Index: llvm/lib/Target/AMDGPU/SILowerControlFlow.cpp
===================================================================
--- llvm/lib/Target/AMDGPU/SILowerControlFlow.cpp
+++ llvm/lib/Target/AMDGPU/SILowerControlFlow.cpp
@@ -113,6 +113,8 @@
 
   void combineMasks(MachineInstr &MI);
 
+  bool removeMBBifRedundant(MachineBasicBlock &MBB);
+
   void process(MachineInstr &MI);
 
   // Skip to the next instruction, ignoring debug instructions, and trivial
@@ -156,7 +158,6 @@
     AU.addPreservedID(LiveVariablesID);
     AU.addPreservedID(MachineLoopInfoID);
     AU.addPreservedID(MachineDominatorsID);
-    AU.setPreservesCFG();
     MachineFunctionPass::getAnalysisUsage(AU);
   }
 };
@@ -615,6 +616,7 @@
       if (LIS)
         LIS->RemoveMachineInstrFromMaps(*MI);
       MI->eraseFromParent();
+      removeMBBifRedundant(MBB);
     }
   }
 }
@@ -669,6 +671,45 @@
   }
 }
 
+bool SILowerControlFlow::removeMBBifRedundant(MachineBasicBlock &MBB) {
+  bool Redundant = true;
+  for (auto &I : MBB.instrs()) {
+    if (!I.isDebugInstr() && !I.isUnconditionalBranch())
+      Redundant = false;
+  }
+  if (Redundant) {
+    MachineBasicBlock *Succ = *MBB.succ_begin();
+    SmallVector<MachineBasicBlock *, 2> Preds(MBB.predecessors());
+    for (auto P : Preds) {
+      P->replaceSuccessor(&MBB, Succ);
+      MachineBasicBlock::iterator I(P->getFirstInstrTerminator());
+      while (I != P->end()) {
+        if (I->isBranch()) {
+          if (TII->getBranchDestBlock(*I) == &MBB) {
+            I->getOperand(0).setMBB(Succ);
+            break;
+          }
+        }
+        I++;
+      }
+      if (I == P->end()) {
+        MachineInstr *Br =
+            BuildMI(P, DebugLoc(), TII->get(AMDGPU::S_BRANCH)).addMBB(Succ);
+        if (LIS)
+          LIS->InsertMachineInstrInMaps(*Br);
+      }
+    }
+    MBB.removeSuccessor(Succ);
+    if (LIS) {
+      for (auto &I : MBB.instrs())
+        LIS->RemoveMachineInstrFromMaps(I);
+    }
+    MBB.eraseFromParent();
+    return true;
+  }
+  return false;
+}
+
 bool SILowerControlFlow::runOnMachineFunction(MachineFunction &MF) {
   const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
   TII = ST.getInstrInfo();
Index: llvm/test/CodeGen/AMDGPU/collapse-endcf.mir
===================================================================
--- llvm/test/CodeGen/AMDGPU/collapse-endcf.mir
+++ llvm/test/CodeGen/AMDGPU/collapse-endcf.mir
@@ -16,16 +16,14 @@
   ; GCN:   $exec = S_MOV_B64_term killed [[S_AND_B64_]]
   ; GCN:   S_CBRANCH_EXECZ %bb.4, implicit $exec
   ; GCN: bb.1:
-  ; GCN:   successors: %bb.2(0x40000000), %bb.3(0x40000000)
+  ; GCN:   successors: %bb.2(0x40000000), %bb.4(0x40000000)
   ; GCN:   [[COPY1:%[0-9]+]]:sreg_64 = COPY $exec, implicit-def $exec
   ; GCN:   [[S_AND_B64_1:%[0-9]+]]:sreg_64 = S_AND_B64 [[COPY1]], undef %3:sreg_64, implicit-def dead $scc
