[LLVMdev] Array Dependence Analysis
dpatel at apple.com
Tue Mar 18 09:03:31 PDT 2008
On Mar 18, 2008, at 8:03 AM, Wojciech Matyjewicz wrote:
> Devang Patel wrote:
>> LLVM loop transformer operates at loop level, which is not what many
>> optimizers do in general. So, a loop level interface (i.e. based on
>> LoopPass in llvm) to find loop-carried dependence is preferable to
>> loop optimizer.
> Do you mean making Array Dependence Analysis a loop-level analysis?
> Would its results be available for some function-level pass then?
We could extend pass manager framework to let function-level pass use
loop-level analysis info. However that is not ideal.
A loop level pass operates on a loop only. If a function level pass
needs array dependence analysis info then it expects info. to cover
entire function. Which means, it will need function level array
dependence analysis pass, which is natural. If loop level pass, say
LP, is interested in array dependence info, then in many cases it is
more interested in loop-carried dependence info for a given loop. If
such info. is made available to through a loop level pass then it'd
allow loop pass manager to execute allow loop pass manager to handle
LP together with other loop passes.
More information about the llvm-dev