tree 0c236e5a676798f66fb5fa620ddad7e48229032a
parent 407bbed8c52312cc5c2d55f32d9d0077de0288ce
author Tim King <taking@google.com> 1671166748 -0800
committer Tim King <taking@google.com> 1675201126 +0000

go/ast/inspector: skip ranges that do not contain a node type

Skips inspecting a range of nodes that do not contain any nodes
of a given type. Computes a bitmask of type nodes between push
and pop events. Skips forward to pop if nodes in between cannot
match the type mask.

Benchmarking against previous implementation on "net":
- Preorder filtered by *ast.FuncDecl and *ast.FuncLit
  traversal is faster by 11x.
- Preorder filtered by *ast.CallExpr is faster by 10%.
- Unfiltered traveral is 5% slower.
- Constructing events 3% slower.
- Break even for additional computation is 5 *CallExpr
  filtered traversals or 1 *Func{Decl,Lit} filtered
  traversal.

Change-Id: If4cb566474b84186ff42fb80ed7e1ebb0f692cc2
Reviewed-on: https://go-review.googlesource.com/c/tools/+/458075
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Tim King <taking@google.com>
Reviewed-by: Alan Donovan <adonovan@google.com>