diff --git a/llvm/test/Transforms/SimplifyCFG/HoistCode.ll b/llvm/test/Transforms/SimplifyCFG/HoistCode.ll
@@ -1,6 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -passes=simplifycfg -hoist-common-insts=true -S | FileCheck %s
-; RUN: opt < %s -simplifycfg -hoist-common-insts=true -S | FileCheck %s
+; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -hoist-common-insts=true -S | FileCheck %s
 
 define void @foo(i1 %C, i32* %P) {
 ; CHECK-LABEL: @foo(

diff --git a/llvm/test/Transforms/SimplifyCFG/InfLoop.ll b/llvm/test/Transforms/SimplifyCFG/InfLoop.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -simplifycfg -disable-output
+; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -disable-output
 ; END.
 
 target datalayout = "e-m:o-p:32:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32"

diff --git a/llvm/test/Transforms/SimplifyCFG/UncondBranchToReturn.ll b/llvm/test/Transforms/SimplifyCFG/UncondBranchToReturn.ll
@@ -2,7 +2,7 @@
 ; a PHI node and a return.  Make sure the simplify cfg can straighten out this
 ; important case.  This is basically the most trivial form of tail-duplication.
 
-; RUN: opt < %s -simplifycfg -hoist-common-insts=true -S | \
+; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -hoist-common-insts=true -S | \
 ; RUN:    not grep "br label"
 
 define i32 @test(i1 %B, i32 %A, i32 %B.upgrd.1) {

diff --git a/llvm/test/Transforms/SimplifyCFG/X86/critedge-assume.ll b/llvm/test/Transforms/SimplifyCFG/X86/critedge-assume.ll
@@ -1,4 +1,4 @@
-; RUN: opt -o %t %s -instcombine -simplifycfg -thinlto-bc -verify-assumption-cache
+; RUN: opt -o %t %s -instcombine -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -thinlto-bc -verify-assumption-cache
 ; RUN: llvm-dis -o - %t | FileCheck %s
 
 ; Test that the simplifycfg pass correctly updates the assumption cache

diff --git a/llvm/test/Transforms/SimplifyCFG/X86/empty-cleanuppad.ll b/llvm/test/Transforms/SimplifyCFG/X86/empty-cleanuppad.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -simplifycfg -S -hoist-common-insts=true | FileCheck %s
+; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S -hoist-common-insts=true | FileCheck %s
 
 ; ModuleID = 'cppeh-simplify.cpp'
 target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"

diff --git a/llvm/test/Transforms/SimplifyCFG/X86/pr39187-g.ll b/llvm/test/Transforms/SimplifyCFG/X86/pr39187-g.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -S -simplifycfg -hoist-common-insts=true | FileCheck %s
+; RUN: opt < %s -S -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -hoist-common-insts=true | FileCheck %s
 
 ; SimplifyCFG can hoist any common code in the 'then' and 'else' blocks to
 ; the 'if' basic block.

diff --git a/llvm/test/Transforms/SimplifyCFG/branch-phi-thread.ll b/llvm/test/Transforms/SimplifyCFG/branch-phi-thread.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -simplifycfg -adce -S | \
+; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -adce -S | \
 ; RUN:   not grep "call void @f1"
 ; END.
 

diff --git a/llvm/test/Transforms/SimplifyCFG/debug-info-thread-phi.ll b/llvm/test/Transforms/SimplifyCFG/debug-info-thread-phi.ll
@@ -1,4 +1,4 @@
-; RUN: opt %s -debugify -simplifycfg -S | FileCheck %s
+; RUN: opt %s -debugify -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s
 ; Tests Bug 37966
 
 define void @bar(i32 %aa) {

diff --git a/llvm/test/Transforms/SimplifyCFG/extract-cost.ll b/llvm/test/Transforms/SimplifyCFG/extract-cost.ll
@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -simplifycfg -S  < %s | FileCheck %s
+; RUN: opt -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S  < %s | FileCheck %s
 
 declare { i32, i1 } @llvm.uadd.with.overflow.i32(i32, i32) #1
 

diff --git a/llvm/test/Transforms/SimplifyCFG/hoist-common-code.ll b/llvm/test/Transforms/SimplifyCFG/hoist-common-code.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -simplifycfg -S -hoist-common-insts=true | not grep br
+; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S -hoist-common-insts=true | not grep br
 
 declare void @bar(i32)
 

diff --git a/llvm/test/Transforms/SimplifyCFG/hoist-with-range.ll b/llvm/test/Transforms/SimplifyCFG/hoist-with-range.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -simplifycfg -hoist-common-insts=true -S | FileCheck %s
+; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -hoist-common-insts=true -S | FileCheck %s
 
 define void @foo(i1 %c, i8* %p) {
 ; CHECK: if:

diff --git a/llvm/test/Transforms/SimplifyCFG/implied-cond-matching-imm.ll b/llvm/test/Transforms/SimplifyCFG/implied-cond-matching-imm.ll
@@ -1,4 +1,4 @@
-; RUN: opt %s -S -simplifycfg | FileCheck %s
+; RUN: opt %s -S -simplifycfg -simplifycfg-require-and-preserve-domtree=1 | FileCheck %s
 
 ; cmp1 implies cmp2 is false
 ; CHECK-LABEL: @test1

diff --git a/llvm/test/Transforms/SimplifyCFG/iterative-simplify.ll b/llvm/test/Transforms/SimplifyCFG/iterative-simplify.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -simplifycfg -S | not grep bb17
+; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | not grep bb17
 ; PR1786
 
 define i32 @main() {

diff --git a/llvm/test/Transforms/SimplifyCFG/merge-cond-stores-2.ll b/llvm/test/Transforms/SimplifyCFG/merge-cond-stores-2.ll
@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -S < %s -simplifycfg -simplifycfg-merge-cond-stores=true -simplifycfg-merge-cond-stores-aggressively=false -phi-node-folding-threshold=1 | FileCheck %s
+; RUN: opt -S < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -simplifycfg-merge-cond-stores=true -simplifycfg-merge-cond-stores-aggressively=false -phi-node-folding-threshold=1 | FileCheck %s
 
 target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
 target triple = "armv7--linux-gnueabihf"

diff --git a/llvm/test/Transforms/SimplifyCFG/merge-cond-stores.ll b/llvm/test/Transforms/SimplifyCFG/merge-cond-stores.ll
@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -simplifycfg -instcombine < %s -simplifycfg-merge-cond-stores=true -simplifycfg-merge-cond-stores-aggressively=false -phi-node-folding-threshold=2 -S | FileCheck %s
+; RUN: opt -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -instcombine < %s -simplifycfg-merge-cond-stores=true -simplifycfg-merge-cond-stores-aggressively=false -phi-node-folding-threshold=2 -S | FileCheck %s
 
 ; This test should succeed and end up if-converted.
 define void @test_simple(i32* %p, i32 %a, i32 %b) {

diff --git a/llvm/test/Transforms/SimplifyCFG/pr34131.ll b/llvm/test/Transforms/SimplifyCFG/pr34131.ll
@@ -1,4 +1,4 @@
-; RUN: opt -simplifycfg -S < %s | FileCheck %s
+; RUN: opt -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S < %s | FileCheck %s
 
 ; Just checking for lack of crash here, but we should be able to check the IR?
 ; Earlier version using auto-generated checks from utils/update_test_checks.py

diff --git a/llvm/test/Transforms/SimplifyCFG/pr39807.ll b/llvm/test/Transforms/SimplifyCFG/pr39807.ll
@@ -1,4 +1,4 @@
-; RUN: opt -S -simplifycfg -hoist-common-insts=true < %s | FileCheck %s
+; RUN: opt -S -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -hoist-common-insts=true < %s | FileCheck %s
 
 declare void @personality()
 

diff --git a/llvm/test/Transforms/SimplifyCFG/pr46638.ll b/llvm/test/Transforms/SimplifyCFG/pr46638.ll
@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -S -simplifycfg < %s | FileCheck %s
+; RUN: opt -S -simplifycfg -simplifycfg-require-and-preserve-domtree=1 < %s | FileCheck %s
 
 define void @pr46638(i1 %c, i32 %x) {
 ; CHECK-LABEL: @pr46638(

diff --git a/llvm/test/Transforms/SimplifyCFG/preserve-store-alignment.ll b/llvm/test/Transforms/SimplifyCFG/preserve-store-alignment.ll
@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -simplifycfg -S < %s | FileCheck %s
+; RUN: opt -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S < %s | FileCheck %s
 
 %struct.Counters = type { i64, i64, i64, [8 x i8] }
 

diff --git a/llvm/test/Transforms/SimplifyCFG/sink-common-code.ll b/llvm/test/Transforms/SimplifyCFG/sink-common-code.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -simplifycfg -sink-common-insts -S | FileCheck -enable-var-scope %s
+; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -sink-common-insts -S | FileCheck -enable-var-scope %s
 ; RUN: opt < %s -passes='simplify-cfg<sink-common-insts>' -S | FileCheck -enable-var-scope %s
 
 define zeroext i1 @test1(i1 zeroext %flag, i32 %blksA, i32 %blksB, i32 %nblks) {

diff --git a/llvm/test/Transforms/SimplifyCFG/switch-on-const-select.ll b/llvm/test/Transforms/SimplifyCFG/switch-on-const-select.ll
@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt < %s -simplifycfg -S | FileCheck -enable-var-scope %s
+; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck -enable-var-scope %s
 
 ; Test basic folding to a conditional branch.
 define i32 @foo(i64 %x, i64 %y) nounwind {

diff --git a/llvm/test/Transforms/SimplifyCFG/unprofitable-pr.ll b/llvm/test/Transforms/SimplifyCFG/unprofitable-pr.ll
@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -simplifycfg -simplifycfg-max-small-block-size=10 -S < %s | FileCheck %s
+; RUN: opt -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -simplifycfg-max-small-block-size=10 -S < %s | FileCheck %s
 ; RUN: opt -passes=simplify-cfg -simplifycfg-max-small-block-size=10 -S < %s | FileCheck %s
 
 target datalayout = "e-p:64:64-p5:32:32-A5"