1 files changed, 29 insertions, 0 deletions
diff --git a/src/runtime/_mkmalloc/constants.go b/src/runtime/_mkmalloc/constants.go
new file mode 100644
index 0000000000..ad20c7b52b
--- /dev/null
+++ b/src/runtime/_mkmalloc/constants.go
@@ -0,0 +1,29 @@
+// Copyright 2025 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+const (
+	// Constants that we use and will transfer to the runtime.
+	minHeapAlign = 8
+	maxSmallSize = 32 << 10
+	smallSizeDiv = 8
+	smallSizeMax = 1024
+	largeSizeDiv = 128
+	pageShift    = 13
+	tinySize     = 16
+
+	// Derived constants.
+	pageSize = 1 << pageShift
+)
+
+const (
+	maxPtrSize = max(4, 8)
+	maxPtrBits = 8 * maxPtrSize
+
+	// Maximum size smallScanNoHeader would be called for, which is the
+	// maximum value gc.MinSizeForMallocHeader can have on any platform.
+	// gc.MinSizeForMallocHeader is defined as goarch.PtrSize * goarch.PtrBits.
+	smallScanNoHeaderMax = maxPtrSize * maxPtrBits
+)