Add TailDupAggressiveThreshold to RISCVTuneInfo

Author: wangpc-pp

llvm/lib/Target/RISCV/RISCVInstrInfo.cpp

@@ -3763,9 +3763,10 @@ RISCVInstrInfo::getSerializableMachineMemOperandTargetFlags() const {
   return ArrayRef(TargetFlags);
 }
 
-unsigned int
-RISCVInstrInfo::getTailDuplicateSize(CodeGenOptLevel OptLevel) const {
-  return OptLevel >= CodeGenOptLevel::Aggressive ? 6 : 2;
+unsigned RISCVInstrInfo::getTailDuplicateSize(CodeGenOptLevel OptLevel) const {
+  return OptLevel >= CodeGenOptLevel::Aggressive
+             ? STI.getTailDupAggressiveThreshold()
+             : 2;
 }
 
 // Returns true if this is the sext.w pattern, addiw rd, rs1, 0.

llvm/lib/Target/RISCV/RISCVInstrInfo.h

@@ -288,7 +288,7 @@ class RISCVInstrInfo : public RISCVGenInstrInfo {
   ArrayRef<std::pair<MachineMemOperand::Flags, const char *>>
   getSerializableMachineMemOperandTargetFlags() const override;
 
-  unsigned int getTailDuplicateSize(CodeGenOptLevel OptLevel) const override;
+  unsigned getTailDuplicateSize(CodeGenOptLevel OptLevel) const override;
 
   unsigned getUndefInitOpcode(unsigned RegClassID) const override {
     switch (RegClassID) {

llvm/lib/Target/RISCV/RISCVProcessors.td

@@ -21,6 +21,9 @@ class RISCVTuneInfo {
   bits<32> MaxPrefetchIterationsAhead = -1;
 
   bits<32> MinimumJumpTableEntries = 5;
+
+  // Tail duplication threshold at -O3.
+  bits<32> TailDupAggressiveThreshold = 6;
 }
 
 def RISCVTuneInfoTable : GenericTable {
@@ -29,7 +32,7 @@ def RISCVTuneInfoTable : GenericTable {
   let Fields = ["Name", "PrefFunctionAlignment", "PrefLoopAlignment",
                 "CacheLineSize", "PrefetchDistance",
                 "MinPrefetchStride", "MaxPrefetchIterationsAhead",
-                "MinimumJumpTableEntries"];
+                "MinimumJumpTableEntries", "TailDupAggressiveThreshold"];
 }
 
 def getRISCVTuneInfo : SearchIndex {

llvm/lib/Target/RISCV/RISCVSubtarget.h

@@ -50,6 +50,9 @@ struct RISCVTuneInfo {
   unsigned MaxPrefetchIterationsAhead;
 
   unsigned MinimumJumpTableEntries;
+
+  // Tail duplication threshold at -O3.
+  unsigned TailDupAggressiveThreshold;
 };
 
 #define GET_RISCVTuneInfoTable_DECL
@@ -300,6 +303,10 @@ class RISCVSubtarget : public RISCVGenSubtargetInfo {
 
   unsigned getMinimumJumpTableEntries() const;
 
+  unsigned getTailDupAggressiveThreshold() const {
+    return TuneInfo->TailDupAggressiveThreshold;
+  }
+
   bool supportsInitUndef() const override { return hasVInstructions(); }
 };
 } // End llvm namespace