[LLVMdev] Find all backedges of CFG by MachineDominatorTree. please look at my jpg.

[任坤]

Hi:

I hope to cut all backedges of MachineFunction CFG, then topological sort MachineBasicBlocks.

1. MachineDominatorTree *domintree = new MachineDominatorTree();
   domintree->runOnMachineFunction(mf);

2. Then travel mf one by one.
   When domintree->dominates(next,current) is true, there is a backedge from current node to next node. move this backedge form CFG.

   But I find A LOOP in some CFG, there is backedge from current to next, dominates function reture "FALSE". So my algorithm find Graph can not be
toplogical sort.

3. how do I find all backedges of CFG???

Thanks 
renkun


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