include/qd/fpu.h

0001 /*
0002  * include/fpu.h
0003  *
0004  * This work was supported by the Director, Office of Science, Division
0005  * of Mathematical, Information, and Computational Sciences of the
0006  * U.S. Department of Energy under contract number DE-AC03-76SF00098.
0007  *
0008  * Copyright (c) 2001
0009  *
0010  * Contains functions to set and restore the round-to-double flag in the
0011  * control word of a x86 FPU.  The algorithms in the double-double and
0012  * quad-double package does not function with the extended mode found in
0013  * these FPU.
0014  */
0015 #ifndef _QD_FPU_H
0016 #define _QD_FPU_H
0017
0018 #include <qd/qd_config.h>
0019
0020 #ifdef __cplusplus
0021 extern "C" {
0022 #endif
0023
0024 /*
0025  * Set the round-to-double flag, and save the old control word in old_cw.
0026  * If old_cw is NULL, the old control word is not saved.
0027  */
0028 QD_API void fpu_fix_start(unsigned int *old_cw);
0029
0030 /*
0031  * Restore the control word.
0032  */
0033 QD_API void fpu_fix_end(unsigned int *old_cw);
0034
0035 #ifdef __cplusplus
0036 }
0037 #endif
0038
0039 #endif  /* _QD_FPU_H */