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Re: Dumb register allocation (PPC)


In message <200205151847.OAA25950@makai.watson.ibm.com>, David Edelsohn writes:
 > >>>>> Geoff Keating writes:
 > 
 > Geoff> Either the change is correct or it is not.  If it is correct, it work
 > s
 > Geoff> for all targets.  If it is not, it'll probably break something on mos
 > t
 > Geoff> targets, and we don't want it.
 > 
 > 	So we're essentially in the same position as the store-motion
 > discussion: we believe that enabling the functionality may cause failures,
 > but we do not have a testcase showing a failure.
If the code potentially extends the lifetime of the return register, then
it is incorrect.  

GCC is not prepared to deal with the return register being live except
immediately after a function call and immedietly before the current
function returns.

Jeff


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