[clang][ARC] Add ARCTargetInfo

Based-on-patch-by: Pete Couperus <petecoup@synopsys.com>

Differential Revision: https://reviews.llvm.org/D53100

llvm-svn: 347699

1 files changed, 133 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index fe87f544ed6..0c3b81fabdf 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -8249,6 +8249,137 @@ SparcV9TargetCodeGenInfo::initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
   return false;
 }
 
+// ARC ABI implementation.
+namespace {
+
+class ARCABIInfo : public DefaultABIInfo {
+public:
+  using DefaultABIInfo::DefaultABIInfo;
+
+private:
+  Address EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
+                    QualType Ty) const override;
+
+  void updateState(const ABIArgInfo &Info, QualType Ty, CCState &State) const {
+    if (!State.FreeRegs)
+      return;
+    if (Info.isIndirect() && Info.getInReg())
+      State.FreeRegs--;
+    else if (Info.isDirect() && Info.getInReg()) {
+      unsigned sz = (getContext().getTypeSize(Ty) + 31) / 32;
+      if (sz < State.FreeRegs)
+        State.FreeRegs -= sz;
+      else
+        State.FreeRegs = 0;
+    }
+  }
+
+  void computeInfo(CGFunctionInfo &FI) const override {
+    CCState State(FI.getCallingConvention());
+    // ARC uses 8 registers to pass arguments.
+    State.FreeRegs = 8;
+
+    if (!getCXXABI().classifyReturnType(FI))
+      FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
+    updateState(FI.getReturnInfo(), FI.getReturnType(), State);
+    for (auto &I : FI.arguments()) {
+      I.info = classifyArgumentType(I.type, State.FreeRegs);
+      updateState(I.info, I.type, State);
+    }
+  }
+
+  ABIArgInfo getIndirectByRef(QualType Ty, bool HasFreeRegs) const;
+  ABIArgInfo getIndirectByValue(QualType Ty) const;
+  ABIArgInfo classifyArgumentType(QualType Ty, uint8_t FreeRegs) const;
+  ABIArgInfo classifyReturnType(QualType RetTy) const;
+};
+
+class ARCTargetCodeGenInfo : public TargetCodeGenInfo {
+public:
+  ARCTargetCodeGenInfo(CodeGenTypes &CGT)
+      : TargetCodeGenInfo(new ARCABIInfo(CGT)) {}
+};
+
+
+ABIArgInfo ARCABIInfo::getIndirectByRef(QualType Ty, bool HasFreeRegs) const {
+  return HasFreeRegs ? getNaturalAlignIndirectInReg(Ty) :
+                       getNaturalAlignIndirect(Ty, false);
+}
+
+ABIArgInfo ARCABIInfo::getIndirectByValue(QualType Ty) const {
+  // Compute the byval alignment. 
+  const unsigned MinABIStackAlignInBytes = 4;
+  unsigned TypeAlign = getContext().getTypeAlign(Ty) / 8;
+  return ABIArgInfo::getIndirect(CharUnits::fromQuantity(4), /*ByVal=*/true,
+                                 TypeAlign > MinABIStackAlignInBytes);
+}
+
+Address ARCABIInfo::EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
+                              QualType Ty) const {
+  return emitVoidPtrVAArg(CGF, VAListAddr, Ty, /*indirect*/ false,
+                          getContext().getTypeInfoInChars(Ty),
+                          CharUnits::fromQuantity(4), true);
+}
+
+ABIArgInfo ARCABIInfo::classifyArgumentType(QualType Ty,
+                                            uint8_t FreeRegs) const {
+  // Handle the generic C++ ABI.
+  const RecordType *RT = Ty->getAs<RecordType>();
+  if (RT) {
+    CGCXXABI::RecordArgABI RAA = getRecordArgABI(RT, getCXXABI());
+    if (RAA == CGCXXABI::RAA_Indirect)
+      return getIndirectByRef(Ty, FreeRegs > 0);
+
+    if (RAA == CGCXXABI::RAA_DirectInMemory)
+      return getIndirectByValue(Ty);
+  }
+
+  // Treat an enum type as its underlying type.
+  if (const EnumType *EnumTy = Ty->getAs<EnumType>())
+    Ty = EnumTy->getDecl()->getIntegerType();
+
+  auto SizeInRegs = llvm::alignTo(getContext().getTypeSize(Ty), 32) / 32;
+
+  if (isAggregateTypeForABI(Ty)) {
+    // Structures with flexible arrays are always indirect.
+    if (RT && RT->getDecl()->hasFlexibleArrayMember())
+      return getIndirectByValue(Ty);
+
+    // Ignore empty structs/unions.
+    if (isEmptyRecord(getContext(), Ty, true))
+      return ABIArgInfo::getIgnore();
+
+    llvm::LLVMContext &LLVMContext = getVMContext();
+
+    llvm::IntegerType *Int32 = llvm::Type::getInt32Ty(LLVMContext);
+    SmallVector<llvm::Type *, 3> Elements(SizeInRegs, Int32);
+    llvm::Type *Result = llvm::StructType::get(LLVMContext, Elements);
+
+    return FreeRegs >= SizeInRegs ?
+        ABIArgInfo::getDirectInReg(Result) :
+        ABIArgInfo::getDirect(Result, 0, nullptr, false);
+  }
+
+  return Ty->isPromotableIntegerType() ?
+      (FreeRegs >= SizeInRegs ? ABIArgInfo::getExtendInReg(Ty) :
+                                ABIArgInfo::getExtend(Ty)) :
+      (FreeRegs >= SizeInRegs ? ABIArgInfo::getDirectInReg() :
+                                ABIArgInfo::getDirect());
+}
+
+ABIArgInfo ARCABIInfo::classifyReturnType(QualType RetTy) const {
+  if (RetTy->isAnyComplexType())
+    return ABIArgInfo::getDirectInReg();
+
+  // Arguments of size > 4 registers are indirect.  
+  auto RetSize = llvm::alignTo(getContext().getTypeSize(RetTy), 32) / 32;
+  if (RetSize > 4)
+    return getIndirectByRef(RetTy, /*HasFreeRegs*/ true);
+
+  return DefaultABIInfo::classifyReturnType(RetTy);
+}
+
+} // End anonymous namespace.
 
 //===----------------------------------------------------------------------===//
 // XCore ABI Implementation
@@ -9270,6 +9401,8 @@ const TargetCodeGenInfo &CodeGenModule::getTargetCodeGenInfo() {
     return SetCGInfo(new SparcV9TargetCodeGenInfo(Types));
   case llvm::Triple::xcore:
     return SetCGInfo(new XCoreTargetCodeGenInfo(Types));
+  case llvm::Triple::arc:
+    return SetCGInfo(new ARCTargetCodeGenInfo(Types));
   case llvm::Triple::spir:
   case llvm::Triple::spir64:
     return SetCGInfo(new SPIRTargetCodeGenInfo(Types));