; LLVM IR from Leet-Us-Code/DSA-A-Z-Practice :: Sid's Levels/Level - 1/DynamicProgramming (FriendsPairing)

; 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

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

15:                                               ; preds = %38, %0
  %16 = load i32, ptr %5, align 4, !tbaa !5
  %17 = load i32, ptr %2, align 4, !tbaa !5
  %18 = icmp sle i32 %16, %17
  br i1 %18, label %20, label %19

19:                                               ; preds = %15
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #6
  br label %41

20:                                               ; preds = %15
  %21 = load i32, ptr %5, align 4, !tbaa !5
  %22 = sub nsw i32 %21, 1
  %23 = load i32, ptr %5, align 4, !tbaa !5
  %24 = sub nsw i32 %23, 2
  %25 = sext i32 %24 to i64
  %26 = getelementptr inbounds i32, ptr %11, i64 %25
  %27 = load i32, ptr %26, align 4, !tbaa !5
  %28 = mul nsw i32 %22, %27
  %29 = load i32, ptr %5, align 4, !tbaa !5
  %30 = sub nsw i32 %29, 1
  %31 = sext i32 %30 to i64
  %32 = getelementptr inbounds i32, ptr %11, i64 %31
  %33 = load i32, ptr %32, align 4, !tbaa !5
  %34 = add nsw i32 %28, %33
  %35 = load i32, ptr %5, align 4, !tbaa !5
  %36 = sext i32 %35 to i64
  %37 = getelementptr inbounds i32, ptr %11, i64 %36
  store i32 %34, ptr %37, align 4, !tbaa !5
  br label %38

38:                                               ; preds = %20
  %39 = load i32, ptr %5, align 4, !tbaa !5
  %40 = add nsw i32 %39, 1
  store i32 %40, ptr %5, align 4, !tbaa !5
  br label %15, !llvm.loop !9

41:                                               ; preds = %19
  %42 = load i32, ptr %2, align 4, !tbaa !5
  %43 = sext i32 %42 to i64
  %44 = getelementptr inbounds i32, ptr %11, i64 %43
  %45 = load i32, ptr %44, align 4, !tbaa !5
  %46 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %45)
  %47 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) %46, ptr noundef @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  %48 = load ptr, ptr %3, align 8
  call void @llvm.stackrestore.p0(ptr %48)
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #6
  %49 = load i32, ptr %1, align 4
  ret i32 %49
}

; 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

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) #4 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)) #5

; 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 = { 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 = { 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"}


; 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

; 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) #6
  %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
  %4 = add nsw i32 %3, 1
  %5 = zext i32 %4 to i64
  %6 = call ptr @llvm.stacksave.p0()
  %7 = alloca i32, i64 %5, align 16
  store i32 0, ptr %7, align 16, !tbaa !5
  %8 = getelementptr inbounds i8, ptr %7, i64 4
  store i32 1, ptr %8, align 4, !tbaa !5
  %9 = getelementptr inbounds i8, ptr %7, i64 8
  store i32 2, ptr %9, align 8, !tbaa !5
  %10 = load i32, ptr %1, align 4, !tbaa !5
  %.not8 = icmp slt i32 %10, 3
  br i1 %.not8, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %0
  %11 = zext nneg i32 %10 to i64
  %xtraiter = and i64 %11, 1
  %12 = icmp eq i32 %10, 3
  br i1 %12, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph.preheader.new

.lr.ph.preheader.new:                             ; preds = %.lr.ph.preheader
  %13 = and i64 %11, 2147483646
  %14 = add nsw i64 %13, -4
  br label %.lr.ph

._crit_edge.loopexit.unr-lcssa:                   ; preds = %.lr.ph, %.lr.ph.preheader
  %.unr = phi i32 [ 2, %.lr.ph.preheader ], [ %41, %.lr.ph ]
  %indvars.iv.unr = phi i64 [ 3, %.lr.ph.preheader ], [ %indvars.iv.next.1, %.lr.ph ]
  %lcmp.mod.not = icmp eq i64 %xtraiter, 0
  br i1 %lcmp.mod.not, label %._crit_edge, label %.lr.ph.epil

.lr.ph.epil:                                      ; preds = %._crit_edge.loopexit.unr-lcssa
  %15 = getelementptr i32, ptr %7, i64 %indvars.iv.unr
  %16 = getelementptr i8, ptr %15, i64 -8
  %17 = load i32, ptr %16, align 4, !tbaa !5
  %18 = trunc i64 %indvars.iv.unr to i32
  %19 = add i32 %18, -1
  %20 = mul nsw i32 %17, %19
  %21 = add nsw i32 %20, %.unr
  store i32 %21, ptr %15, align 4, !tbaa !5
  br label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph.epil, %._crit_edge.loopexit.unr-lcssa, %0
  %22 = sext i32 %10 to i64
  %23 = getelementptr inbounds i32, ptr %7, i64 %22
  %24 = load i32, ptr %23, align 4, !tbaa !5
  %25 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %24)
  %26 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) %25, ptr noundef nonnull @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  call void @llvm.stackrestore.p0(ptr %6)
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #6
  ret i32 0

.lr.ph:                                           ; preds = %.lr.ph, %.lr.ph.preheader.new
  %27 = phi i32 [ 2, %.lr.ph.preheader.new ], [ %41, %.lr.ph ]
  %indvars.iv = phi i64 [ 3, %.lr.ph.preheader.new ], [ %indvars.iv.next.1, %.lr.ph ]
  %niter = phi i64 [ 0, %.lr.ph.preheader.new ], [ %niter.next.1, %.lr.ph ]
  %28 = getelementptr i32, ptr %7, i64 %indvars.iv
  %29 = getelementptr i8, ptr %28, i64 -8
  %30 = load i32, ptr %29, align 4, !tbaa !5
  %31 = trunc i64 %indvars.iv to i32
  %32 = add nsw i32 %31, -1
  %33 = mul nsw i32 %30, %32
  %34 = add nsw i32 %33, %27
  store i32 %34, ptr %28, align 4, !tbaa !5
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %35 = getelementptr i32, ptr %7, i64 %indvars.iv.next
  %36 = getelementptr i8, ptr %35, i64 -8
  %37 = load i32, ptr %36, align 4, !tbaa !5
  %38 = trunc i64 %indvars.iv.next to i32
  %39 = add i32 %38, -1
  %40 = mul nsw i32 %37, %39
  %41 = add nsw i32 %40, %34
  store i32 %41, ptr %35, align 4, !tbaa !5
  %indvars.iv.next.1 = add nuw nsw i64 %indvars.iv, 2
  %niter.next.1 = add i64 %niter, 2
  %niter.ncmp.1 = icmp eq i64 %niter, %14
  br i1 %niter.ncmp.1, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph, !llvm.loop !9
}

; 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

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 #4 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)) #5

; 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 = { 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 = { 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"}


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