Re: [PATCH 3/3] coccinelle: misc: minmax: improve performance when no candidate exists

[Julia Lawall <julia.lawall@inria.fr>]

On Sat, 25 Jul 2026, Sang-Heon Jeon wrote:

> The rules that report an opencoded min() or max() search every
> function body, even when the file contains nothing to find.
>
> To avoid this, collect the candidates first and run the search only
> when one exists. A candidate is any conditional expression whose
> condition is a comparison.
>
> Every opencoded min() or max() is also a candidate, so the same
> opportunities are reported as before and the output does not
> change. A report-mode run over every .c file in the tree produces
> identical output.

Applied.

I also added "candidate" rules for minif and maxif, removed the outer
parentheses on rmax etc, and disabled some isomorphisms that caused the
introduction of useless variants of the conditional tests.

julia


>
> Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
> ---
>  scripts/coccinelle/misc/minmax.cocci | 24 +++++++++++++++++++-----
>  1 file changed, 19 insertions(+), 5 deletions(-)
>
> diff --git a/scripts/coccinelle/misc/minmax.cocci b/scripts/coccinelle/misc/minmax.cocci
> index ca4830ae3042..93c074b9439f 100644
> --- a/scripts/coccinelle/misc/minmax.cocci
> +++ b/scripts/coccinelle/misc/minmax.cocci
> @@ -17,7 +17,21 @@ virtual org
>  virtual context
>  virtual patch
>
> -@rmax depends on !patch@
> +@max_candidate@
> +expression E1, E2, E3, E4;
> +binary operator cmp = {>, >=};
> +@@
> +
> +	(E1 cmp E2 ? E3 : E4)
> +
> +@min_candidate@
> +expression E1, E2, E3, E4;
> +binary operator cmp = {<, <=};
> +@@
> +
> +	(E1 cmp E2 ? E3 : E4)
> +
> +@rmax depends on !patch && max_candidate@
>  identifier func;
>  expression x, y;
>  binary operator cmp = {>, >=};
> @@ -51,7 +65,7 @@ func(...)
>  }
>
>  // Ignore errcode returns.
> -@errcode@
> +@errcode depends on min_candidate@
>  position p;
>  identifier func;
>  expression x;
> @@ -65,7 +79,7 @@ func(...)
>  	...>
>  }
>
> -@rmin depends on !patch@
> +@rmin depends on !patch && min_candidate@
>  identifier func;
>  expression x, y;
>  binary operator cmp = {<, <=};
> @@ -98,7 +112,7 @@ func(...)
>  	...>
>  }
>
> -@pmax depends on patch@
> +@pmax depends on patch && max_candidate@
>  identifier func;
>  expression x, y;
>  binary operator cmp = {>=, >};
> @@ -131,7 +145,7 @@ func(...)
>  	...>
>  }
>
> -@pmin depends on patch@
> +@pmin depends on patch && min_candidate@
>  identifier func;
>  expression x, y;
>  binary operator cmp = {<=, <};
> --
> 2.43.0
>
>