From 7a029b6d7e58cb0f1010f14d99d7661e387cfb54 Mon Sep 17 00:00:00 2001
From: Devang Patel <dpatel@apple.com>
Date: Fri, 9 Jul 2010 21:48:31 +0000
Subject: [PATCH] Update DBG_VALUE to refer appropriate stack slot in case of a
 spill.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108023 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/RegAllocFast.cpp | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/lib/CodeGen/RegAllocFast.cpp b/lib/CodeGen/RegAllocFast.cpp
index 272eff24e46..f44478e5dd0 100644
--- a/lib/CodeGen/RegAllocFast.cpp
+++ b/lib/CodeGen/RegAllocFast.cpp
@@ -764,8 +764,25 @@ void RAFast::AllocateBasicBlock() {
         LiveRegMap::iterator LRI = LiveVirtRegs.find(Reg);
         if (LRI != LiveVirtRegs.end())
           setPhysReg(MI, i, LRI->second.PhysReg);
-        else
-          MO.setReg(0); // We can't allocate a physreg for a DebugValue, sorry!
+        else {
+          int SS = StackSlotForVirtReg[Reg];
+          if (SS == -1)
+            MO.setReg(0); // We can't allocate a physreg for a DebugValue, sorry!
+          else {
+            // Modify DBG_VALUE now that the value is in a spill slot.
+            uint64_t Offset = MI->getOperand(1).getImm();
+            const MDNode *MDPtr = 
+              MI->getOperand(MI->getNumOperands()-1).getMetadata();
+            DebugLoc DL = MI->getDebugLoc();
+            if (MachineInstr *NewDV = 
+                TII->emitFrameIndexDebugValue(*MF, SS, Offset, MDPtr, DL)) {
+              DEBUG(dbgs() << "Modifying debug info due to spill:" << "\t" << *MI);
+              MachineBasicBlock *MBB = MI->getParent();
+              MBB->insert(MBB->erase(MI), NewDV);
+            } else
+              MO.setReg(0); // We can't allocate a physreg for a DebugValue, sorry!
+          }
+        }
       }
       // Next instruction.
       continue;