diff --git a/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp b/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
--- a/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
+++ b/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
@@ -26,6 +26,7 @@
 #include "llvm/Analysis/LoopPass.h"
 #include "llvm/Analysis/MemorySSA.h"
 #include "llvm/Analysis/MemorySSAUpdater.h"
+#include "llvm/Analysis/MustExecute.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/Constant.h"
 #include "llvm/IR/Constants.h"
@@ -2070,12 +2071,16 @@
         DominatingSucc, *VMaps.back(), DTUpdates, AC, DT, LI, MSSAU);
   }
 
-  // Drop metadata if we may break its semantics by moving this branch into the
+  // Drop metadata if we may break its semantics by moving this instr into the
   // split block.
-  // TODO: We can keep make.implicit metadata if we prove that TI always
-  // executes and we cannot leave unswitched loop before getting to null check
-  // block. See @test_may_keep_make_implicit_non_trivial.
-  TI.setMetadata(LLVMContext::MD_make_implicit, nullptr);
+  if (TI.getMetadata(LLVMContext::MD_make_implicit)) {
+    // It is only legal to preserve make.implicit metadata if we are guaranteed
+    // to reach implicit null check block after following this branch.
+    ICFLoopSafetyInfo SafetyInfo;
+    SafetyInfo.computeLoopSafetyInfo(&L);
+    if (!SafetyInfo.isGuaranteedToExecute(TI, &DT, &L))
+      TI.setMetadata(LLVMContext::MD_make_implicit, nullptr);
+  }
 
   // The stitching of the branched code back together depends on whether we're
   // doing full unswitching or not with the exception that we always want to
diff --git a/llvm/test/Transforms/SimpleLoopUnswitch/implicit-null-checks.ll b/llvm/test/Transforms/SimpleLoopUnswitch/implicit-null-checks.ll
--- a/llvm/test/Transforms/SimpleLoopUnswitch/implicit-null-checks.ll
+++ b/llvm/test/Transforms/SimpleLoopUnswitch/implicit-null-checks.ll
@@ -2,6 +2,7 @@
 ; RUN: opt -enable-nontrivial-unswitch=true -simple-loop-unswitch -S < %s | FileCheck %s
 ; RUN: opt -enable-nontrivial-unswitch=true -passes='loop(unswitch),verify<loops>' -S < %s | FileCheck %s
 
+declare void @may_exit()
 declare void @throw_npe()
 
 ; It is illegal to preserve make_implicit notion of the condition being
@@ -136,15 +137,11 @@
   ret i32 %x
 }
 
-; TODO: This is a non-trivial unswitch, but it would still be legal to keep
-; !make.implicit in entry block. Currently we do not have enough analysis to
-; prove it.
 define i32 @test_may_keep_make_implicit_non_trivial(i32* %p1, i32* %p2) {
 ; CHECK-LABEL: @test_may_keep_make_implicit_non_trivial(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[NULL_CHECK:%.*]] = icmp eq i32* [[P2:%.*]], null
-; CHECK-NOT:     !make.implicit
-; CHECK-NEXT:    br i1 [[NULL_CHECK]], label [[ENTRY_SPLIT_US:%.*]], label [[ENTRY_SPLIT:%.*]]
+; CHECK-NEXT:    br i1 [[NULL_CHECK]], label [[ENTRY_SPLIT_US:%.*]], label [[ENTRY_SPLIT:%.*]], !make.implicit !0
 ; CHECK:       entry.split.us:
 ; CHECK-NEXT:    br label [[LOOP_US:%.*]]
 ; CHECK:       loop.us:
@@ -208,4 +205,111 @@
   ret i32 %x
 }
 
