[llvm] r345713 - [NFC] Add tests for loop-simplifycfg for further development

Max Kazantsev via llvm-commits llvm-commits at lists.llvm.org
Wed Oct 31 04:28:24 PDT 2018


Author: mkazantsev
Date: Wed Oct 31 04:28:23 2018
New Revision: 345713

URL: http://llvm.org/viewvc/llvm-project?rev=345713&view=rev
Log:
[NFC] Add tests for loop-simplifycfg for further development

Added:
    llvm/trunk/test/Transforms/LoopSimplifyCFG/constant-fold-branch.ll

Added: llvm/trunk/test/Transforms/LoopSimplifyCFG/constant-fold-branch.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopSimplifyCFG/constant-fold-branch.ll?rev=345713&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LoopSimplifyCFG/constant-fold-branch.ll (added)
+++ llvm/trunk/test/Transforms/LoopSimplifyCFG/constant-fold-branch.ll Wed Oct 31 04:28:23 2018
@@ -0,0 +1,1408 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -loop-simplifycfg < %s | FileCheck %s
+; RUN: opt -S -passes='require<domtree>,loop(simplify-cfg)' < %s | FileCheck %s
+; RUN: opt -S -loop-simplifycfg -enable-mssa-loop-dependency=true -verify-memoryssa < %s | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128-ni:1"
+
+; Make sure that we can eliminate a provably dead backedge.
+define i32 @dead_backedge_test_branch_loop(i32 %end) {
+; CHECK-LABEL: @dead_backedge_test_branch_loop(
+; CHECK-NEXT:  preheader:
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[PREHEADER:%.*]] ], [ [[I_BE:%.*]], [[HEADER_BACKEDGE:%.*]] ]
+; CHECK-NEXT:    [[I_1:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp slt i32 [[I_1]], 100
+; CHECK-NEXT:    br i1 [[CMP1]], label [[HEADER_BACKEDGE]], label [[DEAD_BACKEDGE:%.*]]
+; CHECK:       header.backedge:
+; CHECK-NEXT:    [[I_BE]] = phi i32 [ [[I_1]], [[HEADER]] ], [ [[I_2:%.*]], [[DEAD_BACKEDGE]] ]
+; CHECK-NEXT:    br label [[HEADER]]
+; CHECK:       dead_backedge:
+; CHECK-NEXT:    [[I_2]] = add i32 [[I_1]], 10
+; CHECK-NEXT:    br i1 false, label [[HEADER_BACKEDGE]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_2_LCSSA:%.*]] = phi i32 [ [[I_2]], [[DEAD_BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_2_LCSSA]]
+;
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.1, %header], [%i.2, %dead_backedge]
+  %i.1 = add i32 %i, 1
+  %cmp1 = icmp slt i32 %i.1, 100
+  br i1 %cmp1, label %header, label %dead_backedge
+
+dead_backedge:
+  %i.2 = add i32 %i.1, 10
+  br i1 false, label %header, label %exit
+
+exit:
+  ret i32 %i.2
+}
+
+; Check that we can eliminate a triangle.
+define i32 @dead_block_test_branch_loop(i32 %end) {
+; CHECK-LABEL: @dead_block_test_branch_loop(
+; CHECK-NEXT:  preheader:
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[PREHEADER:%.*]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br i1 true, label [[BACKEDGE]], label [[DEAD:%.*]]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I_2]], [[DEAD]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[I_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA]]
+;
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  br i1 true, label %backedge, label %dead
+
+dead:
+  %i.2 = add i32 %i, 1
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %header], [%i.2, %dead]
+  %i.inc = add i32 %i.1, 1
+  %cmp = icmp slt i32 %i.inc, %end
+  br i1 %cmp, label %header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+; Check that we can eliminate dead branches of a switch.
+define i32 @dead_block_test_switch_loop(i32 %end) {
+; CHECK-LABEL: @dead_block_test_switch_loop(
+; CHECK-NEXT:  preheader:
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[PREHEADER:%.*]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    switch i32 1, label [[DEAD:%.*]] [
+; CHECK-NEXT:    i32 0, label [[DEAD]]
+; CHECK-NEXT:    i32 1, label [[BACKEDGE]]
+; CHECK-NEXT:    i32 2, label [[DEAD]]
+; CHECK-NEXT:    ]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I_2]], [[DEAD]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[I_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA]]
+;
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  switch i32 1, label %dead [i32 0, label %dead
+  i32 1, label %backedge
+  i32 2, label %dead]
+
+dead:
+  %i.2 = add i32 %i, 1
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %header], [%i.2, %dead]
+  %i.inc = add i32 %i.1, 1
+  %cmp = icmp slt i32 %i.inc, %end
+  br i1 %cmp, label %header, label %exit
+exit:
+  ret i32 %i.inc
+}
+
+; Check that we can eliminate several dead blocks.
+define i32 @dead_block_propogate_test_branch_loop(i32 %end) {
+; CHECK-LABEL: @dead_block_propogate_test_branch_loop(
+; CHECK-NEXT:  preheader:
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[PREHEADER:%.*]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br i1 true, label [[BACKEDGE]], label [[DEAD:%.*]]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I_2]], [[DEAD]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[I_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA]]
+;
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  br i1 true, label %backedge, label %dead
+
+dead:
+  %i.2 = add i32 %i, 1
+  br label %dummy
+
+dummy:
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %header], [%i.2, %dummy]
+  %i.inc = add i32 %i.1, 1
+  %cmp = icmp slt i32 %i.inc, %end
+  br i1 %cmp, label %header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+; Check that we can eliminate several blocks while removing a switch.
