r239421 - [ItaniumMangle] Mangle long double as __float128 for some Power targets

[David Majnemer]

Author: majnemer
Date: Tue Jun  9 13:05:33 2015
New Revision: 239421

URL: http://llvm.org/viewvc/llvm-project?rev=239421&view=rev
Log:
[ItaniumMangle] Mangle long double as __float128 for some Power targets

GCC mangles long double like __float128 in order to support
compatibility with ABI variants which had a different interpretation of
long double.

This fixes PR23791.

Added:
    cfe/trunk/test/CodeGenCXX/mangle-long-double.cpp
Modified:
    cfe/trunk/include/clang/Basic/TargetInfo.h
    cfe/trunk/lib/AST/ItaniumMangle.cpp
    cfe/trunk/lib/Basic/Targets.cpp

Modified: cfe/trunk/include/clang/Basic/TargetInfo.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/TargetInfo.h?rev=239421&r1=239420&r2=239421&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/TargetInfo.h (original)
+++ cfe/trunk/include/clang/Basic/TargetInfo.h Tue Jun  9 13:05:33 2015
@@ -363,6 +363,10 @@ public:
     return *LongDoubleFormat;
   }
 
+  /// \brief Return true if the 'long double' type should be mangled like
+  /// __float128.
+  virtual bool useFloat128ManglingForLongDouble() const { return false; }
+
   /// \brief Return the value for the C99 FLT_EVAL_METHOD macro.
   virtual unsigned getFloatEvalMethod() const { return 0; }
 

Modified: cfe/trunk/lib/AST/ItaniumMangle.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ItaniumMangle.cpp?rev=239421&r1=239420&r2=239421&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ItaniumMangle.cpp (original)
+++ cfe/trunk/lib/AST/ItaniumMangle.cpp Tue Jun  9 13:05:33 2015
@@ -2010,7 +2010,11 @@ void CXXNameMangler::mangleType(const Bu
   case BuiltinType::Half: Out << "Dh"; break;
   case BuiltinType::Float: Out << 'f'; break;
   case BuiltinType::Double: Out << 'd'; break;
-  case BuiltinType::LongDouble: Out << 'e'; break;
+  case BuiltinType::LongDouble:
+    Out << (getASTContext().getTargetInfo().useFloat128ManglingForLongDouble()
+                ? 'g'
+                : 'e');
+    break;
   case BuiltinType::NullPtr: Out << "Dn"; break;
 
 #define BUILTIN_TYPE(Id, SingletonId)

Modified: cfe/trunk/lib/Basic/Targets.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Basic/Targets.cpp?rev=239421&r1=239420&r2=239421&view=diff
==============================================================================
--- cfe/trunk/lib/Basic/Targets.cpp (original)
+++ cfe/trunk/lib/Basic/Targets.cpp Tue Jun  9 13:05:33 2015
@@ -992,6 +992,12 @@ public:
   bool hasSjLjLowering() const override {
     return true;
   }
+
+  bool useFloat128ManglingForLongDouble() const override {
+    return LongDoubleWidth == 128 &&
+           LongDoubleFormat == &llvm::APFloat::PPCDoubleDouble &&
+           getTriple().isOSBinFormatELF();
+  }
 };
 
 const Builtin::Info PPCTargetInfo::BuiltinInfo[] = {

Added: cfe/trunk/test/CodeGenCXX/mangle-long-double.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/mangle-long-double.cpp?rev=239421&view=auto
==============================================================================
--- cfe/trunk/test/CodeGenCXX/mangle-long-double.cpp (added)
+++ cfe/trunk/test/CodeGenCXX/mangle-long-double.cpp Tue Jun  9 13:05:33 2015
@@ -0,0 +1,10 @@
+// RUN: %clang_cc1 -triple powerpc64-unknown-linux-gnu %s -emit-llvm -o - | FileCheck %s --check-prefix=POWER64-LINUX
+// RUN: %clang_cc1 -triple powerpc-unknown-linux-gnu   %s -emit-llvm -o - | FileCheck %s --check-prefix=POWER-LINUX
+// RUN: %clang_cc1 -triple powerpc64-apple-darwin9     %s -emit-llvm -o - | FileCheck %s --check-prefix=POWER64-DARWIN
+// RUN: %clang_cc1 -triple powerpc-apple-darwin9       %s -emit-llvm -o - | FileCheck %s --check-prefix=POWER-DARWIN
+
+void f(long double) {}
+// POWER64-LINUX:  _Z1fg
+// POWER-LINUX:    _Z1fg
+// POWER64-DARWIN: _Z1fe
+// POWER-DARWIN:   _Z1fe