diff --git a/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp b/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
--- a/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
+++ b/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
@@ -169,11 +169,11 @@
 
     auto *Term = BB.getTerminator();
 
-    // Fow now only support `ret`/`resume` function terminators.
-    // FIXME: lift this restriction.
+    // Support function terminators that have no successors.
     switch (Term->getOpcode()) {
     case Instruction::Ret:
     case Instruction::Resume:
+    case Instruction::Unreachable:
       break;
     default:
       continue;
diff --git a/llvm/test/Transforms/PhaseOrdering/AArch64/peel-multiple-unreachable-exits-for-vectorization.ll b/llvm/test/Transforms/PhaseOrdering/AArch64/peel-multiple-unreachable-exits-for-vectorization.ll
--- a/llvm/test/Transforms/PhaseOrdering/AArch64/peel-multiple-unreachable-exits-for-vectorization.ll
+++ b/llvm/test/Transforms/PhaseOrdering/AArch64/peel-multiple-unreachable-exits-for-vectorization.ll
@@ -75,14 +75,10 @@
 ; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], [[AT_WITH_INT_CONVERSION_EXIT11:%.*]] ], [ [[IV_PH]], [[LOOP_PREHEADER20]] ]
 ; CHECK-NEXT:    [[SUM:%.*]] = phi i64 [ [[SUM_NEXT:%.*]], [[AT_WITH_INT_CONVERSION_EXIT11]] ], [ [[SUM_PH]], [[LOOP_PREHEADER20]] ]
 ; CHECK-NEXT:    [[INRANGE_I:%.*]] = icmp ult i64 [[SUB_I]], [[IV]]
-; CHECK-NEXT:    br i1 [[INRANGE_I]], label [[ERROR_I:%.*]], label [[AT_WITH_INT_CONVERSION_EXIT:%.*]]
-; CHECK:       error.i:
-; CHECK-NEXT:    tail call void @error()
-; CHECK-NEXT:    unreachable
-; CHECK:       at_with_int_conversion.exit:
 ; CHECK-NEXT:    [[INRANGE_I7:%.*]] = icmp ult i64 [[SUB_I6_PEEL]], [[IV]]
-; CHECK-NEXT:    br i1 [[INRANGE_I7]], label [[ERROR_I10:%.*]], label [[AT_WITH_INT_CONVERSION_EXIT11]]
-; CHECK:       error.i10:
+; CHECK-NEXT:    [[OR_COND:%.*]] = select i1 [[INRANGE_I]], i1 true, i1 [[INRANGE_I7]]
+; CHECK-NEXT:    br i1 [[OR_COND]], label [[COMMON_UNREACHABLE:%.*]], label [[AT_WITH_INT_CONVERSION_EXIT11]]
+; CHECK:       common.unreachable:
 ; CHECK-NEXT:    tail call void @error()
 ; CHECK-NEXT:    unreachable
 ; CHECK:       at_with_int_conversion.exit11:
@@ -201,25 +197,18 @@
 ; CHECK-NEXT:    [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], [[AT_WITH_INT_CONVERSION_EXIT22:%.*]] ], [ [[IV_PH]], [[LOOP_PREHEADER34]] ]
 ; CHECK-NEXT:    [[SUM:%.*]] = phi i64 [ [[SUM_NEXT:%.*]], [[AT_WITH_INT_CONVERSION_EXIT22]] ], [ [[SUM_PH]], [[LOOP_PREHEADER34]] ]
 ; CHECK-NEXT:    [[INRANGE_I:%.*]] = icmp ult i64 [[SUB_I]], [[IV]]
-; CHECK-NEXT:    br i1 [[INRANGE_I]], label [[ERROR_I:%.*]], label [[AT_WITH_INT_CONVERSION_EXIT:%.*]]
