; LLVM IR from ahampriyanshu/algo-ds-101 :: Algorithms/Stack-Algorithm (immediate_smaller_element)

; 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_istream" = type { ptr, i64, %"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 }
%"class.std::basic_ostream" = type { ptr, %"class.std::basic_ios" }

@_ZSt3cin = external global %"class.std::basic_istream", align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str = external hidden unnamed_addr constant [2 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [3 x i8], align 1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #0 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca ptr, align 8
  %5 = alloca i64, align 8
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #6
  %8 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %2)
  br label %9

9:                                                ; preds = %65, %0
  %10 = load i32, ptr %2, align 4, !tbaa !5
  %11 = add nsw i32 %10, -1
  store i32 %11, ptr %2, align 4, !tbaa !5
  %12 = icmp ne i32 %10, 0
  br i1 %12, label %13, label %69

13:                                               ; preds = %9
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #6
  %14 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %3)
  %15 = load i32, ptr %3, align 4, !tbaa !5
  %16 = zext i32 %15 to i64
  %17 = call ptr @llvm.stacksave.p0()
  store ptr %17, ptr %4, align 8
  %18 = alloca i32, i64 %16, align 16
  store i64 %16, ptr %5, align 8
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #6
  store i32 0, ptr %6, align 4, !tbaa !5
  br label %19

19:                                               ; preds = %29, %13
  %20 = load i32, ptr %6, align 4, !tbaa !5
  %21 = load i32, ptr %3, align 4, !tbaa !5
  %22 = icmp slt i32 %20, %21
  br i1 %22, label %24, label %23

23:                                               ; preds = %19
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #6
  br label %32

24:                                               ; preds = %19
  %25 = load i32, ptr %6, align 4, !tbaa !5
  %26 = sext i32 %25 to i64
  %27 = getelementptr inbounds i32, ptr %18, i64 %26
  %28 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %27)
  br label %29

29:                                               ; preds = %24
  %30 = load i32, ptr %6, align 4, !tbaa !5
  %31 = add nsw i32 %30, 1
  store i32 %31, ptr %6, align 4, !tbaa !5
  br label %19, !llvm.loop !9

32:                                               ; preds = %23
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #6
  store i32 0, ptr %7, align 4, !tbaa !5
  br label %33

33:                                               ; preds = %62, %32
  %34 = load i32, ptr %7, align 4, !tbaa !5
  %35 = load i32, ptr %3, align 4, !tbaa !5
  %36 = sub nsw i32 %35, 1
  %37 = icmp slt i32 %34, %36
  br i1 %37, label %39, label %38

38:                                               ; preds = %33
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #6
  br label %65

39:                                               ; preds = %33
  %40 = load i32, ptr %7, align 4, !tbaa !5
  %41 = sext i32 %40 to i64
  %42 = getelementptr inbounds i32, ptr %18, i64 %41
  %43 = load i32, ptr %42, align 4, !tbaa !5
  %44 = load i32, ptr %7, align 4, !tbaa !5
  %45 = add nsw i32 %44, 1
  %46 = sext i32 %45 to i64
  %47 = getelementptr inbounds i32, ptr %18, i64 %46
  %48 = load i32, ptr %47, align 4, !tbaa !5
  %49 = icmp sgt i32 %43, %48
  br i1 %49, label %50, label %58

50:                                               ; preds = %39
  %51 = load i32, ptr %7, align 4, !tbaa !5
  %52 = add nsw i32 %51, 1
  %53 = sext i32 %52 to i64
  %54 = getelementptr inbounds i32, ptr %18, i64 %53
  %55 = load i32, ptr %54, align 4, !tbaa !5
  %56 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %55)
  %57 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) %56, ptr noundef @.str)
  br label %61

58:                                               ; preds = %39
  %59 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef @.str.1)
  %60 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) %59, ptr noundef @.str)
  br label %61

61:                                               ; preds = %58, %50
  br label %62

62:                                               ; preds = %61
  %63 = load i32, ptr %7, align 4, !tbaa !5
  %64 = add nsw i32 %63, 1
  store i32 %64, ptr %7, align 4, !tbaa !5
  br label %33, !llvm.loop !11

65:                                               ; preds = %38
  %66 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef @.str.1)
  %67 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) %66, ptr noundef @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  %68 = load ptr, ptr %4, align 8
  call void @llvm.stackrestore.p0(ptr %68)
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #6
  br label %9, !llvm.loop !12

69:                                               ; preds = %9
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #6
  ret i32 0
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 4 dereferenceable(4)) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn
declare ptr @llvm.stacksave.p0() #3

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #4

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) #2

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #5 align 2

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_(ptr noundef nonnull align 8 dereferenceable(8)) #4

