; LLVM IR from Leet-Us-Code/DSA-A-Z-Practice :: Sid's Levels/Level - 1/LinkedList/reverseLinkedList1.ll (Z11reverseListP4Node)

; 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"

%struct.Node = type { i32, ptr }

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i32 @_Z7getSizeP4Node(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
declare dso_local noundef ptr @_Z8getAtIndP4Nodei(ptr noundef, i32 noundef) #0

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef ptr @_Z11reverseListP4Node(ptr noundef %0) #0 {
  %2 = alloca ptr, align 8
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  %7 = alloca i32, align 4
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #2
  %8 = load ptr, ptr %2, align 8, !tbaa !5
  %9 = call noundef i32 @_Z7getSizeP4Node(ptr noundef %8)
  %10 = sub nsw i32 %9, 1
  store i32 %10, ptr %3, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  store i32 0, ptr %4, align 4, !tbaa !9
  br label %11

11:                                               ; preds = %15, %1
  %12 = load i32, ptr %4, align 4, !tbaa !9
  %13 = load i32, ptr %3, align 4, !tbaa !9
  %14 = icmp sle i32 %12, %13
  br i1 %14, label %15, label %37

15:                                               ; preds = %11
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  %16 = load ptr, ptr %2, align 8, !tbaa !5
  %17 = load i32, ptr %4, align 4, !tbaa !9
  %18 = call noundef ptr @_Z8getAtIndP4Nodei(ptr noundef %16, i32 noundef %17)
  store ptr %18, ptr %5, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  %19 = load ptr, ptr %2, align 8, !tbaa !5
  %20 = load i32, ptr %3, align 4, !tbaa !9
  %21 = call noundef ptr @_Z8getAtIndP4Nodei(ptr noundef %19, i32 noundef %20)
  store ptr %21, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  %22 = load ptr, ptr %5, align 8, !tbaa !5
  %23 = getelementptr inbounds %struct.Node, ptr %22, i32 0, i32 0
  %24 = load i32, ptr %23, align 8, !tbaa !11
  store i32 %24, ptr %7, align 4, !tbaa !9
  %25 = load ptr, ptr %6, align 8, !tbaa !5
  %26 = getelementptr inbounds %struct.Node, ptr %25, i32 0, i32 0
  %27 = load i32, ptr %26, align 8, !tbaa !11
  %28 = load ptr, ptr %5, align 8, !tbaa !5
  %29 = getelementptr inbounds %struct.Node, ptr %28, i32 0, i32 0
  store i32 %27, ptr %29, align 8, !tbaa !11
  %30 = load i32, ptr %7, align 4, !tbaa !9
  %31 = load ptr, ptr %6, align 8, !tbaa !5
  %32 = getelementptr inbounds %struct.Node, ptr %31, i32 0, i32 0
  store i32 %30, ptr %32, align 8, !tbaa !11
  %33 = load i32, ptr %4, align 4, !tbaa !9
  %34 = add nsw i32 %33, 1
  store i32 %34, ptr %4, align 4, !tbaa !9
  %35 = load i32, ptr %3, align 4, !tbaa !9
  %36 = add nsw i32 %35, -1
  store i32 %36, ptr %3, align 4, !tbaa !9
  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 8, ptr %5) #2
  br label %11, !llvm.loop !13

37:                                               ; preds = %11
  %38 = load ptr, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #2
  ret ptr %38
}

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, !10, i64 0}
!12 = !{!"_ZTS4Node", !10, i64 0, !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 nounwind uwtable
declare dso_local noundef i32 @_Z7getSizeP4Node(ptr noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef ptr @_Z8getAtIndP4Nodei(ptr noundef, i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef ptr @_Z11reverseListP4Node(ptr noundef returned %0) local_unnamed_addr #0 {
  %2 = tail call noundef i32 @_Z7getSizeP4Node(ptr noundef %0)
  %.not.not15 = icmp sgt i32 %2, 0
  br i1 %.not.not15, label %.lr.ph, label %._crit_edge

.lr.ph:                                           ; preds = %1, %.lr.ph
  %.0.in17 = phi i32 [ %.0, %.lr.ph ], [ %2, %1 ]
  %.01416 = phi i32 [ %7, %.lr.ph ], [ 0, %1 ]
  %.0 = add nsw i32 %.0.in17, -1
  %3 = tail call noundef ptr @_Z8getAtIndP4Nodei(ptr noundef %0, i32 noundef %.01416)
  %4 = tail call noundef ptr @_Z8getAtIndP4Nodei(ptr noundef %0, i32 noundef %.0)
  %5 = load i32, ptr %3, align 8, !tbaa !5
  %6 = load i32, ptr %4, align 8, !tbaa !5
  store i32 %6, ptr %3, align 8, !tbaa !5
  store i32 %5, ptr %4, align 8, !tbaa !5
  %7 = add nuw nsw i32 %.01416, 1
  %.not.not = icmp slt i32 %7, %.0
  br i1 %.not.not, label %.lr.ph, label %._crit_edge, !llvm.loop !11

._crit_edge:                                      ; preds = %.lr.ph, %1
  ret ptr %0
}

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, !7, i64 0}
!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"}


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