From afc99847bf2dc52b7f0a97c2ea2599dda04be9e0 Mon Sep 17 00:00:00 2001
From: Eric Christopher <echristo@apple.com>
Date: Tue, 24 Jan 2012 09:43:28 +0000
Subject: [PATCH] Remove generation of DW_AT_sibling. Nothing as far as I can
 tell uses it. Saves about 1.5% on debug info size.

rdar://10278198

llvm-svn: 148794
---
 lib/CodeGen/AsmPrinter/DIE.cpp        |  9 ---------
 lib/CodeGen/AsmPrinter/DIE.h          | 10 ----------
 lib/CodeGen/AsmPrinter/DwarfDebug.cpp |  7 -------
 3 files changed, 26 deletions(-)

diff --git a/lib/CodeGen/AsmPrinter/DIE.cpp b/lib/CodeGen/AsmPrinter/DIE.cpp
index bc4125649cd..331b07cbf3a 100644
--- a/lib/CodeGen/AsmPrinter/DIE.cpp
+++ b/lib/CodeGen/AsmPrinter/DIE.cpp
@@ -112,15 +112,6 @@ DIE::~DIE() {
     delete Children[i];
 }
 
-/// addSiblingOffset - Add a sibling offset field to the front of the DIE.
-///
-DIEValue *DIE::addSiblingOffset(BumpPtrAllocator &A) {
-  DIEInteger *DI = new (A) DIEInteger(0);
-  Values.insert(Values.begin(), DI);
-  Abbrev.AddFirstAttribute(dwarf::DW_AT_sibling, dwarf::DW_FORM_ref4);
-  return DI;
-}
-
 #ifndef NDEBUG
 void DIE::print(raw_ostream &O, unsigned IncIndent) {
   IndentCount += IncIndent;
diff --git a/lib/CodeGen/AsmPrinter/DIE.h b/lib/CodeGen/AsmPrinter/DIE.h
index b4996250c1b..556c80f8c26 100644
--- a/lib/CodeGen/AsmPrinter/DIE.h
+++ b/lib/CodeGen/AsmPrinter/DIE.h
@@ -163,16 +163,6 @@ namespace llvm {
       Values.push_back(Value);
     }
 
-    /// SiblingOffset - Return the offset of the debug information entry's
-    /// sibling.
-    unsigned getSiblingOffset() const { return Offset + Size; }
-
-    /// addSiblingOffset - Add a sibling offset field to the front of the DIE.
-    /// The caller is responsible for deleting the return value at or after the
-    /// same time it destroys this DIE.
-    ///
-    DIEValue *addSiblingOffset(BumpPtrAllocator &A);
-
     /// addChild - Add a child to the DIE.
     ///
     void addChild(DIE *Child) {
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 4e949d42ef8..9c3825f0460 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1488,10 +1488,6 @@ DwarfDebug::computeSizeAndOffset(DIE *Die, unsigned Offset, bool Last) {
   // Get the children.
   const std::vector<DIE *> &Children = Die->getChildren();
 
-  // If not last sibling and has children then add sibling offset attribute.
-  if (!Last && !Children.empty())
-    Die->addSiblingOffset(DIEValueAllocator);
-
   // Record the abbreviation.
   assignAbbrevNumber(Die->getAbbrev());
 
@@ -1602,9 +1598,6 @@ void DwarfDebug::emitDIE(DIE *Die) {
       Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
 
     switch (Attr) {
-    case dwarf::DW_AT_sibling:
-      Asm->EmitInt32(Die->getSiblingOffset());
-      break;
     case dwarf::DW_AT_abstract_origin: {
       DIEEntry *E = cast<DIEEntry>(Values[i]);
       DIE *Origin = E->getEntry();