Skip to content

[MCA] Do not allocate space for DependenceEdge by default in DependencyGraphNode (NFC) #125080

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Jan 31, 2025
Merged

[MCA] Do not allocate space for DependenceEdge by default in DependencyGraphNode (NFC) #125080

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
7714544
[MCA] Do not allocate space for DependenceEdge by default in Dependen…
asi-sc Jan 16, 2025
2347838
fixup! [MCA] Do not allocate space for DependenceEdge by default in D…
asi-sc Jan 31, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 4 additions & 1 deletion llvm/tools/llvm-mca/Views/BottleneckAnalysis.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -228,7 +228,10 @@ class DependencyGraph {
unsigned Depth;

DependencyEdge CriticalPredecessor;
SmallVector<DependencyEdge, 8> OutgoingEdges;
// Measurements show that more than 90% of nodes have no outgoing edges. To
// minimize memory consumption we use SmallVector with zero inline elements
// that is preferred version of std::vector.
SmallVector<DependencyEdge, 0> OutgoingEdges;
Copy link
Collaborator

@adibiagio adibiagio Jan 30, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think it is useful to have a comment (not more than a couple of lines) explaining why zero was used for the number of inline elements. Otherwise it would be unclear for the reader why we chose that number in this case.

};
SmallVector<DGNode, 16> Nodes;

Expand Down