; LLVM IR from HarshCasper/NeoAlgo :: C-Plus-Plus/dp/string_permutations.ll (Z19string_permutationsPcii)

; 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
@.str = external hidden unnamed_addr constant [2 x i8], align 1

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_Z4swapPcS_(ptr noundef, ptr noundef) #0

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

; 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
define dso_local void @_Z19string_permutationsPcii(ptr noundef %0, i32 noundef %1, i32 noundef %2) #2 {
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  store i32 %2, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #4
  %9 = load i32, ptr %5, align 4, !tbaa !9
  %10 = load i32, ptr %6, align 4, !tbaa !9
  %11 = icmp eq i32 %9, %10
  br i1 %11, label %12, label %16

12:                                               ; preds = %3
  %13 = load ptr, ptr %4, align 8, !tbaa !5
  %14 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef %13)
  %15 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) %14, ptr noundef @.str)
  br label %48

16:                                               ; preds = %3
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #4
  %17 = load i32, ptr %5, align 4, !tbaa !9
  store i32 %17, ptr %8, align 4, !tbaa !9
  br label %18

18:                                               ; preds = %44, %16
  %19 = load i32, ptr %8, align 4, !tbaa !9
  %20 = load i32, ptr %6, align 4, !tbaa !9
  %21 = icmp sle i32 %19, %20
  br i1 %21, label %23, label %22

22:                                               ; preds = %18
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #4
  br label %47

23:                                               ; preds = %18
  %24 = load ptr, ptr %4, align 8, !tbaa !5
  %25 = load i32, ptr %5, align 4, !tbaa !9
  %26 = sext i32 %25 to i64
  %27 = getelementptr inbounds i8, ptr %24, i64 %26
  %28 = load ptr, ptr %4, align 8, !tbaa !5
  %29 = load i32, ptr %8, align 4, !tbaa !9
  %30 = sext i32 %29 to i64
  %31 = getelementptr inbounds i8, ptr %28, i64 %30
  call void @_Z4swapPcS_(ptr noundef %27, ptr noundef %31)
  %32 = load ptr, ptr %4, align 8, !tbaa !5
  %33 = load i32, ptr %5, align 4, !tbaa !9
  %34 = add nsw i32 %33, 1
  %35 = load i32, ptr %6, align 4, !tbaa !9
  call void @_Z19string_permutationsPcii(ptr noundef %32, i32 noundef %34, i32 noundef %35)
  %36 = load ptr, ptr %4, align 8, !tbaa !5
  %37 = load i32, ptr %5, align 4, !tbaa !9
  %38 = sext i32 %37 to i64
  %39 = getelementptr inbounds i8, ptr %36, i64 %38
  %40 = load ptr, ptr %4, align 8, !tbaa !5
  %41 = load i32, ptr %8, align 4, !tbaa !9
  %42 = sext i32 %41 to i64
  %43 = getelementptr inbounds i8, ptr %40, i64 %42
  call void @_Z4swapPcS_(ptr noundef %39, ptr noundef %43)
  br label %44

44:                                               ; preds = %23
  %45 = load i32, ptr %8, align 4, !tbaa !9
  %46 = add nsw i32 %45, 1
  store i32 %46, ptr %8, align 4, !tbaa !9
  br label %18, !llvm.loop !11

47:                                               ; preds = %22
  br label %48

48:                                               ; preds = %47, %12
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #4
  ret void
}

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #3

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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = { 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 }

!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 = distinct !{!11, !12}
!12 = !{!"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_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
@.str = external hidden unnamed_addr constant [2 x i8], align 1

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_Z4swapPcS_(ptr noundef, ptr noundef) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
define dso_local void @_Z19string_permutationsPcii(ptr noundef %0, i32 noundef %1, i32 noundef %2) local_unnamed_addr #1 {
  %4 = icmp eq i32 %1, %2
  br i1 %4, label %9, label %.preheader

.preheader:                                       ; preds = %3
  %.not19 = icmp sgt i32 %1, %2
  br i1 %.not19, label %.loopexit, label %.lr.ph

.lr.ph:                                           ; preds = %.preheader
  %5 = sext i32 %1 to i64
  %6 = getelementptr inbounds i8, ptr %0, i64 %5
  %7 = add nsw i32 %1, 1
  %8 = add i32 %2, 1
  br label %12

9:                                                ; preds = %3
  %10 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef %0)
  %11 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) %10, ptr noundef nonnull @.str)
  br label %.loopexit

12:                                               ; preds = %.lr.ph, %12
  %indvars.iv = phi i64 [ %5, %.lr.ph ], [ %indvars.iv.next, %12 ]
  %13 = getelementptr inbounds i8, ptr %0, i64 %indvars.iv
  tail call void @_Z4swapPcS_(ptr noundef %6, ptr noundef %13)
  tail call void @_Z19string_permutationsPcii(ptr noundef %0, i32 noundef %7, i32 noundef %2)
  tail call void @_Z4swapPcS_(ptr noundef %6, ptr noundef %13)
  %indvars.iv.next = add nsw i64 %indvars.iv, 1
  %lftr.wideiv = trunc i64 %indvars.iv.next to i32
  %exitcond.not = icmp eq i32 %8, %lftr.wideiv
  br i1 %exitcond.not, label %.loopexit, label %12, !llvm.loop !5

.loopexit:                                        ; preds = %12, %.preheader, %9
  ret void
}

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) local_unnamed_addr #2

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 = { 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 = { 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" }

!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"}


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