From 32ac1f159212365134142489e205c2a313c17c74 Mon Sep 17 00:00:00 2001
From: Marius Schulz <mds@anthropic.com>
Date: Sun, 7 Jun 2026 16:05:07 +0000
Subject: [PATCH] Inline GetCombinedNodeFlags/GetCombinedModifierFlags bodies
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Replace the generic getCombinedFlags[T] helper with direct field reads
in GetCombinedNodeFlags (node.Flags) and GetCombinedModifierFlags
(node.ModifierFlags()). The parent-walk and OR-accumulation are
unchanged; this just removes the indirect call through a function
pointer at each step.

getCombinedFlags and the trivial getNodeFlags wrapper had no other
callers and are removed.

Adds BenchmarkGetCombinedFlags over the standard fixture set.

BenchmarkGetCombinedFlags (interleaved n=12, GOGC=off, benchtime=200x):

| Fixture                   | Before        | After        | Δ       |
|---------------------------|---------------|--------------|---------|
| checker.ts                | 805.4 µs      | 610.8 µs     | −24.2%  |
| dom.generated.d.ts        | 284.0 µs      | 177.9 µs     | −37.4%  |
| Herebyfile.mjs            | 11.22 µs      | 6.17 µs      | −45.0%  |
| jsxComplexSignature….tsx  | 2.73 µs       | 1.53 µs      | −43.8%  |

VS Code end-to-end (tsgo -p vscode/src --noEmit), single-threaded:

| Metric                                | Before           | After           | Δ                       |
|---------------------------------------|------------------|-----------------|-------------------------|
| instructions:u (GOGC=off, min-of-3)   | 100,168,751,028  | 99,897,715,729  | −0.27%                  |
| wall, mean (interleaved n=14)         | 20.92 s          | 20.66 s         | −1.24% (p=0.149, n.s.)  |
| Types / Symbols / Instantiations      | identical        | identical       |                         |

VS Code end-to-end, parallel (default GOMAXPROCS):

| Metric                          | Before  | After   | Δ                       |
|---------------------------------|---------|---------|-------------------------|
| wall, mean (interleaved n=16)   | 7.07 s  | 7.12 s  | +0.77% (p=0.652, n.s.)  |
---
 internal/ast/utilities.go            | 30 +++++++++--------
 internal/ast/utilities_bench_test.go | 48 ++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+), 13 deletions(-)
 create mode 100644 internal/ast/utilities_bench_test.go

diff --git a/internal/ast/utilities.go b/internal/ast/utilities.go
index 8554c14276a..f1220cea7f4 100644
--- a/internal/ast/utilities.go
+++ b/internal/ast/utilities.go
@@ -1143,32 +1143,36 @@ func GetRootDeclaration(node *Node) *Node {
 	return node
 }
 
-func getCombinedFlags[T ~uint32](node *Node, getFlags func(*Node) T) T {
+func GetCombinedModifierFlags(node *Node) ModifierFlags {
 	node = GetRootDeclaration(node)
-	flags := getFlags(node)
+	flags := node.ModifierFlags()
 	if node.Kind == KindVariableDeclaration {
 		node = node.Parent
 	}
 	if node != nil && node.Kind == KindVariableDeclarationList {
-		flags |= getFlags(node)
+		flags |= node.ModifierFlags()
 		node = node.Parent
 	}
 	if node != nil && node.Kind == KindVariableStatement {
-		flags |= getFlags(node)
+		flags |= node.ModifierFlags()
 	}
 	return flags
 }
 
-func GetCombinedModifierFlags(node *Node) ModifierFlags {
-	return getCombinedFlags(node, (*Node).ModifierFlags)
-}
-
 func GetCombinedNodeFlags(node *Node) NodeFlags {
-	return getCombinedFlags(node, getNodeFlags)
-}
-
-func getNodeFlags(node *Node) NodeFlags {
-	return node.Flags
+	node = GetRootDeclaration(node)
+	flags := node.Flags
+	if node.Kind == KindVariableDeclaration {
+		node = node.Parent
+	}
+	if node != nil && node.Kind == KindVariableDeclarationList {
+		flags |= node.Flags
+		node = node.Parent
+	}
+	if node != nil && node.Kind == KindVariableStatement {
+		flags |= node.Flags
+	}
+	return flags
 }
 
 // Gets whether a bound `VariableDeclaration` or `VariableDeclarationList` is part of an `await using` declaration.
diff --git a/internal/ast/utilities_bench_test.go b/internal/ast/utilities_bench_test.go
new file mode 100644
index 00000000000..30e4465ba1b
--- /dev/null
+++ b/internal/ast/utilities_bench_test.go
@@ -0,0 +1,48 @@
+package ast_test
+
+import (
+	"testing"
+
+	"github.com/microsoft/typescript-go/internal/ast"
+	"github.com/microsoft/typescript-go/internal/core"
+	"github.com/microsoft/typescript-go/internal/parser"
+	"github.com/microsoft/typescript-go/internal/testutil/fixtures"
+	"github.com/microsoft/typescript-go/internal/tspath"
+	"github.com/microsoft/typescript-go/internal/vfs/osvfs"
+)
+
+func BenchmarkGetCombinedFlags(b *testing.B) {
+	for _, f := range fixtures.BenchFixtures {
+		b.Run(f.Name(), func(b *testing.B) {
+			f.SkipIfNotExist(b)
+
+			fileName := tspath.GetNormalizedAbsolutePath(f.Path(), "/")
+			path := tspath.ToPath(fileName, "/", osvfs.FS().UseCaseSensitiveFileNames())
+			sourceText := f.ReadFile(b)
+			scriptKind := core.GetScriptKindFromFileName(fileName)
+
+			sourceFile := parser.ParseSourceFile(ast.SourceFileParseOptions{
+				FileName: fileName,
+				Path:     path,
+			}, sourceText, scriptKind)
+
+			var decls []*ast.Node
+			var collect ast.Visitor
+			collect = func(n *ast.Node) bool {
+				if ast.IsDeclaration(n) {
+					decls = append(decls, n)
+				}
+				n.ForEachChild(collect)
+				return false
+			}
+			sourceFile.AsNode().ForEachChild(collect)
+
+			for b.Loop() {
+				for _, n := range decls {
+					_ = ast.GetCombinedNodeFlags(n)
+					_ = ast.GetCombinedModifierFlags(n)
+				}
+			}
+		})
+	}
+}