; LLVM IR from Lakhankumawat/LearnCPP :: L-LinkedList/D-DoublyLinkedList/Reverse.ll (Z7reversePP4Node)

; 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, ptr }

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z7reversePP4Node(ptr noundef %0) #0 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #2
  store ptr null, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  %5 = load ptr, ptr %2, align 8, !tbaa !5
  %6 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %6, ptr %4, align 8, !tbaa !5
  br label %7

7:                                                ; preds = %10, %1
  %8 = load ptr, ptr %4, align 8, !tbaa !5
  %9 = icmp ne ptr %8, null
  br i1 %9, label %10, label %25

10:                                               ; preds = %7
  %11 = load ptr, ptr %4, align 8, !tbaa !5
  %12 = getelementptr inbounds %class.Node, ptr %11, i32 0, i32 2
  %13 = load ptr, ptr %12, align 8, !tbaa !9
  store ptr %13, ptr %3, align 8, !tbaa !5
  %14 = load ptr, ptr %4, align 8, !tbaa !5
  %15 = getelementptr inbounds %class.Node, ptr %14, i32 0, i32 1
  %16 = load ptr, ptr %15, align 8, !tbaa !12
  %17 = load ptr, ptr %4, align 8, !tbaa !5
  %18 = getelementptr inbounds %class.Node, ptr %17, i32 0, i32 2
  store ptr %16, ptr %18, align 8, !tbaa !9
  %19 = load ptr, ptr %3, align 8, !tbaa !5
  %20 = load ptr, ptr %4, align 8, !tbaa !5
  %21 = getelementptr inbounds %class.Node, ptr %20, i32 0, i32 1
  store ptr %19, ptr %21, align 8, !tbaa !12
  %22 = load ptr, ptr %4, align 8, !tbaa !5
  %23 = getelementptr inbounds %class.Node, ptr %22, i32 0, i32 2
  %24 = load ptr, ptr %23, align 8, !tbaa !9
  store ptr %24, ptr %4, align 8, !tbaa !5
  br label %7, !llvm.loop !13

25:                                               ; preds = %7
  %26 = load ptr, ptr %3, align 8, !tbaa !5
  %27 = icmp ne ptr %26, null
  br i1 %27, label %28, label %33

28:                                               ; preds = %25
  %29 = load ptr, ptr %3, align 8, !tbaa !5
  %30 = getelementptr inbounds %class.Node, ptr %29, i32 0, i32 2
  %31 = load ptr, ptr %30, align 8, !tbaa !9
  %32 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %31, ptr %32, align 8, !tbaa !5
  br label %33

33:                                               ; preds = %28, %25
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #2
  ret void
}

; 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

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, !6, i64 16}
!10 = !{!"_ZTS4Node", !11, i64 0, !6, i64 8, !6, i64 16}
!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 memory(readwrite, inaccessiblemem: none) uwtable
define dso_local void @_Z7reversePP4Node(ptr nocapture noundef %0) local_unnamed_addr #0 {
  %.0.pr = load ptr, ptr %0, align 8, !tbaa !5
  %.not13 = icmp eq ptr %.0.pr, null
  br i1 %.not13, label %._crit_edge.thread, label %.lr.ph

.lr.ph:                                           ; preds = %1, %.lr.ph
  %.014 = phi ptr [ %5, %.lr.ph ], [ %.0.pr, %1 ]
  %2 = getelementptr inbounds i8, ptr %.014, i64 16
  %3 = load ptr, ptr %2, align 8, !tbaa !9
  %4 = getelementptr inbounds i8, ptr %.014, i64 8
  %5 = load ptr, ptr %4, align 8, !tbaa !12
  store ptr %5, ptr %2, align 8, !tbaa !9
  store ptr %3, ptr %4, align 8, !tbaa !12
  %.not = icmp eq ptr %5, null
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !13

._crit_edge:                                      ; preds = %.lr.ph
  %.not12 = icmp eq ptr %3, null
  br i1 %.not12, label %._crit_edge.thread, label %6

6:                                                ; preds = %._crit_edge
  %7 = getelementptr inbounds i8, ptr %3, i64 16
  %8 = load ptr, ptr %7, align 8, !tbaa !9
  store ptr %8, ptr %0, align 8, !tbaa !5
  br label %._crit_edge.thread

._crit_edge.thread:                               ; preds = %1, %6, %._crit_edge
  ret void
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind memory(readwrite, 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, !6, i64 0}
!6 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !6, i64 16}
!10 = !{!"_ZTS4Node", !11, i64 0, !6, i64 8, !6, i64 16}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 8}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


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