[CallSiteInfo][NFC] CallSiteInfo -> CallSiteInfo.ArgRegPairs

CallSiteInfo is originally used only for argument - register pairs. Make
it struct, in which we can store additional data for call sites.

Also, the variables/methods used for CallSiteInfo are named for its
original use case, e.g., CallFwdRegsInfo. Refactor these for the upcoming
use, e.g. addCallArgsForwardingRegs() -> addCallSiteInfo().

An upcoming patch will add type ids for indirect calls to propogate them from
middle-end to the back-end. The type ids will be then used to emit the call
graph section.

Original RFC: https://lists.llvm.org/pipermail/llvm-dev/2021-June/151044.html
Updated RFC: https://lists.llvm.org/pipermail/llvm-dev/2021-July/151739.html

Differential Revision: https://reviews.llvm.org/D107109?id=362888

Author: necipfazil

llvm/include/llvm/CodeGen/MachineFunction.h

@@ -481,9 +481,11 @@ class LLVM_EXTERNAL_VISIBILITY MachineFunction {
       assert(Arg < (1 << 16) && "Arg out of range");
     }
   };
-  /// Vector of call argument and its forwarding register.
-  using CallSiteInfo = SmallVector<ArgRegPair, 1>;
-  using CallSiteInfoImpl = SmallVectorImpl<ArgRegPair>;
+
+  struct CallSiteInfo {
+    /// Vector of call argument and its forwarding register.
+    SmallVector<ArgRegPair, 1> ArgRegPairs;
+  };
 
 private:
   Delegate *TheDelegate = nullptr;
@@ -1345,8 +1347,7 @@ class LLVM_EXTERNAL_VISIBILITY MachineFunction {
   }
 
   /// Start tracking the arguments passed to the call \p CallI.
-  void addCallArgsForwardingRegs(const MachineInstr *CallI,
-                                 CallSiteInfoImpl &&CallInfo) {
+  void addCallSiteInfo(const MachineInstr *CallI, CallSiteInfo &&CallInfo) {
     assert(CallI->isCandidateForCallSiteEntry());
     bool Inserted =
         CallSitesInfo.try_emplace(CallI, std::move(CallInfo)).second;

llvm/include/llvm/CodeGen/SelectionDAG.h

@@ -279,7 +279,6 @@ class SelectionDAG {
   SDDbgInfo *DbgInfo;
 
   using CallSiteInfo = MachineFunction::CallSiteInfo;
-  using CallSiteInfoImpl = MachineFunction::CallSiteInfoImpl;
 
   struct NodeExtraInfo {
     CallSiteInfo CSInfo;
@@ -2259,7 +2258,7 @@ class SelectionDAG {
   }
 
   /// Set CallSiteInfo to be associated with Node.
-  void addCallSiteInfo(const SDNode *Node, CallSiteInfoImpl &&CallInfo) {
+  void addCallSiteInfo(const SDNode *Node, CallSiteInfo &&CallInfo) {
     SDEI[Node].CSInfo = std::move(CallInfo);
   }
   /// Return CallSiteInfo associated with Node, or a default if none exists.

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -798,10 +798,10 @@ static void collectCallSiteParameters(const MachineInstr *CallMI,
                                       ParamSet &Params) {
   const MachineFunction *MF = CallMI->getMF();
   const auto &CalleesMap = MF->getCallSitesInfo();
-  auto CallFwdRegsInfo = CalleesMap.find(CallMI);
+  auto CSInfo = CalleesMap.find(CallMI);
 
   // There is no information for the call instruction.
-  if (CallFwdRegsInfo == CalleesMap.end())
+  if (CSInfo == CalleesMap.end())
     return;
 
   const MachineBasicBlock *MBB = CallMI->getParent();
@@ -815,7 +815,7 @@ static void collectCallSiteParameters(const MachineInstr *CallMI,
       DIExpression::get(MF->getFunction().getContext(), {});
 
   // Add all the forwarding registers into the ForwardedRegWorklist.
-  for (const auto &ArgReg : CallFwdRegsInfo->second) {
+  for (const auto &ArgReg : CSInfo->second.ArgRegPairs) {
     bool InsertedReg =
         ForwardedRegWorklist.insert({ArgReg.Reg, {{ArgReg.Reg, EmptyExpr}}})
             .second;

llvm/lib/CodeGen/MIRParser/MIRParser.cpp

@@ -425,11 +425,11 @@ bool MIRParserImpl::initializeCallSiteInfo(
       Register Reg;
       if (parseNamedRegisterReference(PFS, Reg, ArgRegPair.Reg.Value, Error))
         return error(Error, ArgRegPair.Reg.SourceRange);
-      CSInfo.emplace_back(Reg, ArgRegPair.ArgNo);
+      CSInfo.ArgRegPairs.emplace_back(Reg, ArgRegPair.ArgNo);
     }
 
