; LLVM IR from Lakhankumawat/LearnCPP :: L-LinkedList/S-SinglyLinkedList/PalindromeLinkedList.ll (Z12isPalindromeP4node)

; Unoptimized IR (clang -disable-llvm-passes):
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

%"class.std::stack" = type { %"class.std::deque" }
%"class.std::deque" = type { %"class.std::_Deque_base" }
%"class.std::_Deque_base" = type { %"struct.std::_Deque_base<int, std::allocator<int>>::_Deque_impl" }
%"struct.std::_Deque_base<int, std::allocator<int>>::_Deque_impl" = type { %"struct.std::_Deque_base<int, std::allocator<int>>::_Deque_impl_data" }
%"struct.std::_Deque_base<int, std::allocator<int>>::_Deque_impl_data" = type { ptr, i64, %"struct.std::_Deque_iterator", %"struct.std::_Deque_iterator" }
%"struct.std::_Deque_iterator" = type { ptr, ptr, ptr, ptr }
%class.node = type { i32, ptr }

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

declare i32 @__gxx_personality_v0(...)

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress uwtable
define dso_local noundef zeroext i1 @_Z12isPalindromeP4node(ptr noundef %0) #1 personality ptr @__gxx_personality_v0 {
  %2 = alloca i1, align 1
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca %"class.std::stack", align 8
  %7 = alloca ptr, align 8
  %8 = alloca i32, align 4
  %9 = alloca i32, align 4
  %10 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #4
  %11 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %11, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #4
  %12 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %12, ptr %5, align 8, !tbaa !5
  br label %13

13:                                               ; preds = %23, %1
  %14 = load ptr, ptr %5, align 8, !tbaa !5
  %15 = icmp ne ptr %14, null
  br i1 %15, label %16, label %21

16:                                               ; preds = %13
  %17 = load ptr, ptr %5, align 8, !tbaa !5
  %18 = getelementptr inbounds %class.node, ptr %17, i32 0, i32 1
  %19 = load ptr, ptr %18, align 8, !tbaa !9
  %20 = icmp ne ptr %19, null
  br label %21

21:                                               ; preds = %16, %13
  %22 = phi i1 [ false, %13 ], [ %20, %16 ]
  br i1 %22, label %23, label %32

23:                                               ; preds = %21
  %24 = load ptr, ptr %4, align 8, !tbaa !5
  %25 = getelementptr inbounds %class.node, ptr %24, i32 0, i32 1
  %26 = load ptr, ptr %25, align 8, !tbaa !9
  store ptr %26, ptr %4, align 8, !tbaa !5
  %27 = load ptr, ptr %5, align 8, !tbaa !5
  %28 = getelementptr inbounds %class.node, ptr %27, i32 0, i32 1
  %29 = load ptr, ptr %28, align 8, !tbaa !9
  %30 = getelementptr inbounds %class.node, ptr %29, i32 0, i32 1
  %31 = load ptr, ptr %30, align 8, !tbaa !9
  store ptr %31, ptr %5, align 8, !tbaa !5
  br label %13, !llvm.loop !12

32:                                               ; preds = %21
  %33 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %33, ptr %5, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 80, ptr %6) #4
  call void @_ZNSt5stackIiSt5dequeIiSaIiEEEC2IS2_vEEv(ptr noundef nonnull align 8 dereferenceable(80) %6)
  br label %34

34:                                               ; preds = %40, %32
  %35 = load ptr, ptr %4, align 8, !tbaa !5
  %36 = icmp ne ptr %35, null
  br i1 %36, label %37, label %48

37:                                               ; preds = %34
  %38 = load ptr, ptr %4, align 8, !tbaa !5
  %39 = getelementptr inbounds %class.node, ptr %38, i32 0, i32 0
  invoke void @_ZNSt5stackIiSt5dequeIiSaIiEEE4pushERKi(ptr noundef nonnull align 8 dereferenceable(80) %6, ptr noundef nonnull align 4 dereferenceable(4) %39)
          to label %40 unwind label %44

40:                                               ; preds = %37
  %41 = load ptr, ptr %4, align 8, !tbaa !5
  %42 = getelementptr inbounds %class.node, ptr %41, i32 0, i32 1
  %43 = load ptr, ptr %42, align 8, !tbaa !9
  store ptr %43, ptr %4, align 8, !tbaa !5
  br label %34, !llvm.loop !14

44:                                               ; preds = %37
  %45 = landingpad { ptr, i32 }
          cleanup
  %46 = extractvalue { ptr, i32 } %45, 0
  store ptr %46, ptr %7, align 8
  %47 = extractvalue { ptr, i32 } %45, 1
  store i32 %47, ptr %8, align 4
  br label %77