-; CHECK:       error.i:
+; CHECK-NEXT:    br i1 [[INRANGE_I]], label [[COMMON_UNREACHABLE:%.*]], label [[AT_WITH_INT_CONVERSION_EXIT:%.*]]
+; CHECK:       common.unreachable:
 ; CHECK-NEXT:    tail call void @error()
 ; CHECK-NEXT:    unreachable
 ; CHECK:       at_with_int_conversion.exit:
-; CHECK-NEXT:    [[GEP_IDX_I:%.*]] = getelementptr i64, ptr [[START_I]], i64 [[IV]]
-; CHECK-NEXT:    [[LV_I:%.*]] = load i64, ptr [[GEP_IDX_I]], align 4
 ; CHECK-NEXT:    [[INRANGE_I7:%.*]] = icmp ult i64 [[SUB_I6_PEEL]], [[IV]]
-; CHECK-NEXT:    br i1 [[INRANGE_I7]], label [[ERROR_I10:%.*]], label [[AT_WITH_INT_CONVERSION_EXIT11:%.*]]
-; CHECK:       error.i10:
-; CHECK-NEXT:    tail call void @error()
-; CHECK-NEXT:    unreachable
-; CHECK:       at_with_int_conversion.exit11:
 ; CHECK-NEXT:    [[INRANGE_I18:%.*]] = icmp ult i64 [[SUB_I17_PEEL]], [[IV]]
-; CHECK-NEXT:    br i1 [[INRANGE_I18]], label [[ERROR_I21:%.*]], label [[AT_WITH_INT_CONVERSION_EXIT22]]
-; CHECK:       error.i21:
-; CHECK-NEXT:    tail call void @error()
-; CHECK-NEXT:    unreachable
+; CHECK-NEXT:    [[OR_COND:%.*]] = select i1 [[INRANGE_I7]], i1 true, i1 [[INRANGE_I18]]
+; CHECK-NEXT:    br i1 [[OR_COND]], label [[COMMON_UNREACHABLE]], label [[AT_WITH_INT_CONVERSION_EXIT22]]
 ; CHECK:       at_with_int_conversion.exit22:
+; CHECK-NEXT:    [[GEP_IDX_I:%.*]] = getelementptr i64, ptr [[START_I]], i64 [[IV]]
+; CHECK-NEXT:    [[LV_I:%.*]] = load i64, ptr [[GEP_IDX_I]], align 4
 ; CHECK-NEXT:    [[GEP_IDX_I8:%.*]] = getelementptr i64, ptr [[START_I1_PEEL]], i64 [[IV]]
 ; CHECK-NEXT:    [[LV_I9:%.*]] = load i64, ptr [[GEP_IDX_I8]], align 4
 ; CHECK-NEXT:    [[GEP_IDX_I19:%.*]] = getelementptr i64, ptr [[START_I12_PEEL]], i64 [[IV]]
diff --git a/llvm/test/Transforms/SimplifyCFG/tail-merge-assert.ll b/llvm/test/Transforms/SimplifyCFG/tail-merge-assert.ll
--- a/llvm/test/Transforms/SimplifyCFG/tail-merge-assert.ll
+++ b/llvm/test/Transforms/SimplifyCFG/tail-merge-assert.ll
@@ -25,23 +25,19 @@
 ; CHECK-LABEL: @merge_glibc_asserts(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i32 [[Y:%.*]], [[X:%.*]]
-; CHECK-NEXT:    br i1 [[CMP]], label [[COND_END:%.*]], label [[COND_FALSE:%.*]]
-; CHECK:       cond.false:
-; CHECK-NEXT:    tail call void @glibc_assert_fail(ptr @.str, ptr @.str.1, i32 3, ptr @__PRETTY_FUNCTION__._Z1fjj)
+; CHECK-NEXT:    br i1 [[CMP]], label [[COND_END:%.*]], label [[COMMON_UNREACHABLE:%.*]]
+; CHECK:       common.unreachable:
+; CHECK-NEXT:    [[DOTSINK:%.*]] = phi i32 [ 3, [[ENTRY:%.*]] ], [ 4, [[COND_END]] ], [ 5, [[COND_END4:%.*]] ]
+; CHECK-NEXT:    [[DOTSTR_3_SINK:%.*]] = phi ptr [ @.str, [[ENTRY]] ], [ @.str.2, [[COND_END]] ], [ @.str.3, [[COND_END4]] ]
