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Re: Volatile MEMs in statement expressions and functions inlined as trees


On Dec  3, 2001, Richard Henderson <rth@redhat.com> wrote:

> On Sun, Dec 02, 2001 at 04:02:45PM -0200, Alexandre Oliva wrote:
>> Verification of correct behavior would require scanning
>> the assembly output to verify we don't have too many loads.

> As mentioned in rh internal mail, verification can be done
> via sigsegv handling, though that is also tough because this
> gets to be fairly cpu+os specific.

Does anybody have pointers to existing SIGSEGV handlers that will skip
a faulty instruction on say GNU/Linux/x86 (probably the most common
target these days, and one I happen to have local access to :-)

I've had a look at boehm-gc, but it doesn't seem to skip the
instruction; rather, it plays mmap tricks for garbage collection, and
probably longjmps out of the signal handler to handle faults related
with NULL accesses, which doesn't help in case you want to count how
many accesses you get out of a volatile construct :-(

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer                  aoliva@{cygnus.com, redhat.com}
CS PhD student at IC-Unicamp        oliva@{lsd.ic.unicamp.br, gnu.org}
Free Software Evangelist    *Please* write to mailing lists, not to me


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