+define i32 @dead_block_propogate_test_switch_loop(i32 %end) {
+; CHECK-LABEL: @dead_block_propogate_test_switch_loop(
+; CHECK-NEXT:  preheader:
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[PREHEADER:%.*]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    switch i32 1, label [[DEAD:%.*]] [
+; CHECK-NEXT:    i32 0, label [[DEAD]]
+; CHECK-NEXT:    i32 1, label [[BACKEDGE]]
+; CHECK-NEXT:    i32 2, label [[DEAD]]
+; CHECK-NEXT:    ]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I_2]], [[DEAD]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[I_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA]]
+;
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  switch i32 1, label %dead [i32 0, label %dead
+  i32 1, label %backedge
+  i32 2, label %dead]
+
+dead:
+  %i.2 = add i32 %i, 1
+  br label %dummy
+
+dummy:
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %header], [%i.2, %dummy]
+  %i.inc = add i32 %i.1, 1
+  %cmp = icmp slt i32 %i.inc, %end
+  br i1 %cmp, label %header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+; Check that we preserve static reachibility of a dead exit block while deleting
+; a branch.
+define i32 @dead_exit_test_branch_loop(i32 %end) {
+; CHECK-LABEL: @dead_exit_test_branch_loop(
+; CHECK-NEXT:  preheader:
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[PREHEADER:%.*]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br i1 true, label [[BACKEDGE]], label [[DEAD:%.*]]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_LCSSA:%.*]] = phi i32 [ [[I]], [[HEADER]] ]
+; CHECK-NEXT:    br label [[DUMMY:%.*]]
+; CHECK:       dummy:
+; CHECK-NEXT:    br label [[EXIT:%.*]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[I_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[HEADER]], label [[EXIT_LOOPEXIT:%.*]]
+; CHECK:       exit.loopexit:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I_LCSSA]], [[DUMMY]] ], [ [[I_INC_LCSSA]], [[EXIT_LOOPEXIT]] ]
+; CHECK-NEXT:    ret i32 [[I_1]]
+;
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  br i1 true, label %backedge, label %dead
+
+dead:
+  br label %dummy
+
+dummy:
+  br label %exit
+
+backedge:
+  %i.inc = add i32 %i, 1
+  %cmp = icmp slt i32 %i.inc, %end
+  br i1 %cmp, label %header, label %exit
+
+exit:
+  %i.1 = phi i32 [%i.inc, %backedge], [%i, %dummy]
+  ret i32 %i.1
+}
+
+; Check that we preserve static reachibility of a dead exit block while deleting
+; a switch.
+define i32 @dead_exit_test_switch_loop(i32 %end) {
+; CHECK-LABEL: @dead_exit_test_switch_loop(
+; CHECK-NEXT:  preheader:
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[PREHEADER:%.*]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    switch i32 1, label [[DEAD:%.*]] [
+; CHECK-NEXT:    i32 0, label [[DEAD]]
+; CHECK-NEXT:    i32 1, label [[BACKEDGE]]
+; CHECK-NEXT:    i32 2, label [[DEAD]]
+; CHECK-NEXT:    ]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_LCSSA:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I]], [[HEADER]] ], [ [[I]], [[HEADER]] ]
+; CHECK-NEXT:    br label [[DUMMY:%.*]]
+; CHECK:       dummy:
+; CHECK-NEXT:    br label [[EXIT:%.*]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[I_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[HEADER]], label [[EXIT_LOOPEXIT:%.*]]
+; CHECK:       exit.loopexit:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I_LCSSA]], [[DUMMY]] ], [ [[I_INC_LCSSA]], [[EXIT_LOOPEXIT]] ]
+; CHECK-NEXT:    ret i32 [[I_1]]
+;
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  switch i32 1, label %dead [i32 0, label %dead
+  i32 1, label %backedge
+  i32 2, label %dead]
+
+dead:
+  br label %dummy
+
+dummy:
+  br label %exit
+
+backedge:
+  %i.inc = add i32 %i, 1
+  %cmp = icmp slt i32 %i.inc, %end
+  br i1 %cmp, label %header, label %exit
+
+exit:
+  %i.1 = phi i32 [%i.inc, %backedge], [%i, %dummy]
+  ret i32 %i.1
+}
+
+; Check that we can completely eliminate the current loop, branch case.
+define i32 @dead_loop_test_branch_loop(i32 %end) {
+; CHECK-LABEL: @dead_loop_test_branch_loop(
+; CHECK-NEXT:  preheader:
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[PREHEADER:%.*]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br i1 true, label [[BACKEDGE]], label [[DEAD:%.*]]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I_2]], [[DEAD]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[I_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 false, label [[HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA]]
+;
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  br i1 true, label %backedge, label %dead
+
+dead:
+  %i.2 = add i32 %i, 1
+  br label %dummy
+
+dummy:
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %header], [%i.2, %dummy]
+  %i.inc = add i32 %i.1, 1
+  %cmp = icmp slt i32 %i.inc, %end
+  br i1 false, label %header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+; Check that we can completely eliminate the current loop, switch case.