+; CHECK-NEXT:    tail call void @glibc_assert_fail(ptr [[DOTSTR_3_SINK]], ptr @.str.1, i32 [[DOTSINK]], ptr @__PRETTY_FUNCTION__._Z1fjj)
 ; CHECK-NEXT:    unreachable
 ; CHECK:       cond.end:
 ; CHECK-NEXT:    [[SUB:%.*]] = sub i32 [[Y]], [[X]]
 ; CHECK-NEXT:    [[CMP1:%.*]] = icmp ugt i32 [[SUB]], 7
-; CHECK-NEXT:    br i1 [[CMP1]], label [[COND_END4:%.*]], label [[COND_FALSE3:%.*]]
-; CHECK:       cond.false3:
-; CHECK-NEXT:    tail call void @glibc_assert_fail(ptr @.str.2, ptr @.str.1, i32 4, ptr @__PRETTY_FUNCTION__._Z1fjj)
-; CHECK-NEXT:    unreachable
+; CHECK-NEXT:    br i1 [[CMP1]], label [[COND_END4]], label [[COMMON_UNREACHABLE]]
 ; CHECK:       cond.end4:
 ; CHECK-NEXT:    [[CMP6:%.*]] = icmp ult i32 [[SUB]], 40
-; CHECK-NEXT:    br i1 [[CMP6]], label [[COND_END9:%.*]], label [[COND_FALSE8:%.*]]
-; CHECK:       cond.false8:
-; CHECK-NEXT:    tail call void @glibc_assert_fail(ptr @.str.3, ptr @.str.1, i32 5, ptr @__PRETTY_FUNCTION__._Z1fjj)
-; CHECK-NEXT:    unreachable
+; CHECK-NEXT:    br i1 [[CMP6]], label [[COND_END9:%.*]], label [[COMMON_UNREACHABLE]]
 ; CHECK:       cond.end9:
 ; CHECK-NEXT:    ret void
 ;
diff --git a/llvm/test/Transforms/SimplifyCFG/tail-merge-noreturn.ll b/llvm/test/Transforms/SimplifyCFG/tail-merge-noreturn.ll
--- a/llvm/test/Transforms/SimplifyCFG/tail-merge-noreturn.ll
+++ b/llvm/test/Transforms/SimplifyCFG/tail-merge-noreturn.ll
@@ -10,22 +10,16 @@
 define void @merge_simple() {
 ; CHECK-LABEL: @merge_simple(
 ; CHECK-NEXT:    [[C1:%.*]] = call i1 @foo()
-; CHECK-NEXT:    br i1 [[C1]], label [[CONT1:%.*]], label [[A1:%.*]]
-; CHECK:       a1:
+; CHECK-NEXT:    br i1 [[C1]], label [[CONT1:%.*]], label [[COMMON_UNREACHABLE:%.*]]
+; CHECK:       common.unreachable:
 ; CHECK-NEXT:    call void @assert_fail_1(i32 0)
 ; CHECK-NEXT:    unreachable
 ; CHECK:       cont1:
 ; CHECK-NEXT:    [[C2:%.*]] = call i1 @foo()
-; CHECK-NEXT:    br i1 [[C2]], label [[CONT2:%.*]], label [[A2:%.*]]
-; CHECK:       a2:
-; CHECK-NEXT:    call void @assert_fail_1(i32 0)
-; CHECK-NEXT:    unreachable
+; CHECK-NEXT:    br i1 [[C2]], label [[CONT2:%.*]], label [[COMMON_UNREACHABLE]]
 ; CHECK:       cont2:
 ; CHECK-NEXT:    [[C3:%.*]] = call i1 @foo()
-; CHECK-NEXT:    br i1 [[C3]], label [[CONT3:%.*]], label [[A3:%.*]]
-; CHECK:       a3:
-; CHECK-NEXT:    call void @assert_fail_1(i32 0)
-; CHECK-NEXT:    unreachable
+; CHECK-NEXT:    br i1 [[C3]], label [[CONT3:%.*]], label [[COMMON_UNREACHABLE]]
 ; CHECK:       cont3:
 ; CHECK-NEXT:    ret void
 ;
@@ -54,22 +48,17 @@
 ; CHECK-LABEL: @phi_three_constants(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[C1:%.*]] = call i1 @foo()
-; CHECK-NEXT:    br i1 [[C1]], label [[CONT1:%.*]], label [[A1:%.*]]
-; CHECK:       a1:
