From 1616d2e7c91d12ef9bde2e05b5d770b2f553d61d Mon Sep 17 00:00:00 2001
From: Jan Kotas <jkotas@microsoft.com>
Date: Wed, 22 Jul 2020 11:10:44 -0700
Subject: [PATCH] Add rules for changing InstructionSetDesc.txt (#39777)

---
 .../Common/JitInterface/ThunkGenerator/InstructionSetDesc.txt | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/coreclr/src/tools/Common/JitInterface/ThunkGenerator/InstructionSetDesc.txt b/src/coreclr/src/tools/Common/JitInterface/ThunkGenerator/InstructionSetDesc.txt
index 615fc9648ed58a..d8fe3984a92515 100644
--- a/src/coreclr/src/tools/Common/JitInterface/ThunkGenerator/InstructionSetDesc.txt
+++ b/src/coreclr/src/tools/Common/JitInterface/ThunkGenerator/InstructionSetDesc.txt
@@ -15,6 +15,10 @@
 ; Copy instruction sets defined for other architecture at this point in the file.
 ; copyinstructionsets,<architecture>,<copytoarchitecture>
 
+; UPDATE JIT/EE INTERFACE GUID WHEN CHANGING THESE DEFINITIONS. The instruction set definitions are part of JIT/EE interface contract.
+
+; DO NOT CHANGE R2R NUMERIC VALUES OF THE EXISTING SETS. Changing R2R numberic values definitions would be R2R format breaking change.
+
 ; Definition of X86 instruction sets
 definearch         ,X86   ,32Bit     ,X64