   ; GCN:   $exec = S_MOV_B64_term killed [[S_AND_B64_1]]
-  ; GCN:   S_CBRANCH_EXECZ %bb.3, implicit $exec
+  ; GCN:   S_CBRANCH_EXECZ %bb.4, implicit $exec
   ; GCN: bb.2:
-  ; GCN:   successors: %bb.3(0x80000000)
-  ; GCN: bb.3:
   ; GCN:   successors: %bb.4(0x80000000)
-  ; GCN:   DBG_VALUE
+  ; GCN:   S_BRANCH %bb.4
   ; GCN: bb.4:
   ; GCN:   $exec = S_OR_B64 $exec, [[COPY]], implicit-def $scc
   ; GCN:   DBG_VALUE
@@ -68,15 +66,14 @@
   ; GCN:   $exec = S_MOV_B64_term killed [[S_AND_B64_]]
   ; GCN:   S_CBRANCH_EXECZ %bb.5, implicit $exec
   ; GCN: bb.1:
-  ; GCN:   successors: %bb.2(0x40000000), %bb.3(0x40000000)
+  ; GCN:   successors: %bb.2(0x40000000), %bb.4(0x40000000)
   ; GCN:   [[COPY1:%[0-9]+]]:sreg_64 = COPY $exec, implicit-def $exec
   ; GCN:   [[S_AND_B64_1:%[0-9]+]]:sreg_64 = S_AND_B64 [[COPY1]], undef %3:sreg_64, implicit-def dead $scc
   ; GCN:   $exec = S_MOV_B64_term killed [[S_AND_B64_1]]
-  ; GCN:   S_CBRANCH_EXECZ %bb.3, implicit $exec
+  ; GCN:   S_CBRANCH_EXECZ %bb.4, implicit $exec
   ; GCN: bb.2:
-  ; GCN:   successors: %bb.3(0x80000000)
-  ; GCN: bb.3:
   ; GCN:   successors: %bb.4(0x80000000)
+  ; GCN:   S_BRANCH %bb.4
   ; GCN: bb.4:
   ; GCN:   successors: %bb.5(0x80000000)
   ; GCN: bb.5:
@@ -118,15 +115,14 @@
   ; GCN:   $exec = S_MOV_B64_term killed [[S_AND_B64_]]
   ; GCN:   S_CBRANCH_EXECZ %bb.5, implicit $exec
   ; GCN: bb.1:
-  ; GCN:   successors: %bb.2(0x40000000), %bb.3(0x40000000)
+  ; GCN:   successors: %bb.2(0x40000000), %bb.4(0x40000000)
   ; GCN:   [[COPY1:%[0-9]+]]:sreg_64 = COPY $exec, implicit-def $exec
   ; GCN:   [[S_AND_B64_1:%[0-9]+]]:sreg_64 = S_AND_B64 [[COPY1]], undef %3:sreg_64, implicit-def dead $scc
   ; GCN:   $exec = S_MOV_B64_term killed [[S_AND_B64_1]]
-  ; GCN:   S_CBRANCH_EXECZ %bb.3, implicit $exec
+  ; GCN:   S_CBRANCH_EXECZ %bb.4, implicit $exec
   ; GCN: bb.2:
-  ; GCN:   successors: %bb.3(0x80000000)
-  ; GCN: bb.3:
   ; GCN:   successors: %bb.4(0x80000000)
+  ; GCN:   S_BRANCH %bb.4
   ; GCN: bb.4:
   ; GCN:   successors: %bb.5(0x80000000)
   ; GCN:   DBG_VALUE
@@ -387,14 +383,12 @@
   ; GCN:   $exec = S_MOV_B64_term killed [[S_AND_B64_]]
   ; GCN:   S_CBRANCH_EXECZ %bb.4, implicit $exec
   ; GCN: bb.1:
-  ; GCN:   successors: %bb.2(0x40000000), %bb.3(0x40000000)
+  ; GCN:   successors: %bb.2(0x40000000), %bb.5(0x40000000)
   ; GCN:   [[COPY1:%[0-9]+]]:sreg_64 = COPY $exec, implicit-def $exec
   ; GCN:   [[S_AND_B64_1:%[0-9]+]]:sreg_64 = S_AND_B64 [[COPY1]], undef %3:sreg_64, implicit-def dead $scc
   ; GCN:   $exec = S_MOV_B64_term killed [[S_AND_B64_1]]
-  ; GCN:   S_CBRANCH_EXECZ %bb.3, implicit $exec
+  ; GCN:   S_CBRANCH_EXECZ %bb.5, implicit $exec
   ; GCN: bb.2:
-  ; GCN:   successors: %bb.3(0x80000000)
-  ; GCN: bb.3:
   ; GCN:   successors: %bb.5(0x80000000)
   ; GCN:   S_BRANCH %bb.5
   ; GCN: bb.4: