; LLVM IR from priyankchheda/algorithms :: _other_languages/cpp/LinkedList (lengthOfLoop)

; 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.LinkedList::Node" = type { i32, ptr }

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z18detectAndCountLoopPN10LinkedList4NodeIiEE(ptr noundef %0) #1 {
  %2 = alloca i32, align 4
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = alloca ptr, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  %9 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %9, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %10, ptr %5, align 8, !tbaa !5
  br label %11

11:                                               ; preds = %34, %1
  %12 = load ptr, ptr %5, align 8, !tbaa !5
  %13 = icmp ne ptr %12, null
  br i1 %13, label %14, label %19

14:                                               ; preds = %11
  %15 = load ptr, ptr %5, align 8, !tbaa !5
  %16 = getelementptr inbounds %"struct.LinkedList::Node", ptr %15, i32 0, i32 1
  %17 = load ptr, ptr %16, align 8, !tbaa !9
  %18 = icmp ne ptr %17, null
  br label %19

19:                                               ; preds = %14, %11
  %20 = phi i1 [ false, %11 ], [ %18, %14 ]
  br i1 %20, label %21, label %35

21:                                               ; preds = %19
  %22 = load ptr, ptr %5, align 8, !tbaa !5
  %23 = getelementptr inbounds %"struct.LinkedList::Node", ptr %22, i32 0, i32 1
  %24 = load ptr, ptr %23, align 8, !tbaa !9
  %25 = getelementptr inbounds %"struct.LinkedList::Node", ptr %24, i32 0, i32 1
  %26 = load ptr, ptr %25, align 8, !tbaa !9
  store ptr %26, ptr %5, align 8, !tbaa !5
  %27 = load ptr, ptr %4, align 8, !tbaa !5
  %28 = getelementptr inbounds %"struct.LinkedList::Node", ptr %27, i32 0, i32 1
  %29 = load ptr, ptr %28, align 8, !tbaa !9
  store ptr %29, ptr %4, align 8, !tbaa !5
  %30 = load ptr, ptr %4, align 8, !tbaa !5
  %31 = load ptr, ptr %5, align 8, !tbaa !5
  %32 = icmp eq ptr %30, %31
  br i1 %32, label %33, label %34

33:                                               ; preds = %21
  br label %35

34:                                               ; preds = %21
  br label %11, !llvm.loop !12

35:                                               ; preds = %33, %19
  %36 = load ptr, ptr %5, align 8, !tbaa !5
  %37 = icmp eq ptr %36, null
  br i1 %37, label %43, label %38

38:                                               ; preds = %35
  %39 = load ptr, ptr %5, align 8, !tbaa !5
  %40 = getelementptr inbounds %"struct.LinkedList::Node", ptr %39, i32 0, i32 1
  %41 = load ptr, ptr %40, align 8, !tbaa !9
  %42 = icmp eq ptr %41, null
  br i1 %42, label %43, label %44

43:                                               ; preds = %38, %35
  store i32 0, ptr %2, align 4
  store i32 1, ptr %6, align 4
  br label %60

44:                                               ; preds = %38
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  store i32 1, ptr %7, align 4, !tbaa !14
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #2
  %45 = load ptr, ptr %4, align 8, !tbaa !5
  %46 = getelementptr inbounds %"struct.LinkedList::Node", ptr %45, i32 0, i32 1
  %47 = load ptr, ptr %46, align 8, !tbaa !9
  store ptr %47, ptr %8, align 8, !tbaa !5
  br label %48

48:                                               ; preds = %52, %44
  %49 = load ptr, ptr %8, align 8, !tbaa !5
  %50 = load ptr, ptr %4, align 8, !tbaa !5
  %51 = icmp ne ptr %49, %50
  br i1 %51, label %52, label %58

