; LLVM IR from div-bargali/Data-Structures-and-Algorithms :: C++/Algorithms/Backtracking (RAT IN MAZE  problem)

; 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 }

@_ZSt3cin = external global %"class.std::basic_istream", align 8

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

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

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z10ratInAMazePA20_ii(ptr noundef, i32 noundef) #1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #2 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca [20 x [20 x i32]], align 16
  %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 1600, ptr %3) #4
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #4
  store i32 0, ptr %4, align 4, !tbaa !5
  br label %8

8:                                                ; preds = %31, %0
  %9 = load i32, ptr %4, align 4, !tbaa !5
  %10 = load i32, ptr %2, align 4, !tbaa !5
  %11 = icmp slt i32 %9, %10
  br i1 %11, label %13, label %12

12:                                               ; preds = %8
  store i32 2, ptr %5, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #4
  br label %34

13:                                               ; preds = %8
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #4
  store i32 0, ptr %6, align 4, !tbaa !5
  br label %14

14:                                               ; preds = %27, %13
  %15 = load i32, ptr %6, align 4, !tbaa !5
  %16 = load i32, ptr %2, align 4, !tbaa !5
  %17 = icmp slt i32 %15, %16
  br i1 %17, label %19, label %18

18:                                               ; preds = %14
  store i32 5, ptr %5, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #4
  br label %30

19:                                               ; preds = %14
  %20 = load i32, ptr %4, align 4, !tbaa !5
  %21 = sext i32 %20 to i64
  %22 = getelementptr inbounds [20 x [20 x i32]], ptr %3, i64 0, i64 %21
  %23 = load i32, ptr %6, align 4, !tbaa !5
  %24 = sext i32 %23 to i64
  %25 = getelementptr inbounds [20 x i32], ptr %22, i64 0, i64 %24
  %26 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %25)
  br label %27

27:                                               ; preds = %19
  %28 = load i32, ptr %6, align 4, !tbaa !5
  %29 = add nsw i32 %28, 1
  store i32 %29, ptr %6, align 4, !tbaa !5
  br label %14, !llvm.loop !9

30:                                               ; preds = %18
  br label %31

31:                                               ; preds = %30
  %32 = load i32, ptr %4, align 4, !tbaa !5
  %33 = add nsw i32 %32, 1
  store i32 %33, ptr %4, align 4, !tbaa !5
  br label %8, !llvm.loop !11

34:                                               ; preds = %12
  %35 = getelementptr inbounds [20 x [20 x i32]], ptr %3, i64 0, i64 0
  %36 = load i32, ptr %2, align 4, !tbaa !5
  call void @_Z10ratInAMazePA20_ii(ptr noundef %35, i32 noundef %36)
  call void @llvm.lifetime.end.p0(i64 1600, ptr %3) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #4
  %37 = load i32, ptr %1, align 4
  ret i32 %37
}

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

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #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 = { 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}


; 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 }

@_ZSt3cin = external global %"class.std::basic_istream", align 8

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

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

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z10ratInAMazePA20_ii(ptr noundef, i32 noundef) local_unnamed_addr #1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #2 {
  %1 = alloca i32, align 4
  %2 = alloca [20 x [20 x i32]], align 16
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #4
  %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)
  call void @llvm.lifetime.start.p0(i64 1600, ptr nonnull %2) #4
  %4 = load i32, ptr %1, align 4, !tbaa !5
  %5 = icmp sgt i32 %4, 0
  br i1 %5, label %.preheader, label %._crit_edge11

.preheader:                                       ; preds = %0, %._crit_edge
  %6 = phi i32 [ %8, %._crit_edge ], [ %4, %0 ]
  %indvars.iv15 = phi i64 [ %indvars.iv.next16, %._crit_edge ], [ 0, %0 ]
  %7 = icmp sgt i32 %6, 0
  br i1 %7, label %.lr.ph, label %.preheader.._crit_edge_crit_edge

.preheader.._crit_edge_crit_edge:                 ; preds = %.preheader
  %.pre = sext i32 %6 to i64
  br label %._crit_edge

._crit_edge11:                                    ; preds = %._crit_edge, %0
  %.lcssa = phi i32 [ %4, %0 ], [ %8, %._crit_edge ]
  call void @_Z10ratInAMazePA20_ii(ptr noundef nonnull %2, i32 noundef %.lcssa)
  call void @llvm.lifetime.end.p0(i64 1600, ptr nonnull %2) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #4
  ret i32 0

._crit_edge:                                      ; preds = %.lr.ph, %.preheader.._crit_edge_crit_edge
  %.pre-phi = phi i64 [ %.pre, %.preheader.._crit_edge_crit_edge ], [ %13, %.lr.ph ]
  %8 = phi i32 [ %6, %.preheader.._crit_edge_crit_edge ], [ %12, %.lr.ph ]
  %indvars.iv.next16 = add nuw nsw i64 %indvars.iv15, 1
  %9 = icmp slt i64 %indvars.iv.next16, %.pre-phi
  br i1 %9, label %.preheader, label %._crit_edge11, !llvm.loop !9

.lr.ph:                                           ; preds = %.preheader, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %.preheader ]
  %10 = getelementptr inbounds [20 x [20 x i32]], ptr %2, i64 0, i64 %indvars.iv15, i64 %indvars.iv
  %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) %10)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %12 = load i32, ptr %1, align 4, !tbaa !5
  %13 = sext i32 %12 to i64
  %14 = icmp slt i64 %indvars.iv.next, %13
  br i1 %14, label %.lr.ph, label %._crit_edge, !llvm.loop !12
}

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

attributes #0 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #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 = { 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, !11}
!10 = !{!"llvm.loop.mustprogress"}
!11 = !{!"llvm.loop.unswitch.partial.disable"}
!12 = distinct !{!12, !10}


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