[llvm-dev] Spill Weight In InlineSpiller

[Kerbow, Austin Michael via llvm-dev]

I'm trying to compute and print a weighted spill cost based upon the execution frequency of the basic block where the spill is inserted. My goal is to analyse what effect scheduling changes have on the sum of this weighted spill cost in some benchmarks. I've experimented doing this directly before a spill is inserted in InlineSpiller.cpp using MBFI.getBlockFreq() and LiveIntervals::getSpillWeight. My question is why are these functions sometimes indicating that the frequency of a block, or the weight of a spill is 0? A frequency of 0 doesn't make sense to me.

Thanks,

Austin Kerbow