; 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-10=Character-arrays_and_2D-arra_6cabc485 (Z15printSubstringsPc)

; 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_ostream" = type { ptr, %"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 }

@_ZSt4cout = external global %"class.std::basic_ostream", align 8

; Function Attrs: mustprogress uwtable
define dso_local void @_Z15printSubstringsPc(ptr noundef %0) #0 {
  %2 = alloca ptr, align 8
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #4
  store i32 1, ptr %3, align 4, !tbaa !9
  br label %8

8:                                                ; preds = %53, %1
  %9 = load i32, ptr %3, align 4, !tbaa !9
  %10 = sext i32 %9 to i64
  %11 = load ptr, ptr %2, align 8, !tbaa !5
  %12 = call i64 @strlen(ptr noundef %11) #5
  %13 = icmp ule i64 %10, %12
  br i1 %13, label %15, label %14

14:                                               ; preds = %8
  store i32 2, ptr %4, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #4
  br label %56

15:                                               ; preds = %8
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #4
  store i32 0, ptr %5, align 4, !tbaa !9
  br label %16

16:                                               ; preds = %49, %15
  %17 = load i32, ptr %5, align 4, !tbaa !9
  %18 = sext i32 %17 to i64
  %19 = load ptr, ptr %2, align 8, !tbaa !5
  %20 = call i64 @strlen(ptr noundef %19) #5
  %21 = load i32, ptr %3, align 4, !tbaa !9
  %22 = sext i32 %21 to i64
  %23 = sub i64 %20, %22
  %24 = icmp ule i64 %18, %23
  br i1 %24, label %26, label %25

25:                                               ; preds = %16
  store i32 5, ptr %4, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #4
  br label %52

26:                                               ; preds = %16
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #4
  %27 = load i32, ptr %5, align 4, !tbaa !9
  %28 = load i32, ptr %3, align 4, !tbaa !9
  %29 = add nsw i32 %27, %28
  %30 = sub nsw i32 %29, 1
  store i32 %30, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #4
  %31 = load i32, ptr %5, align 4, !tbaa !9
  store i32 %31, ptr %7, align 4, !tbaa !9
  br label %32

32:                                               ; preds = %44, %26
  %33 = load i32, ptr %7, align 4, !tbaa !9
  %34 = load i32, ptr %6, align 4, !tbaa !9
  %35 = icmp sle i32 %33, %34
  br i1 %35, label %37, label %36

36:                                               ; preds = %32
  store i32 8, ptr %4, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #4
  br label %47

37:                                               ; preds = %32
  %38 = load ptr, ptr %2, align 8, !tbaa !5
  %39 = load i32, ptr %7, align 4, !tbaa !9
  %40 = sext i32 %39 to i64
  %41 = getelementptr inbounds i8, ptr %38, i64 %40
  %42 = load i8, ptr %41, align 1, !tbaa !11
  %43 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i8 noundef signext %42)
  br label %44

44:                                               ; preds = %37
  %45 = load i32, ptr %7, align 4, !tbaa !9
  %46 = add nsw i32 %45, 1
  store i32 %46, ptr %7, align 4, !tbaa !9
  br label %32, !llvm.loop !12

47:                                               ; preds = %36
  %48 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #4
  br label %49

49:                                               ; preds = %47
  %50 = load i32, ptr %5, align 4, !tbaa !9
  %51 = add nsw i32 %50, 1
  store i32 %51, ptr %5, align 4, !tbaa !9
  br label %16, !llvm.loop !14

52:                                               ; preds = %25
  br label %53

53:                                               ; preds = %52
  %54 = load i32, ptr %3, align 4, !tbaa !9
  %55 = add nsw i32 %54, 1
  store i32 %55, ptr %3, align 4, !tbaa !9
  br label %8, !llvm.loop !15

56:                                               ; preds = %14
  ret void
}

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

; Function Attrs: nounwind willreturn memory(read)
declare i64 @strlen(ptr noundef) #2

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8), i8 noundef signext) #3

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

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #0 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)) #3

attributes #0 = { 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 #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { nounwind willreturn memory(read) "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 = { 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 #4 = { nounwind }
attributes #5 = { nounwind willreturn memory(read) }

!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"}
!14 = distinct !{!14, !13}
!15 = distinct !{!15, !13}


; 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_ostream" = type { ptr, %"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 }

@_ZSt4cout = external global %"class.std::basic_ostream", align 8

; Function Attrs: mustprogress uwtable
define dso_local void @_Z15printSubstringsPc(ptr nocapture noundef readonly %0) local_unnamed_addr #0 {
  %char0 = load i8, ptr %0, align 1
  %.not21 = icmp eq i8 %char0, 0
  br i1 %.not21, label %._crit_edge, label %.preheader

.preheader:                                       ; preds = %1, %2
  %indvars.iv27 = phi i64 [ %indvars.iv.next28, %2 ], [ 1, %1 ]
  br label %3

._crit_edge:                                      ; preds = %2, %1
  ret void

2:                                                ; preds = %5
  %indvars.iv.next28 = add nuw nsw i64 %indvars.iv27, 1
  %.not.not = icmp ugt i64 %7, %indvars.iv27
  br i1 %.not.not, label %.preheader, label %._crit_edge, !llvm.loop !5

3:                                                ; preds = %.preheader, %5
  %indvars.iv = phi i64 [ 0, %.preheader ], [ %indvars.iv.next, %5 ]
  %4 = add nuw nsw i64 %indvars.iv, %indvars.iv27
  br label %9

5:                                                ; preds = %9
  %6 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef nonnull @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %7 = tail call i64 @strlen(ptr noundef nonnull dereferenceable(1) %0) #3
  %8 = sub i64 %7, %indvars.iv27
  %.not17.not = icmp ugt i64 %8, %indvars.iv
  br i1 %.not17.not, label %3, label %2, !llvm.loop !7

9:                                                ; preds = %3, %9
  %indvars.iv23 = phi i64 [ %indvars.iv, %3 ], [ %indvars.iv.next24, %9 ]
  %10 = getelementptr inbounds i8, ptr %0, i64 %indvars.iv23
  %11 = load i8, ptr %10, align 1, !tbaa !8
  %12 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i8 noundef signext %11)
  %indvars.iv.next24 = add nuw nsw i64 %indvars.iv23, 1
  %.not18.not = icmp ult i64 %indvars.iv.next24, %4
  br i1 %.not18.not, label %9, label %5, !llvm.loop !11
}

; Function Attrs: mustprogress nofree nounwind willreturn memory(argmem: read)
declare i64 @strlen(ptr nocapture noundef) local_unnamed_addr #1

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8), i8 noundef signext) 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 #0 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)) #2

attributes #0 = { 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 #1 = { mustprogress nofree nounwind willreturn memory(argmem: read) "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 = { 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 #3 = { nounwind willreturn memory(read) }

!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 = distinct !{!5, !6}
!6 = !{!"llvm.loop.mustprogress"}
!7 = distinct !{!7, !6}
!8 = !{!9, !9, i64 0}
!9 = !{!"omnipotent char", !10, i64 0}
!10 = !{!"Simple C++ TBAA"}
!11 = distinct !{!11, !6}


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