+define i32 @dead_loop_test_switch_loop(i32 %end) {
+; CHECK-LABEL: @dead_loop_test_switch_loop(
+; CHECK-NEXT:  preheader:
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[PREHEADER:%.*]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    switch i32 1, label [[DEAD:%.*]] [
+; CHECK-NEXT:    i32 0, label [[DEAD]]
+; CHECK-NEXT:    i32 1, label [[BACKEDGE]]
+; CHECK-NEXT:    i32 2, label [[DEAD]]
+; CHECK-NEXT:    ]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I_2]], [[DEAD]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[I_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 false, label [[HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA]]
+;
+preheader:
+  br label %header
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  switch i32 1, label %dead [i32 0, label %dead
+  i32 1, label %backedge
+  i32 2, label %dead]
+dead:
+  %i.2 = add i32 %i, 1
+  br label %dummy
+
+dummy:
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %header], [%i.2, %dummy]
+  %i.inc = add i32 %i.1, 1
+  %cmp = icmp slt i32 %i.inc, %end
+  br i1 false, label %header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+; Check that we can delete a dead inner loop entirely.
+define i32 @dead_sub_loop_test_branch_loop(i32 %end) {
+; CHECK-LABEL: @dead_sub_loop_test_branch_loop(
+; CHECK-NEXT:  preheader:
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[PREHEADER:%.*]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br i1 true, label [[LIVE_PREHEADER:%.*]], label [[DEAD_PREHEADER:%.*]]
+; CHECK:       live_preheader:
+; CHECK-NEXT:    br label [[LIVE_LOOP:%.*]]
+; CHECK:       live_loop:
+; CHECK-NEXT:    [[A:%.*]] = phi i32 [ 0, [[LIVE_PREHEADER]] ], [ [[A_INC:%.*]], [[LIVE_LOOP]] ]
+; CHECK-NEXT:    [[A_INC]] = add i32 [[A]], 1
+; CHECK-NEXT:    [[CMP_A:%.*]] = icmp slt i32 [[A_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP_A]], label [[LIVE_LOOP]], label [[EXIT_A:%.*]]
+; CHECK:       exit.a:
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       dead_preheader:
+; CHECK-NEXT:    br label [[DEAD_LOOP:%.*]]
+; CHECK:       dead_loop:
+; CHECK-NEXT:    [[B:%.*]] = phi i32 [ 0, [[DEAD_PREHEADER]] ], [ [[B_INC:%.*]], [[DEAD_LOOP]] ]
+; CHECK-NEXT:    [[B_INC]] = add i32 [[B]], 1
+; CHECK-NEXT:    [[CMP_B:%.*]] = icmp slt i32 [[B_INC]], [[END]]
+; CHECK-NEXT:    br i1 [[CMP_B]], label [[DEAD_LOOP]], label [[EXIT_B:%.*]]
+; CHECK:       exit.b:
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[I_INC]], [[END]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA]]
+;
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  br i1 true, label %live_preheader, label %dead_preheader
+
+live_preheader:
+  br label %live_loop
+
+live_loop:
+  %a = phi i32 [0, %live_preheader], [%a.inc, %live_loop]
+  %a.inc = add i32 %a, 1
+  %cmp.a = icmp slt i32 %a.inc, %end
+  br i1 %cmp.a, label %live_loop, label %exit.a
+
+exit.a:
+  br label %backedge
+
+dead_preheader:
+  br label %dead_loop
+
+dead_loop:
+  %b = phi i32 [0, %dead_preheader], [%b.inc, %dead_loop]
+  %b.inc = add i32 %b, 1
+  %cmp.b = icmp slt i32 %b.inc, %end
+  br i1 %cmp.b, label %dead_loop, label %exit.b
+
+exit.b:
+  br label %backedge
+
+backedge:
+  %i.inc = add i32 %i, 1
+  %cmp = icmp slt i32 %i.inc, %end
+  br i1 %cmp, label %header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+define i32 @dead_sub_loop_test_switch_loop(i32 %end) {
+; CHECK-LABEL: @dead_sub_loop_test_switch_loop(
+; CHECK-NEXT:  preheader:
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[PREHEADER:%.*]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    switch i32 1, label [[DEAD_PREHEADER:%.*]] [
+; CHECK-NEXT:    i32 0, label [[DEAD_PREHEADER]]
+; CHECK-NEXT:    i32 1, label [[LIVE_PREHEADER:%.*]]
+; CHECK-NEXT:    i32 2, label [[DEAD_PREHEADER]]
+; CHECK-NEXT:    ]
+; CHECK:       live_preheader:
+; CHECK-NEXT:    br label [[LIVE_LOOP:%.*]]
+; CHECK:       live_loop:
+; CHECK-NEXT:    [[A:%.*]] = phi i32 [ 0, [[LIVE_PREHEADER]] ], [ [[A_INC:%.*]], [[LIVE_LOOP]] ]
+; CHECK-NEXT:    [[A_INC]] = add i32 [[A]], 1
+; CHECK-NEXT:    [[CMP_A:%.*]] = icmp slt i32 [[A_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP_A]], label [[LIVE_LOOP]], label [[EXIT_A:%.*]]
+; CHECK:       exit.a:
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       dead_preheader:
+; CHECK-NEXT:    br label [[DEAD_LOOP:%.*]]
+; CHECK:       dead_loop:
+; CHECK-NEXT:    [[B:%.*]] = phi i32 [ 0, [[DEAD_PREHEADER]] ], [ [[B_INC:%.*]], [[DEAD_LOOP]] ]
+; CHECK-NEXT:    [[B_INC]] = add i32 [[B]], 1
+; CHECK-NEXT:    [[CMP_B:%.*]] = icmp slt i32 [[B_INC]], [[END]]
+; CHECK-NEXT:    br i1 [[CMP_B]], label [[DEAD_LOOP]], label [[EXIT_B:%.*]]
+; CHECK:       exit.b:
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[I_INC]], [[END]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA]]
+;
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  switch i32 1, label %dead_preheader [i32 0, label %dead_preheader
+  i32 1, label %live_preheader
+  i32 2, label %dead_preheader]
+
+live_preheader:
+  br label %live_loop
+
+live_loop:
+  %a = phi i32 [0, %live_preheader], [%a.inc, %live_loop]
+  %a.inc = add i32 %a, 1