48:                                               ; preds = %34
  call void @llvm.lifetime.start.p0(i64 4, ptr %9) #4
  %49 = invoke noundef i64 @_ZNKSt5stackIiSt5dequeIiSaIiEEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(80) %6)
          to label %50 unwind label %65

50:                                               ; preds = %48
  %51 = trunc i64 %49 to i32
  store i32 %51, ptr %9, align 4, !tbaa !15
  br label %52

52:                                               ; preds = %70, %50
  %53 = load i32, ptr %9, align 4, !tbaa !15
  %54 = add nsw i32 %53, -1
  store i32 %54, ptr %9, align 4, !tbaa !15
  %55 = icmp ne i32 %53, 0
  br i1 %55, label %56, label %74

56:                                               ; preds = %52
  %57 = load ptr, ptr %5, align 8, !tbaa !5
  %58 = getelementptr inbounds %class.node, ptr %57, i32 0, i32 0
  %59 = load i32, ptr %58, align 8, !tbaa !16
  %60 = invoke noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt5stackIiSt5dequeIiSaIiEEE3topEv(ptr noundef nonnull align 8 dereferenceable(80) %6)
          to label %61 unwind label %65

61:                                               ; preds = %56
  %62 = load i32, ptr %60, align 4, !tbaa !15
  %63 = icmp ne i32 %59, %62
  br i1 %63, label %64, label %69

64:                                               ; preds = %61
  store i1 false, ptr %2, align 1
  store i32 1, ptr %10, align 4
  br label %75

65:                                               ; preds = %69, %56, %48
  %66 = landingpad { ptr, i32 }
          cleanup
  %67 = extractvalue { ptr, i32 } %66, 0
  store ptr %67, ptr %7, align 8
  %68 = extractvalue { ptr, i32 } %66, 1
  store i32 %68, ptr %8, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #4
  br label %77

69:                                               ; preds = %61
  invoke void @_ZNSt5stackIiSt5dequeIiSaIiEEE3popEv(ptr noundef nonnull align 8 dereferenceable(80) %6)
          to label %70 unwind label %65

70:                                               ; preds = %69
  %71 = load ptr, ptr %5, align 8, !tbaa !5
  %72 = getelementptr inbounds %class.node, ptr %71, i32 0, i32 1
  %73 = load ptr, ptr %72, align 8, !tbaa !9
  store ptr %73, ptr %5, align 8, !tbaa !5
  br label %52, !llvm.loop !17

74:                                               ; preds = %52
  store i1 true, ptr %2, align 1
  store i32 1, ptr %10, align 4
  br label %75

75:                                               ; preds = %74, %64
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #4
  call void @_ZNSt5stackIiSt5dequeIiSaIiEEED2Ev(ptr noundef nonnull align 8 dereferenceable(80) %6) #4
  call void @llvm.lifetime.end.p0(i64 80, ptr %6) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #4
  %76 = load i1, ptr %2, align 1
  ret i1 %76

77:                                               ; preds = %65, %44
  call void @_ZNSt5stackIiSt5dequeIiSaIiEEED2Ev(ptr noundef nonnull align 8 dereferenceable(80) %6) #4
  call void @llvm.lifetime.end.p0(i64 80, ptr %6) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #4
  br label %78

78:                                               ; preds = %77
  %79 = load ptr, ptr %7, align 8
  %80 = load i32, ptr %8, align 4
  %81 = insertvalue { ptr, i32 } poison, ptr %79, 0
  %82 = insertvalue { ptr, i32 } %81, i32 %80, 1
  resume { ptr, i32 } %82
}

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt5stackIiSt5dequeIiSaIiEEEC2IS2_vEEv(ptr noundef nonnull align 8 dereferenceable(80)) unnamed_addr #1 align 2

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt5stackIiSt5dequeIiSaIiEEE4pushERKi(ptr noundef nonnull align 8 dereferenceable(80), ptr noundef nonnull align 4 dereferenceable(4)) #1 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i64 @_ZNKSt5stackIiSt5dequeIiSaIiEEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(80)) #2 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt5stackIiSt5dequeIiSaIiEEE3topEv(ptr noundef nonnull align 8 dereferenceable(80)) #2 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZNSt5stackIiSt5dequeIiSaIiEEE3popEv(ptr noundef nonnull align 8 dereferenceable(80)) #2 align 2

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local void @_ZNSt5stackIiSt5dequeIiSaIiEEED2Ev(ptr noundef nonnull align 8 dereferenceable(80)) unnamed_addr #3 align 2

