3 files changed, 28 insertions, 0 deletions
diff --git a/clang/lib/CodeGen/ABIInfo.h b/clang/lib/CodeGen/ABIInfo.h
index 530a7ef560c..ac31dfdaf3e 100644
--- a/clang/lib/CodeGen/ABIInfo.h
+++ b/clang/lib/CodeGen/ABIInfo.h
@@ -142,6 +142,8 @@ namespace swiftcall {
                                            llvm::Type *eltTy,
                                            unsigned elts) const;
 
+    virtual bool isSwiftErrorInRegister() const = 0;
+
     static bool classof(const ABIInfo *info) {
       return info->supportsSwift();
     }
diff --git a/clang/lib/CodeGen/SwiftCallingConv.cpp b/clang/lib/CodeGen/SwiftCallingConv.cpp
index 1629c443652..0bfe30a32c8 100644
--- a/clang/lib/CodeGen/SwiftCallingConv.cpp
+++ b/clang/lib/CodeGen/SwiftCallingConv.cpp
@@ -828,3 +828,8 @@ void swiftcall::computeABIInfo(CodeGenModule &CGM, CGFunctionInfo &FI) {
     argInfo.info = classifyArgumentType(CGM, argInfo.type);
   }
 }
+
+// Is swifterror lowered to a register by the target ABI.
+bool swiftcall::isSwiftErrorLoweredInRegister(CodeGenModule &CGM) {
+  return getSwiftABIInfo(CGM).isSwiftErrorInRegister();
+}
diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index caac27b965c..e4f7d99bef6 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -958,6 +958,11 @@ public:
     // scalar registers.
     return occupiesMoreThan(CGT, scalars, /*total*/ 3);
   }  
+
+  bool isSwiftErrorInRegister() const override {
+    // x86-32 lowering does not support passing swifterror in a register.
+    return false;
+  }
 };
 
 class X86_32TargetCodeGenInfo : public TargetCodeGenInfo {
@@ -2012,6 +2017,9 @@ public:
                                     bool asReturnValue) const override {
     return occupiesMoreThan(CGT, scalars, /*total*/ 4);
   }  
+  bool isSwiftErrorInRegister() const override {
+    return true;
+  }
 };
 
 /// WinX86_64ABIInfo - The Windows X86_64 ABI information.
@@ -2043,6 +2051,10 @@ public:
     return occupiesMoreThan(CGT, scalars, /*total*/ 4);
   }
 
+  bool isSwiftErrorInRegister() const override {
+    return true;
+  }
+
 private:
   ABIArgInfo classify(QualType Ty, unsigned &FreeSSERegs,
                       bool IsReturnType) const;
@@ -4628,6 +4640,9 @@ private:
                                     bool asReturnValue) const override {
     return occupiesMoreThan(CGT, scalars, /*total*/ 4);
   }
+  bool isSwiftErrorInRegister() const override {
+    return true;
+  }
 };
 
 class AArch64TargetCodeGenInfo : public TargetCodeGenInfo {
@@ -5181,6 +5196,9 @@ private:
                                     bool asReturnValue) const override {
     return occupiesMoreThan(CGT, scalars, /*total*/ 4);
   }
+  bool isSwiftErrorInRegister() const override {
+    return true;
+  }
 };
 
 class ARMTargetCodeGenInfo : public TargetCodeGenInfo {
@@ -5949,6 +5967,9 @@ public:
                                     bool asReturnValue) const override {
     return occupiesMoreThan(CGT, scalars, /*total*/ 4);
   }
+  bool isSwiftErrorInRegister() const override {
+    return true;
+  }
 };
 
 class SystemZTargetCodeGenInfo : public TargetCodeGenInfo {