+  %cmp.a = icmp slt i32 %a.inc, %end
+  br i1 %cmp.a, label %live_loop, label %exit.a
+
+exit.a:
+  br label %backedge
+
+dead_preheader:
+  br label %dead_loop
+
+dead_loop:
+  %b = phi i32 [0, %dead_preheader], [%b.inc, %dead_loop]
+  %b.inc = add i32 %b, 1
+  %cmp.b = icmp slt i32 %b.inc, %end
+  br i1 %cmp.b, label %dead_loop, label %exit.b
+
+exit.b:
+  br label %backedge
+
+backedge:
+  %i.inc = add i32 %i, 1
+  %cmp = icmp slt i32 %i.inc, %end
+  br i1 %cmp, label %header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+; Check that we preserve static reachability of an exit block even if we prove
+; that the loop is infinite. Branch case.
+define i32 @inf_loop_test_branch_loop(i32 %end) {
+; CHECK-LABEL: @inf_loop_test_branch_loop(
+; CHECK-NEXT:  preheader:
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[PREHEADER:%.*]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br i1 true, label [[BACKEDGE]], label [[DEAD:%.*]]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I_2]], [[DEAD]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[I_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 true, label [[HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA]]
+;
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  br i1 true, label %backedge, label %dead
+
+dead:
+  %i.2 = add i32 %i, 1
+  br label %dummy
+
+dummy:
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %header], [%i.2, %dummy]
+  %i.inc = add i32 %i.1, 1
+  %cmp = icmp slt i32 %i.inc, %end
+  br i1 true, label %header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+define i32 @inf_loop_test_switch_loop(i32 %end) {
+; CHECK-LABEL: @inf_loop_test_switch_loop(
+; CHECK-NEXT:  preheader:
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[PREHEADER:%.*]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    switch i32 1, label [[DEAD:%.*]] [
+; CHECK-NEXT:    i32 0, label [[DEAD]]
+; CHECK-NEXT:    i32 1, label [[BACKEDGE]]
+; CHECK-NEXT:    i32 2, label [[DEAD]]
+; CHECK-NEXT:    ]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I_2]], [[DEAD]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[I_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 true, label [[HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA]]
+;
+preheader:
+  br label %header
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  switch i32 1, label %dead [i32 0, label %dead
+  i32 1, label %backedge
+  i32 2, label %dead]
+dead:
+  %i.2 = add i32 %i, 1
+  br label %dummy
+dummy:
+  br label %backedge
+backedge:
+  %i.1 = phi i32 [%i, %header], [%i.2, %dummy]
+  %i.inc = add i32 %i.1, 1
+  %cmp = icmp slt i32 %i.inc, %end
+  br i1 true, label %header, label %exit
+exit:
+  ret i32 %i.inc
+}
+
+; Check that when the block is not actually dead, we don't remove it.
+define i32 @no_live_block_test_branch_loop(i1 %c, i32 %end) {
+; CHECK-LABEL: @no_live_block_test_branch_loop(
+; CHECK-NEXT:  preheader:
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[PREHEADER:%.*]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br i1 [[C:%.*]], label [[CHECK:%.*]], label [[LIVE:%.*]]
+; CHECK:       check:
+; CHECK-NEXT:    br i1 true, label [[BACKEDGE]], label [[LIVE]]
+; CHECK:       live:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[CHECK]] ], [ [[I_2]], [[LIVE]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[I_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA]]
+;
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  br i1 %c, label %check, label %live
+
+check:
+  br i1 true, label %backedge, label %live
+
+live:
+  %i.2 = add i32 %i, 1
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %check], [%i.2, %live]
+  %i.inc = add i32 %i.1, 1
+  %cmp = icmp slt i32 %i.inc, %end
+  br i1 %cmp, label %header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+define i32 @no_live_block_test_switch_loop(i1 %c, i32 %end) {
+; CHECK-LABEL: @no_live_block_test_switch_loop(
+; CHECK-NEXT:  preheader:
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[PREHEADER:%.*]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br i1 [[C:%.*]], label [[CHECK:%.*]], label [[LIVE:%.*]]
+; CHECK:       check:
+; CHECK-NEXT:    switch i32 1, label [[LIVE]] [
+; CHECK-NEXT:    i32 0, label [[LIVE]]
+; CHECK-NEXT:    i32 1, label [[BACKEDGE]]
+; CHECK-NEXT:    i32 2, label [[LIVE]]
+; CHECK-NEXT:    ]
+; CHECK:       live:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[CHECK]] ], [ [[I_2]], [[LIVE]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[I_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA]]
+;
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  br i1 %c, label %check, label %live
+
+check:
+  switch i32 1, label %live [i32 0, label %live
+  i32 1, label %backedge
+  i32 2, label %live]
+
+live:
+  %i.2 = add i32 %i, 1
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %check], [%i.2, %live]
+  %i.inc = add i32 %i.1, 1
+  %cmp = icmp slt i32 %i.inc, %end
+  br i1 %cmp, label %header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+; Check that we can remove part of blocks of inner loop while the loop still
+; preserves, in presence of outer loop.
+define i32 @partial_sub_loop_test_branch_loop(i32 %end) {
+; CHECK-LABEL: @partial_sub_loop_test_branch_loop(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[OUTER_HEADER:%.*]]
+; CHECK:       outer_header:
+; CHECK-NEXT:    [[J:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[J_INC:%.*]], [[OUTER_BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[OUTER_HEADER]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br i1 true, label [[BACKEDGE]], label [[DEAD:%.*]]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I_2]], [[DEAD]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[I_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[HEADER]], label [[OUTER_BACKEDGE]]
+; CHECK:       outer_backedge:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    [[J_INC]] = add i32 [[J]], 1
+; CHECK-NEXT:    [[CMP_J:%.*]] = icmp slt i32 [[J_INC]], [[END]]
+; CHECK-NEXT:    br i1 [[CMP_J]], label [[OUTER_HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA_LCSSA:%.*]] = phi i32 [ [[I_INC_LCSSA]], [[OUTER_BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA_LCSSA]]
+;
+entry:
+  br label %outer_header
+
+outer_header:
+  %j = phi i32 [0, %entry], [%j.inc, %outer_backedge]
+  br label %preheader
+
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  br i1 true, label %backedge, label %dead
+
+dead:
+  %i.2 = add i32 %i, 1
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %header], [%i.2, %dead]
+  %i.inc = add i32 %i.1, 1
+  %cmp = icmp slt i32 %i.inc, %end
+  br i1 %cmp, label %header, label %outer_backedge
+
+outer_backedge:
+  %j.inc = add i32 %j, 1
+  %cmp.j = icmp slt i32 %j.inc, %end
+  br i1 %cmp.j, label %outer_header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+define i32 @partial_sub_loop_test_switch_loop(i32 %end) {
+; CHECK-LABEL: @partial_sub_loop_test_switch_loop(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[OUTER_HEADER:%.*]]
+; CHECK:       outer_header:
+; CHECK-NEXT:    [[J:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[J_INC:%.*]], [[OUTER_BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[OUTER_HEADER]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    switch i32 1, label [[DEAD:%.*]] [
+; CHECK-NEXT:    i32 0, label [[DEAD]]
+; CHECK-NEXT:    i32 1, label [[BACKEDGE]]
+; CHECK-NEXT:    i32 2, label [[DEAD]]
+; CHECK-NEXT:    ]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I_2]], [[DEAD]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[I_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP]], label [[HEADER]], label [[OUTER_BACKEDGE]]
+; CHECK:       outer_backedge:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    [[J_INC]] = add i32 [[J]], 1
+; CHECK-NEXT:    [[CMP_J:%.*]] = icmp slt i32 [[J_INC]], [[END]]
+; CHECK-NEXT:    br i1 [[CMP_J]], label [[OUTER_HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA_LCSSA:%.*]] = phi i32 [ [[I_INC_LCSSA]], [[OUTER_BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA_LCSSA]]
+;
+entry:
+  br label %outer_header
+
+outer_header:
+  %j = phi i32 [0, %entry], [%j.inc, %outer_backedge]
+  br label %preheader
+
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  switch i32 1, label %dead [i32 0, label %dead
+  i32 1, label %backedge
+  i32 2, label %dead]
+
+dead:
+  %i.2 = add i32 %i, 1
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %header], [%i.2, %dead]
+  %i.inc = add i32 %i.1, 1
+  %cmp = icmp slt i32 %i.inc, %end
+  br i1 %cmp, label %header, label %outer_backedge
+
+outer_backedge:
+  %j.inc = add i32 %j, 1
+  %cmp.j = icmp slt i32 %j.inc, %end
+  br i1 %cmp.j, label %outer_header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+; Check that we can completely delete inner loop and preserve the outer loop.
