[PATCH] D19926: Simplify CFG before assigning discriminator.

[Dehao Chen via llvm-commits]

danielcdh added a comment.

In http://reviews.llvm.org/D19926#421359, @dblaikie wrote:

> "minimize the impact of optimization on debug info." - what sort of impact are you referring to?


SampleProfile profile is collected on optimized binary. So at profile annotation step, it's better to have an IR resemble the optimized binary structure. Discriminator is the key to represent the profile, and SimplefyCFG is one major optimization that would change CFG. So if we move discriminator assignment after simplycfg, then at profile used at annotation would be more likely to resemble the optimized binary that is used for profiling.


http://reviews.llvm.org/D19926