- Add getLSDAEncoding to the PowerPC backend.

- Greatly improve the comments to the getLSDAEncoding method.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93796 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 46 insertions, 2 deletions

diff --git a/lib/Target/PowerPC/PPCTargetMachine.cpp b/lib/Target/PowerPC/PPCTargetMachine.cpp
index 8079c6e9cc..c80a530c88 100644
--- a/lib/Target/PowerPC/PPCTargetMachine.cpp
+++ b/lib/Target/PowerPC/PPCTargetMachine.cpp
@@ -194,4 +194,19 @@ bool PPCTargetMachine::addSimpleCodeEmitter(PassManagerBase &PM,
   return false;
 }
 
-
+/// getLSDAEncoding - Returns the LSDA pointer encoding. The choices are 4-byte,
+/// 8-byte, and target default. The CIE is hard-coded to indicate that the LSDA
+/// pointer in the FDE section is an "sdata4", and should be encoded as a 4-byte
+/// pointer by default. However, some systems may require a different size due
+/// to bugs or other conditions. We will default to a 4-byte encoding unless the
+/// system tells us otherwise.
+///
+/// FIXME: This call-back isn't good! We should be using the correct encoding
+/// regardless of the system. However, there are some systems which have bugs
+/// that prevent this from occuring.
+DwarfLSDAEncoding::Encoding PPCTargetMachine::getLSDAEncoding() const {
+  if (Subtarget.isDarwin() && Subtarget.getDarwinVers() != 10)
+    return DwarfLSDAEncoding::Default;
+
+  return DwarfLSDAEncoding::EightByte;
+}
diff --git a/lib/Target/PowerPC/PPCTargetMachine.h b/lib/Target/PowerPC/PPCTargetMachine.h
index 3399ac8918..4afcb23415 100644
--- a/lib/Target/PowerPC/PPCTargetMachine.h
+++ b/lib/Target/PowerPC/PPCTargetMachine.h
@@ -62,6 +62,18 @@ public:
     return &MachOWriterInfo;
   }
 
+  /// getLSDAEncoding - Returns the LSDA pointer encoding. The choices are
+  /// 4-byte, 8-byte, and target default. The CIE is hard-coded to indicate that
+  /// the LSDA pointer in the FDE section is an "sdata4", and should be encoded
+  /// as a 4-byte pointer by default. However, some systems may require a
+  /// different size due to bugs or other conditions. We will default to a
+  /// 4-byte encoding unless the system tells us otherwise.
+  ///
+  /// FIXME: This call-back isn't good! We should be using the correct encoding
+  /// regardless of the system. However, there are some systems which have bugs
+  /// that prevent this from occuring.
+  virtual DwarfLSDAEncoding::Encoding getLSDAEncoding() const;
+
   // Pass Pipeline Configuration
   virtual bool addInstSelector(PassManagerBase &PM, CodeGenOpt::Level OptLevel);
   virtual bool addPreEmitPass(PassManagerBase &PM, CodeGenOpt::Level OptLevel);
diff --git a/lib/Target/X86/X86TargetMachine.cpp b/lib/Target/X86/X86TargetMachine.cpp
index 547fa8eeeb..684e1fc573 100644
--- a/lib/Target/X86/X86TargetMachine.cpp
+++ b/lib/Target/X86/X86TargetMachine.cpp
@@ -250,12 +250,19 @@ void X86TargetMachine::setCodeModelForJIT() {
     setCodeModel(CodeModel::Small);
 }
 
+/// getLSDAEncoding - Returns the LSDA pointer encoding. The choices are 4-byte,
+/// 8-byte, and target default. The CIE is hard-coded to indicate that the LSDA
+/// pointer in the FDE section is an "sdata4", and should be encoded as a 4-byte
+/// pointer by default. However, some systems may require a different size due
+/// to bugs or other conditions. We will default to a 4-byte encoding unless the
+/// system tells us otherwise.
+///
 /// FIXME: This call-back isn't good! We should be using the correct encoding
 /// regardless of the system. However, there are some systems which have bugs
 /// that prevent this from occuring.
 DwarfLSDAEncoding::Encoding X86TargetMachine::getLSDAEncoding() const {
   if (Subtarget.isTargetDarwin() && Subtarget.getDarwinVers() != 10)
-    return DwarfLSDAEncoding::FourByte;
+    return DwarfLSDAEncoding::Default;
 
   return DwarfLSDAEncoding::EightByte;
 }
diff --git a/lib/Target/X86/X86TargetMachine.h b/lib/Target/X86/X86TargetMachine.h
index c42aa89ff9..d05bebd071 100644
--- a/lib/Target/X86/X86TargetMachine.h
+++ b/lib/Target/X86/X86TargetMachine.h
@@ -62,6 +62,16 @@ public:
     return Subtarget.isTargetELF() ? &ELFWriterInfo : 0;
   }
 
+  /// getLSDAEncoding - Returns the LSDA pointer encoding. The choices are
+  /// 4-byte, 8-byte, and target default. The CIE is hard-coded to indicate that
+  /// the LSDA pointer in the FDE section is an "sdata4", and should be encoded
+  /// as a 4-byte pointer by default. However, some systems may require a
+  /// different size due to bugs or other conditions. We will default to a
+  /// 4-byte encoding unless the system tells us otherwise.
+  ///
+  /// FIXME: This call-back isn't good! We should be using the correct encoding
+  /// regardless of the system. However, there are some systems which have bugs
+  /// that prevent this from occuring.
   virtual DwarfLSDAEncoding::Encoding getLSDAEncoding() const;
 
   // Set up the pass pipeline.