DBG_VALUE does not have any side effects; it also makes no sense to mark it cheap as a copy.

llvm-svn: 123031

3 files changed, 8 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/MachineInstr.cpp b/llvm/lib/CodeGen/MachineInstr.cpp
index bc2a545a5f2..ccb2ffbab1d 100644
--- a/llvm/lib/CodeGen/MachineInstr.cpp
+++ b/llvm/lib/CodeGen/MachineInstr.cpp
@@ -1115,7 +1115,9 @@ bool MachineInstr::isSafeToMove(const TargetInstrInfo *TII,
     SawStore = true;
     return false;
   }
-  if (TID->isTerminator() || TID->hasUnmodeledSideEffects())
+
+  if (isLabel() || isDebugValue() ||
+      TID->isTerminator() || TID->hasUnmodeledSideEffects())
     return false;
 
   // See if this instruction does a load.  If so, we have to guarantee that the
diff --git a/llvm/lib/CodeGen/PeepholeOptimizer.cpp b/llvm/lib/CodeGen/PeepholeOptimizer.cpp
index 07c2b80dcb0..1ddfe8b7c23 100644
--- a/llvm/lib/CodeGen/PeepholeOptimizer.cpp
+++ b/llvm/lib/CodeGen/PeepholeOptimizer.cpp
@@ -336,7 +336,9 @@ bool PeepholeOptimizer::runOnMachineFunction(MachineFunction &MF) {
       MachineInstr *MI = &*MII++;
       LocalMIs.insert(MI);
 
-      if (MI->getDesc().hasUnmodeledSideEffects())
+      if (MI->isLabel() || MI->isPHI() || MI->isImplicitDef() ||
+          MI->isKill() || MI->isInlineAsm() || MI->isDebugValue() ||
+          MI->getDesc().hasUnmodeledSideEffects())
         continue;
 
       if (MI->getDesc().isCompare()) {
diff --git a/llvm/lib/CodeGen/VirtRegRewriter.cpp b/llvm/lib/CodeGen/VirtRegRewriter.cpp
index 14ee69da4c2..d04b9285bab 100644
--- a/llvm/lib/CodeGen/VirtRegRewriter.cpp
+++ b/llvm/lib/CodeGen/VirtRegRewriter.cpp
@@ -1620,7 +1620,8 @@ static bool isSafeToDelete(MachineInstr &MI) {
   const TargetInstrDesc &TID = MI.getDesc();
   if (TID.mayLoad() || TID.mayStore() || TID.isCall() || TID.isTerminator() ||
       TID.isCall() || TID.isBarrier() || TID.isReturn() ||
-      TID.hasUnmodeledSideEffects())
+      TID.hasUnmodeledSideEffects() ||
+      MI.isLabel() || MI.isDebugValue())
     return false;
   for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
     MachineOperand &MO = MI.getOperand(i);