[NFC][Outliner] Delete default ctors for Candidate & OutlinedFunction.

I think it's good practice to avoid having default ctors unless they're really
valid/useful. For OutlinedFunction the default ctor was used to represent a
bail-out value for getOutliningCandidateInfo(), so I changed the API to return
an optional<getOutliningCandidateInfo> instead which seems a tad cleaner.

Differential Revision: https://reviews.llvm.org/D146375

diff --git a/llvm/include/llvm/CodeGen/MachineOutliner.h b/llvm/include/llvm/CodeGen/MachineOutliner.h
index f968089..d0ff02f 100644 (file)
--- a/llvm/include/llvm/CodeGen/MachineOutliner.h
+++ b/llvm/include/llvm/CodeGen/MachineOutliner.h
@@ -199,7 +199,7 @@ public:
             unsigned FunctionIdx, unsigned Flags)
       : StartIdx(StartIdx), Len(Len), FirstInst(FirstInst), LastInst(LastInst),
         MBB(MBB), FunctionIdx(FunctionIdx), Flags(Flags) {}
-  Candidate() = default;
+  Candidate() = delete;
 
   /// Used to ensure that \p Candidates are outlined in an order that
   /// preserves the start and end indices of other \p Candidates.
@@ -268,7 +268,7 @@ public:
       C.Benefit = B;
   }
 
-  OutlinedFunction() = default;
+  OutlinedFunction() = delete;
 };
 } // namespace outliner
 } // namespace llvm

diff --git a/llvm/include/llvm/CodeGen/TargetInstrInfo.h b/llvm/include/llvm/CodeGen/TargetInstrInfo.h
index 92c283a..b4a7bbb 100644 (file)
--- a/llvm/include/llvm/CodeGen/TargetInstrInfo.h
+++ b/llvm/include/llvm/CodeGen/TargetInstrInfo.h
@@ -1966,8 +1966,9 @@ public:
   }
 
   /// Returns a \p outliner::OutlinedFunction struct containing target-specific
-  /// information for a set of outlining candidates.
-  virtual outliner::OutlinedFunction getOutliningCandidateInfo(
+  /// information for a set of outlining candidates. Returns None if the
+  /// candidates are not suitable for outlining.
+  virtual std::optional<outliner::OutlinedFunction> getOutliningCandidateInfo(
       std::vector<outliner::Candidate> &RepeatedSequenceLocs) const {
     llvm_unreachable(
         "Target didn't implement TargetInstrInfo::getOutliningCandidateInfo!");

diff --git a/llvm/lib/CodeGen/MachineOutliner.cpp b/llvm/lib/CodeGen/MachineOutliner.cpp
index 856b9bf..8d72208 100644 (file)
--- a/llvm/lib/CodeGen/MachineOutliner.cpp
+++ b/llvm/lib/CodeGen/MachineOutliner.cpp
@@ -655,21 +655,21 @@ void MachineOutliner::findCandidates(
     const TargetInstrInfo *TII =
         CandidatesForRepeatedSeq[0].getMF()->getSubtarget().getInstrInfo();
 
-    OutlinedFunction OF =
+    std::optional<OutlinedFunction> OF =
         TII->getOutliningCandidateInfo(CandidatesForRepeatedSeq);
 
     // If we deleted too many candidates, then there's nothing worth outlining.
     // FIXME: This should take target-specified instruction sizes into account.
-    if (OF.Candidates.size() < 2)
+    if (!OF || OF->Candidates.size() < 2)
       continue;
 
     // Is it better to outline this candidate than not?
-    if (OF.getBenefit() < 1) {
-      emitNotOutliningCheaperRemark(StringLen, CandidatesForRepeatedSeq, OF);
+    if (OF->getBenefit() < 1) {
+      emitNotOutliningCheaperRemark(StringLen, CandidatesForRepeatedSeq, *OF);
       continue;
     }
 