-; CHECK-NEXT:    call void @assert_fail_1(i32 0)
+; CHECK-NEXT:    br i1 [[C1]], label [[CONT1:%.*]], label [[COMMON_UNREACHABLE:%.*]]
+; CHECK:       common.unreachable:
+; CHECK-NEXT:    [[DOTSINK:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ 1, [[CONT1]] ], [ 2, [[CONT2:%.*]] ]
+; CHECK-NEXT:    call void @assert_fail_1(i32 [[DOTSINK]])
 ; CHECK-NEXT:    unreachable
 ; CHECK:       cont1:
 ; CHECK-NEXT:    [[C2:%.*]] = call i1 @foo()
-; CHECK-NEXT:    br i1 [[C2]], label [[CONT2:%.*]], label [[A2:%.*]]
-; CHECK:       a2:
-; CHECK-NEXT:    call void @assert_fail_1(i32 1)
-; CHECK-NEXT:    unreachable
+; CHECK-NEXT:    br i1 [[C2]], label [[CONT2]], label [[COMMON_UNREACHABLE]]
 ; CHECK:       cont2:
 ; CHECK-NEXT:    [[C3:%.*]] = call i1 @foo()
-; CHECK-NEXT:    br i1 [[C3]], label [[CONT3:%.*]], label [[A3:%.*]]
-; CHECK:       a3:
-; CHECK-NEXT:    call void @assert_fail_1(i32 2)
-; CHECK-NEXT:    unreachable
+; CHECK-NEXT:    br i1 [[C3]], label [[CONT3:%.*]], label [[COMMON_UNREACHABLE]]
 ; CHECK:       cont3:
 ; CHECK-NEXT:    ret void
 ;
@@ -98,16 +87,14 @@
 define void @dont_phi_values(i32 %x, i32 %y) {
 ; CHECK-LABEL: @dont_phi_values(
 ; CHECK-NEXT:    [[C1:%.*]] = call i1 @foo()
-; CHECK-NEXT:    br i1 [[C1]], label [[CONT1:%.*]], label [[A1:%.*]]
-; CHECK:       a1:
-; CHECK-NEXT:    call void @assert_fail_1(i32 [[X:%.*]])
+; CHECK-NEXT:    br i1 [[C1]], label [[CONT1:%.*]], label [[COMMON_UNREACHABLE:%.*]]
+; CHECK:       common.unreachable:
+; CHECK-NEXT:    [[Y_SINK:%.*]] = phi i32 [ [[X:%.*]], [[TMP0:%.*]] ], [ [[Y:%.*]], [[CONT1]] ]
+; CHECK-NEXT:    call void @assert_fail_1(i32 [[Y_SINK]])
 ; CHECK-NEXT:    unreachable
 ; CHECK:       cont1:
 ; CHECK-NEXT:    [[C2:%.*]] = call i1 @foo()
-; CHECK-NEXT:    br i1 [[C2]], label [[CONT2:%.*]], label [[A2:%.*]]
-; CHECK:       a2:
-; CHECK-NEXT:    call void @assert_fail_1(i32 [[Y:%.*]])
-; CHECK-NEXT:    unreachable
+; CHECK-NEXT:    br i1 [[C2]], label [[CONT2:%.*]], label [[COMMON_UNREACHABLE]]
 ; CHECK:       cont2:
 ; CHECK-NEXT:    ret void
 ;
@@ -166,18 +153,17 @@
 ; CHECK-NEXT:    br i1 [[C:%.*]], label [[S1:%.*]], label [[S2:%.*]]
 ; CHECK:       s1:
 ; CHECK-NEXT:    [[C1:%.*]] = call i1 @foo()
-; CHECK-NEXT:    br i1 [[C1]], label [[A1:%.*]], label [[A2:%.*]]
+; CHECK-NEXT:    br i1 [[C1]], label [[COMMON_UNREACHABLE:%.*]], label [[A2:%.*]]
 ; CHECK:       s2:
 ; CHECK-NEXT:    [[C2:%.*]] = call i1 @bar()
-; CHECK-NEXT:    br i1 [[C2]], label [[A1]], label [[A2]]
-; CHECK:       a1:
-; CHECK-NEXT:    [[L1:%.*]] = phi i32 [ 0, [[S1]] ], [ 1, [[S2]] ]
-; CHECK-NEXT:    call void @assert_fail_1(i32 [[L1]])
+; CHECK-NEXT:    br i1 [[C2]], label [[COMMON_UNREACHABLE]], label [[A2]]
+; CHECK:       common.unreachable:
