1 files changed, 28 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/ssa/id.go b/src/cmd/compile/internal/ssa/id.go
new file mode 100644
index 0000000..725279e
--- /dev/null
+++ b/src/cmd/compile/internal/ssa/id.go
@@ -0,0 +1,28 @@
+// Copyright 2015 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 ssa
+
+type ID int32
+
+// idAlloc provides an allocator for unique integers.
+type idAlloc struct {
+	last ID
+}
+
+// get allocates an ID and returns it. IDs are always > 0.
+func (a *idAlloc) get() ID {
+	x := a.last
+	x++
+	if x == 1<<31-1 {
+		panic("too many ids for this function")
+	}
+	a.last = x
+	return x
+}
+
+// num returns the maximum ID ever returned + 1.
+func (a *idAlloc) num() int {
+	return int(a.last + 1)
+}