[PATCH] blockfreq: Rewrite block frequency analysis

[Duncan P. N. Exon Smith]

On Mar 25, 2014, at 7:23 PM, Chandler Carruth <chandlerc at google.com> wrote:

> 
> Ok. I think having the terminology clarified will also help me understand the code.
> 
> 
> The only thing that I think really needs to be sorted out (other than the stuff you've clarified you're planning to do already) prior to commit is the positive float issue. I'm just a bit hesitant to put that into Support only to rip it back out. ;] But maybe that doesn't matter too much.

FYI, I committed the preparatory patches recently: r204740 and r204741.

Here’s a new plan for the remainder that minimizes churn in Support:

 1. Move BlockMass and PositiveFloat into private headers.  Strip their
    tests from the patch, but hang onto them out of tree.
 
 2. Commit everything as a new class that’s unused.

 3. Move non-trivial things I need from BlockMass and PositiveFloat into
    Support (sharing implementation details with APFloat, where possible). 
    I’ll commit tests for the functionality I need.

 4. Switch from soft-float to power-of-two-except-3 loop-scale.  (Delete
    PositiveFloat at this point.)

 5. Switch to LoopInfo.

 6. Respond to the rest of the review comments incrementally.

 7. Turn it on.

 8. Kill the old one.

Sound good?