Replace r102368 with code that's less fragile. This creates DBG_VALUE instructions for function arguments early and insert them after instruction selection is done.

llvm-svn: 102554

1 files changed, 9 insertions, 28 deletions

diff --git a/llvm/lib/CodeGen/MachineRegisterInfo.cpp b/llvm/lib/CodeGen/MachineRegisterInfo.cpp
index 724d81cdba8..ea5ca0cad8a 100644
--- a/llvm/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/llvm/lib/CodeGen/MachineRegisterInfo.cpp
@@ -147,6 +147,15 @@ bool MachineRegisterInfo::isLiveOut(unsigned Reg) const {
   return false;
 }
 
+/// getLiveInPhysReg - If VReg is a live-in virtual register, return the
+/// corresponding live-in physical register.
+unsigned MachineRegisterInfo::getLiveInPhysReg(unsigned VReg) const {
+  for (livein_iterator I = livein_begin(), E = livein_end(); I != E; ++I)
+    if (I->second == VReg)
+      return I->first;
+  return 0;
+}
+
 static cl::opt<bool>
 SchedLiveInCopies("schedule-livein-copies", cl::Hidden,
                   cl::desc("Schedule copies of livein registers"),
@@ -220,30 +229,6 @@ static void EmitLiveInCopy(MachineBasicBlock *MBB,
   }
 }
 
-/// InsertLiveInDbgValue - Insert a DBG_VALUE instruction for each live-in
-/// register that has a corresponding source information metadata. e.g.
-/// function parameters.
-static void InsertLiveInDbgValue(MachineBasicBlock *MBB,
-                                 MachineBasicBlock::iterator InsertPos,
-                                 unsigned LiveInReg, unsigned VirtReg,
-                                 const MachineRegisterInfo &MRI,
-                                 const TargetInstrInfo &TII) {
-  for (MachineRegisterInfo::use_iterator UI = MRI.use_begin(VirtReg),
-         UE = MRI.use_end(); UI != UE; ++UI) {
-    MachineInstr *UseMI = &*UI;
-    if (!UseMI->isDebugValue() || UseMI->getParent() != MBB)
-      continue;
-    // Found local dbg_value. FIXME: Verify it's not possible to have multiple
-    // dbg_value's which reference the vr in the same mbb.
-    uint64_t Offset = UseMI->getOperand(1).getImm();
-    const MDNode *MDPtr = UseMI->getOperand(2).getMetadata();    
-    BuildMI(*MBB, InsertPos, InsertPos->getDebugLoc(),
-            TII.get(TargetOpcode::DBG_VALUE))
-      .addReg(LiveInReg).addImm(Offset).addMetadata(MDPtr);
-    return;
-  }
-}
-
 /// EmitLiveInCopies - Emit copies to initialize livein virtual registers
 /// into the given entry block.
 void
@@ -260,8 +245,6 @@ MachineRegisterInfo::EmitLiveInCopies(MachineBasicBlock *EntryMBB,
         const TargetRegisterClass *RC = getRegClass(LI->second);
         EmitLiveInCopy(EntryMBB, InsertPos, LI->second, LI->first,
                        RC, CopyRegMap, *this, TRI, TII);
-        InsertLiveInDbgValue(EntryMBB, InsertPos,
-                             LI->first, LI->second, *this, TII);
       }
   } else {
     // Emit the copies into the top of the block.
@@ -273,8 +256,6 @@ MachineRegisterInfo::EmitLiveInCopies(MachineBasicBlock *EntryMBB,
                                         LI->second, LI->first, RC, RC);
         assert(Emitted && "Unable to issue a live-in copy instruction!\n");
         (void) Emitted;
-        InsertLiveInDbgValue(EntryMBB, EntryMBB->begin(),
-                             LI->first, LI->second, *this, TII);
       }
   }