From 74e981e85509ca072b2a45d529dab3a9883613a2 Mon Sep 17 00:00:00 2001
From: Yudi Zheng <yzheng@openjdk.org>
Date: Fri, 9 May 2025 08:39:16 +0000
Subject: [PATCH] 8353735: [JVMCI] Allow specifying storage kind of the callee
 save register

Reviewed-by: dnsimon, cslucas
---
 .../share/classes/jdk/vm/ci/code/RegisterConfig.java | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/code/RegisterConfig.java b/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/code/RegisterConfig.java
index 09360885c0b..525930c8f3b 100644
--- a/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/code/RegisterConfig.java
+++ b/src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/code/RegisterConfig.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2009, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -94,6 +94,16 @@ public interface RegisterConfig {
      */
     RegisterArray getCalleeSaveRegisters();
 
+    /**
+     * Returns the storage kind for a callee-save register, which determines how the register is
+     * saved and restored. For example, according to the Windows x64 ABI, the upper portions of
+     * XMM0-XMM15 are considered destroyed, so saving the full width of these registers is not
+     * necessary.
+     */
+    default PlatformKind getCalleeSaveRegisterStorageKind(Architecture arch, Register calleeSaveRegister) {
+        return arch.getLargestStorableKind(calleeSaveRegister.getRegisterCategory());
+    }
+
     /**
      * Gets a map from register {@linkplain Register#number numbers} to register
      * {@linkplain RegisterAttributes attributes} for this register configuration.