Re: [PATCH] UBIFS: endian handling fixes and annotations

[Jamie Lokier <jamie@shareable.org>]

Sebastian Andrzej Siewior wrote:
> >-	return le32_to_cpu(key->u32[1]) >> UBIFS_S_KEY_BLOCK_BITS;
> >+	return le32_to_cpu(key->j32[1]) >> UBIFS_S_KEY_BLOCK_BITS;
> 
> If you would change such references to something like
> |return le32_to_cpup(&key->j32[1]) >> UBIFS_S_KEY_BLOCK_BITS;
> then on powerpc
> 
>   text    data     bss     dec     hex filename
> 155384    1284      24  156692   26414 ubifs-b4.ko
> 155372    1284      24  156680   26408 ubifs-after.ko
> 
> because now it is possible to load the value as LE from memory instead
> of loading it BE and swapping it afterwads.

If le32_to_cpu used __builtin_bswap32 (a GCC builtin), wouldn't
GCC do this trivial optimisation itself?

-- Jamie