+; CHECK-NEXT:    [[L2_SINK:%.*]] = phi i32 [ [[L2:%.*]], [[A2]] ], [ 0, [[S1]] ], [ 1, [[S2]] ]
+; CHECK-NEXT:    call void @assert_fail_1(i32 [[L2_SINK]])
 ; CHECK-NEXT:    unreachable
 ; CHECK:       a2:
-; CHECK-NEXT:    [[L2:%.*]] = phi i32 [ 2, [[S1]] ], [ 3, [[S2]] ]
-; CHECK-NEXT:    call void @assert_fail_1(i32 [[L2]])
-; CHECK-NEXT:    unreachable
+; CHECK-NEXT:    [[L2]] = phi i32 [ 2, [[S1]] ], [ 3, [[S2]] ]
+; CHECK-NEXT:    br label [[COMMON_UNREACHABLE]]
 ;
 entry:
   br i1 %c, label %s1, label %s2
@@ -201,19 +187,18 @@
 ; CHECK-LABEL: @tail_merge_switch(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    switch i32 [[V:%.*]], label [[RET:%.*]] [
-; CHECK-NEXT:    i32 0, label [[A1:%.*]]
+; CHECK-NEXT:    i32 0, label [[COMMON_UNREACHABLE:%.*]]
 ; CHECK-NEXT:    i32 13, label [[A2:%.*]]
 ; CHECK-NEXT:    i32 42, label [[A3:%.*]]
 ; CHECK-NEXT:    ]
-; CHECK:       a1:
-; CHECK-NEXT:    call void @assert_fail_1(i32 0)
+; CHECK:       common.unreachable:
+; CHECK-NEXT:    [[DOTSINK:%.*]] = phi i32 [ 2, [[A3]] ], [ 1, [[A2]] ], [ 0, [[ENTRY:%.*]] ]
+; CHECK-NEXT:    call void @assert_fail_1(i32 [[DOTSINK]])
 ; CHECK-NEXT:    unreachable
 ; CHECK:       a2:
-; CHECK-NEXT:    call void @assert_fail_1(i32 1)
-; CHECK-NEXT:    unreachable
+; CHECK-NEXT:    br label [[COMMON_UNREACHABLE]]
 ; CHECK:       a3:
-; CHECK-NEXT:    call void @assert_fail_1(i32 2)
-; CHECK-NEXT:    unreachable
+; CHECK-NEXT:    br label [[COMMON_UNREACHABLE]]
 ; CHECK:       ret:
 ; CHECK-NEXT:    ret void
 ;
@@ -239,18 +224,14 @@
 define void @need_to_add_bb2_preds(i1 %c1) {
 ; CHECK-LABEL: @need_to_add_bb2_preds(
 ; CHECK-NEXT:  bb1:
-; CHECK-NEXT:    br i1 [[C1:%.*]], label [[BB2:%.*]], label [[A1:%.*]]
+; CHECK-NEXT:    br i1 [[C1:%.*]], label [[BB2:%.*]], label [[COMMON_UNREACHABLE:%.*]]
 ; CHECK:       bb2:
 ; CHECK-NEXT:    [[C2:%.*]] = call i1 @bar()
-; CHECK-NEXT:    br i1 [[C2]], label [[A2:%.*]], label [[A3:%.*]]
-; CHECK:       a1:
-; CHECK-NEXT:    call void @assert_fail_1(i32 0)
-; CHECK-NEXT:    unreachable
-; CHECK:       a2:
-; CHECK-NEXT:    call void @assert_fail_1(i32 1)
-; CHECK-NEXT:    unreachable
-; CHECK:       a3:
-; CHECK-NEXT:    call void @assert_fail_1(i32 2)
+; CHECK-NEXT:    [[SPEC_SELECT:%.*]] = select i1 [[C2]], i32 1, i32 2
+; CHECK-NEXT:    br label [[COMMON_UNREACHABLE]]
+; CHECK:       common.unreachable:
+; CHECK-NEXT:    [[DOTSINK:%.*]] = phi i32 [ 0, [[BB1:%.*]] ], [ [[SPEC_SELECT]], [[BB2]] ]
+; CHECK-NEXT:    call void @assert_fail_1(i32 [[DOTSINK]])
 ; CHECK-NEXT:    unreachable
 ;
 bb1:
@@ -274,20 +255,17 @@
 ; CHECK-LABEL: @phi_in_bb2(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[C1:%.*]] = call i1 @foo()
