; LLVM IR from afrozchakure/Competitive-Programming-Solutions :: HackerRank/Problem-Solving (CompareTwoLinkedLists)

; 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.SinglyLinkedListNode = type { i32, ptr }

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

; 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 @_Z13compare_listsP20SinglyLinkedListNodeS0_(ptr noundef %0, ptr noundef %1) #1 {
  %3 = alloca i1, align 1
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  %7 = alloca ptr, align 8
  %8 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #2
  %9 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %9, ptr %6, align 8, !tbaa !5
  %10 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %10, ptr %7, align 8, !tbaa !5
  %11 = load ptr, ptr %6, align 8, !tbaa !5
  %12 = icmp eq ptr %11, null
  br i1 %12, label %13, label %17

13:                                               ; preds = %2
  %14 = load ptr, ptr %7, align 8, !tbaa !5
  %15 = icmp eq ptr %14, null
  br i1 %15, label %16, label %17

16:                                               ; preds = %13
  store i1 true, ptr %3, align 1
  store i32 1, ptr %8, align 4
  br label %41

17:                                               ; preds = %13, %2
  %18 = load ptr, ptr %6, align 8, !tbaa !5
  %19 = icmp eq ptr %18, null
  br i1 %19, label %23, label %20

20:                                               ; preds = %17
  %21 = load ptr, ptr %7, align 8, !tbaa !5
  %22 = icmp eq ptr %21, null
  br i1 %22, label %23, label %24

23:                                               ; preds = %20, %17
  store i1 false, ptr %3, align 1
  store i32 1, ptr %8, align 4
  br label %41

24:                                               ; preds = %20
  %25 = load ptr, ptr %6, align 8, !tbaa !5
  %26 = getelementptr inbounds %class.SinglyLinkedListNode, ptr %25, i32 0, i32 0
  %27 = load i32, ptr %26, align 8, !tbaa !9
  %28 = load ptr, ptr %7, align 8, !tbaa !5
  %29 = getelementptr inbounds %class.SinglyLinkedListNode, ptr %28, i32 0, i32 0
  %30 = load i32, ptr %29, align 8, !tbaa !9
  %31 = icmp eq i32 %27, %30
  br i1 %31, label %32, label %40

32:                                               ; preds = %24
  %33 = load ptr, ptr %6, align 8, !tbaa !5
  %34 = getelementptr inbounds %class.SinglyLinkedListNode, ptr %33, i32 0, i32 1
  %35 = load ptr, ptr %34, align 8, !tbaa !12
  %36 = load ptr, ptr %7, align 8, !tbaa !5
  %37 = getelementptr inbounds %class.SinglyLinkedListNode, ptr %36, i32 0, i32 1
  %38 = load ptr, ptr %37, align 8, !tbaa !12
  %39 = call noundef zeroext i1 @_Z13compare_listsP20SinglyLinkedListNodeS0_(ptr noundef %35, ptr noundef %38)
  store i1 %39, ptr %3, align 1
  store i32 1, ptr %8, align 4
  br label %41

40:                                               ; preds = %24
  store i1 false, ptr %3, align 1
  store i32 1, ptr %8, align 4
  br label %41

41:                                               ; preds = %40, %32, %23, %16
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  %42 = load i1, ptr %3, align 1
  ret i1 %42
}

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 = { 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, !11, i64 0}
!10 = !{!"_ZTS20SinglyLinkedListNode", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 8}


; 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"

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(read, inaccessiblemem: none) uwtable
define dso_local noundef zeroext i1 @_Z13compare_listsP20SinglyLinkedListNodeS0_(ptr noundef readonly %0, ptr noundef readonly %1) local_unnamed_addr #0 {
  %3 = icmp eq ptr %0, null
  %4 = icmp eq ptr %1, null
  %or.cond17 = and i1 %3, %4
  br i1 %or.cond17, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %2, %tailrecurse
  %5 = phi i1 [ %16, %tailrecurse ], [ %4, %2 ]
  %6 = phi i1 [ %15, %tailrecurse ], [ %3, %2 ]
  %.tr1619 = phi ptr [ %14, %tailrecurse ], [ %1, %2 ]
  %.tr18 = phi ptr [ %12, %tailrecurse ], [ %0, %2 ]
  %or.cond3 = or i1 %6, %5
  br i1 %or.cond3, label %._crit_edge, label %7

7:                                                ; preds = %.lr.ph
  %8 = load i32, ptr %.tr18, align 8, !tbaa !5
  %9 = load i32, ptr %.tr1619, align 8, !tbaa !5
  %10 = icmp eq i32 %8, %9
  br i1 %10, label %tailrecurse, label %._crit_edge

tailrecurse:                                      ; preds = %7
  %11 = getelementptr inbounds i8, ptr %.tr18, i64 8
  %12 = load ptr, ptr %11, align 8, !tbaa !11
  %13 = getelementptr inbounds i8, ptr %.tr1619, i64 8
  %14 = load ptr, ptr %13, align 8, !tbaa !11
  %15 = icmp eq ptr %12, null
  %16 = icmp eq ptr %14, null
  %or.cond = and i1 %15, %16
  br i1 %or.cond, label %._crit_edge, label %.lr.ph

._crit_edge:                                      ; preds = %tailrecurse, %.lr.ph, %7, %2
  %.0 = phi i1 [ true, %2 ], [ false, %7 ], [ false, %.lr.ph ], [ true, %tailrecurse ]
  ret i1 %.0
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(read, inaccessiblemem: none) 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" }

!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, !7, i64 0}
!6 = !{!"_ZTS20SinglyLinkedListNode", !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 = !{!6, !10, i64 8}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass