[XRay] Use DenseMap::{operator[],try_emplace} (NFC)

[kazutakahirata]

I'm planning to deprecate DenseMap::FindAndConstruct in favor of
operator[]. I'm using try_emplace because "Vertices[I.first];" on its
own might look like a nop statement.

[llvmbot]

@llvm/pr-subscribers-xray

Author: Kazu Hirata (kazutakahirata)

Changes

I'm planning to deprecate DenseMap::FindAndConstruct in favor of
operator[]. I'm using try_emplace because "Vertices[I.first];" on its
own might look like a nop statement.

---

Full diff: https://github.com/llvm/llvm-project/pull/107178.diff

1 Files Affected:

• (modified) llvm/include/llvm/XRay/Graph.h (+7-9)

diff --git a/llvm/include/llvm/XRay/Graph.h b/llvm/include/llvm/XRay/Graph.h index 953ac1aa696371..6c8b178e58ff8c 100644 --- a/llvm/include/llvm/XRay/Graph.h +++ b/llvm/include/llvm/XRay/Graph.h @@ -378,20 +378,18 @@ class Graph { /// Looks up the vertex with identifier I, if it does not exist it default /// constructs it. - VertexAttribute &operator[](const VertexIdentifier &I) { - return Vertices.FindAndConstruct(I).second; - } + VertexAttribute &operator[](const VertexIdentifier &I) { return Vertices[I]; } /// Looks up the edge with identifier I, if it does not exist it default /// constructs it, if it's endpoints do not exist it also default constructs /// them. EdgeAttribute &operator[](const EdgeIdentifier &I) { - auto &P = Edges.FindAndConstruct(I); - Vertices.FindAndConstruct(I.first); - Vertices.FindAndConstruct(I.second); + auto &Attr = Edges[I]; + Vertices.try_emplace(I.first); + Vertices.try_emplace(I.second); InNeighbors[I.second].insert(I.first); OutNeighbors[I.first].insert(I.second); - return P.second; + return Attr; } /// Looks up a vertex with Identifier I, or an error if it does not exist. @@ -479,8 +477,8 @@ class Graph { auto EI = Val.first; const auto &p = Edges.insert(std::move(Val)); if (p.second) { - Vertices.FindAndConstruct(EI.first); - Vertices.FindAndConstruct(EI.second); + Vertices.try_emplace(EI.first); + Vertices.try_emplace(EI.second); InNeighbors[EI.second].insert(EI.first); OutNeighbors[EI.first].insert(EI.second); }; 

[nikic]

LGTM