From 568f528c997505706d3d02a31517338ef7dc2d17 Mon Sep 17 00:00:00 2001
From: Jim Grosbach <grosbach@apple.com>
Date: Fri, 10 Dec 2010 18:41:15 +0000
Subject: [PATCH] Teach isCSRestore() that ARM/Thumb2 functions will use
 post-modify LDR instructions to restore a single register rather than an LDM
 instruction. rdar://8754999

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121498 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/ARM/ARMFrameInfo.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/Target/ARM/ARMFrameInfo.cpp b/lib/Target/ARM/ARMFrameInfo.cpp
index 71b60794f32..e2efbd61fcd 100644
--- a/lib/Target/ARM/ARMFrameInfo.cpp
+++ b/lib/Target/ARM/ARMFrameInfo.cpp
@@ -92,6 +92,11 @@ static bool isCSRestore(MachineInstr *MI,
         return false;
     return true;
   }
+  if ((MI->getOpcode() == ARM::LDR_POST ||
+       MI->getOpcode() == ARM::t2LDR_POST) &&
+      isCalleeSavedRegister(MI->getOperand(0).getReg(), CSRegs) &&
+      MI->getOperand(1).getReg() == ARM::SP)
+    return true;
 
   return false;
 }