Index: llvm/lib/Transforms/Utils/SCCPSolver.cpp
===================================================================
--- llvm/lib/Transforms/Utils/SCCPSolver.cpp
+++ llvm/lib/Transforms/Utils/SCCPSolver.cpp
@@ -1509,81 +1509,58 @@
     // we force the branch to go one way or the other to make the successor
     // values live.  It doesn't really matter which way we force it.
     Instruction *TI = BB.getTerminator();
-    if (auto *BI = dyn_cast<BranchInst>(TI)) {
-      if (!BI->isConditional())
-        continue;
-      if (!getValueState(BI->getCondition()).isUnknownOrUndef())
-        continue;
-
-      // If the input to SCCP is actually branch on undef, fix the undef to
-      // false.
-      if (isa<UndefValue>(BI->getCondition())) {
-        BI->setCondition(ConstantInt::getFalse(BI->getContext()));
-        markEdgeExecutable(&BB, TI->getSuccessor(1));
-        MadeChange = true;
-        continue;
-      }
-
-      // Otherwise, it is a branch on a symbolic value which is currently
-      // considered to be undef.  Make sure some edge is executable, so a
-      // branch on "undef" always flows somewhere.
-      // FIXME: Distinguish between dead code and an LLVM "undef" value.
-      BasicBlock *DefaultSuccessor = TI->getSuccessor(1);
-      if (markEdgeExecutable(&BB, DefaultSuccessor))
-        MadeChange = true;
-
-      continue;
-    }
-
-    if (auto *IBR = dyn_cast<IndirectBrInst>(TI)) {
-      // Indirect branch with no successor ?. Its ok to assume it branches
-      // to no target.
-      if (IBR->getNumSuccessors() < 1)
-        continue;
-
-      if (!getValueState(IBR->getAddress()).isUnknownOrUndef())
-        continue;
-
-      // If the input to SCCP is actually branch on undef, fix the undef to
-      // the first successor of the indirect branch.
-      if (isa<UndefValue>(IBR->getAddress())) {
-        IBR->setAddress(BlockAddress::get(IBR->getSuccessor(0)));
-        markEdgeExecutable(&BB, IBR->getSuccessor(0));
-        MadeChange = true;
-        continue;
-      }
+    auto* BI = dyn_cast<BranchInst>(TI);
+    auto* IBR = dyn_cast<IndirectBrInst>(TI);
+    auto* SI = dyn_cast<SwitchInst>(TI);
+    if (BI || IBR || SI) {
+      BasicBlock *DefaultSuccessor = nullptr;
+      if (BI) {
+        if (!BI->isConditional() ||
+            !getValueState(BI->getCondition()).isUnknownOrUndef())
+          continue;
 
-      // Otherwise, it is a branch on a symbolic value which is currently
-      // considered to be undef.  Make sure some edge is executable, so a
-      // branch on "undef" always flows somewhere.
-      // FIXME: IndirectBr on "undef" doesn't actually need to go anywhere:
-      // we can assume the branch has undefined behavior instead.
-      BasicBlock *DefaultSuccessor = IBR->getSuccessor(0);
-      if (markEdgeExecutable(&BB, DefaultSuccessor))
-        MadeChange = true;
+        // If the input to SCCP is actually branch on undef, fix the undef to
+        // false.
+        if (isa<UndefValue>(BI->getCondition())) {
+          BI->setCondition(ConstantInt::getFalse(BI->getContext()));
+          MadeChange = true;
+        }
+        DefaultSuccessor = TI->getSuccessor(1);
+      } else if (IBR) {
+        // Indirect branch with no successor? It's ok to assume it branches
+        // to no target.
+        if (IBR->getNumSuccessors() < 1 ||
+            !getValueState(IBR->getAddress()).isUnknownOrUndef())
+          continue;
 
-      continue;
-    }
+        // If the input to SCCP is actually branch on undef, fix the undef to
+        // the first successor of the indirect branch.
+        if (isa<UndefValue>(IBR->getAddress())) {
+          IBR->setAddress(BlockAddress::get(IBR->getSuccessor(0)));
+          MadeChange = true;
+        }
+        DefaultSuccessor = IBR->getSuccessor(0);
+      } else if (SI) {
+        if (!SI->getNumCases() ||
+            !getValueState(SI->getCondition()).isUnknownOrUndef())
+          continue;
 
-    if (auto *SI = dyn_cast<SwitchInst>(TI)) {
-      if (!SI->getNumCases() ||
-          !getValueState(SI->getCondition()).isUnknownOrUndef())
-        continue;
+        // If the input to SCCP is actually switch on undef, fix the undef to
+        // the first constant.
+        if (isa<UndefValue>(SI->getCondition())) {
+          SI->setCondition(SI->case_begin()->getCaseValue());
+          MadeChange = true;
+        }
+        DefaultSuccessor = SI->case_begin()->getCaseSuccessor();
+      } else
+        llvm_unreachable("Unexpected branch type.");
 
-      // If the input to SCCP is actually switch on undef, fix the undef to
-      // the first constant.
-      if (isa<UndefValue>(SI->getCondition())) {
-        SI->setCondition(SI->case_begin()->getCaseValue());
-        markEdgeExecutable(&BB, SI->case_begin()->getCaseSuccessor());
-        MadeChange = true;
-        continue;
-      }
+      assert(DefaultSuccessor && "Default successor unset.");
 
       // Otherwise, it is a branch on a symbolic value which is currently
       // considered to be undef.  Make sure some edge is executable, so a
       // branch on "undef" always flows somewhere.
       // FIXME: Distinguish between dead code and an LLVM "undef" value.
-      BasicBlock *DefaultSuccessor = SI->case_begin()->getCaseSuccessor();
       if (markEdgeExecutable(&BB, DefaultSuccessor))
         MadeChange = true;