; LLVM IR from next-step-for-interview-prep/Coding-Ninjas-DSA-course_code_and_notes_cpp :: Milestone-1=Intro_to_C++/questions and solutions/Lec-5=Patterns-2 (main)

; 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 [2 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 i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #4
  %7 = 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)
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #4
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #4
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #4
  store i32 1, ptr %5, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #4
  %8 = load i32, ptr %2, align 4, !tbaa !5
  %9 = sub nsw i32 %8, 1
  store i32 %9, ptr %6, align 4, !tbaa !5
  store i32 1, ptr %4, align 4, !tbaa !5
  br label %10

10:                                               ; preds = %59, %0
  %11 = load i32, ptr %4, align 4, !tbaa !5
  %12 = load i32, ptr %2, align 4, !tbaa !5
  %13 = icmp sle i32 %11, %12
  br i1 %13, label %14, label %62

14:                                               ; preds = %10
  %15 = load i32, ptr %4, align 4, !tbaa !5
  store i32 %15, ptr %5, align 4, !tbaa !5
  store i32 1, ptr %3, align 4, !tbaa !5
  br label %16

16:                                               ; preds = %22, %14
  %17 = load i32, ptr %3, align 4, !tbaa !5
  %18 = load i32, ptr %6, align 4, !tbaa !5
  %19 = icmp sle i32 %17, %18
  br i1 %19, label %20, label %25

20:                                               ; preds = %16
  %21 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef @.str)
  br label %22

22:                                               ; preds = %20
  %23 = load i32, ptr %3, align 4, !tbaa !5
  %24 = add nsw i32 %23, 1
  store i32 %24, ptr %3, align 4, !tbaa !5
  br label %16, !llvm.loop !9

25:                                               ; preds = %16
  %26 = load i32, ptr %6, align 4, !tbaa !5
  %27 = add nsw i32 %26, -1
  store i32 %27, ptr %6, align 4, !tbaa !5
  store i32 1, ptr %3, align 4, !tbaa !5
  br label %28

28:                                               ; preds = %37, %25
  %29 = load i32, ptr %3, align 4, !tbaa !5
  %30 = load i32, ptr %4, align 4, !tbaa !5
  %31 = icmp sle i32 %29, %30
  br i1 %31, label %32, label %40

32:                                               ; preds = %28
  %33 = load i32, ptr %5, align 4, !tbaa !5
  %34 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %33)
  %35 = load i32, ptr %5, align 4, !tbaa !5
  %36 = add nsw i32 %35, 1
  store i32 %36, ptr %5, align 4, !tbaa !5
  br label %37

37:                                               ; preds = %32
  %38 = load i32, ptr %3, align 4, !tbaa !5
  %39 = add nsw i32 %38, 1
  store i32 %39, ptr %3, align 4, !tbaa !5
  br label %28, !llvm.loop !11

40:                                               ; preds = %28
  %41 = load i32, ptr %5, align 4, !tbaa !5
  %42 = add nsw i32 %41, -1
  store i32 %42, ptr %5, align 4, !tbaa !5
  %43 = load i32, ptr %5, align 4, !tbaa !5
  %44 = add nsw i32 %43, -1
  store i32 %44, ptr %5, align 4, !tbaa !5
  store i32 1, ptr %3, align 4, !tbaa !5
  br label %45

45:                                               ; preds = %54, %40
  %46 = load i32, ptr %3, align 4, !tbaa !5
  %47 = load i32, ptr %4, align 4, !tbaa !5
  %48 = icmp slt i32 %46, %47
  br i1 %48, label %49, label %57

49:                                               ; preds = %45
  %50 = load i32, ptr %5, align 4, !tbaa !5
  %51 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %50)
  %52 = load i32, ptr %5, align 4, !tbaa !5
  %53 = add nsw i32 %52, -1
  store i32 %53, ptr %5, align 4, !tbaa !5
  br label %54

