; LLVM IR from Ayon-SSP/The-SDE-Prep :: 1]_Data Structures/2]_Linked List (11_deletingnode)

; 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 }

@first = external dso_local global ptr, align 8

; 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 void @delete(i32 noundef %0) #1 {
  %2 = alloca i32, align 4
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #3
  %6 = load ptr, ptr @first, align 8, !tbaa !9
  store ptr %6, ptr %3, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #3
  store ptr null, ptr %4, align 8, !tbaa !9
  %7 = load i32, ptr %2, align 4, !tbaa !5
  %8 = icmp eq i32 %7, 1
  br i1 %8, label %9, label %14

9:                                                ; preds = %1
  %10 = load ptr, ptr @first, align 8, !tbaa !9
  %11 = getelementptr inbounds %struct.Node, ptr %10, i32 0, i32 1
  %12 = load ptr, ptr %11, align 8, !tbaa !11
  store ptr %12, ptr @first, align 8, !tbaa !9
  %13 = load ptr, ptr %3, align 8, !tbaa !9
  call void @free(ptr noundef %13) #3
  br label %36

14:                                               ; preds = %1
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  store i32 0, ptr %5, align 4, !tbaa !5
  br label %15

15:                                               ; preds = %26, %14
  %16 = load i32, ptr %5, align 4, !tbaa !5
  %17 = load i32, ptr %2, align 4, !tbaa !5
  %18 = sub nsw i32 %17, 1
  %19 = icmp slt i32 %16, %18
  br i1 %19, label %21, label %20

20:                                               ; preds = %15
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  br label %29

21:                                               ; preds = %15
  %22 = load ptr, ptr %3, align 8, !tbaa !9
  store ptr %22, ptr %4, align 8, !tbaa !9
  %23 = load ptr, ptr %3, align 8, !tbaa !9
  %24 = getelementptr inbounds %struct.Node, ptr %23, i32 0, i32 1
  %25 = load ptr, ptr %24, align 8, !tbaa !11
  store ptr %25, ptr %3, align 8, !tbaa !9
  br label %26

26:                                               ; preds = %21
  %27 = load i32, ptr %5, align 4, !tbaa !5
  %28 = add nsw i32 %27, 1
  store i32 %28, ptr %5, align 4, !tbaa !5
  br label %15, !llvm.loop !13

29:                                               ; preds = %20
  %30 = load ptr, ptr %3, align 8, !tbaa !9
  %31 = getelementptr inbounds %struct.Node, ptr %30, i32 0, i32 1
  %32 = load ptr, ptr %31, align 8, !tbaa !11
  %33 = load ptr, ptr %4, align 8, !tbaa !9
  %34 = getelementptr inbounds %struct.Node, ptr %33, i32 0, i32 1
  store ptr %32, ptr %34, align 8, !tbaa !11
  %35 = load ptr, ptr %3, align 8, !tbaa !9
  call void @free(ptr noundef %35) #3
  br label %36

36:                                               ; preds = %29, %9
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #3
  ret void
}

; Function Attrs: nounwind
declare void @free(ptr noundef) #2

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 "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 }

!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/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = !{!12, !10, i64 8}
!12 = !{!"Node", !6, i64 0, !10, 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"

@first = external dso_local local_unnamed_addr global ptr, align 8

; Function Attrs: nounwind uwtable
define dso_local void @delete(i32 noundef %0) local_unnamed_addr #0 {
  %2 = load ptr, ptr @first, align 8, !tbaa !5
  %3 = icmp eq i32 %0, 1
  br i1 %3, label %27, label %.preheader

.preheader:                                       ; preds = %1
  %4 = icmp sgt i32 %0, 1
  tail call void @llvm.assume(i1 %4)
  %5 = add nsw i32 %0, -2
  %6 = add nsw i32 %0, -1
  %xtraiter = and i32 %6, 7
  %7 = icmp ult i32 %5, 7
  br i1 %7, label %._crit_edge.unr-lcssa, label %.preheader.new

.preheader.new:                                   ; preds = %.preheader
  %unroll_iter = and i32 %6, -8
  br label %.lr.ph

._crit_edge.unr-lcssa:                            ; preds = %.lr.ph, %.preheader
  %.01012.lcssa.ph = phi ptr [ poison, %.preheader ], [ %24, %.lr.ph ]
  %.lcssa.ph = phi ptr [ poison, %.preheader ], [ %26, %.lr.ph ]
  %.01012.unr = phi ptr [ %2, %.preheader ], [ %26, %.lr.ph ]
  %lcmp.mod.not = icmp eq i32 %xtraiter, 0
  br i1 %lcmp.mod.not, label %._crit_edge, label %.lr.ph.epil

