; LLVM IR from div-bargali/Data-Structures-and-Algorithms :: C++/Algorithms/Graph-Algorithms/Depth First Search.ll (ZN5Graph3DFSEi)

; 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"

%class.Graph = type { i32, ptr }

; Function Attrs: nobuiltin allocsize(0)
declare noundef nonnull ptr @_Znam(i64 noundef) #0

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZN5Graph7DFSUtilEiPb(ptr noundef nonnull align 8 dereferenceable(16), i32 noundef, ptr noundef) #1 align 2

; 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

; Function Attrs: mustprogress uwtable
define dso_local void @_ZN5Graph3DFSEi(ptr noundef nonnull align 8 dereferenceable(16) %0, i32 noundef %1) #1 align 2 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !9
  %7 = load ptr, ptr %3, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #3
  %8 = getelementptr inbounds %class.Graph, ptr %7, i32 0, i32 0
  %9 = load i32, ptr %8, align 8, !tbaa !11
  %10 = sext i32 %9 to i64
  %11 = call noalias noundef nonnull ptr @_Znam(i64 noundef %10) #4
  store ptr %11, ptr %5, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #3
  store i32 0, ptr %6, align 4, !tbaa !9
  br label %12

12:                                               ; preds = %23, %2
  %13 = load i32, ptr %6, align 4, !tbaa !9
  %14 = getelementptr inbounds %class.Graph, ptr %7, i32 0, i32 0
  %15 = load i32, ptr %14, align 8, !tbaa !11
  %16 = icmp slt i32 %13, %15
  br i1 %16, label %18, label %17

17:                                               ; preds = %12
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #3
  br label %26

18:                                               ; preds = %12
  %19 = load ptr, ptr %5, align 8, !tbaa !5
  %20 = load i32, ptr %6, align 4, !tbaa !9
  %21 = sext i32 %20 to i64
  %22 = getelementptr inbounds i8, ptr %19, i64 %21
  store i8 0, ptr %22, align 1, !tbaa !13
  br label %23

23:                                               ; preds = %18
  %24 = load i32, ptr %6, align 4, !tbaa !9
  %25 = add nsw i32 %24, 1
  store i32 %25, ptr %6, align 4, !tbaa !9
  br label %12, !llvm.loop !15

26:                                               ; preds = %17
  %27 = load i32, ptr %4, align 4, !tbaa !9
  %28 = load ptr, ptr %5, align 8, !tbaa !5
  call void @_ZN5Graph7DFSUtilEiPb(ptr noundef nonnull align 8 dereferenceable(16) %7, i32 noundef %27, ptr noundef %28)
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #3
  ret void
}

attributes #0 = { 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 #1 = { 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 #2 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!12, !10, i64 0}
!12 = !{!"_ZTS5Graph", !10, i64 0, !6, i64 8}
!13 = !{!14, !14, i64 0}
!14 = !{!"bool", !7, i64 0}
!15 = distinct !{!15, !16}
!16 = !{!"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: nobuiltin allocsize(0)
declare noundef nonnull ptr @_Znam(i64 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZN5Graph7DFSUtilEiPb(ptr noundef nonnull align 8 dereferenceable(16), i32 noundef, ptr noundef) local_unnamed_addr #1 align 2

; Function Attrs: mustprogress uwtable
define dso_local void @_ZN5Graph3DFSEi(ptr noundef nonnull align 8 dereferenceable(16) %0, i32 noundef %1) local_unnamed_addr #1 align 2 {
  %3 = load i32, ptr %0, align 8, !tbaa !5
  %4 = sext i32 %3 to i64
  %5 = tail call noalias noundef nonnull ptr @_Znam(i64 noundef %4) #3
  %6 = icmp sgt i32 %3, 0
  br i1 %6, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %2
  %7 = zext nneg i32 %3 to i64
  tail call void @llvm.memset.p0.i64(ptr nonnull align 1 %5, i8 0, i64 %7, i1 false), !tbaa !11
  br label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph.preheader, %2
  tail call void @_ZN5Graph7DFSUtilEiPb(ptr noundef nonnull align 8 dereferenceable(16) %0, i32 noundef %1, ptr noundef nonnull %5)
  ret void
}

; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #2

attributes #0 = { 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 #1 = { 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 #2 = { nocallback nofree nounwind willreturn memory(argmem: write) }
attributes #3 = { 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 = !{!"_ZTS5Graph", !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 = !{!12, !12, i64 0}
!12 = !{!"bool", !8, i64 0}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,LoopIdiomRecognizePass,LoopRotatePass,LoopSimplifyPass,SROAPass,SimplifyCFGPass,TailCallElimPass