-    FunctionList.push_back(OF);
+    FunctionList.push_back(*OF);
   }
 }
 

diff --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
index 54ad05b..b1cfd68 100644 (file)
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
@@ -7151,7 +7151,8 @@ static bool outliningCandidatesV8_3OpsConsensus(const outliner::Candidate &a,
   return SubtargetA.hasV8_3aOps() == SubtargetB.hasV8_3aOps();
 }
 
-outliner::OutlinedFunction AArch64InstrInfo::getOutliningCandidateInfo(
+std::optional<outliner::OutlinedFunction>
+AArch64InstrInfo::getOutliningCandidateInfo(
     std::vector<outliner::Candidate> &RepeatedSequenceLocs) const {
   outliner::Candidate &FirstCand = RepeatedSequenceLocs[0];
   unsigned SequenceSize =
@@ -7181,7 +7182,7 @@ outliner::OutlinedFunction AArch64InstrInfo::getOutliningCandidateInfo(
             }
             return true;
           }) != RepeatedSequenceLocs.end()) {
-    return outliner::OutlinedFunction();
+    return std::nullopt;
   }
 
   // Since at this point all candidates agree on their return address signing
@@ -7259,7 +7260,7 @@ outliner::OutlinedFunction AArch64InstrInfo::getOutliningCandidateInfo(
 
     // If the sequence doesn't have enough candidates left, then we're done.
     if (RepeatedSequenceLocs.size() < 2)
-      return outliner::OutlinedFunction();
+      return std::nullopt;
   }
 
   // Properties about candidate MBBs that hold for all of them.
@@ -7304,7 +7305,7 @@ outliner::OutlinedFunction AArch64InstrInfo::getOutliningCandidateInfo(
         C.getMF()->getFrameInstructions();
 
     if (CFICount > 0 && CFICount != CFIInstructions.size())
-      return outliner::OutlinedFunction();
+      return std::nullopt;
   }
 
   // Returns true if an instructions is safe to fix up, false otherwise.
@@ -7506,7 +7507,7 @@ outliner::OutlinedFunction AArch64InstrInfo::getOutliningCandidateInfo(
     // If we dropped all of the candidates, bail out here.
     if (RepeatedSequenceLocs.size() < 2) {
       RepeatedSequenceLocs.clear();
-      return outliner::OutlinedFunction();
+      return std::nullopt;
     }
   }
 
@@ -7533,7 +7534,7 @@ outliner::OutlinedFunction AArch64InstrInfo::getOutliningCandidateInfo(
       // We can't fix up the stack. Bail out.
       if (!AllStackInstrsSafe) {
         RepeatedSequenceLocs.clear();
-        return outliner::OutlinedFunction();
+        return std::nullopt;
       }
 
       // Save + restore LR.
@@ -7544,7 +7545,7 @@ outliner::OutlinedFunction AArch64InstrInfo::getOutliningCandidateInfo(
   // If we have CFI instructions, we can only outline if the outlined section
   // can be a tail call
   if (FrameID != MachineOutlinerTailCall && CFICount > 0)
-    return outliner::OutlinedFunction();
+    return std::nullopt;
 
   return outliner::OutlinedFunction(RepeatedSequenceLocs, SequenceSize,
                                     NumBytesToCreateFrame, FrameID);

diff --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.h b/llvm/lib/Target/AArch64/AArch64InstrInfo.h
index 96ec055..59fd05a 100644 (file)
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.h
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.h
@@ -17,6 +17,7 @@
 #include "AArch64RegisterInfo.h"
 #include "llvm/CodeGen/TargetInstrInfo.h"
 #include "llvm/Support/TypeSize.h"
+#include <optional>
 
