diff --git a/llvm/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp b/llvm/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp
diff --git a/llvm/lib/Target/Hexagon/HexagonTargetMachine.cpp b/llvm/lib/Target/Hexagon/HexagonTargetMachine.cpp
@@ -24,6 +24,7 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/TargetRegistry.h"
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/IPO/PassManagerBuilder.h"
 
 using namespace llvm;
 
@@ -98,11 +99,6 @@ static cl::opt<bool> EnableVectorPrint("enable-hexagon-vector-print",
 extern "C" int HexagonTargetMachineModule;
 int HexagonTargetMachineModule = 0;
 
-extern "C" void LLVMInitializeHexagonTarget() {
-  // Register the target.
-  RegisterTargetMachine<HexagonTargetMachine> X(getTheHexagonTarget());
-}
-
 static ScheduleDAGInstrs *createVLIWMachineSched(MachineSchedContext *C) {
   return new VLIWMachineScheduler(C, make_unique<ConvergingVLIWScheduler>());
 }
@@ -114,6 +110,8 @@ SchedCustomRegistry("hexagon", "Run Hexagon's custom scheduler",
 namespace llvm {
   extern char &HexagonExpandCondsetsID;
   void initializeHexagonExpandCondsetsPass(PassRegistry&);
+  void initializeHexagonLoopIdiomRecognizePass(PassRegistry&);
+  Pass *createHexagonLoopIdiomPass();
 
   FunctionPass *createHexagonBitSimplify();
   FunctionPass *createHexagonBranchRelaxation();
@@ -150,6 +148,12 @@ static Reloc::Model getEffectiveRelocModel(Optional<Reloc::Model> RM) {
   return *RM;
 }
 
+extern "C" void LLVMInitializeHexagonTarget() {
+  // Register the target.
+  RegisterTargetMachine<HexagonTargetMachine> X(getTheHexagonTarget());
+  initializeHexagonLoopIdiomRecognizePass(*PassRegistry::getPassRegistry());
+}
+
 HexagonTargetMachine::HexagonTargetMachine(const Target &T, const Triple &TT,
                                            StringRef CPU, StringRef FS,
                                            const TargetOptions &Options,
@@ -196,6 +200,14 @@ HexagonTargetMachine::getSubtargetImpl(const Function &F) const {
   return I.get();
 }
 
+void HexagonTargetMachine::adjustPassManager(PassManagerBuilder &PMB) {
+  PMB.addExtension(
+    PassManagerBuilder::EP_LateLoopOptimizations,
+    [&](const PassManagerBuilder &, legacy::PassManagerBase &PM) {
+      PM.add(createHexagonLoopIdiomPass());
+    });
+}
+
 TargetIRAnalysis HexagonTargetMachine::getTargetIRAnalysis() {
   return TargetIRAnalysis([this](const Function &F) {
     return TargetTransformInfo(HexagonTTIImpl(this, F));

diff --git a/llvm/lib/Target/Hexagon/HexagonTargetMachine.h b/llvm/lib/Target/Hexagon/HexagonTargetMachine.h
@@ -37,6 +37,7 @@ class HexagonTargetMachine : public LLVMTargetMachine {
 
   static unsigned getModuleMatchQuality(const Module &M);
 
+  void adjustPassManager(PassManagerBuilder &PMB) override;
   TargetPassConfig *createPassConfig(PassManagerBase &PM) override;
   TargetIRAnalysis getTargetIRAnalysis() override;
 

