Fix some more places where dbg_value affected codegen.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97765 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/BranchFolding.cpp

@@ -334,7 +334,9 @@ static unsigned ComputeCommonTailLength(MachineBasicBlock *MBB1,
   unsigned TailLen = 0;
   while (I1 != MBB1->begin() && I2 != MBB2->begin()) {
     --I1; --I2;
-    if (!I1->isIdenticalTo(I2) ||
+    // Don't merge debugging pseudos.
+    if (I1->isDebugValue() || I2->isDebugValue() ||
+        !I1->isIdenticalTo(I2) ||
         // FIXME: This check is dubious. It's used to get around a problem where
         // people incorrectly expect inline asm directives to remain in the same
         // relative order. This is untenable because normal compiler
@@ -412,6 +414,8 @@ static unsigned EstimateRuntime(MachineBasicBlock::iterator I,
                                 MachineBasicBlock::iterator E) {
   unsigned Time = 0;
   for (; I != E; ++I) {
+    if (I->isDebugValue())
+      continue;
     const TargetInstrDesc &TID = I->getDesc();
     if (TID.isCall())
       Time += 10;

lib/CodeGen/CriticalAntiDepBreaker.cpp

@@ -119,6 +119,8 @@ void CriticalAntiDepBreaker::FinishBlock() {
 
 void CriticalAntiDepBreaker::Observe(MachineInstr *MI, unsigned Count,
                                      unsigned InsertPosIndex) {
+  if (MI->isDebugValue())
+    return;
   assert(Count < InsertPosIndex && "Instruction index out of expected range!");
 
   // Any register which was defined within the previous scheduling region
@@ -409,6 +411,8 @@ BreakAntiDependencies(std::vector<SUnit>& SUnits,
   for (MachineBasicBlock::iterator I = End, E = Begin;
        I != E; --Count) {
     MachineInstr *MI = --I;
+    if (MI->isDebugValue())
+      continue;
 
     // Check if this instruction has a dependence on the critical path that
     // is an anti-dependence that we may be able to break. If it is, set

lib/CodeGen/MachineSink.cpp

@@ -72,8 +72,13 @@ bool MachineSinking::AllUsesDominatedByBlock(unsigned Reg,
                                              MachineBasicBlock *MBB) const {
   assert(TargetRegisterInfo::isVirtualRegister(Reg) &&
          "Only makes sense for vregs");
-  for (MachineRegisterInfo::use_iterator I = RegInfo->use_begin(Reg),
+  // Ignoring debug uses is necessary so debug info doesn't affect the code.
-       E = RegInfo->use_end(); I != E; ++I) {
+  // This may leave a referencing dbg_value in the original block, before
+  // the definition of the vreg.  Dwarf generator handles this although the
+  // user might not get the right info at runtime.
+  for (MachineRegisterInfo::use_nodbg_iterator I = 
+       RegInfo->use_nodbg_begin(Reg),
+       E = RegInfo->use_nodbg_end(); I != E; ++I) {
     // Determine the block of the use.
     MachineInstr *UseInst = &*I;
     MachineBasicBlock *UseBlock = UseInst->getParent();
@@ -135,7 +140,10 @@ bool MachineSinking::ProcessBlock(MachineBasicBlock &MBB) {
     ProcessedBegin = I == MBB.begin();
     if (!ProcessedBegin)
       --I;
-    
+
+    if (MI->isDebugValue())
+      continue;
+
     if (SinkInstruction(MI, SawStore))
       ++NumSunk, MadeChange = true;
     

lib/CodeGen/PostRASchedulerList.cpp

@@ -460,6 +460,8 @@ void SchedulePostRATDList::FixupKills(MachineBasicBlock *MBB) {
   for (MachineBasicBlock::iterator I = MBB->end(), E = MBB->begin();
        I != E; --Count) {
     MachineInstr *MI = --I;
+    if (MI->isDebugValue())
+      continue;
 
     // Update liveness.  Registers that are defed but not used in this
     // instruction are now dead. Mark register and all subregs as they