; LLVM IR from ahampriyanshu/algo-ds-101 :: Data-Structures/LinkedList/Singly_Linked_List (merge2sortedlinkedlists)

; 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: mustprogress uwtable
define dso_local noundef ptr @_Z10createListPii(ptr noundef %0, i32 noundef %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  %7 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #3
  %8 = call noalias noundef nonnull ptr @_Znwm(i64 noundef 16) #4
  store ptr %8, ptr %5, align 8, !tbaa !5
  store ptr %8, ptr %6, align 8, !tbaa !5
  %9 = load ptr, ptr %3, align 8, !tbaa !5
  %10 = getelementptr inbounds i32, ptr %9, i64 0
  %11 = load i32, ptr %10, align 4, !tbaa !9
  %12 = load ptr, ptr %5, align 8, !tbaa !5
  %13 = getelementptr inbounds %struct.node, ptr %12, i32 0, i32 0
  store i32 %11, ptr %13, align 8, !tbaa !11
  %14 = load ptr, ptr %5, align 8, !tbaa !5
  %15 = getelementptr inbounds %struct.node, ptr %14, i32 0, i32 1
  store ptr null, ptr %15, align 8, !tbaa !13
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #3
  store i32 1, ptr %7, align 4, !tbaa !9
  br label %16

16:                                               ; preds = %37, %2
  %17 = load i32, ptr %7, align 4, !tbaa !9
  %18 = load i32, ptr %4, align 4, !tbaa !9
  %19 = icmp slt i32 %17, %18
  br i1 %19, label %21, label %20

20:                                               ; preds = %16
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #3
  br label %40

21:                                               ; preds = %16
  %22 = call noalias noundef nonnull ptr @_Znwm(i64 noundef 16) #4
  %23 = load ptr, ptr %6, align 8, !tbaa !5
  %24 = getelementptr inbounds %struct.node, ptr %23, i32 0, i32 1
  store ptr %22, ptr %24, align 8, !tbaa !13
  %25 = load ptr, ptr %6, align 8, !tbaa !5
  %26 = getelementptr inbounds %struct.node, ptr %25, i32 0, i32 1
  %27 = load ptr, ptr %26, align 8, !tbaa !13
  store ptr %27, ptr %6, align 8, !tbaa !5
  %28 = load ptr, ptr %3, align 8, !tbaa !5
  %29 = load i32, ptr %7, align 4, !tbaa !9
  %30 = sext i32 %29 to i64
  %31 = getelementptr inbounds i32, ptr %28, i64 %30
  %32 = load i32, ptr %31, align 4, !tbaa !9
  %33 = load ptr, ptr %6, align 8, !tbaa !5
  %34 = getelementptr inbounds %struct.node, ptr %33, i32 0, i32 0
  store i32 %32, ptr %34, align 8, !tbaa !11
  %35 = load ptr, ptr %6, align 8, !tbaa !5
  %36 = getelementptr inbounds %struct.node, ptr %35, i32 0, i32 1
  store ptr null, ptr %36, align 8, !tbaa !13
  br label %37

37:                                               ; preds = %21
  %38 = load i32, ptr %7, align 4, !tbaa !9
  %39 = add nsw i32 %38, 1
  store i32 %39, ptr %7, align 4, !tbaa !9
  br label %16, !llvm.loop !14

40:                                               ; preds = %20
  %41 = load ptr, ptr %5, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #3
  ret ptr %41
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nobuiltin allocsize(0)
declare noundef nonnull ptr @_Znwm(i64 noundef) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

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" }
attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { nobuiltin allocsize(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 }
attributes #4 = { builtin allocsize(0) }

!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
define dso_local noalias noundef nonnull ptr @_Z10createListPii(ptr nocapture noundef readonly %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = tail call noalias noundef nonnull dereferenceable(16) ptr @_Znwm(i64 noundef 16) #2
  %4 = load i32, ptr %0, align 4, !tbaa !5
  store i32 %4, ptr %3, align 8, !tbaa !9
  %5 = getelementptr inbounds i8, ptr %3, i64 8
  store ptr null, ptr %5, align 8, !tbaa !12
  %6 = icmp sgt i32 %1, 1
  br i1 %6, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %2
  %wide.trip.count = zext nneg i32 %1 to i64
  br label %.lr.ph

._crit_edge:                                      ; preds = %.lr.ph, %2
  ret ptr %3

.lr.ph:                                           ; preds = %.lr.ph.preheader, %.lr.ph
  %indvars.iv = phi i64 [ 1, %.lr.ph.preheader ], [ %indvars.iv.next, %.lr.ph ]
  %.01213 = phi ptr [ %3, %.lr.ph.preheader ], [ %7, %.lr.ph ]
  %7 = tail call noalias noundef nonnull dereferenceable(16) ptr @_Znwm(i64 noundef 16) #2
  %8 = getelementptr inbounds i8, ptr %.01213, i64 8
  store ptr %7, ptr %8, align 8, !tbaa !12
  %9 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv
  %10 = load i32, ptr %9, align 4, !tbaa !5
  store i32 %10, ptr %7, align 8, !tbaa !9
  %11 = getelementptr inbounds i8, ptr %7, i64 8
  store ptr null, ptr %11, align 8, !tbaa !12
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %wide.trip.count
  br i1 %exitcond.not, label %._crit_edge, label %.lr.ph, !llvm.loop !13
}

; Function Attrs: nobuiltin allocsize(0)
declare noundef nonnull ptr @_Znwm(i64 noundef) local_unnamed_addr #1

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" }
attributes #1 = { nobuiltin allocsize(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 = { builtin allocsize(0) }

!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 = !{!10, !6, i64 0}
!10 = !{!"_ZTS4node", !6, i64 0, !11, i64 8}
!11 = !{!"any pointer", !7, i64 0}
!12 = !{!10, !11, i64 8}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


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