diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -1270,7 +1270,7 @@ static bool HoistThenElseCodeToIf(BranchInst *BI,
   do {
     // If we are hoisting the terminator instruction, don't move one (making a
     // broken BB), instead clone it, and remove BI.
-    if (isa<TerminatorInst>(I1))
+    if (I1->isTerminator())
       goto HoistTerminator;
 
     // If we're going to hoist a call, make sure that the two instructions we're
@@ -2336,8 +2336,7 @@ static bool FoldTwoEntryPHINode(PHINode *PN, const TargetTransformInfo &TTI,
     IfBlock1 = nullptr;
   } else {
     DomBlock = *pred_begin(IfBlock1);
-    for (BasicBlock::iterator I = IfBlock1->begin(); !isa<TerminatorInst>(I);
-         ++I)
+    for (BasicBlock::iterator I = IfBlock1->begin(); !I->isTerminator(); ++I)
       if (!AggressiveInsts.count(&*I) && !isa<DbgInfoIntrinsic>(I)) {
         // This is not an aggressive instruction that we can promote.
         // Because of this, we won't be able to get rid of the control flow, so
@@ -2350,8 +2349,7 @@ static bool FoldTwoEntryPHINode(PHINode *PN, const TargetTransformInfo &TTI,
     IfBlock2 = nullptr;
   } else {
     DomBlock = *pred_begin(IfBlock2);
-    for (BasicBlock::iterator I = IfBlock2->begin(); !isa<TerminatorInst>(I);
-         ++I)
+    for (BasicBlock::iterator I = IfBlock2->begin(); !I->isTerminator(); ++I)
       if (!AggressiveInsts.count(&*I) && !isa<DbgInfoIntrinsic>(I)) {
         // This is not an aggressive instruction that we can promote.
         // Because of this, we won't be able to get rid of the control flow, so
@@ -2922,7 +2920,7 @@ static bool mergeConditionalStoreToAddress(BasicBlock *PTB, BasicBlock *PFB,
           isa<StoreInst>(I))
         ++N;
       // Free instructions.
-      else if (isa<TerminatorInst>(I) || IsaBitcastOfPointerType(I))
+      else if (I.isTerminator() || IsaBitcastOfPointerType(I))
         continue;
       else
         return false;

diff --git a/llvm/tools/bugpoint/CrashDebugger.cpp b/llvm/tools/bugpoint/CrashDebugger.cpp
@@ -703,7 +703,7 @@ bool ReduceCrashingInstructions::TestInsts(
   // Convert list to set for fast lookup...
   SmallPtrSet<Instruction *, 32> Instructions;
   for (unsigned i = 0, e = Insts.size(); i != e; ++i) {
-    assert(!isa<TerminatorInst>(Insts[i]));
+    assert(!Insts[i]->isTerminator());
     Instructions.insert(cast<Instruction>(VMap[Insts[i]]));
   }
 
@@ -717,7 +717,7 @@ bool ReduceCrashingInstructions::TestInsts(
     for (Function::iterator FI = MI->begin(), FE = MI->end(); FI != FE; ++FI)
       for (BasicBlock::iterator I = FI->begin(), E = FI->end(); I != E;) {
         Instruction *Inst = &*I++;
-        if (!Instructions.count(Inst) && !isa<TerminatorInst>(Inst) &&
+        if (!Instructions.count(Inst) && !Inst->isTerminator() &&
             !Inst->isEHPad() && !Inst->getType()->isTokenTy() &&
             !Inst->isSwiftError()) {
           if (!Inst->getType()->isVoidTy())
@@ -950,7 +950,7 @@ static Error ReduceInsts(BugDriver &BD, BugTester TestFn) {
     for (const Function &F : BD.getProgram())
       for (const BasicBlock &BB : F)
         for (const Instruction &I : BB)
-          if (!isa<TerminatorInst>(&I))
+          if (!I.isTerminator())
             Insts.push_back(&I);
 
     Expected<bool> Result =

diff --git a/llvm/unittests/Transforms/Utils/Local.cpp b/llvm/unittests/Transforms/Utils/Local.cpp
@@ -552,7 +552,7 @@ struct SalvageDebugInfoTest : ::testing::Test {
       auto DI = dyn_cast<DbgValueInst>(&I);
       if (!DI) {
         // The function should only contain debug values and a terminator.
-        ASSERT_TRUE(isa<TerminatorInst>(&I));
+        ASSERT_TRUE(I.isTerminator());
         continue;
       }
       EXPECT_EQ(DI->getVariable()->getName(), "x");

diff --git a/polly/lib/Analysis/ScopBuilder.cpp b/polly/lib/Analysis/ScopBuilder.cpp
@@ -685,7 +685,7 @@ void ScopBuilder::buildAccessFunctions() {
 }
 
 bool ScopBuilder::shouldModelInst(Instruction *Inst, Loop *L) {
-  return !isa<TerminatorInst>(Inst) && !isIgnoredIntrinsic(Inst) &&
+  return !Inst->isTerminator() && !isIgnoredIntrinsic(Inst) &&
          !canSynthesize(Inst, *scop, &SE, L);
 }
 
@@ -1399,7 +1399,7 @@ static void verifyUses(Scop *S, LoopInfo &LI, DominatorTree &DT) {
         continue;
 
       // Branch conditions are encoded in the statement domains.
-      if (isa<TerminatorInst>(&Inst) && Stmt->isBlockStmt())
+      if (Inst.isTerminator() && Stmt->isBlockStmt())
         continue;
 
       // Verify all uses.

diff --git a/polly/lib/Analysis/ScopDetection.cpp b/polly/lib/Analysis/ScopDetection.cpp
@@ -1214,7 +1214,8 @@ bool ScopDetection::isValidInstruction(Instruction &Inst,
       auto *PHI = dyn_cast<PHINode>(OpInst);
       if (PHI) {
         for (User *U : PHI->users()) {
-          if (!isa<TerminatorInst>(U))
+          auto *UI = dyn_cast<Instruction>(U);
+          if (!UI || !UI->isTerminator())
             return false;
         }
       } else {

diff --git a/polly/lib/Support/VirtualInstruction.cpp b/polly/lib/Support/VirtualInstruction.cpp
@@ -178,7 +178,7 @@ static bool isRoot(const Instruction *Inst) {
 
   // Terminator instructions (in region statements) are required for control
   // flow.
-  if (isa<TerminatorInst>(Inst))
+  if (Inst->isTerminator())
     return true;
 
   // Writes to memory must be honored.