6 files changed, 38 insertions, 3 deletions
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 7f17fe8b8cc..c1bbc5f085f 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -8043,7 +8043,9 @@ CallingConv ASTContext::getDefaultCallingConvention(bool IsVariadic,
   if (IsCXXMethod)
     return ABI->getDefaultMethodCallConv(IsVariadic);
 
-  return (LangOpts.MRTD && !IsVariadic) ? CC_X86StdCall : CC_C;
+  if (LangOpts.MRTD && !IsVariadic) return CC_X86StdCall;
+
+  return Target->getDefaultCallingConv(TargetInfo::CCMT_Unknown);
 }
 
 bool ASTContext::isNearlyEmpty(const CXXRecordDecl *RD) const {
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index e4f364d04f8..5a39ca0c6b4 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -1588,6 +1588,8 @@ StringRef FunctionType::getNameForCallConv(CallingConv CC) {
   case CC_AAPCS_VFP: return "aapcs-vfp";
   case CC_PnaclCall: return "pnaclcall";
   case CC_IntelOclBicc: return "intel_ocl_bicc";
+  case CC_SpirFunction: return "spir_function";
+  case CC_SpirKernel: return "spir_kernel";
   }
 
   llvm_unreachable("Invalid calling convention.");
diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
index e36fc175c44..b874dd0b4c2 100644
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -697,6 +697,10 @@ void TypePrinter::printFunctionProtoAfter(const FunctionProtoType *T,
     case CC_X86_64SysV:
       OS << " __attribute__((sysv_abi))";
       break;
+    case CC_SpirFunction:
+    case CC_SpirKernel:
+      // Do nothing. These CCs are not available as attributes.
+      break;
     }
   }
 
diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index 9aac3b78643..476217146ed 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -6346,6 +6346,15 @@ namespace {
     BuiltinVaListKind getBuiltinVaListKind() const override {
       return TargetInfo::VoidPtrBuiltinVaList;
     }
+
+    CallingConvCheckResult checkCallingConvention(CallingConv CC) const override {
+      return (CC == CC_SpirFunction ||
+              CC == CC_SpirKernel) ? CCCR_OK : CCCR_Warning;
+    }
+
+    CallingConv getDefaultCallingConv(CallingConvMethodType MT) const override {
+      return CC_SpirFunction;
+    }
   };
 
 
diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index f9b26b62103..cb035d39c58 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -51,6 +51,8 @@ static unsigned ClangCallConvToLLVMCallConv(CallingConv CC) {
   case CC_X86Pascal: return llvm::CallingConv::C;
   // TODO: Add support for __vectorcall to LLVM.
   case CC_X86VectorCall: return llvm::CallingConv::X86_VectorCall;
+  case CC_SpirFunction: return llvm::CallingConv::SPIR_FUNC;
+  case CC_SpirKernel: return llvm::CallingConv::SPIR_KERNEL;
   }
 }
 
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 7116973cf8d..5624f709c9a 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -2476,8 +2476,24 @@ getCCForDeclaratorChunk(Sema &S, Declarator &D,
     }
   }
 
-  return S.Context.getDefaultCallingConvention(FTI.isVariadic,
-                                               IsCXXInstanceMethod);
+  CallingConv CC = S.Context.getDefaultCallingConvention(FTI.isVariadic,
+                                                         IsCXXInstanceMethod);
+
+  // Attribute AT_OpenCLKernel affects the calling convention only on
+  // the SPIR target, hence it cannot be treated as a calling
+  // convention attribute. This is the simplest place to infer
+  // "spir_kernel" for OpenCL kernels on SPIR.
+  if (CC == CC_SpirFunction) {
+    for (const AttributeList *Attr = D.getDeclSpec().getAttributes().getList();
+         Attr; Attr = Attr->getNext()) {
+      if (Attr->getKind() == AttributeList::AT_OpenCLKernel) {
+        CC = CC_SpirKernel;
+        break;
+      }
+    }
+  }
+
+  return CC;
 }
 
 static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,