Microsoft KB Archive/38831

From BetaArchive Wiki
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.

INF: DB-LIB and Floating Point


The information in this article applies to:

  • Microsoft SQL Server Programmer's Toolkit, version 4.2


This article explains how you can control whether or not DB-Library (DB-Lib) uses a coprocessor for floating-point operations.


DB-Lib uses floating point only if conversion or display of FLOAT data is requested. No other SQL Server data type requires floating point.

The DLL version of DB-Lib was compiled with /FPa and linked with the alternate floating-point library. It will never use the coprocessor, even if one is present and is totally independent of the floating-point compile and link requirements of the applications that call it.

The static-link version of DB-Lib was compiled with /FPi, which generates coprocessor floating-point instructions. This is why you will see 8087 instructions in DB-Lib code. Whether or not a coprocessor is required is determined at link time. If the application is linked with the coprocessor floating-point library (xLIBC7.LIB), DB-LIB will require a coprocessor. If the application is linked with the emulator floating-point library (xLIBCE.LIB), the coprocessor will be used if it is present. The C startup code detects whether a coprocessor is not present and sets up a handler to trap 8087 instructions and emulate them. The automatic selection of a coprocessor at run time may be overridden with the NO87 environment variable. Please refer to pages 508-512 Microsoft C/C++ "Environment and Tools" manual for more information on controlling floating-point options.

Additional query words: dblib Windows NT

Keywords : kbprogramming
Issue type :
Technology : kbSQLServSearch kbAudDeveloper kbSQLServPTK420

Last Reviewed: March 24, 1999
© 2001 Microsoft Corporation. All rights reserved. Terms of Use.