In x86_64, when calling an Objective-C method that returns a _Complex…

… long double, make sure to use the objc_msgSend_fp2ret function which ensures that the return value will be {0, 0} if the receiver is nil.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@143350 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Basic/Builtins.def

@@ -698,6 +698,8 @@ LIBBUILTIN(objc_msgSend, "GGH.",   "f",     "objc/message.h", OBJC_LANG)
 
 // long double objc_msgSend_fpret(id self, SEL op, ...) 
 LIBBUILTIN(objc_msgSend_fpret, "LdGH.", "f", "objc/message.h", OBJC_LANG)
+// _Complex long double objc_msgSend_fp2ret(id self, SEL op, ...)
+LIBBUILTIN(objc_msgSend_fp2ret, "XLdGH.", "f", "objc/message.h", OBJC_LANG)
 // id objc_msgSend_stret (id, SEL, ...)
 LIBBUILTIN(objc_msgSend_stret, "GGH.", "f", "objc/message.h", OBJC_LANG)
 // id objc_msgSendSuper(struct objc_super *super, SEL op, ...)

include/clang/Basic/TargetInfo.h

@@ -91,6 +91,7 @@ class TargetInfo : public llvm::RefCountedBase<TargetInfo> {
 
   unsigned HasAlignMac68kSupport : 1;
   unsigned RealTypeUsesObjCFPRet : 3;
+  unsigned ComplexLongDoubleUsesFP2Ret : 1;
 
   // TargetInfo Constructor.  Default initializes all fields.
   TargetInfo(const std::string &T);
@@ -327,6 +328,12 @@ class TargetInfo : public llvm::RefCountedBase<TargetInfo> {
     return RealTypeUsesObjCFPRet & (1 << T);
   }
 
+  /// \brief Check whether _Complex long double should use the "fp2ret" flavor
+  /// of Obj-C message passing on this target.
+  bool useObjCFP2RetForComplexLongDouble() const {
+    return ComplexLongDoubleUsesFP2Ret;
+  }
+
   ///===---- Other target property query methods --------------------------===//
 
   /// getTargetDefines - Appends the target-specific #define values for this

lib/Basic/TargetInfo.cpp

@@ -74,6 +74,9 @@ TargetInfo::TargetInfo(const std::string &T) : Triple(T) {
   // Default to no types using fpret.
   RealTypeUsesObjCFPRet = 0;
 
+  // Default to not using fp2ret for __Complex long double
+  ComplexLongDoubleUsesFP2Ret = false;
+
   // Default to using the Itanium ABI.
   CXXABI = CXXABI_Itanium;
 

lib/Basic/Targets.cpp

@@ -2245,6 +2245,9 @@ class X86_64TargetInfo : public X86TargetInfo {
     // Use fpret only for long double.
     RealTypeUsesObjCFPRet = (1 << TargetInfo::LongDouble);
 
+    // Use fp2ret for _Complex long double.
+    ComplexLongDoubleUsesFP2Ret = true;
+
     // x86-64 has atomics up to 16 bytes.
     // FIXME: Once the backend is fixed, increase MaxAtomicInlineWidth to 128
     // on CPUs with cmpxchg16b

lib/CodeGen/CGCall.cpp

@@ -611,6 +611,17 @@ bool CodeGenModule::ReturnTypeUsesFPRet(QualType ResultType) {
   return false;
 }
 
+bool CodeGenModule::ReturnTypeUsesFP2Ret(QualType ResultType) {
+  if (const ComplexType *CT = ResultType->getAs<ComplexType>()) {
+    if (const BuiltinType *BT = CT->getElementType()->getAs<BuiltinType>()) {
+      if (BT->getKind() == BuiltinType::LongDouble)
+        return getContext().getTargetInfo().useObjCFP2RetForComplexLongDouble();
+    }
+  }
+
+  return false;
+}
+
 llvm::FunctionType *CodeGenTypes::GetFunctionType(GlobalDecl GD) {
   const CGFunctionInfo &FI = getFunctionInfo(GD);
 

