; LLVM IR from MakeContributions/DSA :: algorithms/C/linked-lists (merge-two-linkedlists)

; 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: nounwind uwtable
define dso_local ptr @merge(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
  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
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #2
  %9 = load i32, ptr %6, align 4, !tbaa !9
  %10 = icmp eq i32 %9, 1
  br i1 %10, label %11, label %14

11:                                               ; preds = %3
  %12 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %12, ptr %7, align 8, !tbaa !5
  %13 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %13, ptr %8, align 8, !tbaa !5
  br label %17

14:                                               ; preds = %3
  %15 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %15, ptr %7, align 8, !tbaa !5
  %16 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %16, ptr %8, align 8, !tbaa !5
  br label %17

17:                                               ; preds = %14, %11
  br label %18

18:                                               ; preds = %23, %17
  %19 = load ptr, ptr %7, align 8, !tbaa !5
  %20 = getelementptr inbounds %struct.node, ptr %19, i32 0, i32 1
  %21 = load ptr, ptr %20, align 8, !tbaa !11
  %22 = icmp ne ptr %21, null
  br i1 %22, label %23, label %27

23:                                               ; preds = %18
  %24 = load ptr, ptr %7, align 8, !tbaa !5
  %25 = getelementptr inbounds %struct.node, ptr %24, i32 0, i32 1
  %26 = load ptr, ptr %25, align 8, !tbaa !11
  store ptr %26, ptr %7, align 8, !tbaa !5
  br label %18, !llvm.loop !13

27:                                               ; preds = %18
  %28 = load ptr, ptr %8, align 8, !tbaa !5
  %29 = load ptr, ptr %7, align 8, !tbaa !5
  %30 = getelementptr inbounds %struct.node, ptr %29, i32 0, i32 1
  store ptr %28, ptr %30, align 8, !tbaa !11
  %31 = load i32, ptr %6, align 4, !tbaa !9
  %32 = icmp eq i32 %31, 1
  br i1 %32, label %33, label %35

33:                                               ; preds = %27
  %34 = load ptr, ptr %4, align 8, !tbaa !5
  br label %37

35:                                               ; preds = %27
  %36 = load ptr, ptr %5, align 8, !tbaa !5
  br label %37

37:                                               ; preds = %35, %33
  %38 = phi ptr [ %34, %33 ], [ %36, %35 ]
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #2
  ret ptr %38
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 = { 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/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!12, !6, i64 8}
!12 = !{!"node", !10, i64 0, !6, i64 8}
!13 = distinct !{!13, !14}
!14 = !{!"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: nofree norecurse nosync nounwind memory(readwrite, inaccessiblemem: none) uwtable
define dso_local noundef ptr @merge(ptr noundef %0, ptr noundef %1, i32 noundef %2) local_unnamed_addr #0 {
  %4 = icmp eq i32 %2, 1
  %. = select i1 %4, ptr %0, ptr %1
  br label %5

5:                                                ; preds = %5, %3
  %.1 = phi ptr [ %., %3 ], [ %7, %5 ]
  %6 = getelementptr inbounds i8, ptr %.1, i64 8
  %7 = load ptr, ptr %6, align 8, !tbaa !5
  %.not = icmp eq ptr %7, null
  br i1 %.not, label %8, label %5, !llvm.loop !11

8:                                                ; preds = %5
  %9 = getelementptr inbounds i8, ptr %.1, i64 8
  %.13 = select i1 %4, ptr %1, ptr %0
  store ptr %.13, ptr %9, align 8, !tbaa !5
  ret ptr %.
}

attributes #0 = { nofree norecurse nosync nounwind memory(readwrite, 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 = !{!"node", !7, i64 0, !10, i64 8}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,LCSSAPass,LICMPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass