Move spill size and alignment info from MC to TargetRegisterInfo

[kparzysz]

Summary

This is another step towards implementing register classes with parametrized register/spill sizes.

[MatzeB]

Makes sense.

include/llvm/Target/TargetRegisterInfo.h

98

How hard would it be to rename this to getSpillSize() to avoid confusing?
We can however do that in a separate patch.

[kparzysz]

include/llvm/Target/TargetRegisterInfo.h

98

That would be easy. However there are some places where this function is called with the intent of getting the register size. AMDGPU and Hexagon both have places like that. I'd like to add the register size as a separate field here, but I'm getting close to completing the first version of the variable class patch which already adds that.

include/llvm/MC/MCRegisterInfo.h

public:
   typedef const MCPhysReg* const_iterator;
 
   const iterator RegsBegin;
   const uint8_t *const RegSet;
   const uint32_t NameIdx;
   const uint16_t RegsSize;
   const uint16_t RegSetSize;
   const uint16_t ID;
-  const uint16_t RegSize, Alignment; // Size & Alignment of register in bytes
   const int8_t CopyCost;
   const bool Allocatable;
 
   /// getID() - Return the register class ID number.
   ///
   unsigned getID() const { return ID; }
 
   /// begin/end - Return all of the registers in this class.
bool contains(unsigned Reg) const {
     return (RegSet[Byte] & (1 << InByte)) != 0;
   }
 
   /// contains - Return true if both registers are in this class.
   bool contains(unsigned Reg1, unsigned Reg2) const {
     return contains(Reg1) && contains(Reg2);
   }
 
-  /// getSize - Return the size of the register in bytes, which is also the size
-  /// of a stack slot allocated to hold a spilled copy of this register.
-  unsigned getSize() const { return RegSize; }
-
-  /// getAlignment - Return the minimum required alignment for a register of
-  /// this class.
-  unsigned getAlignment() const { return Alignment; }
-
   /// getCopyCost - Return the cost of copying a value between two registers in
   /// this class. A negative number means the register class is very expensive
   /// to copy e.g. status flag register classes.
   int getCopyCost() const { return CopyCost; }
 
   /// isAllocatable - Return true if this register class may be used to create
   /// virtual registers.
   bool isAllocatable() const { return Allocatable; }

include/llvm/Target/TargetRegisterInfo.h

 public:
   typedef const MCPhysReg* iterator;
   typedef const MCPhysReg* const_iterator;
   typedef const MVT::SimpleValueType* vt_iterator;
   typedef const TargetRegisterClass* const * sc_iterator;
 
   // Instance variables filled by tablegen, do not use!
   const MCRegisterClass *MC;
+  const uint16_t SpillSize, SpillAlignment;
   const vt_iterator VTs;
   const uint32_t *SubClassMask;
   const uint16_t *SuperRegIndices;
   const LaneBitmask LaneMask;
   /// Classes with a higher priority value are assigned first by register
   /// allocators using a greedy heuristic. The value is in the range [0,63].
   const uint8_t AllocationPriority;
   /// Whether the class supports two (or more) disjunct subregister indices.
public:
 
   /// Return true if both registers are in this class.
   bool contains(unsigned Reg1, unsigned Reg2) const {
     return MC->contains(Reg1, Reg2);
   }
 
   /// Return the size of the register in bytes, which is also the size
   /// of a stack slot allocated to hold a spilled copy of this register.
-  unsigned getSize() const { return MC->getSize(); }
+  unsigned getSize() const { return SpillSize; }
 
   /// Return the minimum required alignment for a register of this class.
-  unsigned getAlignment() const { return MC->getAlignment(); }
+  unsigned getAlignment() const { return SpillAlignment; }
 
   /// Return the cost of copying a value between two registers in this class.
   /// A negative number means the register class is very expensive
   /// to copy e.g. status flag register classes.
   int getCopyCost() const { return MC->getCopyCost(); }
 
   /// Return true if this register class may be used to create virtual
   /// registers.

utils/TableGen/RegisterInfoEmitter.cpp

#endif
   OS << "};\n\n";
 
   OS << "extern const MCRegisterClass " << TargetName
      << "MCRegisterClasses[] = {\n";
 
   for (const auto &RC : RegisterClasses) {
     // Asserts to make sure values will fit in table assuming types from
     // MCRegisterInfo.h
-    assert((RC.SpillSize/8) <= 0xffff && "SpillSize too large.");
-    assert((RC.SpillAlignment/8) <= 0xffff && "SpillAlignment too large.");
     assert(RC.CopyCost >= -128 && RC.CopyCost <= 127 && "Copy cost too large.");
 
     OS << "  { " << RC.getName() << ", " << RC.getName() << "Bits, "
        << RegClassStrings.get(RC.getName()) << ", "
        << RC.getOrder().size() << ", sizeof(" << RC.getName() << "Bits), "
        << RC.getQualifiedName() + "RegClassID" << ", "
-       << RC.SpillSize/8 << ", "
-       << RC.SpillAlignment/8 << ", "
        << RC.CopyCost << ", "
        << ( RC.Allocatable ? "true" : "false" ) << " },\n";
   }
 
   OS << "};\n\n";
 
   EmitRegMappingTables(OS, Regs, false);
 
for (const auto &RC : RegisterClasses) {
       }
     }
 
     // Now emit the actual value-initialized register class instances.
     OS << "\nnamespace " << RegisterClasses.front().Namespace
        << " {   // Register class instances\n";
 
     for (const auto &RC : RegisterClasses) {
+      assert(isUInt<16>(RC.SpillSize/8) && "SpillSize too large.");
+      assert(isUInt<16>(RC.SpillAlignment/8) && "SpillAlignment too large.");
       OS << "  extern const TargetRegisterClass " << RC.getName()
          << "RegClass = {\n    " << '&' << Target.getName()
          << "MCRegisterClasses[" << RC.getName() << "RegClassID],\n    "
+         << RC.SpillSize/8 << ", /* SpillSize */\n    "
+         << RC.SpillAlignment/8 << ", /* SpillAlignment */\n    "
          << "VTLists + " << VTSeqs.get(RC.VTs) << ",\n    " << RC.getName()
          << "SubClassMask,\n    SuperRegIdxSeqs + "
          << SuperRegIdxSeqs.get(SuperRegIdxLists[RC.EnumValue]) << ",\n    ";
       printMask(OS, RC.LaneMask);
       OS << ",\n    " << (unsigned)RC.AllocationPriority << ",\n    "
          << (RC.HasDisjunctSubRegs?"true":"false")
          << ", /* HasDisjunctSubRegs */\n    "
          << (RC.CoveredBySubRegs?"true":"false")