net: tulip: de4x5: Optimize if branch in de4x5_parse_params

[PATCH] net: tulip: de4x5: Optimize if branch in de4x5_parse_params

Posted by Meng Tang 4 years, 3 months ago

In the de4x5_parse_params, 'if (strstr(p, "BNC_AUI"))' condition and
'if (strstr(p, "BNC_AUI"))' condition are both execute the statement
'lp->params.autosense = BNC', these two conditions can be combined.

In addition, in the current code logic, when p = "BNC", the judgments
need to be executed four times. In order to simplify the execution
process and keep the original code design, I used the statement which
is 'if (strstr(p, "BNC") || strstr(p, "BNC_AUI"))' to deal with it,
after that once 'strstr(p, "BNC")' is established, we no longer need
to judge whether 'strstr(p, "BNC_AUI")' is true(not NULL).

In this way, we can execute the judgment statement one time less.

Signed-off-by: Meng Tang <tangmeng@uniontech.com>
---
 drivers/net/ethernet/dec/tulip/de4x5.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/dec/tulip/de4x5.c b/drivers/net/ethernet/dec/tulip/de4x5.c
index 71730ef4cd57..5900b8ef7f6f 100644
--- a/drivers/net/ethernet/dec/tulip/de4x5.c
+++ b/drivers/net/ethernet/dec/tulip/de4x5.c
@@ -5208,9 +5208,7 @@ de4x5_parse_params(struct net_device *dev)
 		lp->params.autosense = TP_NW;
 	    } else if (strstr(p, "TP")) {
 		lp->params.autosense = TP;
-	    } else if (strstr(p, "BNC_AUI")) {
-		lp->params.autosense = BNC;
-	    } else if (strstr(p, "BNC")) {
+	    } else if (strstr(p, "BNC") || strstr(p, "BNC_AUI")) {
 		lp->params.autosense = BNC;
 	    } else if (strstr(p, "AUI")) {
 		lp->params.autosense = AUI;
-- 
2.20.1

Re: [PATCH] net: tulip: de4x5: Optimize if branch in de4x5_parse_params

Posted by Jakub Kicinski 4 years, 3 months ago

On Tue, 15 Mar 2022 15:49:52 +0800 Meng Tang wrote:
> In the de4x5_parse_params, 'if (strstr(p, "BNC_AUI"))' condition and
> 'if (strstr(p, "BNC_AUI"))' condition are both execute the statement
> 'lp->params.autosense = BNC', these two conditions can be combined.
> 
> In addition, in the current code logic, when p = "BNC", the judgments
> need to be executed four times. In order to simplify the execution
> process and keep the original code design, I used the statement which
> is 'if (strstr(p, "BNC") || strstr(p, "BNC_AUI"))' to deal with it,
> after that once 'strstr(p, "BNC")' is established, we no longer need
> to judge whether 'strstr(p, "BNC_AUI")' is true(not NULL).
> 
> In this way, we can execute the judgment statement one time less.
> 
> Signed-off-by: Meng Tang <tangmeng@uniontech.com>

This is ancient code, let's leave it be.