[llvm-commits] [PATCH] Don't allocate out-of-class reserved register in regscavenger

[Jakob Stoklund Olesen]

Hi,

The attached patch fixes a bug in RegScavenger::scavengeRegister():

Reserved registers are not candidates for scavenging, and they are  
removed from the candidate list (a BitVector) like this:

     CreateRegClassMask(RC, Candidates);
     Candidates ^= ReservedRegs;

However, when there are reserved registers outside RC, this causes  
invalid bits to be set in Candidates.

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A better solution would perhaps be to add the method  
BitVector::reset(const BitVector&):

     Candidates.reset(ReservedRegs);

What do you think?

/jakob