write_rnd, read_rnd  Sets and returns IEEE dynamic rounding mode for floatingpoint operations
Standard C Library (libc.so, libc.a)
#include <float.h>
unsigned int write_rnd(
unsigned int rnd);
The write_rnd function sets the dynamic rounding mode in the floatingpoint control register (fpcr) for IEEE floatingpoint operations and returns the previous dynamic rounding mode. Dynamic rounding mode for IEEE floatingpoint operations is enabled for code generated by the C compiler by specifying fprm d to cc(1), and by using the d floatingpoint instruction operator in assembly language code.
Specify rnd as one of the following constants defined in float.h
Constant  Meaning 
FP_RND_RZ 
Round toward zero (chopped rounding)

FP_RND_RN 
Round toward nearest (normal rounding)

FP_RND_RP 
Round toward plus infinity

FP_RND_RM 
Round toward minus infinity

The read_rnd function returns the current dynamic rounding mode for floatingpoint operations.
The write_rnd function returns the previous IEEE floatingpoint rounding mode. The read_rnd function returns the current IEEE floatingpoint rounding mode.
Commands: cc(1).
Files: float.h.
Assembly Language Programmer's Guide.
Alpha Architecture Reference Manual.
IEEE Standard for Binary FloatingPoint Arithmetic delim off