52:                                               ; preds = %48
  %53 = load ptr, ptr %8, align 8, !tbaa !5
  %54 = getelementptr inbounds %"struct.LinkedList::Node", ptr %53, i32 0, i32 1
  %55 = load ptr, ptr %54, align 8, !tbaa !9
  store ptr %55, ptr %8, align 8, !tbaa !5
  %56 = load i32, ptr %7, align 4, !tbaa !14
  %57 = add nsw i32 %56, 1
  store i32 %57, ptr %7, align 4, !tbaa !14
  br label %48, !llvm.loop !15

58:                                               ; preds = %48
  %59 = load i32, ptr %7, align 4, !tbaa !14
  store i32 %59, ptr %2, align 4
  store i32 1, ptr %6, align 4
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  br label %60

60:                                               ; preds = %58, %43
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  %61 = load i32, ptr %2, align 4
  ret i32 %61
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #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 = !{!"_ZTSN10LinkedList4NodeIiEE", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}
!14 = !{!11, !11, i64 0}
!15 = distinct !{!15, !13}


; 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 i32 @_Z18detectAndCountLoopPN10LinkedList4NodeIiEE(ptr noundef readonly %0) local_unnamed_addr #0 {
  %.old1.not = icmp eq ptr %0, null
  br i1 %.old1.not, label %.critedge.thread, label %.preheader35

.preheader35:                                     ; preds = %1, %4
  %.019 = phi ptr [ %8, %4 ], [ %0, %1 ]
  %.018 = phi ptr [ %6, %4 ], [ %0, %1 ]
  %2 = getelementptr inbounds i8, ptr %.018, i64 8
  %3 = load ptr, ptr %2, align 8, !tbaa !5
  %.not = icmp eq ptr %3, null
  br i1 %.not, label %.critedge.thread, label %4

4:                                                ; preds = %.preheader35
  %5 = getelementptr inbounds i8, ptr %3, i64 8
  %6 = load ptr, ptr %5, align 8, !tbaa !5
  %7 = getelementptr inbounds i8, ptr %.019, i64 8
  %8 = load ptr, ptr %7, align 8, !tbaa !5
  %9 = icmp ne ptr %8, %6
  %10 = icmp ne ptr %6, null
  %or.cond = and i1 %10, %9
  br i1 %or.cond, label %.preheader35, label %.critedge, !llvm.loop !11

.critedge:                                        ; preds = %4
  %11 = icmp eq ptr %6, null
  br i1 %11, label %.critedge.thread, label %.critedge.thread30

.critedge.thread30:                               ; preds = %.critedge
  %.phi.trans.insert = getelementptr inbounds i8, ptr %6, i64 8
  %.pre = load ptr, ptr %.phi.trans.insert, align 8, !tbaa !5
  %12 = icmp eq ptr %.pre, null
  br i1 %12, label %.critedge.thread, label %.preheader

.preheader:                                       ; preds = %.critedge.thread30, %.preheader
  %.017 = phi i32 [ %13, %.preheader ], [ 1, %.critedge.thread30 ]
  %.120.pn = phi ptr [ %.0, %.preheader ], [ %8, %.critedge.thread30 ]
  %.0.in = getelementptr inbounds i8, ptr %.120.pn, i64 8
  %.0 = load ptr, ptr %.0.in, align 8, !tbaa !5
  %.not27 = icmp eq ptr %.0, %8
  %13 = add nuw nsw i32 %.017, 1
  br i1 %.not27, label %.critedge.thread, label %.preheader, !llvm.loop !13

.critedge.thread:                                 ; preds = %.preheader35, %.preheader, %1, %.critedge, %.critedge.thread30
  %.021 = phi i32 [ 0, %.critedge.thread30 ], [ 0, %.critedge ], [ 0, %1 ], [ %.017, %.preheader ], [ 0, %.preheader35 ]
  ret i32 %.021
}

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, !10, i64 8}
!6 = !{!"_ZTSN10LinkedList4NodeIiEE", !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 = distinct !{!13, !12}


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