-; CHECK-NEXT:    br i1 [[C1]], label [[CONT1:%.*]], label [[A1:%.*]]
-; CHECK:       a1:
-; CHECK-NEXT:    call void @assert_fail_1(i32 0)
+; CHECK-NEXT:    br i1 [[C1]], label [[CONT1:%.*]], label [[COMMON_UNREACHABLE:%.*]]
+; CHECK:       common.unreachable:
+; CHECK-NEXT:    [[P2_SINK:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ 1, [[CONT1]] ], [ 2, [[CONT2:%.*]] ]
+; CHECK-NEXT:    call void @assert_fail_1(i32 [[P2_SINK]])
 ; CHECK-NEXT:    unreachable
 ; CHECK:       cont1:
 ; CHECK-NEXT:    [[C2:%.*]] = call i1 @foo()
-; CHECK-NEXT:    br i1 [[C2]], label [[CONT2:%.*]], label [[A2:%.*]]
-; CHECK:       a2:
-; CHECK-NEXT:    [[P2:%.*]] = phi i32 [ 1, [[CONT1]] ], [ 2, [[CONT2]] ]
-; CHECK-NEXT:    call void @assert_fail_1(i32 [[P2]])
-; CHECK-NEXT:    unreachable
+; CHECK-NEXT:    br i1 [[C2]], label [[CONT2]], label [[COMMON_UNREACHABLE]]
 ; CHECK:       cont2:
 ; CHECK-NEXT:    [[C3:%.*]] = call i1 @foo()
-; CHECK-NEXT:    br i1 [[C3]], label [[CONT3:%.*]], label [[A2]]
+; CHECK-NEXT:    br i1 [[C3]], label [[CONT3:%.*]], label [[COMMON_UNREACHABLE]]
 ; CHECK:       cont3:
 ; CHECK-NEXT:    ret void
 ;
@@ -335,10 +313,12 @@
 ; CHECK:       if.then1:
 ; CHECK-NEXT:    call void @escape_i32_ptr(ptr nonnull [[X]])
 ; CHECK-NEXT:    br label [[IF_END]]
-; CHECK:       if.end:
-; CHECK-NEXT:    call void @llvm.lifetime.end.p0(i64 4, ptr nonnull [[X]])
+; CHECK:       common.unreachable:
 ; CHECK-NEXT:    call void @abort()
 ; CHECK-NEXT:    unreachable
+; CHECK:       if.end:
+; CHECK-NEXT:    call void @llvm.lifetime.end.p0(i64 4, ptr nonnull [[X]])
+; CHECK-NEXT:    br label [[COMMON_UNREACHABLE:%.*]]
 ; CHECK:       if.then3:
 ; CHECK-NEXT:    call void @llvm.lifetime.start.p0(i64 4, ptr nonnull [[Y]])
 ; CHECK-NEXT:    store i32 0, ptr [[Y]], align 4
@@ -349,8 +329,7 @@
 ; CHECK-NEXT:    br label [[IF_END7]]
 ; CHECK:       if.end7:
 ; CHECK-NEXT:    call void @llvm.lifetime.end.p0(i64 4, ptr nonnull [[Y]])
-; CHECK-NEXT:    call void @abort()
-; CHECK-NEXT:    unreachable
+; CHECK-NEXT:    br label [[COMMON_UNREACHABLE]]
 ; CHECK:       if.end9:
 ; CHECK-NEXT:    ret void
 ;
@@ -404,20 +383,16 @@
 ; CHECK-LABEL: @dead_phi(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[C1:%.*]] = call i1 @foo()
-; CHECK-NEXT:    br i1 [[C1]], label [[CONT1:%.*]], label [[A1:%.*]]
-; CHECK:       a1:
-; CHECK-NEXT:    [[DEAD:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ 1, [[CONT1]] ]
+; CHECK-NEXT:    br i1 [[C1]], label [[CONT1:%.*]], label [[COMMON_UNREACHABLE:%.*]]
+; CHECK:       common.unreachable:
 ; CHECK-NEXT:    call void @assert_fail_1(i32 0)
 ; CHECK-NEXT:    unreachable
 ; CHECK:       cont1:
 ; CHECK-NEXT:    [[C2:%.*]] = call i1 @foo()
