; LLVM IR from next-step-for-interview-prep/Coding-Ninjas-DSA-course_code_and_notes_cpp :: Milestone-2=Intro_to_C++/questions and solutions/Lec-8=Arrays (swap_alternate)

; 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

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_Z13swapAlternatePii(ptr noundef, i32 noundef) #0

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

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

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main(i32 noundef %0, ptr noundef %1) #2 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  %7 = alloca ptr, align 8
  %8 = alloca i64, align 8
  %9 = alloca i32, align 4
  %10 = alloca i32, align 4
  store i32 0, ptr %3, align 4
  store i32 %0, ptr %4, align 4, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #6
  %11 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %6)
  %12 = load i32, ptr %6, align 4, !tbaa !5
  %13 = zext i32 %12 to i64
  %14 = call ptr @llvm.stacksave.p0()
  store ptr %14, ptr %7, align 8
  %15 = alloca i32, i64 %13, align 16
  store i64 %13, ptr %8, align 8
  call void @llvm.lifetime.start.p0(i64 4, ptr %9) #6
  store i32 0, ptr %9, align 4, !tbaa !5
  br label %16

16:                                               ; preds = %26, %2
  %17 = load i32, ptr %9, align 4, !tbaa !5
  %18 = load i32, ptr %6, align 4, !tbaa !5
  %19 = icmp slt i32 %17, %18
  br i1 %19, label %21, label %20

20:                                               ; preds = %16
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #6
  br label %29

21:                                               ; preds = %16
  %22 = load i32, ptr %9, align 4, !tbaa !5
  %23 = sext i32 %22 to i64
  %24 = getelementptr inbounds i32, ptr %15, i64 %23
  %25 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %24)
  br label %26

26:                                               ; preds = %21
  %27 = load i32, ptr %9, align 4, !tbaa !5
  %28 = add nsw i32 %27, 1
  store i32 %28, ptr %9, align 4, !tbaa !5
  br label %16, !llvm.loop !11

29:                                               ; preds = %20
  %30 = load i32, ptr %6, align 4, !tbaa !5
  call void @_Z13swapAlternatePii(ptr noundef %15, i32 noundef %30)
  call void @llvm.lifetime.start.p0(i64 4, ptr %10) #6
  store i32 0, ptr %10, align 4, !tbaa !5
  br label %31

31:                                               ; preds = %43, %29
  %32 = load i32, ptr %10, align 4, !tbaa !5
  %33 = load i32, ptr %6, align 4, !tbaa !5
  %34 = icmp slt i32 %32, %33
  br i1 %34, label %36, label %35

35:                                               ; preds = %31
  call void @llvm.lifetime.end.p0(i64 4, ptr %10) #6
  br label %46

36:                                               ; preds = %31
  %37 = load i32, ptr %10, align 4, !tbaa !5
  %38 = sext i32 %37 to i64
  %39 = getelementptr inbounds i32, ptr %15, i64 %38
  %40 = load i32, ptr %39, align 4, !tbaa !5
  %41 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %40)
  %42 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) %41, ptr noundef @.str)
  br label %43

43:                                               ; preds = %36
  %44 = load i32, ptr %10, align 4, !tbaa !5
  %45 = add nsw i32 %44, 1
  store i32 %45, ptr %10, align 4, !tbaa !5
  br label %31, !llvm.loop !13

46:                                               ; preds = %35
  store i32 0, ptr %3, align 4
  %47 = load ptr, ptr %7, align 8
  call void @llvm.stackrestore.p0(ptr %47)
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #6
  %48 = load i32, ptr %3, align 4
  ret i32 %48
}

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 4 dereferenceable(4)) #3

; Function Attrs: nocallback nofree nosync nounwind willreturn
declare ptr @llvm.stacksave.p0() #4

; 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) #5

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) #3

; Function Attrs: nocallback nofree nosync nounwind willreturn
declare void @llvm.stackrestore.p0(ptr) #4

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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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 #3 = { "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 = { nocallback nofree nosync nounwind willreturn }
attributes #5 = { 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 #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 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = distinct !{!13, !12}


; 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

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_Z13swapAlternatePii(ptr noundef, i32 noundef) local_unnamed_addr #0

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

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

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main(i32 noundef %0, ptr nocapture noundef readnone %1) local_unnamed_addr #2 {
  %3 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %3) #6
  %4 = 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)
  %5 = load i32, ptr %3, align 4, !tbaa !5
  %6 = zext i32 %5 to i64
  %7 = call ptr @llvm.stacksave.p0()
  %8 = alloca i32, i64 %6, align 16
  %9 = load i32, ptr %3, align 4, !tbaa !5
  %10 = icmp sgt i32 %9, 0
  br i1 %10, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph, %2
  %.lcssa = phi i32 [ %9, %2 ], [ %15, %.lr.ph ]
  call void @_Z13swapAlternatePii(ptr noundef nonnull %8, i32 noundef %.lcssa)
  %11 = load i32, ptr %3, align 4, !tbaa !5
  %12 = icmp sgt i32 %11, 0
  br i1 %12, label %.lr.ph12, label %._crit_edge13

.lr.ph:                                           ; preds = %2, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %2 ]
  %13 = getelementptr inbounds i32, ptr %8, i64 %indvars.iv
  %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) %13)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %15 = load i32, ptr %3, align 4, !tbaa !5
  %16 = sext i32 %15 to i64
  %17 = icmp slt i64 %indvars.iv.next, %16
  br i1 %17, label %.lr.ph, label %._crit_edge, !llvm.loop !9

._crit_edge13:                                    ; preds = %.lr.ph12, %._crit_edge
  call void @llvm.stackrestore.p0(ptr %7)
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %3) #6
  ret i32 0

.lr.ph12:                                         ; preds = %._crit_edge, %.lr.ph12
  %indvars.iv16 = phi i64 [ %indvars.iv.next17, %.lr.ph12 ], [ 0, %._crit_edge ]
  %18 = getelementptr inbounds i32, ptr %8, i64 %indvars.iv16
  %19 = load i32, ptr %18, align 4, !tbaa !5
  %20 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %19)
  %21 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) %20, ptr noundef nonnull @.str)
  %indvars.iv.next17 = add nuw nsw i64 %indvars.iv16, 1
  %22 = load i32, ptr %3, align 4, !tbaa !5
  %23 = sext i32 %22 to i64
  %24 = icmp slt i64 %indvars.iv.next17, %23
  br i1 %24, label %.lr.ph12, label %._crit_edge13, !llvm.loop !11
}

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 #3

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn
declare ptr @llvm.stacksave.p0() #4

; 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 #5

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) local_unnamed_addr #3

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn
declare void @llvm.stackrestore.p0(ptr) #4

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 nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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 #3 = { "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 = { mustprogress nocallback nofree nosync nounwind willreturn }
attributes #5 = { 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 #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}


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