[NFC][SPIRV] Move common SPIRV::LinkageType deduction code to a helper in SPIRVUtils (#164248)

There was some repeated code that was used to deduce the
SPIRV::LinkageType from a GlobalVariable/Function.

At several related parts of the code we also had functions taking 2
parameters:
a 'hasLinkage' bool, and a 'LinkageType'. This is error-prone since the
later parameter's meaning depends on the first. This patch also merges
these
two options into a single `std::optional<SPIRV::LinkageType>`.

7 files changed, 46 insertions, 44 deletions

diff --git a/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp b/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp
index dbe8e18..d91923b 100644
--- a/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp
@@ -507,7 +507,9 @@ static Register buildLoadInst(SPIRVType *BaseType, Register PtrRegister,
 static Register buildBuiltinVariableLoad(
     MachineIRBuilder &MIRBuilder, SPIRVType *VariableType,
     SPIRVGlobalRegistry *GR, SPIRV::BuiltIn::BuiltIn BuiltinValue, LLT LLType,
-    Register Reg = Register(0), bool isConst = true, bool hasLinkageTy = true) {
+    Register Reg = Register(0), bool isConst = true,
+    const std::optional<SPIRV::LinkageType::LinkageType> &LinkageTy = {
+        SPIRV::LinkageType::Import}) {
   Register NewRegister =
       MIRBuilder.getMRI()->createVirtualRegister(&SPIRV::pIDRegClass);
   MIRBuilder.getMRI()->setType(
@@ -521,9 +523,8 @@ static Register buildBuiltinVariableLoad(
   // Set up the global OpVariable with the necessary builtin decorations.
   Register Variable = GR->buildGlobalVariable(
       NewRegister, PtrType, getLinkStringForBuiltIn(BuiltinValue), nullptr,
-      SPIRV::StorageClass::Input, nullptr, /* isConst= */ isConst,
-      /* HasLinkageTy */ hasLinkageTy, SPIRV::LinkageType::Import, MIRBuilder,
-      false);
+      SPIRV::StorageClass::Input, nullptr, /* isConst= */ isConst, LinkageTy,
+      MIRBuilder, false);
 
   // Load the value from the global variable.
   Register LoadedRegister =
@@ -1851,7 +1852,7 @@ static bool generateWaveInst(const SPIRV::IncomingCall *Call,
 
   return buildBuiltinVariableLoad(
       MIRBuilder, Call->ReturnType, GR, Value, LLType, Call->ReturnRegister,
-      /* isConst= */ false, /* hasLinkageTy= */ false);
+      /* isConst= */ false, /* LinkageType= */ std::nullopt);
 }
 
 // We expect a builtin
diff --git a/llvm/lib/Target/SPIRV/SPIRVCallLowering.cpp b/llvm/lib/Target/SPIRV/SPIRVCallLowering.cpp
index 9d5f828..9e11c3a 100644
--- a/llvm/lib/Target/SPIRV/SPIRVCallLowering.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVCallLowering.cpp
@@ -479,18 +479,9 @@ bool SPIRVCallLowering::lowerFormalArguments(MachineIRBuilder &MIRBuilder,
                    .addImm(static_cast<uint32_t>(getExecutionModel(*ST, F)))
                    .addUse(FuncVReg);
     addStringImm(F.getName(), MIB);
-  } else if (!F.hasLocalLinkage() &&
-             F.getVisibility() != GlobalValue::HiddenVisibility) {
-    SPIRV::LinkageType::LinkageType LnkTy =
-        F.isDeclaration()
-            ? SPIRV::LinkageType::Import
-            : (F.getLinkage() == GlobalValue::LinkOnceODRLinkage &&
-                       ST->canUseExtension(
-                           SPIRV::Extension::SPV_KHR_linkonce_odr)
-                   ? SPIRV::LinkageType::LinkOnceODR
-                   : SPIRV::LinkageType::Export);
+  } else if (const auto LnkTy = getSpirvLinkageTypeFor(*ST, F)) {
     buildOpDecorate(FuncVReg, MIRBuilder, SPIRV::Decoration::LinkageAttributes,
-                    {static_cast<uint32_t>(LnkTy)}, F.getName());
+                    {static_cast<uint32_t>(*LnkTy)}, F.getName());
   }
 
