[M680x0] Base Patch 2: Changes in the target-independent CodeGen part

 - Allow register to be PCREL
 - Allow target implementation to override register spilling function
 - Add new function to search DebugLoc in a reverse ordering

llvm/include/llvm/CodeGen/MachineBasicBlock.h

@@ -837,13 +837,21 @@ class MachineBasicBlock
   DebugLoc findDebugLoc(iterator MBBI) {
     return findDebugLoc(MBBI.getInstrIterator());
   }
+  DebugLoc rfindDebugLoc(reverse_instr_iterator MBBI);
+  DebugLoc rfindDebugLoc(reverse_iterator MBBI) {
+    return rfindDebugLoc(MBBI.getInstrIterator());
+  }
 
   /// Find the previous valid DebugLoc preceding MBBI, skipping and DBG_VALUE
   /// instructions.  Return UnknownLoc if there is none.
   DebugLoc findPrevDebugLoc(instr_iterator MBBI);
   DebugLoc findPrevDebugLoc(iterator MBBI) {
     return findPrevDebugLoc(MBBI.getInstrIterator());
   }
+  DebugLoc rfindPrevDebugLoc(reverse_instr_iterator MBBI);
+  DebugLoc rfindPrevDebugLoc(reverse_iterator MBBI) {
+    return rfindPrevDebugLoc(MBBI.getInstrIterator());
+  }
 
   /// Find and return the merged DebugLoc of the branch instructions of the
   /// block. Return UnknownLoc if there is none.

llvm/include/llvm/CodeGen/TargetRegisterInfo.h

@@ -275,13 +275,13 @@ class TargetRegisterInfo : public MCRegisterInfo {
 
   /// Return the size in bytes of the stack slot allocated to hold a spilled
   /// copy of a register from class RC.
-  unsigned getSpillSize(const TargetRegisterClass &RC) const {
+  virtual unsigned getSpillSize(const TargetRegisterClass &RC) const {
     return getRegClassInfo(RC).SpillSize / 8;
   }
 
   /// Return the minimum required alignment in bytes for a spill slot for
   /// a register of this class.
-  unsigned getSpillAlignment(const TargetRegisterClass &RC) const {
+  virtual unsigned getSpillAlignment(const TargetRegisterClass &RC) const {
     return getRegClassInfo(RC).SpillAlignment / 8;
   }
 

llvm/lib/CodeGen/MachineBasicBlock.cpp

@@ -1335,6 +1335,13 @@ MachineBasicBlock::findDebugLoc(instr_iterator MBBI) {
     return MBBI->getDebugLoc();
   return {};
 }
+DebugLoc
+MachineBasicBlock::rfindDebugLoc(reverse_instr_iterator MBBI) {
+  // Skip debug declarations, we don't want a DebugLoc from them.
+  MBBI = skipDebugInstructionsBackward(MBBI, instr_rbegin());
+  if (!MBBI->isDebugInstr()) return MBBI->getDebugLoc();
+  return {};
+}
 
 /// Find the previous valid DebugLoc preceding MBBI, skipping and DBG_VALUE
 /// instructions.  Return UnknownLoc if there is none.
@@ -1345,6 +1352,13 @@ DebugLoc MachineBasicBlock::findPrevDebugLoc(instr_iterator MBBI) {
   if (!MBBI->isDebugInstr()) return MBBI->getDebugLoc();
   return {};
 }
+DebugLoc MachineBasicBlock::rfindPrevDebugLoc(reverse_instr_iterator MBBI) {
+  // Skip debug declarations, we don't want a DebugLoc from them.
+  MBBI = skipDebugInstructionsForward(std::prev(MBBI), instr_rend());
+  if (MBBI != instr_rend())
+    return MBBI->getDebugLoc();
+  return {};
+}
 
 /// Find and return the merged DebugLoc of the branch instructions of the block.
 /// Return UnknownLoc if there is none.

llvm/lib/CodeGen/MachineVerifier.cpp

@@ -1645,8 +1645,7 @@ MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
       if (MCOI.OperandType == MCOI::OPERAND_REGISTER &&
           !MO->isReg() && !MO->isFI())
         report("Expected a register operand.", MO, MONum);
-      if ((MCOI.OperandType == MCOI::OPERAND_IMMEDIATE ||
-           MCOI.OperandType == MCOI::OPERAND_PCREL) && MO->isReg())
+      if (MCOI.OperandType == MCOI::OPERAND_IMMEDIATE && MO->isReg())
         report("Expected a non-register operand.", MO, MONum);
     }