# __fpc_wr() — Write the floating-point control register

## Standards

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

Both | OS/390® V2R6 |

## Syntax

```
#include <_Ieee754.h>
void __fpc_wr(_FP_fpcreg_t *fpc_ptr);
```

## General description

The __fpc_wr() function replaces the contents of the floating-point control (FPC) register with the value pointed to by fpc_ptr.

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

## Related information

- __fpc_rd() — Read floating-point control register
- __fpc_rs() — Read floating-point control register and change rounding mode field
- __fpc_rw() — Read and write the floating-point control register
- __fpc_sm() — Set floating-point control register rounding mode field
- __fp_swap_rnd() — Swap rounding mode