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { mustprogress uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #2 = { mustprogress nounwind uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #3 = { inlinehint mustprogress nounwind uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #4 = { nounwind }

!llvm.module.flags = !{!0, !1, !2, !3}
!llvm.ident = !{!4}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 8, !"PIC Level", i32 2}
!2 = !{i32 7, !"PIE Level", i32 2}
!3 = !{i32 7, !"uwtable", i32 2}
!4 = !{!"clang version 19.1.0 (git@github.com:llvm/llvm-project.git a4bf6cd7cfb1a1421ba92bca9d017b49936c55e4)"}
!5 = !{!6, !6, i64 0}
!6 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !6, i64 8}
!10 = !{!"_ZTS4node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}
!14 = distinct !{!14, !13}
!15 = !{!11, !11, i64 0}
!16 = !{!10, !11, i64 0}
!17 = distinct !{!17, !13}


; Optimized IR (opt -passes='default<O3>'):
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

%"class.std::stack" = type { %"class.std::deque" }
%"class.std::deque" = type { %"class.std::_Deque_base" }
%"class.std::_Deque_base" = type { %"struct.std::_Deque_base<int, std::allocator<int>>::_Deque_impl" }
%"struct.std::_Deque_base<int, std::allocator<int>>::_Deque_impl" = type { %"struct.std::_Deque_base<int, std::allocator<int>>::_Deque_impl_data" }
%"struct.std::_Deque_base<int, std::allocator<int>>::_Deque_impl_data" = type { ptr, i64, %"struct.std::_Deque_iterator", %"struct.std::_Deque_iterator" }
%"struct.std::_Deque_iterator" = type { ptr, ptr, ptr, ptr }

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

declare i32 @__gxx_personality_v0(...)

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress uwtable
define dso_local noundef zeroext i1 @_Z12isPalindromeP4node(ptr noundef %0) local_unnamed_addr #1 personality ptr @__gxx_personality_v0 {
  %2 = alloca %"class.std::stack", align 8
  %.not24 = icmp eq ptr %0, null
  br i1 %.not24, label %.critedge.thread, label %.lr.ph

.critedge.thread:                                 ; preds = %1
  call void @llvm.lifetime.start.p0(i64 80, ptr nonnull %2) #4
  call void @_ZNSt5stackIiSt5dequeIiSaIiEEEC2IS2_vEEv(ptr noundef nonnull align 8 dereferenceable(80) %2)
  br label %._crit_edge

.lr.ph:                                           ; preds = %1, %5
  %.01626 = phi ptr [ %7, %5 ], [ %0, %1 ]
  %.01725 = phi ptr [ %9, %5 ], [ %0, %1 ]
  %3 = getelementptr inbounds i8, ptr %.01725, i64 8
  %4 = load ptr, ptr %3, align 8, !tbaa !5
  %.not20 = icmp eq ptr %4, null
  br i1 %.not20, label %.critedge, label %5

5:                                                ; preds = %.lr.ph
  %6 = getelementptr inbounds i8, ptr %.01626, i64 8
  %7 = load ptr, ptr %6, align 8, !tbaa !5
  %8 = getelementptr inbounds i8, ptr %4, i64 8
  %9 = load ptr, ptr %8, align 8, !tbaa !5
  %.not = icmp eq ptr %9, null
  br i1 %.not, label %.critedge, label %.lr.ph, !llvm.loop !11

.critedge:                                        ; preds = %.lr.ph, %5
  %.016.lcssa = phi ptr [ %.01626, %.lr.ph ], [ %7, %5 ]
  call void @llvm.lifetime.start.p0(i64 80, ptr nonnull %2) #4
  call void @_ZNSt5stackIiSt5dequeIiSaIiEEEC2IS2_vEEv(ptr noundef nonnull align 8 dereferenceable(80) %2)
  %.not2129 = icmp eq ptr %.016.lcssa, null
  br i1 %.not2129, label %._crit_edge, label %.lr.ph31

.lr.ph31:                                         ; preds = %.critedge, %10
  %.130 = phi ptr [ %12, %10 ], [ %.016.lcssa, %.critedge ]
  invoke void @_ZNSt5stackIiSt5dequeIiSaIiEEE4pushERKi(ptr noundef nonnull align 8 dereferenceable(80) %2, ptr noundef nonnull align 4 dereferenceable(4) %.130)
          to label %10 unwind label %13

10:                                               ; preds = %.lr.ph31
  %11 = getelementptr inbounds i8, ptr %.130, i64 8
  %12 = load ptr, ptr %11, align 8, !tbaa !5
  %.not21 = icmp eq ptr %12, null
  br i1 %.not21, label %._crit_edge, label %.lr.ph31, !llvm.loop !13

