TableGen's regpressure: emit per-registerclass weight limits.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154518 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Target/TargetRegisterInfo.h

@@ -202,6 +202,13 @@ struct TargetRegisterInfoDesc {
   bool inAllocatableClass;      // Register belongs to an allocatable regclass.
 };
 
+/// Each TargetRegisterClass has a per register weight, and weight
+/// limit which must be less than the limits of its pressure sets.
+struct RegClassWeight {
+  unsigned RegWeigt;
+  unsigned WeightLimit;
+};
+
 /// TargetRegisterInfo base class - We assume that the target defines a static
 /// array of TargetRegisterDesc objects that represent all of the machine
 /// registers that the target has.  As such, we simply have to track a pointer
@@ -509,7 +516,8 @@ public:
   }
 
   /// Get the weight in units of pressure for this register class.
-  virtual unsigned getRegClassWeight(const TargetRegisterClass *RC) const = 0;
+  virtual const RegClassWeight &getRegClassWeight(
+    const TargetRegisterClass *RC) const = 0;
 
   /// Get the number of dimensions of register pressure.
   virtual unsigned getNumRegPressureSets() const = 0;

utils/TableGen/CodeGenRegisters.cpp

@@ -722,6 +722,16 @@ CodeGenRegisterClass::getSuperRegClasses(CodeGenSubRegIndex *SubIdx,
     Out.set((*I)->EnumValue);
 }
 
+// Populate a unique sorted list of units from a register set.
+void CodeGenRegisterClass::buildRegUnitSet(
+  std::vector<unsigned> &RegUnits) const {
+  std::vector<unsigned> TmpUnits;
+  for (RegUnitIterator UnitI(Members); UnitI.isValid(); ++UnitI)
+    TmpUnits.push_back(*UnitI);
+  std::sort(TmpUnits.begin(), TmpUnits.end());
+  std::unique_copy(TmpUnits.begin(), TmpUnits.end(),
+                   std::back_inserter(RegUnits));
+}
 
 //===----------------------------------------------------------------------===//
 //                               CodeGenRegBank
@@ -1130,17 +1140,6 @@ void CodeGenRegBank::computeRegUnitWeights() {
   }
 }
 
-// Populate a unique sorted list of units from a register set.
-static void buildRegUnitSet(const CodeGenRegister::Set &Regs,
-                            std::vector<unsigned> &RegUnits) {
-  std::vector<unsigned> TmpUnits;
-  for (RegUnitIterator UnitI(Regs); UnitI.isValid(); ++UnitI)
-    TmpUnits.push_back(*UnitI);
-  std::sort(TmpUnits.begin(), TmpUnits.end());
-  std::unique_copy(TmpUnits.begin(), TmpUnits.end(),
-                   std::back_inserter(RegUnits));
-}
-
 // Find a set in UniqueSets with the same elements as Set.
 // Return an iterator into UniqueSets.
 static std::vector<RegUnitSet>::const_iterator
@@ -1216,7 +1215,7 @@ void CodeGenRegBank::computeRegUnitSets() {
     RegUnitSets.back().Name = RegClasses[RCIdx]->getName();
 
     // Compute a sorted list of units in this class.
-    buildRegUnitSet(RegClasses[RCIdx]->getMembers(), RegUnitSets.back().Units);
+    RegClasses[RCIdx]->buildRegUnitSet(RegUnitSets.back().Units);
 
     // Find an existing RegUnitSet.
     std::vector<RegUnitSet>::const_iterator SetI =
@@ -1279,7 +1278,7 @@ void CodeGenRegBank::computeRegUnitSets() {
 
     // Recompute the sorted list of units in this class.
     std::vector<unsigned> RegUnits;
-    buildRegUnitSet(RegClasses[RCIdx]->getMembers(), RegUnits);
+    RegClasses[RCIdx]->buildRegUnitSet(RegUnits);
 
     // Don't increase pressure for unallocatable regclasses.
     if (RegUnits.empty())

utils/TableGen/CodeGenRegisters.h

@@ -279,6 +279,9 @@ namespace llvm {
     // getOrder(0).
     const CodeGenRegister::Set &getMembers() const { return Members; }
 
