Reverting r243386 because it has serious post-commit concerns that have not been addressed. Also reverts r243389, which relied on this commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243527 91177308-0d34-0410-b5e6-96231b3b80d8

Author: AaronBallman

docs/ProgrammersManual.rst

@@ -1314,8 +1314,7 @@ never use hash_set and unordered_set because they are generally very expensive
 std::multiset is useful if you're not interested in elimination of duplicates,
 but has all the drawbacks of :ref:`std::set <dss_set>`.  A sorted vector
 (where you don't delete duplicate entries) or some other approach is almost
-always better. LLVM actually offers SortedVector which does the job of a sorted
-std::vector.
+always better.
 
 .. _ds_map:
 

include/llvm/ADT/SortedVector.h

@@ -14,7 +14,6 @@
 #ifndef LLVM_CODEGEN_MACHINEBASICBLOCK_H
 #define LLVM_CODEGEN_MACHINEBASICBLOCK_H
 
-#include "llvm/ADT/SortedVector.h"
 #include "llvm/ADT/GraphTraits.h"
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/Support/DataTypes.h"
@@ -81,7 +80,7 @@ class MachineBasicBlock : public ilist_node<MachineBasicBlock> {
 
   /// LiveIns - Keep track of the physical registers that are livein of
   /// the basicblock.
-  mutable SortedVector<unsigned> LiveIns;
+  std::vector<unsigned> LiveIns;
 
   /// Alignment - Alignment of the basic block. Zero if the basic block does
   /// not need to be aligned.
@@ -319,12 +318,15 @@ class MachineBasicBlock : public ilist_node<MachineBasicBlock> {
   /// Adds the specified register as a live in. Note that it is an error to add
   /// the same register to the same set more than once unless the intention is
   /// to call sortUniqueLiveIns after all registers are added.
-  void addLiveIn(unsigned Reg) { LiveIns.insert(Reg); }
+  void addLiveIn(unsigned Reg) { LiveIns.push_back(Reg); }
 
   /// Sorts and uniques the LiveIns vector. It can be significantly faster to do
   /// this than repeatedly calling isLiveIn before calling addLiveIn for every
   /// LiveIn insertion.
-  void sortUniqueLiveIns() { LiveIns.sortUnique(); }
+  void sortUniqueLiveIns() {
+    std::sort(LiveIns.begin(), LiveIns.end());
+    LiveIns.erase(std::unique(LiveIns.begin(), LiveIns.end()), LiveIns.end());
+  }
 
   /// Add PhysReg as live in to this block, and ensure that there is a copy of
   /// PhysReg to a virtual register of class RC. Return the virtual register
@@ -337,20 +339,14 @@ class MachineBasicBlock : public ilist_node<MachineBasicBlock> {
 
   /// isLiveIn - Return true if the specified register is in the live in set.
   ///
-  bool isLiveIn(unsigned Reg) const { return LiveIns.has(Reg); }
+  bool isLiveIn(unsigned Reg) const;
 
   // Iteration support for live in sets.  These sets are kept in sorted
   // order by their register number.
   typedef std::vector<unsigned>::const_iterator livein_iterator;
+  livein_iterator livein_begin() const { return LiveIns.begin(); }
+  livein_iterator livein_end()   const { return LiveIns.end(); }
   bool            livein_empty() const { return LiveIns.empty(); }
-  livein_iterator livein_begin() const {
-    LiveIns.sortUnique();
-    return LiveIns.begin();
-  }
-  livein_iterator livein_end() const {
-    LiveIns.sortUnique();
-    return LiveIns.end();
-  }
 
   /// getAlignment - Return alignment of the basic block.
   /// The alignment is specified as log2(bytes).

include/llvm/CodeGen/MachineBasicBlock.h

@@ -332,6 +332,11 @@ void MachineBasicBlock::removeLiveIn(unsigned Reg) {
     LiveIns.erase(I);
 }
 
+bool MachineBasicBlock::isLiveIn(unsigned Reg) const {
+  livein_iterator I = std::find(livein_begin(), livein_end(), Reg);
+  return I != livein_end();
+}
+
 unsigned
 MachineBasicBlock::addLiveIn(unsigned PhysReg, const TargetRegisterClass *RC) {
   assert(getParent() && "MBB must be inserted in function");