diff --git a/llvm/test/CodeGen/Hexagon/loop-idiom/hexagon-memmove1.ll b/llvm/test/CodeGen/Hexagon/loop-idiom/hexagon-memmove1.ll
@@ -0,0 +1,36 @@
+; Check for recognizing the "memmove" idiom.
+; RUN: opt -basicaa -hexagon-loop-idiom -S -mtriple hexagon-unknown-elf < %s \
+; RUN:  | FileCheck %s
+; CHECK: call void @llvm.memmove
+
+; Function Attrs: norecurse nounwind
+define void @foo(i32* nocapture %A, i32* nocapture readonly %B, i32 %n) #0 {
+entry:
+  %cmp1 = icmp sgt i32 %n, 0
+  br i1 %cmp1, label %for.body.preheader, label %for.end
+
+for.body.preheader:                               ; preds = %entry
+  %arrayidx.gep = getelementptr i32, i32* %B, i32 0
+  %arrayidx1.gep = getelementptr i32, i32* %A, i32 0
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.preheader, %for.body
+  %arrayidx.phi = phi i32* [ %arrayidx.gep, %for.body.preheader ], [ %arrayidx.inc, %for.body ]
+  %arrayidx1.phi = phi i32* [ %arrayidx1.gep, %for.body.preheader ], [ %arrayidx1.inc, %for.body ]
+  %i.02 = phi i32 [ %inc, %for.body ], [ 0, %for.body.preheader ]
+  %0 = load i32, i32* %arrayidx.phi, align 4
+  store i32 %0, i32* %arrayidx1.phi, align 4
+  %inc = add nuw nsw i32 %i.02, 1
+  %exitcond = icmp ne i32 %inc, %n
+  %arrayidx.inc = getelementptr i32, i32* %arrayidx.phi, i32 1
+  %arrayidx1.inc = getelementptr i32, i32* %arrayidx1.phi, i32 1
+  br i1 %exitcond, label %for.body, label %for.end.loopexit
+
+for.end.loopexit:                                 ; preds = %for.body
+  br label %for.end
+
+for.end:                                          ; preds = %for.end.loopexit, %entry
+  ret void
+}
+
+attributes #0 = { nounwind }
diff --git a/llvm/test/CodeGen/Hexagon/loop-idiom/hexagon-memmove2.ll b/llvm/test/CodeGen/Hexagon/loop-idiom/hexagon-memmove2.ll
@@ -0,0 +1,36 @@
+; RUN: opt -basicaa -hexagon-loop-idiom -S -mtriple hexagon-unknown-elf < %s \
+; RUN:  | FileCheck %s
+
+define void @PR14241(i32* %s, i64 %size) #0 {
+; Ensure that we don't form a memcpy for strided loops. Briefly, when we taught
+; LoopIdiom about memmove and strided loops, this got miscompiled into a memcpy
+; instead of a memmove. If we get the memmove transform back, this will catch
+; regressions.
+;
+; CHECK-LABEL: @PR14241(
+
+entry:
+  %end.idx = add i64 %size, -1
+  %end.ptr = getelementptr inbounds i32, i32* %s, i64 %end.idx
+  br label %while.body
+; CHECK-NOT: memcpy
+; CHECK: memmove
+
+while.body:
+  %phi.ptr = phi i32* [ %s, %entry ], [ %next.ptr, %while.body ]
+  %src.ptr = getelementptr inbounds i32, i32* %phi.ptr, i64 1
+  %val = load i32, i32* %src.ptr, align 4
+; CHECK: load
+  %dst.ptr = getelementptr inbounds i32, i32* %phi.ptr, i64 0
+  store i32 %val, i32* %dst.ptr, align 4
+; CHECK: store
+  %next.ptr = getelementptr inbounds i32, i32* %phi.ptr, i64 1
+  %cmp = icmp eq i32* %next.ptr, %end.ptr
+  br i1 %cmp, label %exit, label %while.body
+
+exit:
+  ret void
+; CHECK: ret void
+}
+
+attributes #0 = { nounwind }
diff --git a/llvm/test/CodeGen/Hexagon/loop-idiom/lcssa.ll b/llvm/test/CodeGen/Hexagon/loop-idiom/lcssa.ll
@@ -0,0 +1,46 @@
+; RUN: opt -hexagon-loop-idiom -loop-deletion -gvn -S < %s
+; REQUIRES: asserts
+
+; This tests that the HexagonLoopIdiom pass does not mark LCSSA information
+; as preserved. The pass calls SimplifyInstruction is a couple of places,
