; LLVM IR from lekkas/c-algorithms :: src/algos (SingleList)

; 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.SingleList = type { ptr, %struct.DataOps }
%struct.DataOps = type { ptr, ptr }
%struct.SingleListNode = type { ptr, 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 void @reverseSingleList(ptr noundef %0) #1 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #2
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  %7 = load ptr, ptr %2, align 8, !tbaa !5
  %8 = getelementptr inbounds %struct.SingleList, ptr %7, i32 0, i32 0
  %9 = load ptr, ptr %8, align 8, !tbaa !9
  %10 = icmp eq ptr %9, null
  br i1 %10, label %11, label %12

11:                                               ; preds = %1
  store i32 1, ptr %6, align 4
  br label %32

12:                                               ; preds = %1
  store ptr null, ptr %4, align 8, !tbaa !5
  %13 = load ptr, ptr %2, align 8, !tbaa !5
  %14 = getelementptr inbounds %struct.SingleList, ptr %13, i32 0, i32 0
  %15 = load ptr, ptr %14, align 8, !tbaa !9
  store ptr %15, ptr %3, align 8, !tbaa !5
  br label %16

16:                                               ; preds = %19, %12
  %17 = load ptr, ptr %3, align 8, !tbaa !5
  %18 = icmp ne ptr %17, null
  br i1 %18, label %19, label %28

19:                                               ; preds = %16
  %20 = load ptr, ptr %3, align 8, !tbaa !5
  %21 = getelementptr inbounds %struct.SingleListNode, ptr %20, i32 0, i32 1
  %22 = load ptr, ptr %21, align 8, !tbaa !12
  store ptr %22, ptr %5, align 8, !tbaa !5
  %23 = load ptr, ptr %4, align 8, !tbaa !5
  %24 = load ptr, ptr %3, align 8, !tbaa !5
  %25 = getelementptr inbounds %struct.SingleListNode, ptr %24, i32 0, i32 1
  store ptr %23, ptr %25, align 8, !tbaa !12
  %26 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %26, ptr %4, align 8, !tbaa !5
  %27 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %27, ptr %3, align 8, !tbaa !5
  br label %16, !llvm.loop !14

28:                                               ; preds = %16
  %29 = load ptr, ptr %4, align 8, !tbaa !5
  %30 = load ptr, ptr %2, align 8, !tbaa !5
  %31 = getelementptr inbounds %struct.SingleList, ptr %30, i32 0, i32 0
  store ptr %29, ptr %31, align 8, !tbaa !9
  store i32 0, ptr %6, align 4
  br label %32

32:                                               ; preds = %28, %11
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #2
  %33 = load i32, ptr %6, align 4
  switch i32 %33, label %35 [
    i32 0, label %34
    i32 1, label %34
  ]

34:                                               ; preds = %32, %32
  ret void

35:                                               ; preds = %32
  unreachable
}

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, !6, i64 0}
!10 = !{!"SingleList", !6, i64 0, !11, i64 8}
!11 = !{!"DataOps", !6, i64 0, !6, i64 8}
!12 = !{!13, !6, i64 8}
!13 = !{!"SingleListNode", !6, i64 0, !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: nofree norecurse nosync nounwind memory(readwrite, inaccessiblemem: none) uwtable
define dso_local void @reverseSingleList(ptr nocapture noundef %0) local_unnamed_addr #0 {
  %2 = load ptr, ptr %0, align 8, !tbaa !5
  %3 = icmp eq ptr %2, null
  br i1 %3, label %7, label %.preheader

.preheader:                                       ; preds = %1, %.preheader
  %.013 = phi ptr [ %5, %.preheader ], [ %2, %1 ]
  %.01012 = phi ptr [ %.013, %.preheader ], [ null, %1 ]
  %4 = getelementptr inbounds i8, ptr %.013, i64 8
  %5 = load ptr, ptr %4, align 8, !tbaa !11
  store ptr %.01012, ptr %4, align 8, !tbaa !11
  %.not = icmp eq ptr %5, null
  br i1 %.not, label %6, label %.preheader, !llvm.loop !13

6:                                                ; preds = %.preheader
  store ptr %.013, ptr %0, align 8, !tbaa !5
  br label %7

7:                                                ; preds = %1, %6
  ret void
}

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, !7, i64 0}
!6 = !{!"SingleList", !7, i64 0, !10, i64 8}
!7 = !{!"any pointer", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!"DataOps", !7, i64 0, !7, i64 8}
!11 = !{!12, !7, i64 8}
!12 = !{!"SingleListNode", !7, i64 0, !7, i64 8}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


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