   // Handle function pointers decoration
diff --git a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
index 6fd1c7e..6181abb 100644
--- a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
@@ -712,9 +712,9 @@ SPIRVGlobalRegistry::buildConstantSampler(Register ResReg, unsigned AddrMode,
 Register SPIRVGlobalRegistry::buildGlobalVariable(
     Register ResVReg, SPIRVType *BaseType, StringRef Name,
     const GlobalValue *GV, SPIRV::StorageClass::StorageClass Storage,
-    const MachineInstr *Init, bool IsConst, bool HasLinkageTy,
-    SPIRV::LinkageType::LinkageType LinkageType, MachineIRBuilder &MIRBuilder,
-    bool IsInstSelector) {
+    const MachineInstr *Init, bool IsConst,
+    const std::optional<SPIRV::LinkageType::LinkageType> &LinkageType,
+    MachineIRBuilder &MIRBuilder, bool IsInstSelector) {
   const GlobalVariable *GVar = nullptr;
   if (GV) {
     GVar = cast<const GlobalVariable>(GV);
@@ -792,9 +792,9 @@ Register SPIRVGlobalRegistry::buildGlobalVariable(
     buildOpDecorate(Reg, MIRBuilder, SPIRV::Decoration::Alignment, {Alignment});
   }
 
-  if (HasLinkageTy)
+  if (LinkageType)
     buildOpDecorate(Reg, MIRBuilder, SPIRV::Decoration::LinkageAttributes,
-                    {static_cast<uint32_t>(LinkageType)}, Name);
+                    {static_cast<uint32_t>(*LinkageType)}, Name);
 
   SPIRV::BuiltIn::BuiltIn BuiltInId;
   if (getSpirvBuiltInIdByName(Name, BuiltInId))
@@ -821,8 +821,8 @@ Register SPIRVGlobalRegistry::getOrCreateGlobalVariableWithBinding(
       MIRBuilder.getMRI()->createVirtualRegister(&SPIRV::iIDRegClass);
 
   buildGlobalVariable(VarReg, VarType, Name, nullptr,
-                      getPointerStorageClass(VarType), nullptr, false, false,
-                      SPIRV::LinkageType::Import, MIRBuilder, false);
+                      getPointerStorageClass(VarType), nullptr, false,
+                      std::nullopt, MIRBuilder, false);
 
   buildOpDecorate(VarReg, MIRBuilder, SPIRV::Decoration::DescriptorSet, {Set});
   buildOpDecorate(VarReg, MIRBuilder, SPIRV::Decoration::Binding, {Binding});
diff --git a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.h b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.h
index a648def..c230e62 100644
--- a/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.h
+++ b/llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.h
@@ -548,14 +548,12 @@ public:
                                 MachineIRBuilder &MIRBuilder);
   Register getOrCreateUndef(MachineInstr &I, SPIRVType *SpvType,
                             const SPIRVInstrInfo &TII);
-  Register buildGlobalVariable(Register Reg, SPIRVType *BaseType,
-                               StringRef Name, const GlobalValue *GV,
-                               SPIRV::StorageClass::StorageClass Storage,
-                               const MachineInstr *Init, bool IsConst,
-                               bool HasLinkageTy,
-                               SPIRV::LinkageType::LinkageType LinkageType,
-                               MachineIRBuilder &MIRBuilder,
-                               bool IsInstSelector);
+  Register buildGlobalVariable(
+      Register Reg, SPIRVType *BaseType, StringRef Name, const GlobalValue *GV,
+      SPIRV::StorageClass::StorageClass Storage, const MachineInstr *Init,
+      bool IsConst,
+      const std::optional<SPIRV::LinkageType::LinkageType> &LinkageType,
+      MachineIRBuilder &MIRBuilder, bool IsInstSelector);
   Register getOrCreateGlobalVariableWithBinding(const SPIRVType *VarType,
                                                 uint32_t Set, uint32_t Binding,
                                                 StringRef Name,
diff --git a/llvm/lib/Target/SPIRV/SPIRVInstructionSelector.cpp b/llvm/lib/Target/SPIRV/SPIRVInstructionSelector.cpp
index 86d1444..5591d9f 100644
--- a/llvm/lib/Target/SPIRV/SPIRVInstructionSelector.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVInstructionSelector.cpp
@@ -4350,14 +4350,8 @@ bool SPIRVInstructionSelector::selectGlobalValue(
   if (hasInitializer(GlobalVar) && !Init)
     return true;
 
-  bool HasLnkTy = !GV->hasLocalLinkage() && !GV->hasHiddenVisibility();
-  SPIRV::LinkageType::LinkageType LnkType =
-      GV->isDeclarationForLinker()
-          ? SPIRV::LinkageType::Import
-          : (GV->hasLinkOnceODRLinkage() &&
-                     STI.canUseExtension(SPIRV::Extension::SPV_KHR_linkonce_odr)
-                 ? SPIRV::LinkageType::LinkOnceODR
-                 : SPIRV::LinkageType::Export);
+  const std::optional<SPIRV::LinkageType::LinkageType> LnkType =
+      getSpirvLinkageTypeFor(STI, *GV);
 
   const unsigned AddrSpace = GV->getAddressSpace();
   SPIRV::StorageClass::StorageClass StorageClass =
@@ -4365,7 +4359,7 @@ bool SPIRVInstructionSelector::selectGlobalValue(
   SPIRVType *ResType = GR.getOrCreateSPIRVPointerType(GVType, I, StorageClass);
   Register Reg = GR.buildGlobalVariable(
       ResVReg, ResType, GlobalIdent, GV, StorageClass, Init,
-      GlobalVar->isConstant(), HasLnkTy, LnkType, MIRBuilder, true);
+      GlobalVar->isConstant(), LnkType, MIRBuilder, true);
   return Reg.isValid();
 }
 
@@ -4516,8 +4510,8 @@ bool SPIRVInstructionSelector::loadVec3BuiltinInputID(
   // builtin variable.
   Register Variable = GR.buildGlobalVariable(
       NewRegister, PtrType, getLinkStringForBuiltIn(BuiltInValue), nullptr,
-      SPIRV::StorageClass::Input, nullptr, true, false,
-      SPIRV::LinkageType::Import, MIRBuilder, false);
+      SPIRV::StorageClass::Input, nullptr, true, std::nullopt, MIRBuilder,
+      false);
 
   // Create new register for loading value.
   MachineRegisterInfo *MRI = MIRBuilder.getMRI();
@@ -4569,8 +4563,8 @@ bool SPIRVInstructionSelector::loadBuiltinInputID(
   // builtin variable.
   Register Variable = GR.buildGlobalVariable(
       NewRegister, PtrType, getLinkStringForBuiltIn(BuiltInValue), nullptr,
-      SPIRV::StorageClass::Input, nullptr, true, false,
-      SPIRV::LinkageType::Import, MIRBuilder, false);
+      SPIRV::StorageClass::Input, nullptr, true, std::nullopt, MIRBuilder,
+      false);
 
   // Load uint value from the global variable.
   auto MIB = BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(SPIRV::OpLoad))
diff --git a/llvm/lib/Target/SPIRV/SPIRVUtils.cpp b/llvm/lib/Target/SPIRV/SPIRVUtils.cpp
index 1d47c89..4e2cc88 100644
--- a/llvm/lib/Target/SPIRV/SPIRVUtils.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVUtils.cpp
@@ -1040,4 +1040,19 @@ getFirstValidInstructionInsertPoint(MachineBasicBlock &BB) {
                                                                      : VarPos;
 }
 
+std::optional<SPIRV::LinkageType::LinkageType>
+getSpirvLinkageTypeFor(const SPIRVSubtarget &ST, const GlobalValue &GV) {
+  if (GV.hasLocalLinkage() || GV.hasHiddenVisibility())
+    return std::nullopt;
+
+  if (GV.isDeclarationForLinker())
+    return SPIRV::LinkageType::Import;
+
+  if (GV.hasLinkOnceODRLinkage() &&
+      ST.canUseExtension(SPIRV::Extension::SPV_KHR_linkonce_odr))
+    return SPIRV::LinkageType::LinkOnceODR;
+
+  return SPIRV::LinkageType::Export;
+}
+
 } // namespace llvm
diff --git a/llvm/lib/Target/SPIRV/SPIRVUtils.h b/llvm/lib/Target/SPIRV/SPIRVUtils.h
index 5777a24..99d9d40 100644
--- a/llvm/lib/Target/SPIRV/SPIRVUtils.h
+++ b/llvm/lib/Target/SPIRV/SPIRVUtils.h
@@ -559,5 +559,8 @@ unsigned getArrayComponentCount(const MachineRegisterInfo *MRI,
                                 const MachineInstr *ResType);
 MachineBasicBlock::iterator
 getFirstValidInstructionInsertPoint(MachineBasicBlock &BB);
+
+std::optional<SPIRV::LinkageType::LinkageType>
+getSpirvLinkageTypeFor(const SPIRVSubtarget &ST, const GlobalValue &GV);
 } // namespace llvm
 #endif // LLVM_LIB_TARGET_SPIRV_SPIRVUTILS_H