SuperWordLoopUnrollAnalysis and loop unrolling

Andrew Haley aph at
Tue Apr 18 07:40:54 UTC 2017

On 18/04/17 07:42, Yang Zhang wrote:
> I have run this test case.
> For aarch64 C2 with SuperWordLoopUnrollAnalysis=false:
> Loop unroll is still controlled by comparing body_size. When loop
> unroll is 16 times, body_size is big enough and it stops.
> For aarch64 C2 with SuperWordLoopUnrollAnalysis=true:
> First loop unroll is controlled by policy_unroll_slp_analysis. When
> loop unroll is 4 times, vectorization happens.
> If vectorization succeeds, loop unroll would be instigated more by
> set_major_progress until body_size is big enough.
> if vectorization fails, loop unroll stops.
> I haven't run the performance test.

I don't really understand what your point is.  How can you have run
the test case but not the performance test?  I think that you should
look at the performance in order to understand the issue.


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