[LLVMdev] Scheduler information

Llopard Ivan ivanllopard at gmail.com
Thu Nov 24 08:13:53 PST 2011


Hi list,

Could anyone help me to roughly understand the internal data dependecy 
structure used by the scheduler ?
As far as I can see in /lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp, 
SUnit nodes are created to wrap SDNodes with scheduling related 
information and SDeps represent all kind of dependencies between them.

Nevertheless, I cannot figure out the graphical form of such structure. 
For example, in a simple SDep::Data dependency like the following one:

Node1: def reg1
Node2: use reg1

Is Node1 the predecessor of Node2 or viceversa ?

Ivan





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