-; CHECK-NEXT:    br i1 [[C2]], label [[CONT2:%.*]], label [[A1]]
+; CHECK-NEXT:    br i1 [[C2]], label [[CONT2:%.*]], label [[COMMON_UNREACHABLE]]
 ; CHECK:       cont2:
 ; CHECK-NEXT:    [[C3:%.*]] = call i1 @foo()
-; CHECK-NEXT:    br i1 [[C3]], label [[CONT3:%.*]], label [[A3:%.*]]
-; CHECK:       a3:
-; CHECK-NEXT:    call void @assert_fail_1(i32 0)
-; CHECK-NEXT:    unreachable
+; CHECK-NEXT:    br i1 [[C3]], label [[CONT3:%.*]], label [[COMMON_UNREACHABLE]]
 ; CHECK:       cont3:
 ; CHECK-NEXT:    ret void
 ;
@@ -446,15 +421,10 @@
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    call void @llvm.dbg.value(metadata i32 [[C:%.*]], metadata [[META5:![0-9]+]], metadata !DIExpression()), !dbg [[DBG7:![0-9]+]]
 ; CHECK-NEXT:    switch i32 [[C]], label [[SW_EPILOG:%.*]] [
-; CHECK-NEXT:    i32 13, label [[SW_BB:%.*]]
-; CHECK-NEXT:    i32 42, label [[SW_BB1:%.*]]
+; CHECK-NEXT:    i32 13, label [[COMMON_UNREACHABLE:%.*]]
+; CHECK-NEXT:    i32 42, label [[COMMON_UNREACHABLE]]
 ; CHECK-NEXT:    ]
-; CHECK:       sw.bb:
-; CHECK-NEXT:    call void @llvm.dbg.value(metadata i32 55, metadata [[META5]], metadata !DIExpression()), !dbg [[DBG7]]
-; CHECK-NEXT:    tail call void @abort()
-; CHECK-NEXT:    unreachable
-; CHECK:       sw.bb1:
-; CHECK-NEXT:    call void @llvm.dbg.value(metadata i32 67, metadata [[META5]], metadata !DIExpression()), !dbg [[DBG7]]
+; CHECK:       common.unreachable:
 ; CHECK-NEXT:    tail call void @abort()
 ; CHECK-NEXT:    unreachable
 ; CHECK:       sw.epilog:
@@ -486,19 +456,11 @@
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    call void @llvm.dbg.value(metadata i32 [[C:%.*]], metadata [[META5]], metadata !DIExpression()), !dbg [[DBG7]]
 ; CHECK-NEXT:    switch i32 [[C]], label [[SW_EPILOG:%.*]] [
-; CHECK-NEXT:    i32 13, label [[SW_BB:%.*]]
-; CHECK-NEXT:    i32 42, label [[SW_BB1:%.*]]
-; CHECK-NEXT:    i32 53, label [[SW_BB2:%.*]]
+; CHECK-NEXT:    i32 13, label [[COMMON_UNREACHABLE:%.*]]
+; CHECK-NEXT:    i32 42, label [[COMMON_UNREACHABLE]]
+; CHECK-NEXT:    i32 53, label [[COMMON_UNREACHABLE]]
 ; CHECK-NEXT:    ]
-; CHECK:       sw.bb:
-; CHECK-NEXT:    [[C_1:%.*]] = phi i32 [ 55, [[ENTRY:%.*]] ], [ 67, [[SW_BB1]] ]
-; CHECK-NEXT:    call void @llvm.dbg.value(metadata i32 [[C_1]], metadata [[META5]], metadata !DIExpression()), !dbg [[DBG7]]
-; CHECK-NEXT:    tail call void @abort()
-; CHECK-NEXT:    unreachable
-; CHECK:       sw.bb1:
-; CHECK-NEXT:    br label [[SW_BB]]
-; CHECK:       sw.bb2:
-; CHECK-NEXT:    call void @llvm.dbg.value(metadata i32 84, metadata [[META5]], metadata !DIExpression()), !dbg [[DBG7]]
+; CHECK:       common.unreachable:
 ; CHECK-NEXT:    tail call void @abort()
 ; CHECK-NEXT:    unreachable
 ; CHECK:       sw.epilog: