2 files changed, 15 insertions, 7 deletions
diff --git a/lib/Target/ARM/ARMConstantIslandPass.cpp b/lib/Target/ARM/ARMConstantIslandPass.cpp
index 13b812ca1a..1b936312c0 100644
--- a/lib/Target/ARM/ARMConstantIslandPass.cpp
+++ b/lib/Target/ARM/ARMConstantIslandPass.cpp
@@ -740,14 +740,11 @@ void ARMConstantIslands::AdjustBBOffsetsAfter(MachineBasicBlock *BB,
             delta -= 2;
           }
         }
-        // Thumb jump tables require padding.  They can be at the end, or
-        // followed by an unconditional branch.
+        // Thumb jump tables require padding.  They should be at the end;
+        // following unconditional branches are removed by AnalyzeBranch.
         MachineInstr *ThumbJTMI = NULL;
         if (prior(MBB->end())->getOpcode() == ARM::tBR_JTr)
           ThumbJTMI = prior(MBB->end());
-        else if (prior(MBB->end()) != MBB->begin() &&
-                prior(prior(MBB->end()))->getOpcode() == ARM::tBR_JTr)
-          ThumbJTMI = prior(prior(MBB->end()));
         if (ThumbJTMI) {
           unsigned newMIOffset = GetOffsetOf(ThumbJTMI);
           unsigned oldMIOffset = newMIOffset - delta;
diff --git a/lib/Target/ARM/ARMInstrInfo.cpp b/lib/Target/ARM/ARMInstrInfo.cpp
index f4b4dbe2e3..b404ec078e 100644
--- a/lib/Target/ARM/ARMInstrInfo.cpp
+++ b/lib/Target/ARM/ARMInstrInfo.cpp
@@ -350,8 +350,8 @@ bool ARMInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB,
     return false;
   }
   
-  // If the block ends with two B's or tB's, handle it.  The second one is not
-  // executed, so remove it.
+  // If the block ends with two unconditional branches, handle it.  The second 
+  // one is not executed, so remove it.
   if ((SecondLastOpc == ARM::B || SecondLastOpc==ARM::tB) &&
       (LastOpc == ARM::B || LastOpc == ARM::tB)) {
     TBB = SecondLastInst->getOperand(0).getMachineBasicBlock();
@@ -360,6 +360,17 @@ bool ARMInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB,
     return false;
   }
 
+  // Likewise if it ends with a branch table followed by an unconditional branch.
+  // The branch folder can create these, and we must get rid of them for
+  // correctness of Thumb constant islands.
+  if ((SecondLastOpc == ARM::BR_JTr || SecondLastOpc==ARM::BR_JTm ||
+       SecondLastOpc == ARM::BR_JTadd || SecondLastOpc==ARM::tBR_JTr) &&
+      (LastOpc == ARM::B || LastOpc == ARM::tB)) {
+    I = LastInst;
+    I->eraseFromParent();
+    return true;
+  } 
+
   // Otherwise, can't handle this.
   return true;
 }