PRB: Undocumented Compiler Switches /QIfdiv, /QIf, and /QI6 (155173)



The information in this article applies to:

  • Microsoft Visual C++, 32-bit Learning Edition 4.0
  • Microsoft Visual C++, 32-bit Learning Edition 4.2
  • Microsoft Visual C++, 32-bit Enterprise Edition 4.2
  • Microsoft Visual C++, 32-bit Professional Edition 4.0
  • Microsoft Visual C++, 32-bit Professional Edition 4.1
  • Microsoft Visual C++, 32-bit Professional Edition 4.2

This article was previously published under Q155173

SYMPTOMS

In Visual C++ version 4.0, the compiler switches /QIfdiv, /Qif, and /QI6 are not documented. In Visual C++ version 4.1, the switch /QIfdiv is now documented. Below is a list of the default behavior of each switch in Visual C++ version 4.0 and version 4.1.

MORE INFORMATION

/QIfdiv

This switch is turned on by default in VC 4.0. It is turned off (/QIfdiv-) by default in VC 4.1. /QIfdiv is a workaround for the Pentium floating-point bug. /QIfdiv causes emulator functions to be used.

/QIf

This switch is unchanged. /QIf forces the .debug$F FPO debug information to be output always. This allows a backtrace of the stack even when some of the kernel stack has been paged out.

/QI6

This was an undocumented switch to work around P6 problems and it was off by default in VC 4.0. This switch was removed in VC 4.1 but its functionality is still there and is turned on by default.


Modification Type:MinorLast Reviewed:7/5/2005
Keywords:kbprb KB155173