[llvm-commits] [llvm] r56326 - in /llvm/trunk: include/llvm/CodeGen/LiveInterval.h include/llvm/CodeGen/LiveIntervalAnalysis.h lib/CodeGen/LiveInterval.cpp lib/CodeGen/LiveIntervalAnalysis.cpp lib/CodeGen/RegAllocLinearScan.cpp

[Dale Johannesen]

On Sep 19, 2008, at 10:48 AMPDT, Evan Cheng wrote:
>>
>>    float weight;        // weight of this interval
>> +    bool isEarlyClobber;
>> +    bool overlapsEarlyClobber;
>
> Hi Dale,
>
> I don't think we want two bits. I'd rather go with one bit and have
> register allocator look at both use and def operands. What do you  
> think?

The comment explains why I don't want to do this:
>>
>> +/// Dropping the distinction between earlyclobber and earlyclobber-
>> conflict,
>> +/// keeping only one bit, looks promising, but two earlyclobber-
>> conflict
>> +/// operands may be assigned the same register if they happen to
>> contain the
>> +/// same value, and that implementation would prevent this.