Re: [PATCH 06/14] Pramfs: Include files

From: Arnd Bergmann
Date: Mon Jun 22 2009 - 19:08:12 EST

On Monday 22 June 2009, JÃrn Engel wrote:
> Four loops doing the same increment with different data types: long,
> u64, we32 (wrong-endian) and we64. Compile with no optimizations.
> Results on my i386 notebook:
> long: 453953 us
> we32: 880273 us
> u64: 504214 us
> we64: 2259953 us
> loops: 100000000

(couldn't resist)

The we64 number is artificially high because the glibc bswap_64
implementation forces the conversion to be done on the stack.
Using __builtin_bswap64 make this look more logical, and
makes your point even stronger (on core 2, using -m32):

long: 236792 us
we32: 500827 us
u64: 265990 us
we64: 757380 us
loops: 100000000

Arnd <><
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at