; LLVM IR from div-bargali/Data-Structures-and-Algorithms :: C++/Data-Structures/Tree (huffman_decoding)

; 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.std::basic_ostream" = type { ptr, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }
%struct.node = type { i32, i8, ptr, ptr }

@_ZSt4cout = external global %"class.std::basic_ostream", 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: mustprogress nounwind uwtable
declare noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32)) #1 align 2

; Function Attrs: mustprogress nounwind uwtable
declare noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32), i64 noundef) #1 align 2

; Function Attrs: mustprogress uwtable
define dso_local void @_Z11decode_huffP4nodeNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef %0, ptr noundef %1) #2 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca ptr, align 8
  %7 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store ptr %1, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #4
  %8 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #4
  %9 = trunc i64 %8 to i32
  store i32 %9, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #4
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %10, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #4
  store i32 0, ptr %7, align 4, !tbaa !9
  br label %11

11:                                               ; preds = %52, %2
  %12 = load i32, ptr %7, align 4, !tbaa !9
  %13 = load i32, ptr %5, align 4, !tbaa !9
  %14 = icmp slt i32 %12, %13
  br i1 %14, label %16, label %15

15:                                               ; preds = %11
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #4
  br label %55

16:                                               ; preds = %11
  %17 = load i32, ptr %7, align 4, !tbaa !9
  %18 = sext i32 %17 to i64
  %19 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %18)
  %20 = load i8, ptr %19, align 1, !tbaa !11
  %21 = sext i8 %20 to i32
  %22 = icmp eq i32 %21, 48
  br i1 %22, label %23, label %27

23:                                               ; preds = %16
  %24 = load ptr, ptr %6, align 8, !tbaa !5
  %25 = getelementptr inbounds %struct.node, ptr %24, i32 0, i32 2
  %26 = load ptr, ptr %25, align 8, !tbaa !12
  store ptr %26, ptr %6, align 8, !tbaa !5
  br label %39

27:                                               ; preds = %16
  %28 = load i32, ptr %7, align 4, !tbaa !9
  %29 = sext i32 %28 to i64
  %30 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %29)
  %31 = load i8, ptr %30, align 1, !tbaa !11
  %32 = sext i8 %31 to i32
  %33 = icmp eq i32 %32, 49
  br i1 %33, label %34, label %38

34:                                               ; preds = %27
  %35 = load ptr, ptr %6, align 8, !tbaa !5
  %36 = getelementptr inbounds %struct.node, ptr %35, i32 0, i32 3
  %37 = load ptr, ptr %36, align 8, !tbaa !14
  store ptr %37, ptr %6, align 8, !tbaa !5
  br label %38

38:                                               ; preds = %34, %27
  br label %39

39:                                               ; preds = %38, %23
  %40 = load ptr, ptr %6, align 8, !tbaa !5
  %41 = getelementptr inbounds %struct.node, ptr %40, i32 0, i32 1
  %42 = load i8, ptr %41, align 4, !tbaa !15
  %43 = sext i8 %42 to i64
  %44 = icmp ne i64 %43, 0
  br i1 %44, label %45, label %51

45:                                               ; preds = %39
  %46 = load ptr, ptr %6, align 8, !tbaa !5
  %47 = getelementptr inbounds %struct.node, ptr %46, i32 0, i32 1
  %48 = load i8, ptr %47, align 4, !tbaa !15
  %49 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i8 noundef signext %48)
  %50 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %50, ptr %6, align 8, !tbaa !5
  br label %51

51:                                               ; preds = %45, %39
  br label %52

52:                                               ; preds = %51
  %53 = load i32, ptr %7, align 4, !tbaa !9
  %54 = add nsw i32 %53, 1
  store i32 %54, ptr %7, align 4, !tbaa !9
  br label %11, !llvm.loop !16

55:                                               ; preds = %15
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #4
  ret void
}

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8), i8 noundef signext) #3

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { mustprogress 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 = { 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 #3 = { inlinehint 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 #4 = { 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++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!7, !7, i64 0}
!12 = !{!13, !6, i64 8}
!13 = !{!"_ZTS4node", !10, i64 0, !7, i64 4, !6, i64 8, !6, i64 16}
!14 = !{!13, !6, i64 16}
!15 = !{!13, !7, i64 4}
!16 = distinct !{!16, !17}
!17 = !{!"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"

%"class.std::basic_ostream" = type { ptr, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }

@_ZSt4cout = external global %"class.std::basic_ostream", align 8

; Function Attrs: mustprogress nounwind uwtable
declare noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32), i64 noundef) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress uwtable
define dso_local void @_Z11decode_huffP4nodeNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr nocapture noundef readonly %0, ptr noundef nonnull %1) local_unnamed_addr #1 {
  %3 = tail call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  %4 = trunc i64 %3 to i32
  %5 = icmp sgt i32 %4, 0
  br i1 %5, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %2
  %wide.trip.count = and i64 %3, 2147483647
  br label %.lr.ph

._crit_edge:                                      ; preds = %20, %2
  ret void

.lr.ph:                                           ; preds = %.lr.ph.preheader, %20
  %indvars.iv = phi i64 [ 0, %.lr.ph.preheader ], [ %indvars.iv.next, %20 ]
  %.01011 = phi ptr [ %0, %.lr.ph.preheader ], [ %.2, %20 ]
  %6 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %indvars.iv)
  %7 = load i8, ptr %6, align 1, !tbaa !5
  %8 = icmp eq i8 %7, 48
  br i1 %8, label %.sink.split, label %9

9:                                                ; preds = %.lr.ph
  %10 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %indvars.iv)
  %11 = load i8, ptr %10, align 1, !tbaa !5
  %12 = icmp eq i8 %11, 49
  br i1 %12, label %.sink.split, label %15

.sink.split:                                      ; preds = %9, %.lr.ph
  %.sink14 = phi i64 [ 8, %.lr.ph ], [ 16, %9 ]
  %13 = getelementptr inbounds i8, ptr %.01011, i64 %.sink14
  %14 = load ptr, ptr %13, align 8, !tbaa !8
  br label %15

15:                                               ; preds = %.sink.split, %9
  %.1 = phi ptr [ %.01011, %9 ], [ %14, %.sink.split ]
  %16 = getelementptr inbounds i8, ptr %.1, i64 4
  %17 = load i8, ptr %16, align 4, !tbaa !10
  %.not = icmp eq i8 %17, 0
  br i1 %.not, label %20, label %18

18:                                               ; preds = %15
  %19 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i8 noundef signext %17)
  br label %20

20:                                               ; preds = %15, %18
  %.2 = phi ptr [ %0, %18 ], [ %.1, %15 ]
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %wide.trip.count
  br i1 %exitcond.not, label %._crit_edge, label %.lr.ph, !llvm.loop !13
}

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8), i8 noundef signext) local_unnamed_addr #2

attributes #0 = { mustprogress 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 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 = { inlinehint 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 #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 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C++ TBAA"}
!8 = !{!9, !9, i64 0}
!9 = !{!"any pointer", !6, i64 0}
!10 = !{!11, !6, i64 4}
!11 = !{!"_ZTS4node", !12, i64 0, !6, i64 4, !9, i64 8, !9, i64 16}
!12 = !{!"int", !6, i64 0}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass