; LLVM IR from ahampriyanshu/algo-ds-101 :: Data-Structures/LinkedList/Singly_Linked_List (LinkedListAndOperations)

; 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.std::basic_ostream" = type { ptr, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }
%struct.list = type { i32, ptr }

@head = external dso_local global ptr, align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8

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

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) #1

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

; Function Attrs: mustprogress uwtable
define dso_local void @_Z17get_max_from_listv() #2 {
  %1 = alloca ptr, align 8
  %2 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 8, ptr %1) #3
  %3 = load ptr, ptr @head, align 8, !tbaa !5
  store ptr %3, ptr %1, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #3
  %4 = load ptr, ptr %1, align 8, !tbaa !5
  %5 = getelementptr inbounds %struct.list, ptr %4, i32 0, i32 0
  %6 = load i32, ptr %5, align 8, !tbaa !9
  store i32 %6, ptr %2, align 4, !tbaa !12
  %7 = load ptr, ptr @head, align 8, !tbaa !5
  %8 = icmp eq ptr %7, null
  br i1 %8, label %9, label %11

9:                                                ; preds = %0
  %10 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef 0)
  br label %30

11:                                               ; preds = %0
  br label %12

12:                                               ; preds = %25, %11
  %13 = load ptr, ptr %1, align 8, !tbaa !5
  %14 = icmp ne ptr %13, null
  br i1 %14, label %15, label %29

15:                                               ; preds = %12
  %16 = load i32, ptr %2, align 4, !tbaa !12
  %17 = load ptr, ptr %1, align 8, !tbaa !5
  %18 = getelementptr inbounds %struct.list, ptr %17, i32 0, i32 0
  %19 = load i32, ptr %18, align 8, !tbaa !9
  %20 = icmp slt i32 %16, %19
  br i1 %20, label %21, label %25

21:                                               ; preds = %15
  %22 = load ptr, ptr %1, align 8, !tbaa !5
  %23 = getelementptr inbounds %struct.list, ptr %22, i32 0, i32 0
  %24 = load i32, ptr %23, align 8, !tbaa !9
  store i32 %24, ptr %2, align 4, !tbaa !12
  br label %25

25:                                               ; preds = %21, %15
  %26 = load ptr, ptr %1, align 8, !tbaa !5
  %27 = getelementptr inbounds %struct.list, ptr %26, i32 0, i32 1
  %28 = load ptr, ptr %27, align 8, !tbaa !13
  store ptr %28, ptr %1, align 8, !tbaa !5
  br label %12, !llvm.loop !14

29:                                               ; preds = %12
  br label %30

30:                                               ; preds = %29, %9
  %31 = load i32, ptr %2, align 4, !tbaa !12
  %32 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %31)
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %1) #3
  ret void
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { "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 = { mustprogress 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 #3 = { 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, !11, i64 0}
!10 = !{!"_ZTS4list", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = !{!11, !11, i64 0}
!13 = !{!10, !6, i64 8}
!14 = distinct !{!14, !15}
!15 = !{!"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"

%"class.std::basic_ostream" = type { ptr, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }

@head = external dso_local local_unnamed_addr global ptr, align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
define dso_local void @_Z17get_max_from_listv() local_unnamed_addr #1 {
  %1 = load ptr, ptr @head, align 8, !tbaa !5
  %2 = load i32, ptr %1, align 8, !tbaa !9
  br label %3

3:                                                ; preds = %0, %3
  %.09 = phi i32 [ %2, %0 ], [ %spec.select, %3 ]
  %.068 = phi ptr [ %1, %0 ], [ %6, %3 ]
  %4 = load i32, ptr %.068, align 8, !tbaa !9
  %spec.select = tail call i32 @llvm.smax.i32(i32 %.09, i32 %4)
  %5 = getelementptr inbounds i8, ptr %.068, i64 8
  %6 = load ptr, ptr %5, align 8, !tbaa !12
  %.not = icmp eq ptr %6, null
  br i1 %.not, label %7, label %3, !llvm.loop !13

7:                                                ; preds = %3
  %8 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %spec.select)
  ret void
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.smax.i32(i32, i32) #2

attributes #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 = { mustprogress 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 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }

!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, !11, i64 0}
!10 = !{!"_ZTS4list", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 8}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


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