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Re: PATCH: Fix 20000724-1.c
>>>>> "Richard" == Richard Henderson <rth@redhat.com> writes:
Richard> No they wouldn't. The stack frame got deallocated too
Richard> early. An interrupt could arrive and clobber the memory
Richard> even if the asm itself wouldn't.
Yup, I get it now.
>> ] If the side-effects of your instruction are not purely
>> external, but ] will affect variables in your program in ways
>> other than reading the ] inputs and clobbering the specified
>> registers or memory, you should ] write the `volatile' keyword
>> to prevent future versions of GNU CC ] from moving the
>> instruction around within a core region.
Richard> On re-reading, this is incredibly misleading.
>> In fact, that sentence seems to say that a volatile asm can
>> mess with anything it wants without having anything in its
>> clobbers at all!
Richard> Definitely incorrect.
OK.
I'll try to straighten this out, as I'm in the docs now anyhow.
Richard> It looks as if Jan's regmove changes never got in. Cause
Richard> they definitely should have handled this sort of case. I
Richard> thought I remembered acking one version of them though...
Richard> I'll track them down and see what's up.
OK. Thanks!
Will you revert my bogus test-case change if you find the patch, too,
please? Thank you!
--
Mark Mitchell mark@codesourcery.com
CodeSourcery, LLC http://www.codesourcery.com