Rebased PNaCl localmods in LLVM to 223109

lib/CodeGen/BranchFolding.cpp

Index: lib/CodeGen/BranchFolding.cpp
diff --git a/lib/CodeGen/BranchFolding.cpp b/lib/CodeGen/BranchFolding.cpp
index 2128da1b8aac0673c84eac151f59765ccaa90bc8..353c8450505da8f1d7a62b4d7f40a3a9f2466da4 100644
--- a/lib/CodeGen/BranchFolding.cpp
+++ b/lib/CodeGen/BranchFolding.cpp
@@ -22,6 +22,7 @@
 #include "llvm/ADT/Statistic.h"
 #include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
 #include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
+#include "llvm/CodeGen/MachineConstantPool.h" //  @LOCALMOD
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineJumpTableInfo.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
@@ -247,6 +248,20 @@ bool BranchFolder::OptimizeFunction(MachineFunction &MF,
       }
   }
 
+  // @LOCALMOD-START
+  // This currently only used on ARM targets where the ConstantPool
+  // subclass is overloading getJumpTableIndex()
+  const std::vector<MachineConstantPoolEntry>& CPs =
+    MF.getConstantPool()->getConstants();
+  for (unsigned i = 0, e = CPs.size(); i != e; ++i) {
+    if (!CPs[i].isMachineConstantPoolEntry()) continue;
+    unsigned *JTIndex = CPs[i].Val.MachineCPVal->getJumpTableIndex();
+    if (!JTIndex) continue;
+    // Remember that this JT is live.
+    JTIsLive.set(*JTIndex);
+  }
+  // @LOCALMOD-END
+
   // Finally, remove dead jump tables.  This happens when the
   // indirect jump was unreachable (and thus deleted).
   for (unsigned i = 0, e = JTIsLive.size(); i != e; ++i)