+; which can invalidate LCSSA. Specifically, the uses of a LCSSA phi variable
+; are replaced by the incoming value.
+
+define hidden void @test() local_unnamed_addr #0 {
+entry:
+  br label %if.then63
+
+if.then63:
+  br i1 undef, label %do.body311, label %if.end375
+
+do.body311:
+  br i1 undef, label %do.end318, label %do.body311
+
+do.end318:
+  br i1 undef, label %if.end322, label %if.end375
+
+if.end322:
+  %sub325 = sub i32 undef, undef
+  br i1 undef, label %do.end329, label %do.body311
+
+do.end329:
+  %sub325.lcssa = phi i32 [ %sub325, %if.end322 ]
+  br label %do.body330
+
+do.body330:
+  %row_width.7 = phi i32 [ %sub325.lcssa, %do.end329 ], [ %dec334, %do.body330 ]
+  %sp.5 = phi i8* [ undef, %do.end329 ], [ %incdec.ptr331, %do.body330 ]
+  %dp.addr.5 = phi i8* [ undef, %do.end329 ], [ %incdec.ptr332, %do.body330 ]
+  %0 = load i8, i8* %sp.5, align 1
+  store i8 %0, i8* %dp.addr.5, align 1
+  %incdec.ptr332 = getelementptr inbounds i8, i8* %dp.addr.5, i32 1
+  %incdec.ptr331 = getelementptr inbounds i8, i8* %sp.5, i32 1
+  %dec334 = add i32 %row_width.7, -1
+  %cmp335 = icmp eq i32 %dec334, 0
+  br i1 %cmp335, label %if.end375, label %do.body330
+
+if.end375:
+  ret void
+}
+
+attributes #0 = { nounwind }
diff --git a/llvm/test/CodeGen/Hexagon/loop-idiom/nullptr-crash.ll b/llvm/test/CodeGen/Hexagon/loop-idiom/nullptr-crash.ll
@@ -0,0 +1,24 @@
+; RUN: opt -basicaa -hexagon-loop-idiom -mtriple hexagon-unknown-elf < %s
+; REQUIRES: asserts
+
+target triple = "hexagon"
+
+; Function Attrs: nounwind
+define void @fred(i8 zeroext %L) #0 {
+entry:
+  br i1 undef, label %if.end53, label %while.body37
+
+while.body37:                                     ; preds = %while.body37, %entry
+  %i.121 = phi i32 [ %inc46, %while.body37 ], [ 0, %entry ]
+  %shl = shl i32 1, %i.121
+  %and39 = and i32 %shl, undef
+  %tobool40 = icmp eq i32 %and39, 0
+  %inc46 = add nuw nsw i32 %i.121, 1
+  %storemerge = select i1 %tobool40, i8 %L, i8 0
+  br i1 undef, label %while.body37, label %if.end53
+
+if.end53:                                         ; preds = %while.body37, %entry
+  ret void
+}
+
+attributes #0 = { nounwind }
diff --git a/llvm/test/CodeGen/Hexagon/loop-idiom/pmpy.ll b/llvm/test/CodeGen/Hexagon/loop-idiom/pmpy.ll
@@ -0,0 +1,33 @@
+; RUN: opt -hexagon-loop-idiom < %s -mtriple=hexagon-unknown-unknown -S \
+; RUN:  | FileCheck %s
+
+target triple = "hexagon"
+
+; CHECK: define i64 @basic_pmpy
+; CHECK: llvm.hexagon.M4.pmpyw
+define i64 @basic_pmpy(i32 %P, i32 %Q) #0 {
+entry:
+  %conv = zext i32 %Q to i64
+  br label %for.body
+
+for.body:                                         ; preds = %entry, %for.body
+  %i.07 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
+  %R.06 = phi i64 [ 0, %entry ], [ %xor.R.06, %for.body ]
+  %shl = shl i32 1, %i.07
+  %and = and i32 %shl, %P
+  %tobool = icmp eq i32 %and, 0
+  %sh_prom = zext i32 %i.07 to i64
+  %shl1 = shl i64 %conv, %sh_prom
+  %xor = xor i64 %shl1, %R.06
+  %xor.R.06 = select i1 %tobool, i64 %R.06, i64 %xor
+  %inc = add nuw nsw i32 %i.07, 1
+  %exitcond = icmp ne i32 %inc, 32
+  br i1 %exitcond, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.body
+  %R.1.lcssa = phi i64 [ %xor.R.06, %for.body ]
+  ret i64 %R.1.lcssa
+}
+
+attributes #0 = { nounwind }
+