13:                                               ; preds = %.lr.ph31
  %14 = landingpad { ptr, i32 }
          cleanup
  call void @_ZNSt5stackIiSt5dequeIiSaIiEEED2Ev(ptr noundef nonnull align 8 dereferenceable(80) %2) #4
  call void @llvm.lifetime.end.p0(i64 80, ptr nonnull %2) #4
  resume { ptr, i32 } %14

._crit_edge:                                      ; preds = %10, %.critedge.thread, %.critedge
  %15 = call noundef i64 @_ZNKSt5stackIiSt5dequeIiSaIiEEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(80) %2)
  %16 = trunc i64 %15 to i32
  %.not2232 = icmp eq i32 %16, 0
  br i1 %.not2232, label %._crit_edge37, label %.lr.ph36

.lr.ph36:                                         ; preds = %._crit_edge, %20
  %.in = phi i32 [ %21, %20 ], [ %16, %._crit_edge ]
  %.11833 = phi ptr [ %23, %20 ], [ %0, %._crit_edge ]
  %17 = load i32, ptr %.11833, align 8, !tbaa !14
  %18 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt5stackIiSt5dequeIiSaIiEEE3topEv(ptr noundef nonnull align 8 dereferenceable(80) %2)
  %19 = load i32, ptr %18, align 4, !tbaa !15
  %.not23 = icmp eq i32 %17, %19
  br i1 %.not23, label %20, label %._crit_edge37

20:                                               ; preds = %.lr.ph36
  %21 = add nsw i32 %.in, -1
  call void @_ZNSt5stackIiSt5dequeIiSaIiEEE3popEv(ptr noundef nonnull align 8 dereferenceable(80) %2)
  %22 = getelementptr inbounds i8, ptr %.11833, i64 8
  %23 = load ptr, ptr %22, align 8, !tbaa !5
  %.not22 = icmp eq i32 %21, 0
  br i1 %.not22, label %._crit_edge37, label %.lr.ph36, !llvm.loop !16

._crit_edge37:                                    ; preds = %.lr.ph36, %20, %._crit_edge
  %.not22.lcssa = phi i1 [ true, %._crit_edge ], [ %.not23, %20 ], [ %.not23, %.lr.ph36 ]
  call void @_ZNSt5stackIiSt5dequeIiSaIiEEED2Ev(ptr noundef nonnull align 8 dereferenceable(80) %2) #4
  call void @llvm.lifetime.end.p0(i64 80, ptr nonnull %2) #4
  ret i1 %.not22.lcssa
}

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt5stackIiSt5dequeIiSaIiEEEC2IS2_vEEv(ptr noundef nonnull align 8 dereferenceable(80)) unnamed_addr #1 align 2

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt5stackIiSt5dequeIiSaIiEEE4pushERKi(ptr noundef nonnull align 8 dereferenceable(80), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #1 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i64 @_ZNKSt5stackIiSt5dequeIiSaIiEEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(80)) local_unnamed_addr #2 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt5stackIiSt5dequeIiSaIiEEE3topEv(ptr noundef nonnull align 8 dereferenceable(80)) local_unnamed_addr #2 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZNSt5stackIiSt5dequeIiSaIiEEE3popEv(ptr noundef nonnull align 8 dereferenceable(80)) local_unnamed_addr #2 align 2

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local void @_ZNSt5stackIiSt5dequeIiSaIiEEED2Ev(ptr noundef nonnull align 8 dereferenceable(80)) unnamed_addr #3 align 2

attributes #0 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { mustprogress uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #2 = { mustprogress nounwind uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #3 = { inlinehint mustprogress nounwind uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #4 = { nounwind }

!llvm.module.flags = !{!0, !1, !2, !3}
!llvm.ident = !{!4}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 8, !"PIC Level", i32 2}
!2 = !{i32 7, !"PIE Level", i32 2}
!3 = !{i32 7, !"uwtable", i32 2}
!4 = !{!"clang version 19.1.0 (git@github.com:llvm/llvm-project.git a4bf6cd7cfb1a1421ba92bca9d017b49936c55e4)"}
!5 = !{!6, !10, i64 8}
!6 = !{!"_ZTS4node", !7, i64 0, !10, i64 8}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = distinct !{!13, !12}
!14 = !{!6, !7, i64 0}
!15 = !{!7, !7, i64 0}
!16 = distinct !{!16, !12}


; Effective O3 passes: CorrelatedValuePropagationPass,EarlyCSEPass,GVNPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass