; LLVM IR from UtkarshPathrabe/Competitive-Coding :: HackerRank Solutions/Data Structures/Linked Lists (Compare two linked lists)

; 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: mustprogress nounwind uwtable
define dso_local noundef zeroext i1 @_Z13compare_listsP20SinglyLinkedListNodeS0_(ptr noundef %0, ptr noundef %1) #0 {
  %3 = alloca i1, align 1
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  store ptr %0, ptr %4, align 8, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !5
  br label %6

6:                                                ; preds = %23, %2
  %7 = load ptr, ptr %4, align 8, !tbaa !5
  %8 = icmp ne ptr %7, null
  br i1 %8, label %9, label %12

9:                                                ; preds = %6
  %10 = load ptr, ptr %5, align 8, !tbaa !5
  %11 = icmp ne ptr %10, null
  br label %12

12:                                               ; preds = %9, %6
  %13 = phi i1 [ false, %6 ], [ %11, %9 ]
  br i1 %13, label %14, label %30

14:                                               ; preds = %12
  %15 = load ptr, ptr %4, align 8, !tbaa !5
  %16 = getelementptr inbounds %class.SinglyLinkedListNode, ptr %15, i32 0, i32 0
  %17 = load i32, ptr %16, align 8, !tbaa !9
  %18 = load ptr, ptr %5, align 8, !tbaa !5
  %19 = getelementptr inbounds %class.SinglyLinkedListNode, ptr %18, i32 0, i32 0
  %20 = load i32, ptr %19, align 8, !tbaa !9
  %21 = icmp ne i32 %17, %20
  br i1 %21, label %22, label %23

22:                                               ; preds = %14
  store i1 false, ptr %3, align 1
  br label %38

23:                                               ; preds = %14
  %24 = load ptr, ptr %4, align 8, !tbaa !5
  %25 = getelementptr inbounds %class.SinglyLinkedListNode, ptr %24, i32 0, i32 1
  %26 = load ptr, ptr %25, align 8, !tbaa !12
  store ptr %26, ptr %4, align 8, !tbaa !5
  %27 = load ptr, ptr %5, align 8, !tbaa !5
  %28 = getelementptr inbounds %class.SinglyLinkedListNode, ptr %27, i32 0, i32 1
  %29 = load ptr, ptr %28, align 8, !tbaa !12
  store ptr %29, ptr %5, align 8, !tbaa !5
  br label %6, !llvm.loop !13

30:                                               ; preds = %12
  %31 = load ptr, ptr %4, align 8, !tbaa !5
  %32 = icmp eq ptr %31, null
  br i1 %32, label %33, label %37

33:                                               ; preds = %30
  %34 = load ptr, ptr %5, align 8, !tbaa !5
  %35 = icmp eq ptr %34, null
  br i1 %35, label %36, label %37

36:                                               ; preds = %33
  store i1 true, ptr %3, align 1
  br label %38

37:                                               ; preds = %33, %30
  store i1 false, ptr %3, align 1
  br label %38

38:                                               ; preds = %37, %36, %22
  %39 = load i1, ptr %3, align 1
  ret i1 %39
}

attributes #0 = { 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" }

!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}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


; 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 ne ptr %0, null
  %4 = icmp ne ptr %1, null
  %5 = and i1 %3, %4
  br i1 %5, label %.lr.ph, label %._crit_edge

.lr.ph:                                           ; preds = %2, %8
  %.015 = phi ptr [ %12, %8 ], [ %1, %2 ]
  %.01014 = phi ptr [ %10, %8 ], [ %0, %2 ]
  %6 = load i32, ptr %.01014, align 8, !tbaa !5
  %7 = load i32, ptr %.015, align 8, !tbaa !5
  %.not = icmp eq i32 %6, %7
  br i1 %.not, label %8, label %.loopexit

8:                                                ; preds = %.lr.ph
  %9 = getelementptr inbounds i8, ptr %.01014, i64 8
  %10 = load ptr, ptr %9, align 8, !tbaa !11
  %11 = getelementptr inbounds i8, ptr %.015, i64 8
  %12 = load ptr, ptr %11, align 8, !tbaa !11
  %13 = icmp ne ptr %10, null
  %14 = icmp ne ptr %12, null
  %15 = select i1 %13, i1 %14, i1 false
  br i1 %15, label %.lr.ph, label %._crit_edge, !llvm.loop !12

._crit_edge:                                      ; preds = %8, %2
  %.010.lcssa = phi ptr [ %0, %2 ], [ %10, %8 ]
  %.0.lcssa = phi ptr [ %1, %2 ], [ %12, %8 ]
  %16 = icmp eq ptr %.010.lcssa, null
  %17 = icmp eq ptr %.0.lcssa, null
  %or.cond = select i1 %16, i1 %17, i1 false
  br label %.loopexit

.loopexit:                                        ; preds = %.lr.ph, %._crit_edge
  %.011 = phi i1 [ %or.cond, %._crit_edge ], [ false, %.lr.ph ]
  ret i1 %.011
}

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}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}


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