 #define GET_INSTRINFO_HEADER
 #include "AArch64GenInstrInfo.inc"
@@ -289,7 +290,7 @@ public:
 
   bool isFunctionSafeToOutlineFrom(MachineFunction &MF,
                                    bool OutlineFromLinkOnceODRs) const override;
-  outliner::OutlinedFunction getOutliningCandidateInfo(
+  std::optional<outliner::OutlinedFunction> getOutliningCandidateInfo(
       std::vector<outliner::Candidate> &RepeatedSequenceLocs) const override;
   outliner::InstrType
   getOutliningTypeImpl(MachineBasicBlock::iterator &MIT, unsigned Flags) const override;

diff --git a/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp b/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
index 77557c3..4a158b3 100644 (file)
--- a/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -5869,7 +5869,8 @@ static bool isLRAvailable(const TargetRegisterInfo &TRI,
   return !Live;
 }
 
-outliner::OutlinedFunction ARMBaseInstrInfo::getOutliningCandidateInfo(
+std::optional<outliner::OutlinedFunction>
+ARMBaseInstrInfo::getOutliningCandidateInfo(
     std::vector<outliner::Candidate> &RepeatedSequenceLocs) const {
   outliner::Candidate &FirstCand = RepeatedSequenceLocs[0];
   unsigned SequenceSize =
@@ -5915,7 +5916,7 @@ outliner::OutlinedFunction ARMBaseInstrInfo::getOutliningCandidateInfo(
 
     // If the sequence doesn't have enough candidates left, then we're done.
     if (RepeatedSequenceLocs.size() < 2)
-      return outliner::OutlinedFunction();
+      return std::nullopt;
   }
 
   // We expect the majority of the outlining candidates to be in consensus with
@@ -5941,7 +5942,7 @@ outliner::OutlinedFunction ARMBaseInstrInfo::getOutliningCandidateInfo(
     RepeatedSequenceLocs.erase(RepeatedSequenceLocs.begin(), NoBTI);
 
   if (RepeatedSequenceLocs.size() < 2)
-    return outliner::OutlinedFunction();
+    return std::nullopt;
 
   // Likewise, partition the candidates according to PAC-RET enablement.
   auto NoPAC =
@@ -5958,7 +5959,7 @@ outliner::OutlinedFunction ARMBaseInstrInfo::getOutliningCandidateInfo(
     RepeatedSequenceLocs.erase(RepeatedSequenceLocs.begin(), NoPAC);
 
   if (RepeatedSequenceLocs.size() < 2)
-    return outliner::OutlinedFunction();
+    return std::nullopt;
 
   // At this point, we have only "safe" candidates to outline. Figure out
   // frame + call instruction information.

diff --git a/llvm/lib/Target/ARM/ARMBaseInstrInfo.h b/llvm/lib/Target/ARM/ARMBaseInstrInfo.h
index 70c3be2..5efcc1a 100644 (file)
--- a/llvm/lib/Target/ARM/ARMBaseInstrInfo.h
+++ b/llvm/lib/Target/ARM/ARMBaseInstrInfo.h
@@ -348,7 +348,7 @@ public:
   /// ARM supports the MachineOutliner.
   bool isFunctionSafeToOutlineFrom(MachineFunction &MF,
                                    bool OutlineFromLinkOnceODRs) const override;
-  outliner::OutlinedFunction getOutliningCandidateInfo(
+  std::optional<outliner::OutlinedFunction> getOutliningCandidateInfo(
       std::vector<outliner::Candidate> &RepeatedSequenceLocs) const override;
   void mergeOutliningCandidateAttributes(
       Function &F, std::vector<outliner::Candidate> &Candidates) const override;

diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp b/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
index d525365..d1a8a41 100644 (file)
--- a/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
@@ -1925,7 +1925,8 @@ bool RISCVInstrInfo::shouldOutlineFromFunctionByDefault(
   return MF.getFunction().hasMinSize();
 }
 
-outliner::OutlinedFunction RISCVInstrInfo::getOutliningCandidateInfo(
+std::optional<outliner::OutlinedFunction>
+RISCVInstrInfo::getOutliningCandidateInfo(
     std::vector<outliner::Candidate> &RepeatedSequenceLocs) const {
 
   // First we need to filter out candidates where the X5 register (IE t0) can't
@@ -1939,7 +1940,7 @@ outliner::OutlinedFunction RISCVInstrInfo::getOutliningCandidateInfo(
 
   // If the sequence doesn't have enough candidates left, then we're done.
   if (RepeatedSequenceLocs.size() < 2)
-    return outliner::OutlinedFunction();
+    return std::nullopt;
 
   unsigned SequenceSize = 0;
 

diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.h b/llvm/lib/Target/RISCV/RISCVInstrInfo.h
index cc84e9c..e3b394e 100644 (file)
--- a/llvm/lib/Target/RISCV/RISCVInstrInfo.h
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfo.h
@@ -159,7 +159,7 @@ public:
   bool shouldOutlineFromFunctionByDefault(MachineFunction &MF) const override;
 
   // Calculate target-specific information for a set of outlining candidates.
-  outliner::OutlinedFunction getOutliningCandidateInfo(
+  std::optional<outliner::OutlinedFunction> getOutliningCandidateInfo(
       std::vector<outliner::Candidate> &RepeatedSequenceLocs) const override;
 
   // Return if/how a given MachineInstr should be outlined.

diff --git a/llvm/lib/Target/X86/X86InstrInfo.cpp b/llvm/lib/Target/X86/X86InstrInfo.cpp
index 557e18c..dbf5e8d 100644 (file)
--- a/llvm/lib/Target/X86/X86InstrInfo.cpp
+++ b/llvm/lib/Target/X86/X86InstrInfo.cpp
@@ -43,6 +43,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetOptions.h"
+#include <optional>
 
 using namespace llvm;
 
@@ -9598,7 +9599,8 @@ enum MachineOutlinerClass {
   MachineOutlinerTailCall
 };
 
-outliner::OutlinedFunction X86InstrInfo::getOutliningCandidateInfo(
+std::optional<outliner::OutlinedFunction>
+X86InstrInfo::getOutliningCandidateInfo(
     std::vector<outliner::Candidate> &RepeatedSequenceLocs) const {
   unsigned SequenceSize =
       std::accumulate(RepeatedSequenceLocs[0].front(),
@@ -9631,7 +9633,7 @@ outliner::OutlinedFunction X86InstrInfo::getOutliningCandidateInfo(
         C.getMF()->getFrameInstructions();
 
     if (CFICount > 0 && CFICount != CFIInstructions.size())
-      return outliner::OutlinedFunction();
+      return std::nullopt;
   }
 
   // FIXME: Use real size in bytes for call and ret instructions.
@@ -9646,7 +9648,7 @@ outliner::OutlinedFunction X86InstrInfo::getOutliningCandidateInfo(
   }
 
   if (CFICount > 0)
-    return outliner::OutlinedFunction();
+    return std::nullopt;
 
   for (outliner::Candidate &C : RepeatedSequenceLocs)
     C.setCallInfo(MachineOutlinerDefault, 1);

diff --git a/llvm/lib/Target/X86/X86InstrInfo.h b/llvm/lib/Target/X86/X86InstrInfo.h
index ff588b1..f8016b3 100644 (file)
--- a/llvm/lib/Target/X86/X86InstrInfo.h
+++ b/llvm/lib/Target/X86/X86InstrInfo.h
@@ -551,7 +551,7 @@ public:
   ArrayRef<std::pair<unsigned, const char *>>
   getSerializableDirectMachineOperandTargetFlags() const override;
 
-  outliner::OutlinedFunction getOutliningCandidateInfo(
+  std::optional<outliner::OutlinedFunction> getOutliningCandidateInfo(
       std::vector<outliner::Candidate> &RepeatedSequenceLocs) const override;
 
   bool isFunctionSafeToOutlineFrom(MachineFunction &MF,