Michael Zolotukhin 805e09d964 [SCEV] createAddRecFromPHI: Optimize for the most common case.
Summary:
The existing implementation creates a symbolic SCEV expression every
time we analyze a phi node and then has to remove it, when the analysis
is finished. This is very expensive, and in most of the cases it's also
unnecessary. According to the data I collected, ~60-70% of analyzed phi
nodes (measured on SPEC) have the following form:
  PN = phi(Start, OP(Self, Constant))
Handling such cases separately significantly speeds this up.

Reviewers: sanjoy, pete

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D32663

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302096 91177308-0d34-0410-b5e6-96231b3b80d8
2017-05-03 23:53:38 +00:00
..
2017-05-03 20:33:52 +00:00
2017-05-03 23:32:51 +00:00