[PATCH] can: isotp: make const array static, makes object smaller

[PATCH] can: isotp: make const array static, makes object smaller

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

Don't populate the const array plen on the stack but instead it
static. Makes the object code smaller by 926 bytes.

Before:
   text	   data	    bss	    dec	    hex	filename
  26531	   1943	     64	  28538	   6f7a	net/can/isotp.o

After:
   text	   data	    bss	    dec	    hex	filename
  25509	   2039	     64	  27612	   6bdc	net/can/isotp.o

(gcc version 10.2.0)

Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 net/can/isotp.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/net/can/isotp.c b/net/can/isotp.c
index 4c2062875893..3fd714f81875 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -252,14 +252,16 @@ static void isotp_rcv_skb(struct sk_buff *skb, struct sock *sk)
 
 static u8 padlen(u8 datalen)
 {
-	const u8 plen[] = {8, 8, 8, 8, 8, 8, 8, 8, 8,		/* 0 - 8 */
-			   12, 12, 12, 12,			/* 9 - 12 */
-			   16, 16, 16, 16,			/* 13 - 16 */
-			   20, 20, 20, 20,			/* 17 - 20 */
-			   24, 24, 24, 24,			/* 21 - 24 */
-			   32, 32, 32, 32, 32, 32, 32, 32,	/* 25 - 32 */
-			   48, 48, 48, 48, 48, 48, 48, 48,	/* 33 - 40 */
-			   48, 48, 48, 48, 48, 48, 48, 48};	/* 41 - 48 */
+	static const u8 plen[] = {
+		8, 8, 8, 8, 8, 8, 8, 8, 8,	/* 0 - 8 */
+		12, 12, 12, 12,			/* 9 - 12 */
+		16, 16, 16, 16,			/* 13 - 16 */
+		20, 20, 20, 20,			/* 17 - 20 */
+		24, 24, 24, 24,			/* 21 - 24 */
+		32, 32, 32, 32, 32, 32, 32, 32,	/* 25 - 32 */
+		48, 48, 48, 48, 48, 48, 48, 48,	/* 33 - 40 */
+		48, 48, 48, 48, 48, 48, 48, 48	/* 41 - 48 */
+	};
 
 	if (datalen > 48)
 		return 64;
-- 
2.27.0

Re: [PATCH] can: isotp: make const array static, makes object smaller

[Marc Kleine-Budde]

[-- Attachment #1.1: Type: text/plain, Size: 883 bytes --]

On 10/20/20 5:42 PM, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> Don't populate the const array plen on the stack but instead it
> static. Makes the object code smaller by 926 bytes.
> 
> Before:
>    text	   data	    bss	    dec	    hex	filename
>   26531	   1943	     64	  28538	   6f7a	net/can/isotp.o
> 
> After:
>    text	   data	    bss	    dec	    hex	filename
>   25509	   2039	     64	  27612	   6bdc	net/can/isotp.o
> 
> (gcc version 10.2.0)
> 
> Signed-off-by: Colin Ian King <colin.king@canonical.com>

applied to linux-can/testing.

Thanks,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
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