; Function Attrs: nocallback nofree nosync nounwind willreturn
declare void @llvm.stackrestore.p0(ptr) #3

attributes #0 = { mustprogress norecurse 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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { "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 = { nocallback nofree nosync nounwind willreturn }
attributes #4 = { 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 #5 = { 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 #6 = { 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++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}
!11 = distinct !{!11, !10}
!12 = distinct !{!12, !10}


; 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_istream" = type { ptr, i64, %"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 }
%"class.std::basic_ostream" = type { ptr, %"class.std::basic_ios" }

@_ZSt3cin = external global %"class.std::basic_istream", align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str = external hidden unnamed_addr constant [2 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [3 x i8], align 1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #0 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #6
  %3 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %1)
  %4 = load i32, ptr %1, align 4, !tbaa !5
  %5 = add nsw i32 %4, -1
  store i32 %5, ptr %1, align 4, !tbaa !5
  %.not13 = icmp eq i32 %4, 0
  br i1 %.not13, label %._crit_edge16, label %.lr.ph15

.lr.ph15:                                         ; preds = %0, %._crit_edge
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #6
  %6 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %2)
  %7 = load i32, ptr %2, align 4, !tbaa !5
  %8 = zext i32 %7 to i64
  %9 = call ptr @llvm.stacksave.p0()
  %10 = alloca i32, i64 %8, align 16
  %11 = load i32, ptr %2, align 4, !tbaa !5
  %12 = icmp sgt i32 %11, 0
  br i1 %12, label %.lr.ph, label %._crit_edge

.preheader:                                       ; preds = %.lr.ph
  %13 = icmp sgt i32 %16, 1
  br i1 %13, label %.lr.ph12, label %._crit_edge

.lr.ph:                                           ; preds = %.lr.ph15, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %.lr.ph15 ]
  %14 = getelementptr inbounds i32, ptr %10, i64 %indvars.iv
  %15 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %14)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %16 = load i32, ptr %2, align 4, !tbaa !5
  %17 = sext i32 %16 to i64
  %18 = icmp slt i64 %indvars.iv.next, %17
  br i1 %18, label %.lr.ph, label %.preheader, !llvm.loop !9

._crit_edge:                                      ; preds = %32, %.lr.ph15, %.preheader
  %19 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef nonnull @.str.1)
  %20 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) %19, ptr noundef nonnull @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  call void @llvm.stackrestore.p0(ptr %9)
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #6
  %21 = load i32, ptr %1, align 4, !tbaa !5
  %22 = add nsw i32 %21, -1
  store i32 %22, ptr %1, align 4, !tbaa !5
  %.not = icmp eq i32 %21, 0
  br i1 %.not, label %._crit_edge16, label %.lr.ph15, !llvm.loop !11

.lr.ph12:                                         ; preds = %.preheader, %32
  %indvars.iv18 = phi i64 [ %indvars.iv.next19, %32 ], [ 0, %.preheader ]
  %23 = getelementptr inbounds i32, ptr %10, i64 %indvars.iv18
  %24 = load i32, ptr %23, align 4, !tbaa !5
  %indvars.iv.next19 = add nuw nsw i64 %indvars.iv18, 1
  %25 = getelementptr inbounds i32, ptr %10, i64 %indvars.iv.next19
  %26 = load i32, ptr %25, align 4, !tbaa !5
  %27 = icmp sgt i32 %24, %26
  br i1 %27, label %28, label %30

28:                                               ; preds = %.lr.ph12
  %29 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %26)
  br label %32

30:                                               ; preds = %.lr.ph12
  %31 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef nonnull @.str.1)
  br label %32

32:                                               ; preds = %28, %30
  %.sink = phi ptr [ %29, %28 ], [ %31, %30 ]
  %33 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) %.sink, ptr noundef nonnull @.str)
  %34 = load i32, ptr %2, align 4, !tbaa !5
  %35 = add nsw i32 %34, -1
  %36 = sext i32 %35 to i64
  %37 = icmp slt i64 %indvars.iv.next19, %36
  br i1 %37, label %.lr.ph12, label %._crit_edge, !llvm.loop !12

._crit_edge16:                                    ; preds = %._crit_edge, %0
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #6
  ret i32 0
}

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #2

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn
declare ptr @llvm.stacksave.p0() #3

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) local_unnamed_addr #4

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) local_unnamed_addr #2

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) local_unnamed_addr #5 align 2

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_(ptr noundef nonnull align 8 dereferenceable(8)) #4

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn
declare void @llvm.stackrestore.p0(ptr) #3

attributes #0 = { mustprogress norecurse 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 nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { "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 = { mustprogress nocallback nofree nosync nounwind willreturn }
attributes #4 = { 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 #5 = { 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 #6 = { 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++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}
!11 = distinct !{!11, !10}
!12 = distinct !{!12, !10}


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