Revert these. They may have been causing 483_xalancbmk to fail:

$ svn merge -c -91161 https://llvm.org/svn/llvm-project/llvm/trunk
--- Reverse-merging r91161 into '.':
U    lib/CodeGen/BranchFolding.cpp
U    lib/CodeGen/MachineBasicBlock.cpp
$ svn merge -c -91113 https://llvm.org/svn/llvm-project/llvm/trunk
--- Reverse-merging r91113 into '.':
G    lib/CodeGen/MachineBasicBlock.cpp
$ svn merge -c -91101 https://llvm.org/svn/llvm-project/llvm/trunk
--- Reverse-merging r91101 into '.':
U    include/llvm/CodeGen/MachineBasicBlock.h
G    lib/CodeGen/MachineBasicBlock.cpp
$ svn merge -c -91092 https://llvm.org/svn/llvm-project/llvm/trunk
--- Reverse-merging r91092 into '.':
G    include/llvm/CodeGen/MachineBasicBlock.h
G    lib/CodeGen/MachineBasicBlock.cpp



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91376 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 29 deletions

diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
index 3b4b080c63..a58286d61b 100644
--- a/lib/CodeGen/MachineBasicBlock.cpp
+++ b/lib/CodeGen/MachineBasicBlock.cpp
@@ -13,16 +13,15 @@
 
 #include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/BasicBlock.h"
-#include "llvm/ADT/SmallSet.h"
-#include "llvm/Assembly/Writer.h"
 #include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/Target/TargetRegisterInfo.h"
 #include "llvm/Target/TargetData.h"
 #include "llvm/Target/TargetInstrDesc.h"
 #include "llvm/Target/TargetInstrInfo.h"
 #include "llvm/Target/TargetMachine.h"
-#include "llvm/Target/TargetRegisterInfo.h"
 #include "llvm/Support/LeakDetector.h"
 #include "llvm/Support/raw_ostream.h"
+#include "llvm/Assembly/Writer.h"
 #include <algorithm>
 using namespace llvm;
 
@@ -449,28 +448,10 @@ void MachineBasicBlock::ReplaceUsesOfBlockWith(MachineBasicBlock *Old,
   addSuccessor(New);
 }
 
-/// BranchesToLandingPad - The basic block is a landing pad or branches only to
-/// a landing pad. No other instructions are present other than the
-/// unconditional branch.
-bool
-MachineBasicBlock::BranchesToLandingPad(const MachineBasicBlock *MBB) const {
-  SmallSet<const MachineBasicBlock*, 32> Visited;
-  const MachineBasicBlock *CurMBB = MBB;
-
-  while (!CurMBB->isLandingPad()) {
-    if (CurMBB->succ_size() != 1) break;
-    if (!Visited.insert(CurMBB)) break;
-    CurMBB = *CurMBB->succ_begin();
-  }
-
-  return CurMBB->isLandingPad();
-}
-
 /// CorrectExtraCFGEdges - Various pieces of code can cause excess edges in the
 /// CFG to be inserted.  If we have proven that MBB can only branch to DestA and
 /// DestB, remove any other MBB successors from the CFG.  DestA and DestB can
 /// be null.
-/// 
 /// Besides DestA and DestB, retain other edges leading to LandingPads
 /// (currently there can be only one; we don't check or require that here).
 /// Note it is possible that DestA and/or DestB are LandingPads.
@@ -500,17 +481,16 @@ bool MachineBasicBlock::CorrectExtraCFGEdges(MachineBasicBlock *DestA,
   }
   
   MachineBasicBlock::succ_iterator SI = succ_begin();
-  const MachineBasicBlock *OrigDestA = DestA, *OrigDestB = DestB;
+  MachineBasicBlock *OrigDestA = DestA, *OrigDestB = DestB;
   while (SI != succ_end()) {
-    const MachineBasicBlock *MBB = *SI;
-    if (MBB == DestA) {
+    if (*SI == DestA) {
       DestA = 0;
       ++SI;
-    } else if (MBB == DestB) {
+    } else if (*SI == DestB) {
       DestB = 0;
       ++SI;
-    } else if (MBB != OrigDestA && MBB != OrigDestB &&
-               BranchesToLandingPad(MBB)) {
+    } else if ((*SI)->isLandingPad() && 
+               *SI!=OrigDestA && *SI!=OrigDestB) {
       ++SI;
     } else {
       // Otherwise, this is a superfluous edge, remove it.
@@ -518,14 +498,12 @@ bool MachineBasicBlock::CorrectExtraCFGEdges(MachineBasicBlock *DestA,
       MadeChange = true;
     }
   }
-
   if (!AddedFallThrough) {
     assert(DestA == 0 && DestB == 0 &&
            "MachineCFG is missing edges!");
   } else if (isCond) {
     assert(DestA == 0 && "MachineCFG is missing edges!");
   }
-
   return MadeChange;
 }