; LLVM IR from TheAlgorithms/C-Plus-Plus :: operations_on_datastructures/reverse_a_linked_list_using_recusion.ll (Z7reverseP4nodeS0_)

; 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 }

@start = external dso_local global ptr, align 8

; Function Attrs: mustprogress uwtable
define dso_local void @_Z7reverseP4nodeS0_(ptr noundef %0, ptr noundef %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  store ptr %1, ptr %4, align 8, !tbaa !5
  %5 = load ptr, ptr %4, align 8, !tbaa !5
  %6 = getelementptr inbounds %struct.node, ptr %5, i32 0, i32 1
  %7 = load ptr, ptr %6, align 8, !tbaa !9
  %8 = icmp eq ptr %7, null
  br i1 %8, label %9, label %16

9:                                                ; preds = %2
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  %11 = load ptr, ptr %4, align 8, !tbaa !5
  %12 = getelementptr inbounds %struct.node, ptr %11, i32 0, i32 1
  store ptr %10, ptr %12, align 8, !tbaa !9
  %13 = load ptr, ptr %3, align 8, !tbaa !5
  %14 = getelementptr inbounds %struct.node, ptr %13, i32 0, i32 1
  store ptr null, ptr %14, align 8, !tbaa !9
  %15 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %15, ptr @start, align 8, !tbaa !5
  br label %26

16:                                               ; preds = %2
  %17 = load ptr, ptr %4, align 8, !tbaa !5
  %18 = load ptr, ptr %4, align 8, !tbaa !5
  %19 = getelementptr inbounds %struct.node, ptr %18, i32 0, i32 1
  %20 = load ptr, ptr %19, align 8, !tbaa !9
  call void @_Z7reverseP4nodeS0_(ptr noundef %17, ptr noundef %20)
  %21 = load ptr, ptr %3, align 8, !tbaa !5
  %22 = load ptr, ptr %4, align 8, !tbaa !5
  %23 = getelementptr inbounds %struct.node, ptr %22, i32 0, i32 1
  store ptr %21, ptr %23, align 8, !tbaa !9
  %24 = load ptr, ptr %3, align 8, !tbaa !5
  %25 = getelementptr inbounds %struct.node, ptr %24, i32 0, i32 1
  store ptr null, ptr %25, align 8, !tbaa !9
  br label %26

26:                                               ; preds = %16, %9
  ret void
}

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" }

!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}


; 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"

@start = external dso_local local_unnamed_addr global ptr, align 8

; Function Attrs: mustprogress nofree nosync nounwind memory(readwrite, inaccessiblemem: none) uwtable
define dso_local void @_Z7reverseP4nodeS0_(ptr noundef %0, ptr noundef %1) local_unnamed_addr #0 {
  %3 = getelementptr inbounds i8, ptr %1, i64 8
  %4 = load ptr, ptr %3, align 8, !tbaa !5
  %5 = icmp eq ptr %4, null
  br i1 %5, label %6, label %8

6:                                                ; preds = %2
  store ptr %1, ptr @start, align 8, !tbaa !11
  br label %common.ret

common.ret:                                       ; preds = %6, %8
  store ptr %0, ptr %3, align 8
  %7 = getelementptr inbounds i8, ptr %0, i64 8
  store ptr null, ptr %7, align 8
  ret void

8:                                                ; preds = %2
  tail call void @_Z7reverseP4nodeS0_(ptr noundef nonnull %1, ptr noundef nonnull %4)
  br label %common.ret
}

attributes #0 = { mustprogress nofree 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 = !{!"_ZTS4node", !7, i64 0, !10, i64 8}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = !{!10, !10, i64 0}


; Effective O3 passes: CorrelatedValuePropagationPass,EarlyCSEPass,GlobalOptPass,InstCombinePass,MergedLoadStoreMotionPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass