diff mbox series

[1/1] lib: maple_tree: remove unneeded initialization in mtree_range_walk()

Message ID 20221026120029.12555-2-lukas.bulwahn@gmail.com
State New
Headers
Series Dead stores in maple-tree |

Commit Message

Lukas Bulwahn Oct. 26, 2022, noon UTC 
  Before the do-while loop in mtree_range_walk(), the variables next, min,
max need to be initialized. The variables last, prev_min and prev_max are
set within the loop body before they are eventually used after exiting the
loop body.

As it is a do-while loop, the loop body is executed at least once, so the
variables last, prev_min and prev_max do not need to be initialized before
the loop body.

Remove unneeded initialization of last and prev_min.

The needless initialization was reported by clang-analyzer as Dead Stores.

As the compiler already identifies these assignments as unneeded, it
optimizes the assignments away. Hence:

No functional change. No change in object code.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
---
 lib/maple_tree.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Liam R. Howlett Oct. 26, 2022, 2:25 p.m. UTC | #1 
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>

* Lukas Bulwahn <lukas.bulwahn@gmail.com> [221026 08:01]:
> Before the do-while loop in mtree_range_walk(), the variables next, min,
> max need to be initialized. The variables last, prev_min and prev_max are
> set within the loop body before they are eventually used after exiting the
> loop body.
> 
> As it is a do-while loop, the loop body is executed at least once, so the
> variables last, prev_min and prev_max do not need to be initialized before
> the loop body.
> 
> Remove unneeded initialization of last and prev_min.
> 
> The needless initialization was reported by clang-analyzer as Dead Stores.
> 
> As the compiler already identifies these assignments as unneeded, it
> optimizes the assignments away. Hence:
> 
> No functional change. No change in object code.
> 
> Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
> ---
>  lib/maple_tree.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index e1743803c851..fbde494444b8 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -2903,8 +2903,8 @@ static inline void *mtree_range_walk(struct ma_state *mas)
>  	unsigned long max, min;
>  	unsigned long prev_max, prev_min;
>  
> -	last = next = mas->node;
> -	prev_min = min = mas->min;
> +	next = mas->node;
> +	min = mas->min;
>  	max = mas->max;
>  	do {
>  		offset = 0;
> -- 
> 2.17.1
>
diff mbox series

Patch

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index e1743803c851..fbde494444b8 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -2903,8 +2903,8 @@  static inline void *mtree_range_walk(struct ma_state *mas)
 	unsigned long max, min;
 	unsigned long prev_max, prev_min;
 
-	last = next = mas->node;
-	prev_min = min = mas->min;
+	next = mas->node;
+	min = mas->min;
 	max = mas->max;
 	do {
 		offset = 0;