2019-07-15 12:21:50 +00:00
|
|
|
[< back to index](../doc_index.md)
|
2018-04-02 22:21:26 +00:00
|
|
|
|
2018-02-01 21:39:38 +00:00
|
|
|
# Macros and inlining
|
2018-01-04 00:15:04 +00:00
|
|
|
|
2018-02-01 21:39:38 +00:00
|
|
|
## Macros
|
2018-01-04 00:15:04 +00:00
|
|
|
|
2018-02-01 21:39:38 +00:00
|
|
|
`macro` keyword
|
2018-01-04 00:15:04 +00:00
|
|
|
|
|
|
|
|
## Automatic inlining
|
|
|
|
|
|
2019-06-11 22:20:24 +00:00
|
|
|
You can control inlining behavior in several ways:
|
|
|
|
|
|
|
|
|
|
* functions declared with the `inline` keyword will be inlined if possible
|
|
|
|
|
|
|
|
|
|
* functions declared with the `noinline` keyword will never be inlined
|
|
|
|
|
|
|
|
|
|
* the remaining functions may be inlined only if the `-finline` command-line option is enabled
|
|
|
|
|
and the compiler decides the function is worth doing
|
2018-02-01 21:39:38 +00:00
|
|
|
|
2019-12-01 02:16:09 +00:00
|
|
|
## Automatic subroutine extraction
|
|
|
|
|
|
|
|
|
|
Subroutine extraction is the opposite of inlining.
|
|
|
|
|
|
|
|
|
|
When given the `-fsubroutine-extraction`, the compiler will attempt to extract common code fragments to new subroutines.
|
|
|
|
|
The code will get smaller and slower.
|
|
|
|
|
|
|
|
|
|
Generally, when using `-fsubroutine-extraction`, it's recommended to also use `-finline`.
|
|
|
|
|
This allows the compiler to first inline and optimize code and then extract it back when appropriate.
|
