From 87d8f7d9fb0673d09fb245511a8ed0b1a4e3eee3 Mon Sep 17 00:00:00 2001
From: Andy Ayers <andya@microsoft.com>
Date: Fri, 17 Jul 2020 16:21:27 -0700
Subject: [PATCH] Revert "Kill REG_PROFILER_RET_SCRATCH (#37679)" (#39335)

This reverts commit b179e198403adbfbf275a40741cef7b252cda186.
---
 src/coreclr/src/jit/lsraarm.cpp | 2 --
 src/coreclr/src/jit/target.h    | 4 +---
 2 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/src/coreclr/src/jit/lsraarm.cpp b/src/coreclr/src/jit/lsraarm.cpp
index da91c7b9dde4bf..f3b480fddd6d01 100644
--- a/src/coreclr/src/jit/lsraarm.cpp
+++ b/src/coreclr/src/jit/lsraarm.cpp
@@ -491,8 +491,6 @@ int LinearScan::BuildNode(GenTree* tree)
 
         case GT_RETURN:
             srcCount = BuildReturn(tree);
-            killMask = getKillSetForReturn();
-            BuildDefsWithKills(tree, 0, RBM_NONE, killMask);
             break;
 
         case GT_RETFILT:
diff --git a/src/coreclr/src/jit/target.h b/src/coreclr/src/jit/target.h
index 6e79bfac3df531..c9fc28df7bb1c8 100644
--- a/src/coreclr/src/jit/target.h
+++ b/src/coreclr/src/jit/target.h
@@ -1103,9 +1103,7 @@ typedef unsigned char   regNumberSmall;
   // The registers trashed by profiler enter/leave/tailcall hook
   // See vm\arm\asmhelpers.asm for more details.
   #define RBM_PROFILER_ENTER_TRASH     RBM_NONE
-  // While REG_PROFILER_RET_SCRATCH is not trashed by the method, the register allocator must
-  // consider it killed by the return.
-  #define RBM_PROFILER_LEAVE_TRASH     RBM_PROFILER_RET_SCRATCH
+  #define RBM_PROFILER_LEAVE_TRASH     RBM_NONE
   #define RBM_PROFILER_TAILCALL_TRASH  RBM_NONE
 
   // Which register are int and long values returned in ?