# __fpc_rs() — Read floating-point control register and change rounding mode field

## Standards

Standards / Extensions | C or C++ | Dependencies |
---|---|---|

Both | OS/390® V2R6 |

## Syntax

```
#include <_Ieee754.h>
void __fpc_rs(_FP_fpcreg_t *cur_ptr, _FP_rmode_t rmode);
```

## General description

The __fpc_rs() function
stores the current contents of the floating-point control (FPC) register
at the location pointed to by cur_ptr and
then sets the rounding mode field of the FPC based on the value specified
by rmode as follows:

**Value****Rounding Mode**- _RMODE_RN
- Round to nearest
- _RMODE_RZ
- Round toward zero
- _RMODE_RP
- Round toward +Infinity
- _RMODE_RM
- Round toward -Infinity

Note:

- When processing IEEE floating-point values, the C/C++ runtime library math functions require IEEE rounding mode of round to nearest. The C/C++ runtime library takes care of setting round to nearest rounding mode while executing math functions and restoring application rounding mode before returning to the caller.
- This function does not return or update decimal floating-point rounding mode bits.

## Return values

None