; LLVM IR from edualgo/dsa-code-store :: Linked-List/Linked-List-master/Source.ll (Z14getNthFromLastP4Nodei)

; 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.Node = type { i32, ptr }

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i32 @_Z6lengthP4Node(ptr noundef) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z14getNthFromLastP4Nodei(ptr noundef %0, i32 noundef %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca ptr, align 8
  %7 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  store i32 0, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  %8 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %8, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  %9 = load ptr, ptr %3, align 8, !tbaa !5
  %10 = call noundef i32 @_Z6lengthP4Node(ptr noundef %9)
  store i32 %10, ptr %7, align 4, !tbaa !9
  br label %11

11:                                               ; preds = %22, %2
  %12 = load ptr, ptr %6, align 8, !tbaa !5
  %13 = icmp ne ptr %12, null
  br i1 %13, label %14, label %20

14:                                               ; preds = %11
  %15 = load i32, ptr %5, align 4, !tbaa !9
  %16 = load i32, ptr %7, align 4, !tbaa !9
  %17 = load i32, ptr %4, align 4, !tbaa !9
  %18 = sub nsw i32 %16, %17
  %19 = icmp slt i32 %15, %18
  br label %20

20:                                               ; preds = %14, %11
  %21 = phi i1 [ false, %11 ], [ %19, %14 ]
  br i1 %21, label %22, label %28

22:                                               ; preds = %20
  %23 = load ptr, ptr %6, align 8, !tbaa !5
  %24 = getelementptr inbounds %class.Node, ptr %23, i32 0, i32 1
  %25 = load ptr, ptr %24, align 8, !tbaa !11
  store ptr %25, ptr %6, align 8, !tbaa !5
  %26 = load i32, ptr %5, align 4, !tbaa !9
  %27 = add nsw i32 %26, 1
  store i32 %27, ptr %5, align 4, !tbaa !9
  br label %11, !llvm.loop !13

28:                                               ; preds = %20
  %29 = load ptr, ptr %6, align 8, !tbaa !5
  %30 = getelementptr inbounds %class.Node, ptr %29, i32 0, i32 0
  %31 = load i32, ptr %30, align 8, !tbaa !15
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  ret i32 %31
}

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" }
attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!12, !6, i64 8}
!12 = !{!"_ZTS4Node", !10, i64 0, !6, i64 8}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}
!15 = !{!12, !10, i64 0}


; 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 nounwind uwtable
declare dso_local noundef i32 @_Z6lengthP4Node(ptr noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z14getNthFromLastP4Nodei(ptr noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = tail call noundef i32 @_Z6lengthP4Node(ptr noundef %0)
  %4 = sub nsw i32 %3, %1
  %.not10 = icmp ne ptr %0, null
  %5 = icmp sgt i32 %4, 0
  %or.cond11 = select i1 %.not10, i1 %5, i1 false
  br i1 %or.cond11, label %.lr.ph, label %.critedge

.lr.ph:                                           ; preds = %2, %.lr.ph
  %.013 = phi i32 [ %8, %.lr.ph ], [ 0, %2 ]
  %.0812 = phi ptr [ %7, %.lr.ph ], [ %0, %2 ]
  %6 = getelementptr inbounds i8, ptr %.0812, i64 8
  %7 = load ptr, ptr %6, align 8, !tbaa !5
  %8 = add nuw nsw i32 %.013, 1
  %.not = icmp ne ptr %7, null
  %9 = icmp slt i32 %8, %4
  %or.cond = select i1 %.not, i1 %9, i1 false
  br i1 %or.cond, label %.lr.ph, label %.critedge, !llvm.loop !11

.critedge:                                        ; preds = %.lr.ph, %2
  %.08.lcssa = phi ptr [ %0, %2 ], [ %7, %.lr.ph ]
  %10 = load i32, ptr %.08.lcssa, align 8, !tbaa !13
  ret i32 %10
}

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, !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 = !{!6, !7, i64 0}


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