; LLVM IR from ravireddy07/cpp-book :: src/Algorithm-Based (KnightsTour)

; 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 @_Z11knightsTourPPiiiiii(ptr noundef, i32 noundef, i32 noundef, i32 noundef, i32 noundef, i32 noundef) #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 i32, align 4
  %8 = alloca ptr, align 8
  %9 = alloca i32, align 4
  %10 = alloca i32, align 4
  %11 = alloca i32, align 4
  %12 = 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
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #6
  %13 = 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)
  %14 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) %13, ptr noundef nonnull align 4 dereferenceable(4) %7)
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #6
  %15 = load i32, ptr %6, align 4, !tbaa !5
  %16 = sext i32 %15 to i64
  %17 = call { i64, i1 } @llvm.umul.with.overflow.i64(i64 %16, i64 8)
  %18 = extractvalue { i64, i1 } %17, 1
  %19 = extractvalue { i64, i1 } %17, 0
  %20 = select i1 %18, i64 -1, i64 %19
  %21 = call noalias noundef nonnull ptr @_Znam(i64 noundef %20) #7
  store ptr %21, ptr %8, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %9) #6
  store i32 0, ptr %9, align 4, !tbaa !5
  br label %22

22:                                               ; preds = %39, %2
  %23 = load i32, ptr %9, align 4, !tbaa !5
  %24 = load i32, ptr %6, align 4, !tbaa !5
  %25 = icmp slt i32 %23, %24
  br i1 %25, label %27, label %26

26:                                               ; preds = %22
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #6
  br label %42

27:                                               ; preds = %22
  %28 = load i32, ptr %7, align 4, !tbaa !5
  %29 = sext i32 %28 to i64
  %30 = call { i64, i1 } @llvm.umul.with.overflow.i64(i64 %29, i64 4)
  %31 = extractvalue { i64, i1 } %30, 1
  %32 = extractvalue { i64, i1 } %30, 0
  %33 = select i1 %31, i64 -1, i64 %32
  %34 = call noalias noundef nonnull ptr @_Znam(i64 noundef %33) #7
  %35 = load ptr, ptr %8, align 8, !tbaa !9
  %36 = load i32, ptr %9, align 4, !tbaa !5
  %37 = sext i32 %36 to i64
  %38 = getelementptr inbounds ptr, ptr %35, i64 %37
  store ptr %34, ptr %38, align 8, !tbaa !9
  br label %39

39:                                               ; preds = %27
  %40 = load i32, ptr %9, align 4, !tbaa !5
  %41 = add nsw i32 %40, 1
  store i32 %41, ptr %9, align 4, !tbaa !5
  br label %22, !llvm.loop !11

42:                                               ; preds = %26
  call void @llvm.lifetime.start.p0(i64 4, ptr %10) #6
  store i32 0, ptr %10, align 4, !tbaa !5
  br label %43

43:                                               ; preds = %67, %42
  %44 = load i32, ptr %10, align 4, !tbaa !5
  %45 = load i32, ptr %6, align 4, !tbaa !5
  %46 = icmp slt i32 %44, %45
  br i1 %46, label %48, label %47

47:                                               ; preds = %43
  store i32 5, ptr %11, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %10) #6
  br label %70

48:                                               ; preds = %43
  call void @llvm.lifetime.start.p0(i64 4, ptr %12) #6
  store i32 0, ptr %12, align 4, !tbaa !5
  br label %49

49:                                               ; preds = %63, %48
  %50 = load i32, ptr %12, align 4, !tbaa !5
  %51 = load i32, ptr %7, align 4, !tbaa !5
  %52 = icmp slt i32 %50, %51
  br i1 %52, label %54, label %53

53:                                               ; preds = %49
  store i32 8, ptr %11, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %12) #6
  br label %66

54:                                               ; preds = %49
  %55 = load ptr, ptr %8, align 8, !tbaa !9
  %56 = load i32, ptr %10, align 4, !tbaa !5
  %57 = sext i32 %56 to i64
  %58 = getelementptr inbounds ptr, ptr %55, i64 %57
  %59 = load ptr, ptr %58, align 8, !tbaa !9
  %60 = load i32, ptr %12, align 4, !tbaa !5
  %61 = sext i32 %60 to i64
  %62 = getelementptr inbounds i32, ptr %59, i64 %61
  store i32 -1, ptr %62, align 4, !tbaa !5
  br label %63

63:                                               ; preds = %54
  %64 = load i32, ptr %12, align 4, !tbaa !5
  %65 = add nsw i32 %64, 1
  store i32 %65, ptr %12, align 4, !tbaa !5
  br label %49, !llvm.loop !13

66:                                               ; preds = %53
  br label %67

67:                                               ; preds = %66
  %68 = load i32, ptr %10, align 4, !tbaa !5
  %69 = add nsw i32 %68, 1
  store i32 %69, ptr %10, align 4, !tbaa !5
  br label %43, !llvm.loop !14

70:                                               ; preds = %47
  %71 = load ptr, ptr %8, align 8, !tbaa !9
  %72 = load i32, ptr %6, align 4, !tbaa !5
  %73 = load i32, ptr %7, align 4, !tbaa !5
  call void @_Z11knightsTourPPiiiiii(ptr noundef %71, i32 noundef 2, i32 noundef 2, i32 noundef %72, i32 noundef %73, i32 noundef 0)
  store i32 0, ptr %3, align 4
  store i32 1, ptr %11, align 4
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #6
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #6
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #6
  %74 = load i32, ptr %3, align 4
  ret i32 %74
}

