[llvm] [CodeGen][StaticDataPartitioning]Place local-linkage global variables in hot or unlikely prefixed sections based on profile information (PR #125756)

[Snehasish Kumar via llvm-commits]

================
@@ -0,0 +1,103 @@
+//===- StaticDataAnnotator - Annotate static data's section prefix --------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// To reason about module-wide data hotness in a module granularity, this file
+// implements a module pass StaticDataAnnotator to work coordinately with the
+// StaticDataSplitter pass.
+//
+// The StaticDataSplitter pass is a machine function pass. It analyzes data
+// hotness based on code and adds counters in the StaticDataProfileInfo.
+// The StaticDataAnnotator pass is a module pass. It iterates global variables
+// in the module, looks up counters from StaticDataProfileInfo and sets the
+// section prefix based on profiles.
+//
+// The three-pass structure is implemented for practical reasons, to work around
----------------
snehasish wrote:

The text above could be a little bit clearer that StaticDataProfileInfoWrapper is also a pass. When reading three-pass here I was a little confused.

https://github.com/llvm/llvm-project/pull/125756