; LLVM IR from HarshCasper/NeoAlgo :: C-Plus-Plus/ds/palindrome_doubly_linked_list.ll (Z6insertP4nodec)

; 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 { i8, ptr, ptr }

; Function Attrs: mustprogress uwtable
define dso_local void @_Z6insertP4nodec(ptr noundef %0, i8 noundef signext %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca i8, align 1
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  store i8 %1, ptr %4, align 1, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #3
  %7 = call noalias noundef nonnull ptr @_Znwm(i64 noundef 24) #4
  store ptr %7, ptr %5, align 8, !tbaa !5
  %8 = load i8, ptr %4, align 1, !tbaa !9
  %9 = load ptr, ptr %5, align 8, !tbaa !5
  %10 = getelementptr inbounds %struct.node, ptr %9, i32 0, i32 0
  store i8 %8, ptr %10, align 8, !tbaa !10
  %11 = load ptr, ptr %5, align 8, !tbaa !5
  %12 = getelementptr inbounds %struct.node, ptr %11, i32 0, i32 1
  store ptr null, ptr %12, align 8, !tbaa !12
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #3
  %13 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %13, ptr %6, align 8, !tbaa !5
  br label %14

14:                                               ; preds = %19, %2
  %15 = load ptr, ptr %6, align 8, !tbaa !5
  %16 = getelementptr inbounds %struct.node, ptr %15, i32 0, i32 1
  %17 = load ptr, ptr %16, align 8, !tbaa !12
  %18 = icmp ne ptr %17, null
  br i1 %18, label %19, label %23

19:                                               ; preds = %14
  %20 = load ptr, ptr %6, align 8, !tbaa !5
  %21 = getelementptr inbounds %struct.node, ptr %20, i32 0, i32 1
  %22 = load ptr, ptr %21, align 8, !tbaa !12
  store ptr %22, ptr %6, align 8, !tbaa !5
  br label %14, !llvm.loop !13

23:                                               ; preds = %14
  %24 = load ptr, ptr %5, align 8, !tbaa !5
  %25 = load ptr, ptr %6, align 8, !tbaa !5
  %26 = getelementptr inbounds %struct.node, ptr %25, i32 0, i32 1
  store ptr %24, ptr %26, align 8, !tbaa !12
  %27 = load ptr, ptr %6, align 8, !tbaa !5
  %28 = load ptr, ptr %5, align 8, !tbaa !5
  %29 = getelementptr inbounds %struct.node, ptr %28, i32 0, i32 2
  store ptr %27, ptr %29, align 8, !tbaa !15
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #3
  ret void
}

; 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 = !{!7, !7, i64 0}
!10 = !{!11, !7, i64 0}
!11 = !{!"_ZTS4node", !7, i64 0, !6, i64 8, !6, i64 16}
!12 = !{!11, !6, i64 8}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}
!15 = !{!11, !6, i64 16}


; 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 void @_Z6insertP4nodec(ptr noundef %0, i8 noundef signext %1) local_unnamed_addr #0 {
  %3 = tail call noalias noundef nonnull dereferenceable(24) ptr @_Znwm(i64 noundef 24) #2
  store i8 %1, ptr %3, align 8, !tbaa !5
  %4 = getelementptr inbounds i8, ptr %3, i64 8
  store ptr null, ptr %4, align 8, !tbaa !10
  br label %5

5:                                                ; preds = %5, %2
  %.0 = phi ptr [ %0, %2 ], [ %7, %5 ]
  %6 = getelementptr inbounds i8, ptr %.0, i64 8
  %7 = load ptr, ptr %6, align 8, !tbaa !10
  %.not = icmp eq ptr %7, null
  br i1 %.not, label %8, label %5, !llvm.loop !11

8:                                                ; preds = %5
  %9 = getelementptr inbounds i8, ptr %.0, i64 8
  store ptr %3, ptr %9, align 8, !tbaa !10
  %10 = getelementptr inbounds i8, ptr %3, i64 16
  store ptr %.0, ptr %10, align 8, !tbaa !13
  ret void
}

; 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, !7, i64 0}
!6 = !{!"_ZTS4node", !7, i64 0, !9, i64 8, !9, i64 16}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!"any pointer", !7, i64 0}
!10 = !{!6, !9, i64 8}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = !{!6, !9, i64 16}


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