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 speculatable willreturn memory(none)
declare { i64, i1 } @llvm.umul.with.overflow.i64(i64, i64) #4

; Function Attrs: nobuiltin allocsize(0)
declare noundef nonnull ptr @_Znam(i64 noundef) #5

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 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
attributes #5 = { nobuiltin allocsize(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 }
attributes #7 = { builtin allocsize(0) }

!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}
!14 = distinct !{!14, !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 }

@_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 @_Z11knightsTourPPiiiiii(ptr noundef, i32 noundef, i32 noundef, i32 noundef, i32 noundef, i32 noundef) local_unnamed_addr #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
  %4 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %3) #5
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %4) #5
  %5 = 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)
  %6 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) %5, ptr noundef nonnull align 4 dereferenceable(4) %4)
  %7 = load i32, ptr %3, align 4, !tbaa !5
  %8 = sext i32 %7 to i64
  %9 = icmp slt i32 %7, 0
  %10 = shl nsw i64 %8, 3
  %11 = select i1 %9, i64 -1, i64 %10
  %12 = call noalias noundef nonnull ptr @_Znam(i64 noundef %11) #6
  %13 = icmp sgt i32 %7, 0
  %.pre30.pre = load i32, ptr %4, align 4, !tbaa !5
  br i1 %13, label %.lr.ph, label %._crit_edge20

.lr.ph:                                           ; preds = %2
  %14 = sext i32 %.pre30.pre to i64
  %15 = icmp slt i32 %.pre30.pre, 0
  %16 = shl nsw i64 %14, 2
  %17 = select i1 %15, i64 -1, i64 %16
  %wide.trip.count = zext nneg i32 %7 to i64
  br label %19

.preheader15:                                     ; preds = %19
  %18 = icmp sgt i32 %.pre30.pre, 0
  %or.cond = select i1 %13, i1 %18, i1 false
  br i1 %or.cond, label %.preheader, label %._crit_edge20

19:                                               ; preds = %.lr.ph, %19
  %indvars.iv = phi i64 [ 0, %.lr.ph ], [ %indvars.iv.next, %19 ]
  %20 = call noalias noundef nonnull ptr @_Znam(i64 noundef %17) #6
  %21 = getelementptr inbounds ptr, ptr %12, i64 %indvars.iv
  store ptr %20, ptr %21, align 8, !tbaa !9
  %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 %.preheader15, label %19, !llvm.loop !11

.preheader:                                       ; preds = %.preheader15, %._crit_edge
  %22 = phi i32 [ %28, %._crit_edge ], [ %7, %.preheader15 ]
  %23 = phi i32 [ %29, %._crit_edge ], [ %.pre30.pre, %.preheader15 ]
  %indvars.iv27 = phi i64 [ %indvars.iv.next28, %._crit_edge ], [ 0, %.preheader15 ]
  %24 = icmp sgt i32 %23, 0
  br i1 %24, label %.lr.ph18, label %._crit_edge

.lr.ph18:                                         ; preds = %.preheader
  %25 = getelementptr inbounds ptr, ptr %12, i64 %indvars.iv27
  %26 = load ptr, ptr %25, align 8, !tbaa !9
  br label %32

._crit_edge20:                                    ; preds = %._crit_edge, %2, %.preheader15
  %27 = phi i32 [ %.pre30.pre, %.preheader15 ], [ %.pre30.pre, %2 ], [ %29, %._crit_edge ]
  %.lcssa = phi i32 [ %7, %.preheader15 ], [ %7, %2 ], [ %28, %._crit_edge ]
  call void @_Z11knightsTourPPiiiiii(ptr noundef nonnull %12, i32 noundef 2, i32 noundef 2, i32 noundef %.lcssa, i32 noundef %27, i32 noundef 0)
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %4) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %3) #5
  ret i32 0

._crit_edge.loopexit:                             ; preds = %32
  %.pre = load i32, ptr %3, align 4, !tbaa !5
  br label %._crit_edge

._crit_edge:                                      ; preds = %._crit_edge.loopexit, %.preheader
  %28 = phi i32 [ %.pre, %._crit_edge.loopexit ], [ %22, %.preheader ]
  %29 = phi i32 [ %34, %._crit_edge.loopexit ], [ %23, %.preheader ]
  %indvars.iv.next28 = add nuw nsw i64 %indvars.iv27, 1
  %30 = sext i32 %28 to i64
  %31 = icmp slt i64 %indvars.iv.next28, %30
  br i1 %31, label %.preheader, label %._crit_edge20, !llvm.loop !13

32:                                               ; preds = %.lr.ph18, %32
  %indvars.iv24 = phi i64 [ 0, %.lr.ph18 ], [ %indvars.iv.next25, %32 ]
  %33 = getelementptr inbounds i32, ptr %26, i64 %indvars.iv24
  store i32 -1, ptr %33, align 4, !tbaa !5
  %indvars.iv.next25 = add nuw nsw i64 %indvars.iv24, 1
  %34 = load i32, ptr %4, align 4, !tbaa !5
  %35 = sext i32 %34 to i64
  %36 = icmp slt i64 %indvars.iv.next25, %35
  br i1 %36, label %32, label %._crit_edge.loopexit, !llvm.loop !15
}

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: nobuiltin allocsize(0)
declare noundef nonnull ptr @_Znam(i64 noundef) local_unnamed_addr #4

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 = { nobuiltin allocsize(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 = { nounwind }
attributes #6 = { builtin allocsize(0) }

!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, !14}
!14 = !{!"llvm.loop.unswitch.partial.disable"}
!15 = distinct !{!15, !12}


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