; LLVM IR from codemistic/Data-Structures-and-Algorithms :: CPP/LINKED LIST/SOME LEET CODE QUESTIONS/leetcode92.ll (Z17reverselinkedlistP4nodeS0_)

; 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
define dso_local noundef ptr @_Z17reverselinkedlistP4nodeS0_(ptr noundef %0, ptr noundef %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  %7 = alloca ptr, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  store ptr %1, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  store ptr null, ptr %5, align 8, !tbaa !5
  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 8, ptr %7) #2
  %9 = load ptr, ptr %6, align 8, !tbaa !5
  %10 = getelementptr inbounds %class.node, ptr %9, i32 0, i32 1
  %11 = load ptr, ptr %10, align 8, !tbaa !9
  store ptr %11, ptr %7, align 8, !tbaa !5
  br label %12

12:                                               ; preds = %23, %2
  %13 = load ptr, ptr %6, align 8, !tbaa !5
  %14 = icmp ne ptr %13, null
  br i1 %14, label %15, label %21

15:                                               ; preds = %12
  %16 = load ptr, ptr %3, align 8, !tbaa !5
  %17 = getelementptr inbounds %class.node, ptr %16, i32 0, i32 1
  %18 = load ptr, ptr %17, align 8, !tbaa !9
  %19 = load ptr, ptr %4, align 8, !tbaa !5
  %20 = icmp ne ptr %18, %19
  br label %21

21:                                               ; preds = %15, %12
  %22 = phi i1 [ false, %12 ], [ %20, %15 ]
  br i1 %22, label %23, label %32

23:                                               ; preds = %21
  %24 = load ptr, ptr %6, align 8, !tbaa !5
  %25 = getelementptr inbounds %class.node, ptr %24, i32 0, i32 1
  %26 = load ptr, ptr %25, align 8, !tbaa !9
  store ptr %26, ptr %7, align 8, !tbaa !5
  %27 = load ptr, ptr %5, align 8, !tbaa !5
  %28 = load ptr, ptr %6, align 8, !tbaa !5
  %29 = getelementptr inbounds %class.node, ptr %28, i32 0, i32 1
  store ptr %27, ptr %29, align 8, !tbaa !9
  %30 = load ptr, ptr %6, align 8, !tbaa !5
  store ptr %30, ptr %5, align 8, !tbaa !5
  %31 = load ptr, ptr %7, align 8, !tbaa !5
  store ptr %31, ptr %6, align 8, !tbaa !5
  br label %12, !llvm.loop !12

32:                                               ; preds = %21
  %33 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %33, ptr %3, align 8, !tbaa !5
  %34 = load ptr, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 8, 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
  ret ptr %34
}

; 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 8}
!10 = !{!"_ZTS4node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"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 noundef ptr @_Z17reverselinkedlistP4nodeS0_(ptr noundef %0, ptr noundef readnone %1) local_unnamed_addr #0 {
  %3 = getelementptr inbounds i8, ptr %0, i64 8
  %.not14 = icmp eq ptr %0, null
  br i1 %.not14, label %.critedge, label %.lr.ph

.lr.ph:                                           ; preds = %2, %5
  %.016 = phi ptr [ %7, %5 ], [ %0, %2 ]
  %.01215 = phi ptr [ %.016, %5 ], [ null, %2 ]
  %4 = load ptr, ptr %3, align 8, !tbaa !5
  %.not13 = icmp eq ptr %4, %1
  br i1 %.not13, label %.critedge, label %5

5:                                                ; preds = %.lr.ph
  %6 = getelementptr inbounds i8, ptr %.016, i64 8
  %7 = load ptr, ptr %6, align 8, !tbaa !5
  store ptr %.01215, ptr %6, align 8, !tbaa !5
  %.not = icmp eq ptr %7, null
  br i1 %.not, label %.critedge, label %.lr.ph, !llvm.loop !11

.critedge:                                        ; preds = %.lr.ph, %5, %2
  %.012.lcssa = phi ptr [ null, %2 ], [ %.016, %5 ], [ %.01215, %.lr.ph ]
  ret ptr %.012.lcssa
}

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, !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"}


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