+define i32 @full_sub_loop_test_branch_loop(i32 %end) {
+; CHECK-LABEL: @full_sub_loop_test_branch_loop(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[OUTER_HEADER:%.*]]
+; CHECK:       outer_header:
+; CHECK-NEXT:    [[J:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[J_INC:%.*]], [[OUTER_BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[OUTER_HEADER]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    [[MUL:%.*]] = mul i32 [[I]], [[I]]
+; CHECK-NEXT:    br i1 false, label [[BACKEDGE]], label [[DEAD:%.*]]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I_2]], [[DEAD]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    br i1 false, label [[HEADER]], label [[OUTER_BACKEDGE]]
+; CHECK:       outer_backedge:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    [[J_INC]] = add i32 [[J]], 1
+; CHECK-NEXT:    [[CMP_J:%.*]] = icmp slt i32 [[J_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP_J]], label [[OUTER_HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA_LCSSA:%.*]] = phi i32 [ [[I_INC_LCSSA]], [[OUTER_BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA_LCSSA]]
+;
+entry:
+  br label %outer_header
+
+outer_header:
+  %j = phi i32 [0, %entry], [%j.inc, %outer_backedge]
+  br label %preheader
+
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  br label  %live_part
+
+live_part:
+  %mul = mul i32 %i, %i
+  br i1 false, label %backedge, label %dead
+
+dead:
+  %i.2 = add i32 %i, 1
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %live_part], [%i.2, %dead]
+  %i.inc = add i32 %i.1, 1
+  br i1 false, label %header, label %outer_backedge
+
+outer_backedge:
+  %j.inc = add i32 %j, 1
+  %cmp.j = icmp slt i32 %j.inc, %end
+  br i1 %cmp.j, label %outer_header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+define i32 @full_sub_loop_test_switch_loop(i32 %end) {
+; CHECK-LABEL: @full_sub_loop_test_switch_loop(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[OUTER_HEADER:%.*]]
+; CHECK:       outer_header:
+; CHECK-NEXT:    [[J:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[J_INC:%.*]], [[OUTER_BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[OUTER_HEADER]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    [[MUL:%.*]] = mul i32 [[I]], [[I]]
+; CHECK-NEXT:    switch i32 1, label [[DEAD:%.*]] [
+; CHECK-NEXT:    i32 0, label [[BACKEDGE]]
+; CHECK-NEXT:    ]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I_2]], [[DEAD]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    switch i32 1, label [[OUTER_BACKEDGE]] [
+; CHECK-NEXT:    i32 0, label [[HEADER]]
+; CHECK-NEXT:    ]
+; CHECK:       outer_backedge:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    [[J_INC]] = add i32 [[J]], 1
+; CHECK-NEXT:    [[CMP_J:%.*]] = icmp slt i32 [[J_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP_J]], label [[OUTER_HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA_LCSSA:%.*]] = phi i32 [ [[I_INC_LCSSA]], [[OUTER_BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA_LCSSA]]
+;
+entry:
+  br label %outer_header
+
+outer_header:
+  %j = phi i32 [0, %entry], [%j.inc, %outer_backedge]
+  br label %preheader
+
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  br label  %live_part
+
+live_part:
+  %mul = mul i32 %i, %i
+  switch i32 1, label %dead [i32 0, label %backedge]
+
+dead:
+  %i.2 = add i32 %i, 1
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %live_part], [%i.2, %dead]
+  %i.inc = add i32 %i.1, 1
+  switch i32 1, label %outer_backedge [i32 0, label %header]
+
+outer_backedge:
+  %j.inc = add i32 %j, 1
+  %cmp.j = icmp slt i32 %j.inc, %end
+  br i1 %cmp.j, label %outer_header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+; Inverted condition in live_part.
+define i32 @full_sub_loop_test_branch_loop_inverse_1(i32 %end) {
+; CHECK-LABEL: @full_sub_loop_test_branch_loop_inverse_1(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[OUTER_HEADER:%.*]]
+; CHECK:       outer_header:
+; CHECK-NEXT:    [[J:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[J_INC:%.*]], [[OUTER_BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[OUTER_HEADER]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    [[MUL:%.*]] = mul i32 [[I]], [[I]]
+; CHECK-NEXT:    br i1 true, label [[BACKEDGE]], label [[DEAD:%.*]]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I_2]], [[DEAD]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    br i1 false, label [[HEADER]], label [[OUTER_BACKEDGE]]
+; CHECK:       outer_backedge:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    [[J_INC]] = add i32 [[J]], 1
+; CHECK-NEXT:    [[CMP_J:%.*]] = icmp slt i32 [[J_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP_J]], label [[OUTER_HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA_LCSSA:%.*]] = phi i32 [ [[I_INC_LCSSA]], [[OUTER_BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA_LCSSA]]
+;
+entry:
+  br label %outer_header
+
+outer_header:
+  %j = phi i32 [0, %entry], [%j.inc, %outer_backedge]
+  br label %preheader
+
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  br label  %live_part
+
+live_part:
+  %mul = mul i32 %i, %i
