tree 1e7924721c322a7a0d6dc7176520b17639a2c6a8
parent 063360f92f43b9451c74b1a58b3aad6f5153f908
author Zvonimir Pavlinovic <zpavlinovic@google.com> 1724265143 +0000
committer Zvonimir Pavlinovic <zpavlinovic@google.com> 1725052161 +0000

go/callgraph/vta: add return parameter nodes for functions

The change improves the performance of VTA. If a function returns F
values, has R return instructions, and is called at C places (as
given by the initial call graph), previously we could generate
R x F x C edges in the type propagation graph. With the approach
of introducing artificial return parameters, we create F x (R + C)
edges instead.

Measured on a large project, this introduces ~5% time savings on
average. When the initial call graph is CHA, the type propagation graph
is ~31% smaller. When the resulting call graph is then used as the
initial call graph, then the graph is ~21% smaller.

This will also enable use of one-direction callgraphs.

Change-Id: I5de1774f11ce3bf23ac3c768df9e2c9f37777817
Reviewed-on: https://go-review.googlesource.com/c/tools/+/609318
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Alan Donovan <adonovan@google.com>
Reviewed-by: Tim King <taking@google.com>