[PATCH] D15548: Remove the restriction that known and unknown probabilities cannot coexist when being normalized.

Xinliang David Li via llvm-commits llvm-commits at lists.llvm.org
Wed Dec 16 10:45:36 PST 2015


On Wed, Dec 16, 2015 at 10:41 AM, Cong Hou <congh at google.com> wrote:
> congh added a comment.
>
> In http://reviews.llvm.org/D15548#312148, @davidxl wrote:
>
>> While it makes sense to do this -- can we start to teach producers not to pass unknown Probabilities in the first place?
>
>
> If you search addSuccessor in LLVM, you will find about 200 users for different platforms without probability passed explicitly. Some are conditionally used such as:
>
> MBB->addSuccessor(Succ1);
> if (...)
>
>   MBB->addSuccessor(Succ2);
>
> It seems that a default probability is more convenient but I don't object to add probabilities explicitly. There are just some tradeoffs.

yes -- that is a longer term cleanup. After all the cases are cleaned
up, we can add more restrictions.

David
>
>
> http://reviews.llvm.org/D15548
>
>
>


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