identify non-countable loops in LLVM

How can I i开发者_StackOverflow中文版dentify if a loop is countable or not in LLVM? Is there some library function that can be directly used?

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Try hasLoopInvariantBackedgeTakenCount on ScalarEvolution. See http://llvm.org/doxygen/classllvm_1_1ScalarEvolution.html#aecd7aba4460358813feef37d71d5024e .

(If that isn't what you are looking for, please clarify.)