+  br i1 true, label %backedge, label %dead
+
+dead:
+  %i.2 = add i32 %i, 1
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %live_part], [%i.2, %dead]
+  %i.inc = add i32 %i.1, 1
+  br i1 false, label %header, label %outer_backedge
+
+outer_backedge:
+  %j.inc = add i32 %j, 1
+  %cmp.j = icmp slt i32 %j.inc, %end
+  br i1 %cmp.j, label %outer_header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+define i32 @full_sub_loop_test_switch_loop_inverse_1(i32 %end) {
+; CHECK-LABEL: @full_sub_loop_test_switch_loop_inverse_1(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[OUTER_HEADER:%.*]]
+; CHECK:       outer_header:
+; CHECK-NEXT:    [[J:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[J_INC:%.*]], [[OUTER_BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[OUTER_HEADER]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    [[MUL:%.*]] = mul i32 [[I]], [[I]]
+; CHECK-NEXT:    switch i32 1, label [[BACKEDGE]] [
+; CHECK-NEXT:    i32 0, label [[DEAD:%.*]]
+; CHECK-NEXT:    ]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I_2]], [[DEAD]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    switch i32 1, label [[OUTER_BACKEDGE]] [
+; CHECK-NEXT:    i32 0, label [[HEADER]]
+; CHECK-NEXT:    ]
+; CHECK:       outer_backedge:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    [[J_INC]] = add i32 [[J]], 1
+; CHECK-NEXT:    [[CMP_J:%.*]] = icmp slt i32 [[J_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP_J]], label [[OUTER_HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA_LCSSA:%.*]] = phi i32 [ [[I_INC_LCSSA]], [[OUTER_BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA_LCSSA]]
+;
+entry:
+  br label %outer_header
+
+outer_header:
+  %j = phi i32 [0, %entry], [%j.inc, %outer_backedge]
+  br label %preheader
+
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  br label  %live_part
+
+live_part:
+  %mul = mul i32 %i, %i
+  switch i32 1, label %backedge [i32 0, label %dead]
+
+dead:
+  %i.2 = add i32 %i, 1
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %live_part], [%i.2, %dead]
+  %i.inc = add i32 %i.1, 1
+  switch i32 1, label %outer_backedge [i32 0, label %header]
+
+outer_backedge:
+  %j.inc = add i32 %j, 1
+  %cmp.j = icmp slt i32 %j.inc, %end
+  br i1 %cmp.j, label %outer_header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+define i32 @full_sub_loop_test_branch_loop_inverse_2(i32 %end) {
+; CHECK-LABEL: @full_sub_loop_test_branch_loop_inverse_2(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[OUTER_HEADER:%.*]]
+; CHECK:       outer_header:
+; CHECK-NEXT:    [[J:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[J_INC:%.*]], [[OUTER_BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[OUTER_HEADER]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    [[MUL:%.*]] = mul i32 [[I]], [[I]]
+; CHECK-NEXT:    br i1 false, label [[BACKEDGE]], label [[DEAD:%.*]]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I_2]], [[DEAD]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    br i1 true, label [[HEADER]], label [[OUTER_BACKEDGE]]
+; CHECK:       outer_backedge:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    [[J_INC]] = add i32 [[J]], 1
+; CHECK-NEXT:    [[CMP_J:%.*]] = icmp slt i32 [[J_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP_J]], label [[OUTER_HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA_LCSSA:%.*]] = phi i32 [ [[I_INC_LCSSA]], [[OUTER_BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA_LCSSA]]
+;
+entry:
+  br label %outer_header
+
+outer_header:
+  %j = phi i32 [0, %entry], [%j.inc, %outer_backedge]
+  br label %preheader
+
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  br label  %live_part
+
+live_part:
+  %mul = mul i32 %i, %i
+  br i1 false, label %backedge, label %dead
+
+dead:
+  %i.2 = add i32 %i, 1
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %live_part], [%i.2, %dead]
+  %i.inc = add i32 %i.1, 1
+  br i1 true, label %header, label %outer_backedge
+
+outer_backedge:
+  %j.inc = add i32 %j, 1
+  %cmp.j = icmp slt i32 %j.inc, %end
+  br i1 %cmp.j, label %outer_header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+define i32 @full_sub_loop_test_switch_loop_inverse_2(i32 %end) {
+; CHECK-LABEL: @full_sub_loop_test_switch_loop_inverse_2(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[OUTER_HEADER:%.*]]
+; CHECK:       outer_header:
+; CHECK-NEXT:    [[J:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[J_INC:%.*]], [[OUTER_BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[OUTER_HEADER]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    [[MUL:%.*]] = mul i32 [[I]], [[I]]
+; CHECK-NEXT:    switch i32 1, label [[DEAD:%.*]] [
+; CHECK-NEXT:    i32 0, label [[BACKEDGE]]
+; CHECK-NEXT:    ]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I_2]], [[DEAD]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    switch i32 1, label [[HEADER]] [
+; CHECK-NEXT:    i32 0, label [[OUTER_BACKEDGE]]
+; CHECK-NEXT:    ]
+; CHECK:       outer_backedge:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    [[J_INC]] = add i32 [[J]], 1
