Index: llvm/include/llvm/Analysis/TargetTransformInfo.h
===================================================================
--- llvm/include/llvm/Analysis/TargetTransformInfo.h
+++ llvm/include/llvm/Analysis/TargetTransformInfo.h
@@ -532,6 +532,11 @@
                                    DominatorTree *DT,
                                    const LoopAccessInfo *LAI) const;
 
+  /// Query the target whether lowering of the llvm.get.active.lane.mask
+  /// intrinsic is supported and if emitting it is desired for this loop.
+  bool emitGetActiveLaneMask(Loop *L, LoopInfo *LI, ScalarEvolution &SE,
+                             bool TailFolded) const;
+
   /// @}
 
   /// \name Scalar Target Information
@@ -1265,6 +1270,8 @@
   preferPredicateOverEpilogue(Loop *L, LoopInfo *LI, ScalarEvolution &SE,
                               AssumptionCache &AC, TargetLibraryInfo *TLI,
                               DominatorTree *DT, const LoopAccessInfo *LAI) = 0;
+  virtual bool emitGetActiveLaneMask(Loop *L, LoopInfo *LI, ScalarEvolution &SE,
+                                     bool TailFolded) = 0;
   virtual bool isLegalAddImmediate(int64_t Imm) = 0;
   virtual bool isLegalICmpImmediate(int64_t Imm) = 0;
   virtual bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV,
@@ -1556,6 +1563,10 @@
                                    const LoopAccessInfo *LAI) override {
     return Impl.preferPredicateOverEpilogue(L, LI, SE, AC, TLI, DT, LAI);
   }
+  bool emitGetActiveLaneMask(Loop *L, LoopInfo *LI, ScalarEvolution &SE,
+                             bool TailFolded) override {
+    return Impl.emitGetActiveLaneMask(L, LI, SE, TailFolded);
+  }
   bool isLegalAddImmediate(int64_t Imm) override {
     return Impl.isLegalAddImmediate(Imm);
   }
Index: llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
===================================================================
--- llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
+++ llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
@@ -140,6 +140,11 @@
     return false;
   }
 
+  bool emitGetActiveLaneMask(Loop *L, LoopInfo *LI, ScalarEvolution &SE,
+                             bool TailFold) const {
+    return false;
+  }
+
   void getUnrollingPreferences(Loop *, ScalarEvolution &,
                                TTI::UnrollingPreferences &) {}
 
Index: llvm/include/llvm/CodeGen/BasicTTIImpl.h
===================================================================
--- llvm/include/llvm/CodeGen/BasicTTIImpl.h
+++ llvm/include/llvm/CodeGen/BasicTTIImpl.h
@@ -486,6 +486,11 @@
     return BaseT::preferPredicateOverEpilogue(L, LI, SE, AC, TLI, DT, LAI);
   }
 
+  bool emitGetActiveLaneMask(Loop *L, LoopInfo *LI, ScalarEvolution &SE,
+                             bool TailFold) {
+    return BaseT::emitGetActiveLaneMask(L, LI, SE, TailFold);
+  }
+
   int getInstructionLatency(const Instruction *I) {
     if (isa<LoadInst>(I))
       return getST()->getSchedModel().DefaultLoadLatency;
Index: llvm/lib/Analysis/TargetTransformInfo.cpp
===================================================================
--- llvm/lib/Analysis/TargetTransformInfo.cpp
+++ llvm/lib/Analysis/TargetTransformInfo.cpp
@@ -307,6 +307,11 @@
   return TTIImpl->preferPredicateOverEpilogue(L, LI, SE, AC, TLI, DT, LAI);
 }
 
+bool TargetTransformInfo::emitGetActiveLaneMask(Loop *L, LoopInfo *LI,
+    ScalarEvolution &SE, bool TailFolded) const {
+  return TTIImpl->emitGetActiveLaneMask(L, LI, SE, TailFolded);
+}
+
 void TargetTransformInfo::getUnrollingPreferences(
     Loop *L, ScalarEvolution &SE, UnrollingPreferences &UP) const {
   return TTIImpl->getUnrollingPreferences(L, SE, UP);
Index: llvm/lib/Target/ARM/ARMTargetTransformInfo.h
===================================================================
--- llvm/lib/Target/ARM/ARMTargetTransformInfo.h
+++ llvm/lib/Target/ARM/ARMTargetTransformInfo.h
@@ -250,6 +250,9 @@
   void getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
                                TTI::UnrollingPreferences &UP);
 
+  bool emitGetActiveLaneMask(Loop *L, LoopInfo *LI, ScalarEvolution &SE,
+                             bool TailFolded) const;
+
   bool shouldBuildLookupTablesForConstant(Constant *C) const {
     // In the ROPI and RWPI relocation models we can't have pointers to global
     // variables or functions in constant data, so don't convert switches to
Index: llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
===================================================================
--- llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
+++ llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
@@ -1385,7 +1385,14 @@
   return canTailPredicateLoop(L, LI, SE, DL, LAI);
 }
 
-
+bool ARMTTIImpl::emitGetActiveLaneMask(Loop *L, LoopInfo *LI,
+    ScalarEvolution &SE, bool TailFolded) const {
+  // TODO: if this loop is tail-folded, we want to emit the
+  // llvm.get.active.lane.mask intrinsic so that this can be picked up in the
+  // MVETailPredication pass that needs to know the number of elements
+  // processed by this vector loop.
+  return false;
+}
 void ARMTTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
                                          TTI::UnrollingPreferences &UP) {
   // Only currently enable these preferences for M-Class cores.