- Add getLSDAEncoding to the PowerPC backend.

- Greatly improve the comments to the getLSDAEncoding method.

llvm-svn: 93796

1 files changed, 6 insertions, 1 deletions

diff --git a/llvm/include/llvm/Target/TargetMachine.h b/llvm/include/llvm/Target/TargetMachine.h
index 15f4e6c35c0..b0ed6b3aa79 100644
--- a/llvm/include/llvm/Target/TargetMachine.h
+++ b/llvm/include/llvm/Target/TargetMachine.h
@@ -201,7 +201,12 @@ public:
   static void setAsmVerbosityDefault(bool);
 
   /// getLSDAEncoding - Returns the LSDA pointer encoding. The choices are
-  /// 4-byte, 8-byte, and target default.
+  /// 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.