+; CHECK-NEXT:    [[CMP_J:%.*]] = icmp slt i32 [[J_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP_J]], label [[OUTER_HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA_LCSSA:%.*]] = phi i32 [ [[I_INC_LCSSA]], [[OUTER_BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA_LCSSA]]
+;
+entry:
+  br label %outer_header
+
+outer_header:
+  %j = phi i32 [0, %entry], [%j.inc, %outer_backedge]
+  br label %preheader
+
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  br label  %live_part
+
+live_part:
+  %mul = mul i32 %i, %i
+  switch i32 1, label %dead [i32 0, label %backedge]
+
+dead:
+  %i.2 = add i32 %i, 1
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %live_part], [%i.2, %dead]
+  %i.inc = add i32 %i.1, 1
+  switch i32 1, label %header [i32 0, label %outer_backedge]
+
+outer_backedge:
+  %j.inc = add i32 %j, 1
+  %cmp.j = icmp slt i32 %j.inc, %end
+  br i1 %cmp.j, label %outer_header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+
+define i32 @full_sub_loop_test_branch_loop_inverse_3(i32 %end) {
+; CHECK-LABEL: @full_sub_loop_test_branch_loop_inverse_3(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[OUTER_HEADER:%.*]]
+; CHECK:       outer_header:
+; CHECK-NEXT:    [[J:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[J_INC:%.*]], [[OUTER_BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[OUTER_HEADER]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    [[MUL:%.*]] = mul i32 [[I]], [[I]]
+; CHECK-NEXT:    br i1 true, label [[BACKEDGE]], label [[DEAD:%.*]]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I_2]], [[DEAD]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    br i1 true, label [[HEADER]], label [[OUTER_BACKEDGE]]
+; CHECK:       outer_backedge:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    [[J_INC]] = add i32 [[J]], 1
+; CHECK-NEXT:    [[CMP_J:%.*]] = icmp slt i32 [[J_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP_J]], label [[OUTER_HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA_LCSSA:%.*]] = phi i32 [ [[I_INC_LCSSA]], [[OUTER_BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA_LCSSA]]
+;
+entry:
+  br label %outer_header
+
+outer_header:
+  %j = phi i32 [0, %entry], [%j.inc, %outer_backedge]
+  br label %preheader
+
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  br label  %live_part
+
+live_part:
+  %mul = mul i32 %i, %i
+  br i1 true, label %backedge, label %dead
+
+dead:
+  %i.2 = add i32 %i, 1
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %live_part], [%i.2, %dead]
+  %i.inc = add i32 %i.1, 1
+  br i1 true, label %header, label %outer_backedge
+
+outer_backedge:
+  %j.inc = add i32 %j, 1
+  %cmp.j = icmp slt i32 %j.inc, %end
+  br i1 %cmp.j, label %outer_header, label %exit
+
+exit:
+  ret i32 %i.inc
+}
+
+define i32 @full_sub_loop_test_switch_loop_inverse_3(i32 %end) {
+; CHECK-LABEL: @full_sub_loop_test_switch_loop_inverse_3(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[OUTER_HEADER:%.*]]
+; CHECK:       outer_header:
+; CHECK-NEXT:    [[J:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[J_INC:%.*]], [[OUTER_BACKEDGE:%.*]] ]
+; CHECK-NEXT:    br label [[HEADER:%.*]]
+; CHECK:       header:
+; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[OUTER_HEADER]] ], [ [[I_INC:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    [[MUL:%.*]] = mul i32 [[I]], [[I]]
+; CHECK-NEXT:    switch i32 1, label [[BACKEDGE]] [
+; CHECK-NEXT:    i32 0, label [[DEAD:%.*]]
+; CHECK-NEXT:    ]
+; CHECK:       dead:
+; CHECK-NEXT:    [[I_2:%.*]] = add i32 [[I]], 1
+; CHECK-NEXT:    br label [[BACKEDGE]]
+; CHECK:       backedge:
+; CHECK-NEXT:    [[I_1:%.*]] = phi i32 [ [[I]], [[HEADER]] ], [ [[I_2]], [[DEAD]] ]
+; CHECK-NEXT:    [[I_INC]] = add i32 [[I_1]], 1
+; CHECK-NEXT:    switch i32 1, label [[HEADER]] [
+; CHECK-NEXT:    i32 0, label [[OUTER_BACKEDGE]]
+; CHECK-NEXT:    ]
+; CHECK:       outer_backedge:
+; CHECK-NEXT:    [[I_INC_LCSSA:%.*]] = phi i32 [ [[I_INC]], [[BACKEDGE]] ]
+; CHECK-NEXT:    [[J_INC]] = add i32 [[J]], 1
+; CHECK-NEXT:    [[CMP_J:%.*]] = icmp slt i32 [[J_INC]], [[END:%.*]]
+; CHECK-NEXT:    br i1 [[CMP_J]], label [[OUTER_HEADER]], label [[EXIT:%.*]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[I_INC_LCSSA_LCSSA:%.*]] = phi i32 [ [[I_INC_LCSSA]], [[OUTER_BACKEDGE]] ]
+; CHECK-NEXT:    ret i32 [[I_INC_LCSSA_LCSSA]]
+;
+entry:
+  br label %outer_header
+
+outer_header:
+  %j = phi i32 [0, %entry], [%j.inc, %outer_backedge]
+  br label %preheader
+
+preheader:
+  br label %header
+
+header:
+  %i = phi i32 [0, %preheader], [%i.inc, %backedge]
+  br label  %live_part
+
+live_part:
+  %mul = mul i32 %i, %i
+  switch i32 1, label %backedge [i32 0, label %dead]
+
+dead:
+  %i.2 = add i32 %i, 1
+  br label %backedge
+
+backedge:
+  %i.1 = phi i32 [%i, %live_part], [%i.2, %dead]
+  %i.inc = add i32 %i.1, 1
+  switch i32 1, label %header [i32 0, label %outer_backedge]
+
+outer_backedge:
+  %j.inc = add i32 %j, 1
+  %cmp.j = icmp slt i32 %j.inc, %end
+  br i1 %cmp.j, label %outer_header, label %exit
+
+exit:
+  ret i32 %i.inc
+}




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