[Skiboot] [PATCH] Honor DEAD_CODE_ELIMINATION flag

[Nicholas Piggin]

Mauro Rodrigues's on February 29, 2020 12:54 am:
> On Fri, Feb 28, 2020 at 12:00:44PM +1000, Nicholas Piggin wrote:
>> 
>> Obviously required, I got the same thing lying around.
>> 
>> Reviewed-by: Nicholas Piggin <npiggin at gmail.com>
>> 
>> Did you get much savings? It wasn't a great deal when I last tried.
>> 
> 
> Thanks for your review Nick!
> 
> In my last test I was able to save 55KiB out of 479KiB, so ~11%. But
> please bear in mind that this was achieved testing on top of some TSS
> changes we're developing - including mbedtls and ibmtpm20tss libraries
> as subtrees.
> 
> Testing at v6.0.21 it is indeed irrelevant, I was able to save just
> 1KiB.

Re-tested with upstream plus your patch

   text	   data	    bss	    dec	 filename
1486029	 259992	  48552	1794573	 skiboot.elf
1409501	 270736	  40080	1720317	 skiboot.elf.dce    ( -4.1%)
1302629	 246784	  48552	1597965	 skiboot.elf.le     ( -9.6%)
1243629	 239928	  40080	1523637	 skiboot.elf.le.dce (-15.1%)

Not too bad with LE :)

Interesting how the data section gets a bit larger with DCE with BE, I
didn't look why that is.

Thanks,
Nick