; LLVM IR from HarshCasper/NeoAlgo :: C-Plus-Plus/ds/Append_Last_N_To_First.ll (Z7length1P4Node)

; 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: 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 uwtable
define dso_local noundef i32 @_Z7length1P4Node(ptr noundef %0) #1 {
  %2 = alloca i32, align 4
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  %5 = load ptr, ptr %3, align 8, !tbaa !5
  %6 = icmp eq ptr %5, null
  br i1 %6, label %7, label %8

7:                                                ; preds = %1
  store i32 0, ptr %2, align 4
  br label %21

8:                                                ; preds = %1
  %9 = load ptr, ptr %3, align 8, !tbaa !5
  %10 = getelementptr inbounds %class.Node, ptr %9, i32 0, i32 1
  %11 = load ptr, ptr %10, align 8, !tbaa !9
  %12 = icmp eq ptr %11, null
  br i1 %12, label %13, label %14

13:                                               ; preds = %8
  store i32 1, ptr %2, align 4
  br label %21

14:                                               ; preds = %8
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  %15 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %15, ptr %4, align 8, !tbaa !5
  %16 = load ptr, ptr %4, 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 = call noundef i32 @_Z7length1P4Node(ptr noundef %18)
  %20 = add nsw i32 1, %19
  store i32 %20, ptr %2, align 4
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  br label %21

21:                                               ; preds = %14, %13, %7
  %22 = load i32, ptr %2, align 4
  ret i32 %22
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = { 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}


; 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 @_Z7length1P4Node(ptr noundef readonly %0) local_unnamed_addr #0 {
  %2 = icmp eq ptr %0, null
  br i1 %2, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %1, %.lr.ph
  %.tr7 = phi ptr [ %4, %.lr.ph ], [ %0, %1 ]
  %accumulator.tr6 = phi i32 [ %6, %.lr.ph ], [ 0, %1 ]
  %3 = getelementptr inbounds i8, ptr %.tr7, i64 8
  %4 = load ptr, ptr %3, align 8, !tbaa !5
  %5 = icmp eq ptr %4, null
  %6 = add nuw nsw i32 %accumulator.tr6, 1
  br i1 %5, label %._crit_edge.loopexit, label %.lr.ph

._crit_edge.loopexit:                             ; preds = %.lr.ph
  %7 = add nuw nsw i32 %accumulator.tr6, 1
  br label %._crit_edge

._crit_edge:                                      ; preds = %._crit_edge.loopexit, %1
  %accumulator.ret.tr = phi i32 [ 0, %1 ], [ %7, %._crit_edge.loopexit ]
  ret i32 %accumulator.ret.tr
}

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 = !{!"_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}


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