     if (TM.Options.EmitCallSiteInfo)
-      MF.addCallArgsForwardingRegs(&*CallI, std::move(CSInfo));
+      MF.addCallSiteInfo(&*CallI, std::move(CSInfo));
   }
 
   if (YamlMF.CallSitesInfo.size() && !TM.Options.EmitCallSiteInfo)

llvm/lib/CodeGen/MIRPrinter.cpp

@@ -540,7 +540,7 @@ void MIRPrinter::convertCallSiteObjects(yaml::MachineFunction &YMF,
         std::distance(CallI->getParent()->instr_begin(), CallI);
     YmlCS.CallLocation = CallLocation;
     // Construct call arguments and theirs forwarding register info.
-    for (auto ArgReg : CSInfo.second) {
+    for (auto ArgReg : CSInfo.second.ArgRegPairs) {
       yaml::CallSiteInfo::ArgRegPair YmlArgReg;
       YmlArgReg.ArgNo = ArgReg.ArgNo;
       printRegMIR(ArgReg.Reg, YmlArgReg.Reg, TRI);

llvm/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp

@@ -888,8 +888,9 @@ EmitSchedule(MachineBasicBlock::iterator &InsertPos) {
     }
 
     if (MI->isCandidateForCallSiteEntry() &&
-        DAG->getTarget().Options.EmitCallSiteInfo)
-      MF.addCallArgsForwardingRegs(MI, DAG->getCallSiteInfo(Node));
+        DAG->getTarget().Options.EmitCallSiteInfo) {
+      MF.addCallSiteInfo(MI, DAG->getCallSiteInfo(Node));
+    }
 
     if (DAG->getNoMergeSiteInfo(Node)) {
       MI->setFlag(MachineInstr::MIFlag::NoMerge);

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

@@ -8219,9 +8219,10 @@ AArch64TargetLowering::LowerCall(CallLoweringInfo &CLI,
         // Call site info is used for function's parameter entry value
         // tracking. For now we track only simple cases when parameter
         // is transferred through whole register.
-        llvm::erase_if(CSInfo, [&VA](MachineFunction::ArgRegPair ArgReg) {
-          return ArgReg.Reg == VA.getLocReg();
-        });
+        llvm::erase_if(CSInfo.ArgRegPairs,
+                       [&VA](MachineFunction::ArgRegPair ArgReg) {
+                         return ArgReg.Reg == VA.getLocReg();
+                       });
       } else {
         // Add an extra level of indirection for streaming mode changes by
         // using a pseudo copy node that cannot be rematerialised between a
@@ -8233,7 +8234,7 @@ AArch64TargetLowering::LowerCall(CallLoweringInfo &CLI,
         RegsUsed.insert(VA.getLocReg());
         const TargetOptions &Options = DAG.getTarget().Options;
         if (Options.EmitCallSiteInfo)
-          CSInfo.emplace_back(VA.getLocReg(), i);
+          CSInfo.ArgRegPairs.emplace_back(VA.getLocReg(), i);
       }
     } else {
       assert(VA.isMemLoc());

llvm/lib/Target/ARM/ARMISelLowering.cpp

@@ -2571,7 +2571,7 @@ ARMTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
       }
       const TargetOptions &Options = DAG.getTarget().Options;
       if (Options.EmitCallSiteInfo)
-        CSInfo.emplace_back(VA.getLocReg(), i);
+        CSInfo.ArgRegPairs.emplace_back(VA.getLocReg(), i);
       RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
     } else if (isByVal) {
       assert(VA.isMemLoc());

llvm/lib/Target/Mips/MipsISelLowering.cpp

@@ -3382,7 +3382,7 @@ MipsTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
       // Collect CSInfo about which register passes which parameter.
       const TargetOptions &Options = DAG.getTarget().Options;
       if (Options.SupportsDebugEntryValues)
-        CSInfo.emplace_back(VA.getLocReg(), i);
+        CSInfo.ArgRegPairs.emplace_back(VA.getLocReg(), i);
 
       continue;
     }

llvm/lib/Target/X86/X86ISelLoweringCall.cpp

@@ -2224,7 +2224,7 @@ X86TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
       RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
       const TargetOptions &Options = DAG.getTarget().Options;
       if (Options.EmitCallSiteInfo)
-        CSInfo.emplace_back(VA.getLocReg(), I);
+        CSInfo.ArgRegPairs.emplace_back(VA.getLocReg(), I);
       if (isVarArg && IsWin64) {
         // Win64 ABI requires argument XMM reg to be copied to the corresponding
         // shadow reg if callee is a varargs function.