regcall: Implement regcall Calling Conv in clang

This patch implements the register call calling convention, which ensures
as many values as possible are passed in registers. CodeGen changes
were committed in https://reviews.llvm.org/rL284108.

Differential Revision: https://reviews.llvm.org/D25204

llvm-svn: 285849

2 files changed, 11 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 917d414f967..1be69c5276a 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -3839,6 +3839,10 @@ static void handleCallConvAttr(Sema &S, Decl *D, const AttributeList &Attr) {
                SysVABIAttr(Attr.getRange(), S.Context,
                            Attr.getAttributeSpellingListIndex()));
     return;
+  case AttributeList::AT_RegCall:
+    D->addAttr(::new (S.Context) RegCallAttr(
+        Attr.getRange(), S.Context, Attr.getAttributeSpellingListIndex()));
+    return;
   case AttributeList::AT_Pcs: {
     PcsAttr::PCSType PCS;
     switch (CC) {
@@ -3900,6 +3904,7 @@ bool Sema::CheckCallingConvAttr(const AttributeList &attr, CallingConv &CC,
   case AttributeList::AT_Pascal: CC = CC_X86Pascal; break;
   case AttributeList::AT_SwiftCall: CC = CC_Swift; break;
   case AttributeList::AT_VectorCall: CC = CC_X86VectorCall; break;
+  case AttributeList::AT_RegCall: CC = CC_X86RegCall; break;
   case AttributeList::AT_MSABI:
     CC = Context.getTargetInfo().getTriple().isOSWindows() ? CC_C :
                                                              CC_X86_64Win64;
@@ -5871,6 +5876,7 @@ static void ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D,
   case AttributeList::AT_FastCall:
   case AttributeList::AT_ThisCall:
   case AttributeList::AT_Pascal:
+  case AttributeList::AT_RegCall:
   case AttributeList::AT_SwiftCall:
   case AttributeList::AT_VectorCall:
   case AttributeList::AT_MSABI:
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 4e6725eb626..e9acd9db73d 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -106,6 +106,7 @@ static void diagnoseBadTypeAttribute(Sema &S, const AttributeList &attr,
     case AttributeList::AT_FastCall: \
     case AttributeList::AT_StdCall: \
     case AttributeList::AT_ThisCall: \
+    case AttributeList::AT_RegCall: \
     case AttributeList::AT_Pascal: \
     case AttributeList::AT_SwiftCall: \
     case AttributeList::AT_VectorCall: \
@@ -4750,6 +4751,8 @@ static AttributeList::Kind getAttrListKind(AttributedType::Kind kind) {
     return AttributeList::AT_StdCall;
   case AttributedType::attr_thiscall:
     return AttributeList::AT_ThisCall;
+  case AttributedType::attr_regcall:
+    return AttributeList::AT_RegCall;
   case AttributedType::attr_pascal:
     return AttributeList::AT_Pascal;
   case AttributedType::attr_swiftcall:
@@ -6086,6 +6089,8 @@ static AttributedType::Kind getCCTypeAttrKind(AttributeList &Attr) {
     return AttributedType::attr_stdcall;
   case AttributeList::AT_ThisCall:
     return AttributedType::attr_thiscall;
+  case AttributeList::AT_RegCall:
+    return AttributedType::attr_regcall;
   case AttributeList::AT_Pascal:
     return AttributedType::attr_pascal;
   case AttributeList::AT_SwiftCall: