IPv4 checksum oddness (gcc compiler bug?)
mike at urgle.com
Wed Aug 25 04:12:24 PDT 2004
On Wed, 2004-08-25 at 00:57, Li, Qing wrote:
> I ran into a checksum problem and filed the following bug
> See if it's related.
To quote from Apple's GCC 3.3 docs:
You can't expect a sequence of volatile asm instructions to remain
perfectly consecutive. If you want consecutive output, use a single
asm. Also, GCC will perform some optimizations across a volatile asm
instruction; GCC does not "forget everything" when it encounters a
volatile asm instruction the way some other compilers do.
I've added a patch to the PR above which uses a single asm statement;
I'll make some noise about it post 5.3.
Mike Bristow - http://www.urgle.com/~mike/ - mike at urgle.com
Why did the farmer call his horse Blacksmith?
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