003
Keywords:	kbprb KB37507