Commit Graph

3 Commits

Author SHA1 Message Date
Easwaran Raman 06a715333a Remove CallGraphTraits and use equivalent methods in GraphTraits
Summary:
D42698 adds child_edge_{begin|end} and children_edges to GraphTraits
which are used here. The reason for this change is to make it easy to
use count propagation on ModulesummaryIndex. As it stands,
CallGraphTraits is in Analysis while ModuleSummaryIndex is in IR.

Reviewers: davidxl, dberlin

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42703

llvm-svn: 323994
2018-02-01 19:40:35 +00:00
Easwaran Raman 8410c37465 [SyntheticCounts] Rewrite the code using only graph traits.
Summary:
The intent of this is to allow the code to be used with ThinLTO. In
Thinlink phase, a traditional Callgraph can not be computed even though
all the necessary information (nodes and edges of a call graph) is
available. This is due to the fact that CallGraph class is closely tied
to the IR. This patch first extends GraphTraits to add a CallGraphTraits
graph. This is then used to implement a version of counts propagation
on a generic callgraph.

Reviewers: davidxl

Subscribers: mehdi_amini, tejohnson, llvm-commits

Differential Revision: https://reviews.llvm.org/D42311

llvm-svn: 323475
2018-01-25 22:02:29 +00:00
Easwaran Raman bdf20261d8 Add a pass to generate synthetic function entry counts.
Summary:
This pass synthesizes function entry counts by traversing the callgraph
and using the relative block frequencies of the callsites. The intended
use of these counts is in inlining to determine hot/cold callsites in
the absence of profile information.

The pass is split into two files with the code that propagates the
counts in a callgraph in a Utils file. I plan to add support for
propagation in the thinlto link phase and the propagation code will be
shared and hence this split. I did not add support to the old PM since
hot callsite determination in inlining is not possible in old PM
(although we could use hot callee heuristic with synthetic counts in the
old PM it is not worth the effort tuning it)

Reviewers: davidxl, silvas

Subscribers: mgorny, mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D41604

llvm-svn: 322110
2018-01-09 19:39:35 +00:00