54:                                               ; preds = %49
  %55 = load i32, ptr %3, align 4, !tbaa !5
  %56 = add nsw i32 %55, 1
  store i32 %56, ptr %3, align 4, !tbaa !5
  br label %45, !llvm.loop !12

57:                                               ; preds = %45
  %58 = 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)
  br label %59

59:                                               ; preds = %57
  %60 = load i32, ptr %4, align 4, !tbaa !5
  %61 = add nsw i32 %60, 1
  store i32 %61, ptr %4, align 4, !tbaa !5
  br label %10, !llvm.loop !13

62:                                               ; preds = %10
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #4
  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: 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) #3

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

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

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 = { 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 = !{!"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}
!13 = distinct !{!13, !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 [2 x i8], align 1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #0 {
  %1 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #4
  %2 = 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)
  %3 = load i32, ptr %1, align 4, !tbaa !5
  %.not34 = icmp slt i32 %3, 1
  br i1 %.not34, label %._crit_edge38, label %.preheader25

.preheader25:                                     ; preds = %0, %._crit_edge
  %indvars.iv = phi i32 [ %indvars.iv.next, %._crit_edge ], [ 2, %0 ]
  %.0.in36 = phi i32 [ %.037, %._crit_edge ], [ %3, %0 ]
  %.02035 = phi i32 [ %13, %._crit_edge ], [ 1, %0 ]
  %.037 = add nsw i32 %.0.in36, -1
  %.not23.not26 = icmp sgt i32 %.0.in36, 1
  br i1 %.not23.not26, label %.lr.ph, label %.preheader.preheader

.lr.ph:                                           ; preds = %.preheader25, %.lr.ph
  %.02127 = phi i32 [ %5, %.lr.ph ], [ 1, %.preheader25 ]
  %4 = 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)
  %5 = add nuw nsw i32 %.02127, 1
  %exitcond.not = icmp eq i32 %5, %.0.in36
  br i1 %exitcond.not, label %.preheader.preheader, label %.lr.ph, !llvm.loop !9

.preheader.preheader:                             ; preds = %.lr.ph, %.preheader25
  br label %.preheader

.preheader:                                       ; preds = %.preheader.preheader, %.preheader
  %.01929 = phi i32 [ %7, %.preheader ], [ %.02035, %.preheader.preheader ]
  %6 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %.01929)
  %7 = add nuw i32 %.01929, 1
  %exitcond39.not = icmp eq i32 %7, %indvars.iv
  br i1 %exitcond39.not, label %8, label %.preheader, !llvm.loop !11

8:                                                ; preds = %.preheader
  %9 = icmp ugt i32 %.02035, 1
  br i1 %9, label %.lr.ph32, label %._crit_edge

.lr.ph32:                                         ; preds = %8, %.lr.ph32
  %.131.in = phi i32 [ %.131, %.lr.ph32 ], [ %.01929, %8 ]
  %.230 = phi i32 [ %11, %.lr.ph32 ], [ 1, %8 ]
  %.131 = add nsw i32 %.131.in, -1
  %10 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %.131)
  %11 = add nuw nsw i32 %.230, 1
  %exitcond40.not = icmp eq i32 %11, %.02035
  br i1 %exitcond40.not, label %._crit_edge, label %.lr.ph32, !llvm.loop !12

._crit_edge:                                      ; preds = %.lr.ph32, %8
  %12 = 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)
  %13 = add nuw nsw i32 %.02035, 1
  %14 = load i32, ptr %1, align 4, !tbaa !5
  %.not.not = icmp slt i32 %.02035, %14
  %indvars.iv.next = add i32 %indvars.iv, 2
  br i1 %.not.not, label %.preheader25, label %._crit_edge38, !llvm.loop !13

._crit_edge38:                                    ; preds = %._crit_edge, %0
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #4
  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: 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 #3

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

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 = { 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 = !{!"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}
!13 = distinct !{!13, !10}


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