Update DBG_VALUE to refer appropriate stack slot in case of a spill.

llvm-svn: 108023

1 files changed, 19 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/RegAllocFast.cpp b/llvm/lib/CodeGen/RegAllocFast.cpp
index 272eff24e46..f44478e5dd0 100644
--- a/llvm/lib/CodeGen/RegAllocFast.cpp
+++ b/llvm/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;