lib/CodeGen/CGObjCMac.cpp

@@ -99,6 +99,22 @@ class ObjCCommonTypesHelper {
 
   }
 
+  /// _Complex long double objc_msgSend_fp2ret(id self, SEL op, ...)
+  ///
+  /// The messenger used when the return value is returned in two values on the
+  /// x87 floating point stack; without a special entrypoint, the nil case
+  /// would be unbalanced. Only used on 64-bit X86.
+  llvm::Constant *getMessageSendFp2retFn() const {
+    llvm::Type *params[] = { ObjectPtrTy, SelectorPtrTy };
+    llvm::Type *longDoubleType = llvm::Type::getX86_FP80Ty(VMContext);
+    llvm::Type *resultType = 
+      llvm::StructType::get(longDoubleType, longDoubleType, NULL);
+
+    return CGM.CreateRuntimeFunction(llvm::FunctionType::get(resultType,
+                                                             params, true),
+                                     "objc_msgSend_fp2ret");
+  }
+
   /// id objc_msgSendSuper(struct objc_super *super, SEL op, ...)
   ///
   /// The messenger used for super calls, which have different dispatch
@@ -391,6 +407,14 @@ class ObjCCommonTypesHelper {
     return IsSuper ? getMessageSendSuperFpretFn2() : getMessageSendFpretFn();
   }
 
+  llvm::Constant *getSendFp2retFn(bool IsSuper) const {
+    return IsSuper ? getMessageSendSuperFn() : getMessageSendFp2retFn();
+  }
+
+  llvm::Constant *getSendFp2RetFn2(bool IsSuper) const {
+    return IsSuper ? getMessageSendSuperFn2() : getMessageSendFp2retFn();
+  }
+
   ObjCCommonTypesHelper(CodeGen::CodeGenModule &cgm);
   ~ObjCCommonTypesHelper(){}
 };
@@ -1590,6 +1614,9 @@ CGObjCCommonMac::EmitMessageSend(CodeGen::CodeGenFunction &CGF,
   } else if (CGM.ReturnTypeUsesFPRet(ResultType)) {
     Fn = (ObjCABI == 2) ? ObjCTypes.getSendFpretFn2(IsSuper)
       : ObjCTypes.getSendFpretFn(IsSuper);
+  } else if (CGM.ReturnTypeUsesFP2Ret(ResultType)) {
+    Fn = (ObjCABI == 2) ? ObjCTypes.getSendFp2RetFn2(IsSuper)
+      : ObjCTypes.getSendFp2retFn(IsSuper);
   } else {
     Fn = (ObjCABI == 2) ? ObjCTypes.getSendFn2(IsSuper)
       : ObjCTypes.getSendFn(IsSuper);

lib/CodeGen/CodeGenModule.h

@@ -715,10 +715,14 @@ class CodeGenModule : public CodeGenTypeCache {
   /// as a return type.
   bool ReturnTypeUsesSRet(const CGFunctionInfo &FI);
 
-  /// ReturnTypeUsesSret - Return true iff the given type uses 'fpret' when used
-  /// as a return type.
+  /// ReturnTypeUsesFPRet - Return true iff the given type uses 'fpret' when
+  /// used as a return type.
   bool ReturnTypeUsesFPRet(QualType ResultType);
 
+  /// ReturnTypeUsesFP2Ret - Return true iff the given type uses 'fp2ret' when
+  /// used as a return type.
+  bool ReturnTypeUsesFP2Ret(QualType ResultType);
+
   /// ConstructAttributeList - Get the LLVM attributes and calling convention to
   /// use for a particular function type.
   ///

test/CodeGenObjC/fp2ret.m

@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -triple i386-apple-darwin9 -fobjc-fragile-abi -emit-llvm -o - %s | \
+// RUN:   FileCheck --check-prefix=CHECK-X86_32 %s
+//
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fobjc-fragile-abi -emit-llvm -o - %s | \
+// RUN:   FileCheck --check-prefix=CHECK-X86_64 %s
+//
+// RUN: %clang_cc1 -triple armv7-apple-darwin10 -fobjc-fragile-abi -emit-llvm -target-abi apcs-gnu -o - %s | \
+// RUN:   FileCheck --check-prefix=CHECK-ARMV7 %s
+
+@interface A
+-(_Complex long double) complexLongDoubleValue;
+@end
+
+
+// CHECK-X86_32: define void @t0()
+// CHECK-X86_32: call void bitcast {{.*}} @objc_msgSend_stret to
+// CHECK-X86_32: }
+//
+// CHECK-X86_64: define void @t0()
+// CHECK-X86_64: call { x86_fp80, x86_fp80 } bitcast {{.*}} @objc_msgSend_fp2ret to
+// CHECK-X86_64: }
+//
+// CHECK-ARMV7: define void @t0()
+// CHECK-ARMV7: call i128 bitcast {{.*}} @objc_msgSend to
+// CHECK-ARMV7: }
+void t0() {
+  [(A*)0 complexLongDoubleValue];
+}