:orphan:
# PETSC_ATTRIBUTE_COLD
Indicate to the compiler that a function is very unlikely to be executed 


## Notes
The marked function is often optimized for size rather than speed and may be grouped alongside
other equally frigid routines improving code locality of lukewarm or hotter parts of program.

The paths leading to cold functions are usually automatically marked as unlikely by the
compiler. It may thus be useful to mark functions used to handle unlikely conditions -- such
as error handlers -- as cold to improve optimization of the surrounding temperate functions.


## Example Usage
```none
  void my_error_handler(...) PETSC_ATTRIBUTE_COLD;

  if (temperature < 0) {
    return my_error_handler(...); // chilly!
  }
```



## See Also
 `PetscUnlikely()`, `PetscUnlikelyDebug()`, `PetscLikely()`, `PetscLikelyDebug()`,
`PetscUnreachable()`, `PETSC_ATTRIBUTE_FORMAT`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/include/petscmacros.h.html#PETSC_ATTRIBUTE_COLD">include/petscmacros.h</A>


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