.lr.ph.epil:                                      ; preds = %._crit_edge.unr-lcssa, %.lr.ph.epil
  %.01012.epil = phi ptr [ %9, %.lr.ph.epil ], [ %.01012.unr, %._crit_edge.unr-lcssa ]
  %epil.iter = phi i32 [ %epil.iter.next, %.lr.ph.epil ], [ 0, %._crit_edge.unr-lcssa ]
  %8 = getelementptr inbounds i8, ptr %.01012.epil, i64 8
  %9 = load ptr, ptr %8, align 8, !tbaa !9
  %epil.iter.next = add i32 %epil.iter, 1
  %epil.iter.cmp.not = icmp eq i32 %epil.iter.next, %xtraiter
  br i1 %epil.iter.cmp.not, label %._crit_edge, label %.lr.ph.epil, !llvm.loop !12

._crit_edge:                                      ; preds = %.lr.ph.epil, %._crit_edge.unr-lcssa
  %.01012.lcssa = phi ptr [ %.01012.lcssa.ph, %._crit_edge.unr-lcssa ], [ %.01012.epil, %.lr.ph.epil ]
  %.lcssa = phi ptr [ %.lcssa.ph, %._crit_edge.unr-lcssa ], [ %9, %.lr.ph.epil ]
  %10 = getelementptr inbounds i8, ptr %.01012.lcssa, i64 8
  br label %27

.lr.ph:                                           ; preds = %.lr.ph, %.preheader.new
  %.01012 = phi ptr [ %2, %.preheader.new ], [ %26, %.lr.ph ]
  %niter = phi i32 [ 0, %.preheader.new ], [ %niter.next.7, %.lr.ph ]
  %11 = getelementptr inbounds i8, ptr %.01012, i64 8
  %12 = load ptr, ptr %11, align 8, !tbaa !9
  %13 = getelementptr inbounds i8, ptr %12, i64 8
  %14 = load ptr, ptr %13, align 8, !tbaa !9
  %15 = getelementptr inbounds i8, ptr %14, i64 8
  %16 = load ptr, ptr %15, align 8, !tbaa !9
  %17 = getelementptr inbounds i8, ptr %16, i64 8
  %18 = load ptr, ptr %17, align 8, !tbaa !9
  %19 = getelementptr inbounds i8, ptr %18, i64 8
  %20 = load ptr, ptr %19, align 8, !tbaa !9
  %21 = getelementptr inbounds i8, ptr %20, i64 8
  %22 = load ptr, ptr %21, align 8, !tbaa !9
  %23 = getelementptr inbounds i8, ptr %22, i64 8
  %24 = load ptr, ptr %23, align 8, !tbaa !9
  %25 = getelementptr inbounds i8, ptr %24, i64 8
  %26 = load ptr, ptr %25, align 8, !tbaa !9
  %niter.next.7 = add i32 %niter, 8
  %niter.ncmp.7 = icmp eq i32 %niter.next.7, %unroll_iter
  br i1 %niter.ncmp.7, label %._crit_edge.unr-lcssa, label %.lr.ph, !llvm.loop !14

27:                                               ; preds = %1, %._crit_edge
  %.lcssa.sink18 = phi ptr [ %.lcssa, %._crit_edge ], [ %2, %1 ]
  %.sink16 = phi ptr [ %10, %._crit_edge ], [ @first, %1 ]
  %28 = getelementptr inbounds i8, ptr %.lcssa.sink18, i64 8
  %29 = load ptr, ptr %28, align 8, !tbaa !9
  store ptr %29, ptr %.sink16, align 8, !tbaa !5
  tail call void @free(ptr noundef %.lcssa.sink18) #3
  ret void
}

; Function Attrs: mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite)
declare void @free(ptr allocptr nocapture noundef) local_unnamed_addr #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(inaccessiblemem: write)
declare void @llvm.assume(i1 noundef) #2

attributes #0 = { 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 nounwind willreturn allockind("free") memory(argmem: readwrite, 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 = { nocallback nofree nosync nounwind willreturn memory(inaccessiblemem: write) }
attributes #3 = { 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, !6, i64 8}
!10 = !{!"Node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.unroll.disable"}
!14 = distinct !{!14, !15}
!15 = !{!"llvm.loop.mustprogress"}


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