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

; 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::vector" = type { %"struct.std::_Vector_base" }
%"struct.std::_Vector_base" = type { %"struct.std::_Vector_base<std::__cxx11::basic_string<char>, std::allocator<std::__cxx11::basic_string<char>>>::_Vector_impl" }
%"struct.std::_Vector_base<std::__cxx11::basic_string<char>, std::allocator<std::__cxx11::basic_string<char>>>::_Vector_impl" = type { %"struct.std::_Vector_base<std::__cxx11::basic_string<char>, std::allocator<std::__cxx11::basic_string<char>>>::_Vector_impl_data" }
%"struct.std::_Vector_base<std::__cxx11::basic_string<char>, std::allocator<std::__cxx11::basic_string<char>>>::_Vector_impl_data" = type { ptr, ptr, ptr }

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 8 dereferenceable(32) ptr @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) #1 align 2

; 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 nounwind uwtable
declare dso_local void @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EEC2EOS7_(ptr noundef nonnull align 8 dereferenceable(24), ptr noundef nonnull align 8 dereferenceable(24)) unnamed_addr #1 align 2

; Function Attrs: mustprogress uwtable
define dso_local void @_Z13checkVerticalSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EEiiS5_(ptr dead_on_unwind noalias writable sret(%"class.std::vector") align 8 %0, ptr noundef %1, i32 noundef %2, i32 noundef %3, ptr noundef %4) #2 {
  %6 = alloca ptr, align 8
  %7 = alloca ptr, align 8
  %8 = alloca i32, align 4
  %9 = alloca i32, align 4
  %10 = alloca ptr, align 8
  %11 = alloca i32, align 4
  %12 = alloca i32, align 4
  %13 = alloca i32, align 4
  store ptr %0, ptr %6, align 8
  store ptr %1, ptr %7, align 8, !tbaa !5
  store i32 %2, ptr %8, align 4, !tbaa !9
  store i32 %3, ptr %9, align 4, !tbaa !9
  store ptr %4, ptr %10, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %11) #3
  %14 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %4) #3
  %15 = trunc i64 %14 to i32
  store i32 %15, ptr %11, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %12) #3
  store i32 0, ptr %12, align 4, !tbaa !9
  br label %16

16:                                               ; preds = %67, %5
  %17 = load i32, ptr %12, align 4, !tbaa !9
  %18 = load i32, ptr %11, align 4, !tbaa !9
  %19 = icmp slt i32 %17, %18
  br i1 %19, label %21, label %20

20:                                               ; preds = %16
  store i32 2, ptr %13, align 4
  br label %70

21:                                               ; preds = %16
  %22 = load i32, ptr %8, align 4, !tbaa !9
  %23 = load i32, ptr %12, align 4, !tbaa !9
  %24 = add nsw i32 %22, %23
  %25 = sext i32 %24 to i64
  %26 = call noundef nonnull align 8 dereferenceable(32) ptr @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EEixEm(ptr noundef nonnull align 8 dereferenceable(24) %1, i64 noundef %25) #3
  %27 = load i32, ptr %9, align 4, !tbaa !9
  %28 = sext i32 %27 to i64
  %29 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %26, i64 noundef %28)
  %30 = load i8, ptr %29, align 1, !tbaa !11
  %31 = sext i8 %30 to i32
  %32 = icmp eq i32 %31, 45
  br i1 %32, label %50, label %33

33:                                               ; preds = %21
  %34 = load i32, ptr %8, align 4, !tbaa !9
  %35 = load i32, ptr %12, align 4, !tbaa !9
  %36 = add nsw i32 %34, %35
  %37 = sext i32 %36 to i64
  %38 = call noundef nonnull align 8 dereferenceable(32) ptr @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EEixEm(ptr noundef nonnull align 8 dereferenceable(24) %1, i64 noundef %37) #3
  %39 = load i32, ptr %9, align 4, !tbaa !9
  %40 = sext i32 %39 to i64
  %41 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %38, i64 noundef %40)
  %42 = load i8, ptr %41, align 1, !tbaa !11
  %43 = sext i8 %42 to i32
  %44 = load i32, ptr %12, align 4, !tbaa !9
  %45 = sext i32 %44 to i64
  %46 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %4, i64 noundef %45)
  %47 = load i8, ptr %46, align 1, !tbaa !11
  %48 = sext i8 %47 to i32
  %49 = icmp eq i32 %43, %48
  br i1 %49, label %50, label %63

50:                                               ; preds = %33, %21
  %51 = load i32, ptr %12, align 4, !tbaa !9
  %52 = sext i32 %51 to i64
  %53 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %4, i64 noundef %52)
  %54 = load i8, ptr %53, align 1, !tbaa !11
  %55 = load i32, ptr %8, align 4, !tbaa !9
  %56 = load i32, ptr %12, align 4, !tbaa !9
  %57 = add nsw i32 %55, %56
  %58 = sext i32 %57 to i64
  %59 = call noundef nonnull align 8 dereferenceable(32) ptr @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EEixEm(ptr noundef nonnull align 8 dereferenceable(24) %1, i64 noundef %58) #3
  %60 = load i32, ptr %9, align 4, !tbaa !9
  %61 = sext i32 %60 to i64
  %62 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %59, i64 noundef %61)
  store i8 %54, ptr %62, align 1, !tbaa !11
  br label %66

63:                                               ; preds = %33
  %64 = call noundef nonnull align 8 dereferenceable(32) ptr @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EEixEm(ptr noundef nonnull align 8 dereferenceable(24) %1, i64 noundef 0) #3
  %65 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %64, i64 noundef 0)
  store i8 64, ptr %65, align 1, !tbaa !11
  call void @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EEC2EOS7_(ptr noundef nonnull align 8 dereferenceable(24) %0, ptr noundef nonnull align 8 dereferenceable(24) %1) #3
  store i32 1, ptr %13, align 4
  br label %70

66:                                               ; preds = %50
  br label %67

67:                                               ; preds = %66
  %68 = load i32, ptr %12, align 4, !tbaa !9
  %69 = add nsw i32 %68, 1
  store i32 %69, ptr %12, align 4, !tbaa !9
  br label %16, !llvm.loop !12

70:                                               ; preds = %63, %20
  call void @llvm.lifetime.end.p0(i64 4, ptr %12) #3
  %71 = load i32, ptr %13, align 4
  switch i32 %71, label %73 [
    i32 2, label %72
  ]

72:                                               ; preds = %70
  call void @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EEC2EOS7_(ptr noundef nonnull align 8 dereferenceable(24) %0, ptr noundef nonnull align 8 dereferenceable(24) %1) #3
  store i32 1, ptr %13, align 4
  br label %73

73:                                               ; preds = %72, %70
  call void @llvm.lifetime.end.p0(i64 4, ptr %11) #3
  ret void
}

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 = { 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 = distinct !{!12, !13}
!13 = !{!"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::vector" = type { %"struct.std::_Vector_base" }
%"struct.std::_Vector_base" = type { %"struct.std::_Vector_base<std::__cxx11::basic_string<char>, std::allocator<std::__cxx11::basic_string<char>>>::_Vector_impl" }
%"struct.std::_Vector_base<std::__cxx11::basic_string<char>, std::allocator<std::__cxx11::basic_string<char>>>::_Vector_impl" = type { %"struct.std::_Vector_base<std::__cxx11::basic_string<char>, std::allocator<std::__cxx11::basic_string<char>>>::_Vector_impl_data" }
%"struct.std::_Vector_base<std::__cxx11::basic_string<char>, std::allocator<std::__cxx11::basic_string<char>>>::_Vector_impl_data" = type { ptr, ptr, ptr }

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 8 dereferenceable(32) ptr @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) local_unnamed_addr #0 align 2

; 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 nounwind uwtable
declare dso_local void @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EEC2EOS7_(ptr noundef nonnull align 8 dereferenceable(24), ptr noundef nonnull align 8 dereferenceable(24)) unnamed_addr #0 align 2

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z13checkVerticalSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EEiiS5_(ptr dead_on_unwind noalias writable sret(%"class.std::vector") align 8 %0, ptr noundef %1, i32 noundef %2, i32 noundef %3, ptr noundef nonnull %4) local_unnamed_addr #0 {
  %6 = tail call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %4) #1
  %7 = trunc i64 %6 to i32
  %.not16 = icmp sgt i32 %7, 0
  br i1 %.not16, label %.lr.ph, label %.critedge

.lr.ph:                                           ; preds = %5
  %8 = sext i32 %3 to i64
  %9 = sext i32 %2 to i64
  %wide.trip.count = and i64 %6, 2147483647
  br label %10

10:                                               ; preds = %.lr.ph, %23
  %indvars.iv = phi i64 [ 0, %.lr.ph ], [ %indvars.iv.next, %23 ]
  %11 = add nsw i64 %indvars.iv, %9
  %12 = tail call noundef nonnull align 8 dereferenceable(32) ptr @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EEixEm(ptr noundef nonnull align 8 dereferenceable(24) %1, i64 noundef %11) #1
  %13 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %12, i64 noundef %8)
  %14 = load i8, ptr %13, align 1, !tbaa !5
  %15 = icmp eq i8 %14, 45
  br i1 %15, label %23, label %16

16:                                               ; preds = %10
  %17 = tail call noundef nonnull align 8 dereferenceable(32) ptr @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EEixEm(ptr noundef nonnull align 8 dereferenceable(24) %1, i64 noundef %11) #1
  %18 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %17, i64 noundef %8)
  %19 = load i8, ptr %18, align 1, !tbaa !5
  %20 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %4, i64 noundef %indvars.iv)
  %21 = load i8, ptr %20, align 1, !tbaa !5
  %22 = icmp eq i8 %19, %21
  br i1 %22, label %23, label %28

23:                                               ; preds = %16, %10
  %24 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %4, i64 noundef %indvars.iv)
  %25 = load i8, ptr %24, align 1, !tbaa !5
  %26 = tail call noundef nonnull align 8 dereferenceable(32) ptr @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EEixEm(ptr noundef nonnull align 8 dereferenceable(24) %1, i64 noundef %11) #1
  %27 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %26, i64 noundef %8)
  store i8 %25, ptr %27, align 1, !tbaa !5
  %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 %.critedge, label %10, !llvm.loop !8

28:                                               ; preds = %16
  %29 = tail call noundef nonnull align 8 dereferenceable(32) ptr @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EEixEm(ptr noundef nonnull align 8 dereferenceable(24) %1, i64 noundef 0) #1
  %30 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %29, i64 noundef 0)
  store i8 64, ptr %30, align 1, !tbaa !5
  br label %.critedge

.critedge:                                        ; preds = %23, %5, %28
  tail call void @_ZNSt6vectorINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEESaIS5_EEC2EOS7_(ptr noundef nonnull align 8 dereferenceable(24) %0, ptr noundef nonnull align 8 dereferenceable(24) %1) #1
  ret void
}

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 = { 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 = distinct !{!8, !9}
!9 = !{!"llvm.loop.mustprogress"}


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