; LLVM IR from PacktPublishing/CPP-Data-Structures-and-Algorithms :: Chapter02/Std_List/main.ll (Z11GetIteratorSt14_List_iteratorIiEi)

; 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.std::_List_iterator" = type { ptr }

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

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

; Function Attrs: mustprogress nounwind uwtable
define dso_local ptr @_Z11GetIteratorSt14_List_iteratorIiEi(ptr %0, i32 noundef %1) #1 {
  %3 = alloca %"struct.std::_List_iterator", align 8
  %4 = alloca %"struct.std::_List_iterator", align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = getelementptr inbounds %"struct.std::_List_iterator", ptr %4, i32 0, i32 0
  store ptr %0, ptr %7, align 8
  store i32 %1, ptr %5, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #3
  store i32 0, ptr %6, align 4, !tbaa !5
  br label %8

8:                                                ; preds = %14, %2
  %9 = load i32, ptr %6, align 4, !tbaa !5
  %10 = load i32, ptr %5, align 4, !tbaa !5
  %11 = icmp slt i32 %9, %10
  br i1 %11, label %13, label %12

12:                                               ; preds = %8
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #3
  br label %18

13:                                               ; preds = %8
  br label %14

14:                                               ; preds = %13
  %15 = load i32, ptr %6, align 4, !tbaa !5
  %16 = add nsw i32 %15, 1
  store i32 %16, ptr %6, align 4, !tbaa !5
  %17 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSt14_List_iteratorIiEppEv(ptr noundef nonnull align 8 dereferenceable(8) %4) #3
  br label %8, !llvm.loop !9

18:                                               ; preds = %12
  call void @llvm.memcpy.p0.p0.i64(ptr align 8 %3, ptr align 8 %4, i64 8, i1 false), !tbaa.struct !11
  %19 = getelementptr inbounds %"struct.std::_List_iterator", ptr %3, i32 0, i32 0
  %20 = load ptr, ptr %19, align 8
  ret ptr %20
}

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 8 dereferenceable(8) ptr @_ZNSt14_List_iteratorIiEppEv(ptr noundef nonnull align 8 dereferenceable(8)) #1 align 2

; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
declare void @llvm.memcpy.p0.p0.i64(ptr noalias nocapture writeonly, ptr noalias nocapture readonly, i64, i1 immarg) #2

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 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}
!11 = !{i64 0, i64 8, !12}
!12 = !{!13, !13, i64 0}
!13 = !{!"any pointer", !7, i64 0}


; 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"

%"struct.std::_List_iterator" = type { ptr }

; Function Attrs: mustprogress nounwind uwtable
define dso_local ptr @_Z11GetIteratorSt14_List_iteratorIiEi(ptr %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = alloca %"struct.std::_List_iterator", align 8
  store ptr %0, ptr %3, align 8
  %4 = icmp sgt i32 %1, 0
  br i1 %4, label %.lr.ph, label %._crit_edge

._crit_edge.loopexit:                             ; preds = %.lr.ph
  %.sroa.0.0.copyload.pre = load ptr, ptr %3, align 8, !tbaa !5
  br label %._crit_edge

._crit_edge:                                      ; preds = %._crit_edge.loopexit, %2
  %.sroa.0.0.copyload = phi ptr [ %.sroa.0.0.copyload.pre, %._crit_edge.loopexit ], [ %0, %2 ]
  ret ptr %.sroa.0.0.copyload

.lr.ph:                                           ; preds = %2, %.lr.ph
  %.03 = phi i32 [ %5, %.lr.ph ], [ 0, %2 ]
  %5 = add nuw nsw i32 %.03, 1
  %6 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSt14_List_iteratorIiEppEv(ptr noundef nonnull align 8 dereferenceable(8) %3) #1
  %exitcond.not = icmp eq i32 %5, %1
  br i1 %exitcond.not, label %._crit_edge.loopexit, label %.lr.ph, !llvm.loop !9
}

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 8 dereferenceable(8) ptr @_ZNSt14_List_iteratorIiEppEv(ptr noundef nonnull align 8 dereferenceable(8)) local_unnamed_addr #0 align 2

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 = { 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 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass