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write_rnd, read_rnd - Sets and returns IEEE dynamic rounding mode for floating-point 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 floating-point control register (fpcr) for IEEE floating-point operations and returns the previous dynamic rounding mode. Dynamic rounding mode for IEEE floating-point operations is enabled for code generated by the C compiler by specifying -fprm d to cc(1), and by using the d floating-point 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 floating-point operations.
The write_rnd function returns the previous IEEE floating-point rounding mode. The read_rnd function returns the current IEEE floating-point rounding mode.
Commands: cc(1).
Files: float.h.
Assembly Language Programmer's Guide.
Alpha Architecture Reference Manual.
IEEE Standard for Binary Floating-Point Arithmetic delim off