+    // Populate a unique sorted list of units from a register set.
+    void buildRegUnitSet(std::vector<unsigned> &RegUnits) const;
+
     CodeGenRegisterClass(CodeGenRegBank&, Record *R);
 
     // A key representing the parts of a register class used for forming
@@ -449,6 +452,15 @@ namespace llvm {
       return RegUnitWeights[RUID];
     }
 
+    // Get the sum of unit weights.
+    unsigned getRegUnitSetWeight(const std::vector<unsigned> &Units) const {
+      unsigned Weight = 0;
+      for (std::vector<unsigned>::const_iterator
+             I = Units.begin(), E = Units.end(); I != E; ++I)
+        Weight += getRegUnitWeight(*I);
+      return Weight;
+    }
+
     // Increase a RegUnitWeight.
     void increaseRegUnitWeight(unsigned RUID, unsigned Inc) {
       RegUnitWeights[RUID] += Inc;

utils/TableGen/RegisterInfoEmitter.cpp

@@ -125,19 +125,23 @@ EmitRegUnitPressure(raw_ostream &OS, const CodeGenRegBank &RegBank,
   unsigned NumSets = RegBank.getNumRegPressureSets();
 
   OS << "/// Get the weight in units of pressure for this register class.\n"
-     << "unsigned " << ClassName << "::\n"
+     << "const RegClassWeight &" << ClassName << "::\n"
      << "getRegClassWeight(const TargetRegisterClass *RC) const {\n"
-     << "  static const unsigned RCWeightTable[] = {\n";
+     << "  static const RegClassWeight RCWeightTable[] = {\n";
   for (unsigned i = 0, e = NumRCs; i != e; ++i) {
     const CodeGenRegisterClass &RC = *RegBank.getRegClasses()[i];
     const CodeGenRegister::Set &Regs = RC.getMembers();
     if (Regs.empty())
-      OS << "    0";
-    else
-      OS << "    " << (*Regs.begin())->getWeight(RegBank);
-    OS << ",  \t// " << RC.getName() << "\n";
+      OS << "    {0, 0";
+    else {
+      std::vector<unsigned> RegUnits;
+      RC.buildRegUnitSet(RegUnits);
+      OS << "    {" << (*Regs.begin())->getWeight(RegBank)
+         << ", " << RegBank.getRegUnitSetWeight(RegUnits);
+    }
+    OS << "},  \t// " << RC.getName() << "\n";
   }
-  OS << "    0 };\n"
+  OS << "    {0, 0} };\n"
      << "  return RCWeightTable[RC->getID()];\n"
      << "}\n\n";
 
@@ -153,12 +157,7 @@ EmitRegUnitPressure(raw_ostream &OS, const CodeGenRegBank &RegBank,
      << "  static const unsigned PressureLimitTable[] = {\n";
   for (unsigned i = 0; i < NumSets; ++i ) {
     const RegUnitSet &RegUnits = RegBank.getRegPressureSet(i);
-    unsigned Weight = 0;
-    for (RegUnitSet::iterator
-           I = RegUnits.Units.begin(), E = RegUnits.Units.end(); I != E; ++I) {
-      Weight += RegBank.getRegUnitWeight(*I);
-    }
-    OS << "    " << Weight
+    OS << "    " << RegBank.getRegUnitSetWeight(RegUnits.Units)
        << ",  \t// " << i << ": " << RegBank.getRegPressureSet(i).Name << "\n";
   }
   OS << "    0 };\n"
@@ -668,7 +667,8 @@ RegisterInfoEmitter::runTargetHeader(raw_ostream &OS, CodeGenTarget &Target,
      << "  const TargetRegisterClass *getMatchingSuperRegClass("
         "const TargetRegisterClass*, const TargetRegisterClass*, "
         "unsigned) const;\n"
-     << "  unsigned getRegClassWeight(const TargetRegisterClass *RC) const;\n"
+     << "  const RegClassWeight &getRegClassWeight("
+     << "const TargetRegisterClass *RC) const;\n"
      << "  unsigned getNumRegPressureSets() const;\n"
      << "  unsigned getRegPressureSetLimit(unsigned Idx) const;\n"
      << "  const int *getRegClassPressureSets("