; LLVM IR from CodersForLife/Data-Structures-Algorithms :: Structures/LinkedList.ll (Z6appendi)

; 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 }

@_ZL4head = external hidden global ptr, align 8

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z6appendi(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca ptr, align 8
  store i32 %0, ptr %2, align 4, !tbaa !5
  %4 = load ptr, ptr @_ZL4head, align 8, !tbaa !9
  %5 = icmp ne ptr %4, null
  br i1 %5, label %13, label %6

6:                                                ; preds = %1
  %7 = call noalias ptr @malloc(i64 noundef 16) #3
  store ptr %7, ptr @_ZL4head, align 8, !tbaa !9
  %8 = load i32, ptr %2, align 4, !tbaa !5
  %9 = load ptr, ptr @_ZL4head, align 8, !tbaa !9
  %10 = getelementptr inbounds %struct.Node, ptr %9, i32 0, i32 0
  store i32 %8, ptr %10, align 8, !tbaa !11
  %11 = load ptr, ptr @_ZL4head, align 8, !tbaa !9
  %12 = getelementptr inbounds %struct.Node, ptr %11, i32 0, i32 1
  store ptr null, ptr %12, align 8, !tbaa !13
  br label %37

13:                                               ; preds = %1
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #4
  %14 = load ptr, ptr @_ZL4head, align 8, !tbaa !9
  store ptr %14, ptr %3, align 8, !tbaa !9
  br label %15

15:                                               ; preds = %20, %13
  %16 = load ptr, ptr %3, align 8, !tbaa !9
  %17 = getelementptr inbounds %struct.Node, ptr %16, i32 0, i32 1
  %18 = load ptr, ptr %17, align 8, !tbaa !13
  %19 = icmp ne ptr %18, null
  br i1 %19, label %20, label %24

20:                                               ; preds = %15
  %21 = load ptr, ptr %3, align 8, !tbaa !9
  %22 = getelementptr inbounds %struct.Node, ptr %21, i32 0, i32 1
  %23 = load ptr, ptr %22, align 8, !tbaa !13
  store ptr %23, ptr %3, align 8, !tbaa !9
  br label %15, !llvm.loop !14

24:                                               ; preds = %15
  %25 = call noalias ptr @malloc(i64 noundef 16) #3
  %26 = load ptr, ptr %3, align 8, !tbaa !9
  %27 = getelementptr inbounds %struct.Node, ptr %26, i32 0, i32 1
  store ptr %25, ptr %27, align 8, !tbaa !13
  %28 = load i32, ptr %2, align 4, !tbaa !5
  %29 = load ptr, ptr %3, align 8, !tbaa !9
  %30 = getelementptr inbounds %struct.Node, ptr %29, i32 0, i32 1
  %31 = load ptr, ptr %30, align 8, !tbaa !13
  %32 = getelementptr inbounds %struct.Node, ptr %31, i32 0, i32 0
  store i32 %28, ptr %32, align 8, !tbaa !11
  %33 = load ptr, ptr %3, align 8, !tbaa !9
  %34 = getelementptr inbounds %struct.Node, ptr %33, i32 0, i32 1
  %35 = load ptr, ptr %34, align 8, !tbaa !13
  %36 = getelementptr inbounds %struct.Node, ptr %35, i32 0, i32 1
  store ptr null, ptr %36, align 8, !tbaa !13
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #4
  br label %37

37:                                               ; preds = %24, %6
  ret void
}

; Function Attrs: nounwind allocsize(0)
declare noalias ptr @malloc(i64 noundef) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #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 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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #3 = { nounwind allocsize(0) }
attributes #4 = { 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 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = !{!12, !6, i64 0}
!12 = !{!"_ZTS4Node", !6, i64 0, !10, i64 8}
!13 = !{!12, !10, 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"

@_ZL4head = external hidden local_unnamed_addr global ptr, align 8

; Function Attrs: mustprogress nofree nounwind uwtable
define dso_local void @_Z6appendi(i32 noundef %0) local_unnamed_addr #0 {
  %2 = load ptr, ptr @_ZL4head, align 8, !tbaa !5
  %.not = icmp eq ptr %2, null
  br i1 %.not, label %7, label %.preheader

.preheader:                                       ; preds = %1, %.preheader
  %.0 = phi ptr [ %4, %.preheader ], [ %2, %1 ]
  %3 = getelementptr inbounds i8, ptr %.0, i64 8
  %4 = load ptr, ptr %3, align 8, !tbaa !9
  %.not8 = icmp eq ptr %4, null
  br i1 %.not8, label %5, label %.preheader, !llvm.loop !12

5:                                                ; preds = %.preheader
  %6 = getelementptr inbounds i8, ptr %.0, i64 8
  br label %7

7:                                                ; preds = %1, %5
  %.sink11 = phi ptr [ %6, %5 ], [ @_ZL4head, %1 ]
  %8 = tail call noalias dereferenceable_or_null(16) ptr @malloc(i64 noundef 16) #2
  store ptr %8, ptr %.sink11, align 8, !tbaa !5
  store i32 %0, ptr %8, align 8, !tbaa !14
  %9 = getelementptr inbounds i8, ptr %8, i64 8
  store ptr null, ptr %9, align 8, !tbaa !9
  ret void
}

; Function Attrs: mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite)
declare noalias noundef ptr @malloc(i64 noundef) local_unnamed_addr #1

attributes #0 = { mustprogress nofree 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 = { mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite) "alloc-family"="malloc" "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 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, !6, i64 8}
!10 = !{!"_ZTS4Node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}
!14 = !{!10, !11, i64 0}


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