Re: [PATCH] wireless: iwlegacy: make const array static to shink object code size Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit

[Colin Ian King]

On 22/09/17 11:03, Joe Perches wrote:
> On Fri, 2017-09-22 at 09:23 +0200, Julia Lawall wrote:
>>
>> On Thu, 21 Sep 2017, Colin King wrote:
>>
>>> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>>>
>>> Don't populate const array ac_to_fifo on the stack in an inlined
>>> function, instead make it static.  Makes the object code smaller
>>> by over 800 bytes:
>>>
>>>    text	   data	    bss	    dec	    hex	filename
>>>  159029	  33154	   1216	 193399	  2f377	4965-mac.o
>>>
>>>    text	   data	    bss	    dec	    hex	filename
>>>  158122	  33250	   1216	 192588	  2f04c	4965-mac.o
>>>
>>> (gcc version 7.2.0 x86_64)
>>
>> Gcc 7 must be much more aggressive about inlining than gcc 4.  Here is the
>> change that I got on this file:
>>
>>      text          data     bss     dec     hex filename
>> -   76346          1494     152   77992   130a8 drivers/net/wireless/intel/iwlegacy/4965-mac.o
>> +   76298          1494     152   77944   13078 drivers/net/wireless/intel/iwlegacy/4965-mac.o
>> decrease of 48
> 
> More likely different CONFIG options.
> 
> e.g. allyesconfig vs defconfig with wireless
> 
yup, I used allyesconfig