+; Here make.implicit notion should be dropped because of exiting call.
+define i32 @test_should_drop_make_implicit_exiting_call(i32* %p1, i32* %p2) {
+; CHECK-LABEL: @test_should_drop_make_implicit_exiting_call(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[NULL_CHECK:%.*]] = icmp eq i32* [[P2:%.*]], null
+; CHECK-NOT:     !make.implicit
+; CHECK-NEXT:    br i1 [[NULL_CHECK]], label [[ENTRY_SPLIT_US:%.*]], label [[ENTRY_SPLIT:%.*]]
+; CHECK:       entry.split.us:
+; CHECK-NEXT:    br label [[LOOP_US:%.*]]
+; CHECK:       loop.us:
+; CHECK-NEXT:    [[IV_US:%.*]] = phi i32 [ 0, [[ENTRY_SPLIT_US]] ]
+; CHECK-NEXT:    call void @may_exit()
+; CHECK-NEXT:    [[X_US:%.*]] = load i32, i32* [[P1:%.*]], align 4
+; CHECK-NEXT:    [[SIDE_EXIT_COND_US:%.*]] = icmp eq i32 [[X_US]], 0
+; CHECK-NEXT:    br label [[THROW_NPE_SPLIT_US:%.*]]
+; CHECK:       throw_npe.split.us:
+; CHECK-NEXT:    br label [[THROW_NPE:%.*]]
+; CHECK:       entry.split:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, [[ENTRY_SPLIT]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    call void @may_exit()
+; CHECK-NEXT:    [[X:%.*]] = load i32, i32* [[P1]], align 4
+; CHECK-NEXT:    [[SIDE_EXIT_COND:%.*]] = icmp eq i32 [[X]], 0
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[IV_NEXT]] = add i32 [[IV]], 1
+; CHECK-NEXT:    [[LOOP_COND:%.*]] = icmp slt i32 [[IV_NEXT]], 10000
+; CHECK-NEXT:    br i1 [[LOOP_COND]], label [[LOOP]], label [[EXIT:%.*]]
+; CHECK:       throw_npe:
+; CHECK-NEXT:    call void @throw_npe()
+; CHECK-NEXT:    unreachable
+; CHECK:       exit:
+; CHECK-NEXT:    [[X_LCSSA1:%.*]] = phi i32 [ [[X]], [[BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[X_LCSSA1]]
+;
+entry:
+  %null_check = icmp eq i32* %p2, null
+  br label %loop
+loop:
+  %iv = phi i32 [0, %entry], [%iv.next, %backedge]
+  call void @may_exit()
+  %x = load i32, i32* %p1
+  %side_exit_cond = icmp eq i32 %x, 0
+  br i1 %null_check, label %throw_npe, label %backedge, !make.implicit !0
+
+backedge:
+  %iv.next = add i32 %iv,1
+  %loop_cond = icmp slt i32 %iv.next, 10000
+  br i1 %loop_cond, label %loop, label %exit
+
+throw_npe:
+  call void @throw_npe()
+  unreachable
+
+exit:
+  ret i32 %x
+}
+
+; Here exiting call goes after the null check, so make.implicit may be preserved.
+define i32 @test_may_keep_make_implicit_exiting_call(i32* %p1, i32* %p2) {
+; CHECK-LABEL: @test_may_keep_make_implicit_exiting_call(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[NULL_CHECK:%.*]] = icmp eq i32* [[P2:%.*]], null
+; CHECK-NEXT:    br i1 [[NULL_CHECK]], label [[THROW_NPE:%.*]], label [[ENTRY_SPLIT:%.*]], !make.implicit !0
+; CHECK:       entry.split:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, [[ENTRY_SPLIT]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    [[X:%.*]] = load i32, i32* [[P1:%.*]], align 4
+; CHECK-NEXT:    [[SIDE_EXIT_COND:%.*]] = icmp eq i32 [[X]], 0
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[IV_NEXT]] = add i32 [[IV]], 1
+; CHECK-NEXT:    [[LOOP_COND:%.*]] = icmp slt i32 [[IV_NEXT]], 10000
+; CHECK-NEXT:    call void @may_exit()
+; CHECK-NEXT:    br i1 [[LOOP_COND]], label [[LOOP]], label [[EXIT:%.*]]
+; CHECK:       throw_npe:
+; CHECK-NEXT:    call void @throw_npe()
+; CHECK-NEXT:    unreachable
+; CHECK:       exit:
+; CHECK-NEXT:    [[X_LCSSA1:%.*]] = phi i32 [ [[X]], [[BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[X_LCSSA1]]
+;
+entry:
+  %null_check = icmp eq i32* %p2, null
+  br label %loop
+loop:
+  %iv = phi i32 [0, %entry], [%iv.next, %backedge]
+  %x = load i32, i32* %p1
+  %side_exit_cond = icmp eq i32 %x, 0
+  br i1 %null_check, label %throw_npe, label %backedge, !make.implicit !0
+
+backedge:
+  %iv.next = add i32 %iv,1
+  %loop_cond = icmp slt i32 %iv.next, 10000
+  call void @may_exit()
+  br i1 %loop_cond, label %loop, label %exit
+
+throw_npe:
+  call void @throw_npe()
+  unreachable
+
+exit:
+  ret i32 %x
+}
+
 !0 = !{}