; LLVM IR from HarshCasper/NeoAlgo :: C-Plus-Plus/ds/alternate_merging_of_linked_list.ll (Z10merge_listP4nodeS0_i)

; 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.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
declare dso_local noundef ptr @_Z8new_listi(i32 noundef) #1

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z10merge_listP4nodeS0_i(ptr noundef %0, ptr noundef %1, i32 noundef %2) #1 {
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  %7 = alloca ptr, align 8
  %8 = alloca ptr, align 8
  %9 = alloca ptr, align 8
  store ptr %0, ptr %4, align 8, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !5
  store i32 %2, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #2
  store ptr null, ptr %7, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #2
  %10 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %10, ptr %8, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %9) #2
  %11 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %11, ptr %9, align 8, !tbaa !5
  br label %12

12:                                               ; preds = %15, %3
  %13 = load i32, ptr %6, align 4, !tbaa !9
  %14 = icmp ne i32 %13, 0
  br i1 %14, label %15, label %32

15:                                               ; preds = %12
  %16 = load ptr, ptr %8, align 8, !tbaa !5
  %17 = getelementptr inbounds %struct.node, ptr %16, i32 0, i32 0
  %18 = load i32, ptr %17, align 8, !tbaa !11
  %19 = call noundef ptr @_Z8new_listi(i32 noundef %18)
  store ptr %19, ptr %7, align 8, !tbaa !5
  %20 = load ptr, ptr %9, align 8, !tbaa !5
  %21 = getelementptr inbounds %struct.node, ptr %20, i32 0, i32 0
  %22 = load i32, ptr %21, align 8, !tbaa !11
  %23 = call noundef ptr @_Z8new_listi(i32 noundef %22)
  store ptr %23, ptr %7, align 8, !tbaa !5
  %24 = load ptr, ptr %8, align 8, !tbaa !5
  %25 = getelementptr inbounds %struct.node, ptr %24, i32 0, i32 1
  %26 = load ptr, ptr %25, align 8, !tbaa !13
  store ptr %26, ptr %8, align 8, !tbaa !5
  %27 = load ptr, ptr %9, align 8, !tbaa !5
  %28 = getelementptr inbounds %struct.node, ptr %27, i32 0, i32 1
  %29 = load ptr, ptr %28, align 8, !tbaa !13
  store ptr %29, ptr %9, align 8, !tbaa !5
  %30 = load i32, ptr %6, align 4, !tbaa !9
  %31 = add nsw i32 %30, -1
  store i32 %31, ptr %6, align 4, !tbaa !9
  br label %12, !llvm.loop !14

32:                                               ; preds = %12
  %33 = load ptr, ptr %7, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 8, ptr %9) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #2
  ret ptr %33
}

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, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!12, !10, i64 0}
!12 = !{!"_ZTS4node", !10, i64 0, !6, i64 8}
!13 = !{!12, !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"

; Function Attrs: mustprogress uwtable
declare dso_local noundef ptr @_Z8new_listi(i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z10merge_listP4nodeS0_i(ptr nocapture noundef readonly %0, ptr nocapture noundef readonly %1, i32 noundef %2) local_unnamed_addr #0 {
  %.not11 = icmp eq i32 %2, 0
  br i1 %.not11, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %3, %.lr.ph
  %.014 = phi ptr [ %11, %.lr.ph ], [ %1, %3 ]
  %.0813 = phi ptr [ %9, %.lr.ph ], [ %0, %3 ]
  %.01012 = phi i32 [ %12, %.lr.ph ], [ %2, %3 ]
  %4 = load i32, ptr %.0813, align 8, !tbaa !5
  %5 = tail call noundef ptr @_Z8new_listi(i32 noundef %4)
  %6 = load i32, ptr %.014, align 8, !tbaa !5
  %7 = tail call noundef ptr @_Z8new_listi(i32 noundef %6)
  %8 = getelementptr inbounds i8, ptr %.0813, i64 8
  %9 = load ptr, ptr %8, align 8, !tbaa !11
  %10 = getelementptr inbounds i8, ptr %.014, i64 8
  %11 = load ptr, ptr %10, align 8, !tbaa !11
  %12 = add nsw i32 %.01012, -1
  %.not = icmp eq i32 %12, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !12

._crit_edge:                                      ; preds = %.lr.ph, %3
  %.09.lcssa = phi ptr [ null, %3 ], [ %7, %.lr.ph ]
  ret ptr %.09.lcssa
}

attributes #0 = { 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" }

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


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