Index: lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -8010,8 +8010,24 @@
         // The jump block hasn't been inserted yet; insert it here.
         MachineBasicBlock *JumpMBB = JT->MBB;
         CurMF->insert(BBI, JumpMBB);
-        addSuccessorWithWeight(CurMBB, Fallthrough);
-        addSuccessorWithWeight(CurMBB, JumpMBB);
+
+        // Collect the sum of weights of outgoing edges from JumpMBB, which will
+        // be the edge weight on CurMBB->JumpMBB.
+        uint64_t JumpWeight = 0;
+        for (auto Succ : JumpMBB->successors())
+          JumpWeight += getEdgeWeight(JumpMBB, Succ);
+        uint32_t FallthruWeight = getEdgeWeight(CurMBB, Fallthrough);
+
+        // Scale down the sum if it cannot fit in 32-bit.
+        if (JumpWeight > UINT32_MAX) {
+          uint32_t Scale = JumpWeight / UINT32_MAX + 1;
+          JumpWeight /= Scale;
+          FallthruWeight /= Scale;
+        }
+
+        addSuccessorWithWeight(CurMBB, Fallthrough, FallthruWeight);
+        addSuccessorWithWeight(CurMBB, JumpMBB,
+                               static_cast<uint32_t>(JumpWeight));
 
         // The jump table header will be inserted in our current block, do the
         // range check, and fall through to our fallthrough block.
Index: test/CodeGen/ARM/jump-table-islands.ll
===================================================================
--- test/CodeGen/ARM/jump-table-islands.ll
+++ test/CodeGen/ARM/jump-table-islands.ll
@@ -13,7 +13,7 @@
 ; CHECK:   .long LBB{{[0-9]+_[0-9]+}}-[[JUMP_TABLE]]
 
 ; CHECK: [[SKIP_TABLE]]:
-; CHECK:   add pc, {{r[0-9]+}}, {{r[0-9]+}}
+; CHECK:   add pc, lr, {{r[0-9]+}}
   br i1 %tst, label %simple, label %complex
 
 simple:
Index: test/CodeGen/Mips/nacl-align.ll
===================================================================
--- test/CodeGen/Mips/nacl-align.ll
+++ test/CodeGen/Mips/nacl-align.ll
@@ -44,18 +44,17 @@
 ; CHECK-NEXT:    ${{BB[0-9]+_[0-9]+}}:
 ; CHECK-NEXT:        jr      $ra
 ; CHECK-NEXT:        addiu   $2, $zero, 111
-; CHECK-NEXT:        .align  4
 ; CHECK-NEXT:    ${{BB[0-9]+_[0-9]+}}:
 ; CHECK-NEXT:        jr      $ra
-; CHECK-NEXT:        addiu   $2, $zero, 222
+; CHECK-NEXT:        addiu   $2, $zero, 555
 ; CHECK-NEXT:        .align  4
 ; CHECK-NEXT:    ${{BB[0-9]+_[0-9]+}}:
 ; CHECK-NEXT:        jr      $ra
-; CHECK-NEXT:        addiu   $2, $zero, 333
+; CHECK-NEXT:        addiu   $2, $zero, 222
 ; CHECK-NEXT:        .align  4
 ; CHECK-NEXT:    ${{BB[0-9]+_[0-9]+}}:
 ; CHECK-NEXT:        jr      $ra
-; CHECK-NEXT:        addiu   $2, $zero, 444
+; CHECK-NEXT:        addiu   $2, $zero, 333
 
 }
 
Index: test/CodeGen/X86/switch-jump-table.ll
===================================================================
--- test/CodeGen/X86/switch-jump-table.ll
+++ test/CodeGen/X86/switch-jump-table.ll
@@ -7,11 +7,11 @@
 ; CHECK-LABEL: sum2:
 ; CHECK: movl 4(%esp), [[REG:%e[a-z]{2}]]
 ; CHECK: cmpl $3, [[REG]]
-; CHECK: jbe .LBB0_1
+; CHECK: ja .LBB0_6
+; CHECK-NEXT: # BB#1:
+; CHECK-NEXT: jmpl *.LJTI0_0(,[[REG]],4)
 ; CHECK: movl $4
 ; CHECK: retl
-; CHECK-LABEL: .LBB0_1:
-; CHECK-NEXT: jmpl *.LJTI0_0(,[[REG]],4)
 
 entry:
   switch i32 %x, label %default [
Index: test/CodeGen/X86/switch.ll
===================================================================
--- test/CodeGen/X86/switch.ll
+++ test/CodeGen/X86/switch.ll
@@ -90,7 +90,7 @@
 ; but with 6-8, the whole switch is suitable for a jump table.
 ; CHECK-LABEL: jt_is_better
 ; CHECK: cmpl $8
-; CHECK: jbe
+; CHECK: ja
 ; CHECK: jmpq *.LJTI
 }