; LLVM IR from MakeContributions/DSA :: algorithms/CPlusPlus/Strings (delete-alternate-characters)

; 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::__cxx11::basic_string" = type { %"struct.std::__cxx11::basic_string<char>::_Alloc_hider", i64, %union.anon }
%"struct.std::__cxx11::basic_string<char>::_Alloc_hider" = type { ptr }
%union.anon = type { i64, [8 x i8] }

; Function Attrs: mustprogress uwtable
define dso_local void @_Z12delAlternateNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef %1) #0 personality ptr @__gxx_personality_v0 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i1, align 1
  %6 = alloca i32, align 4
  %7 = alloca ptr, align 8
  %8 = alloca i32, align 4
  store ptr %0, ptr %3, align 8
  store ptr %1, ptr %4, align 8, !tbaa !5
  store i1 false, ptr %5, align 1
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32) %0) #3
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #3
  store i32 0, ptr %6, align 4, !tbaa !9
  br label %9

9:                                                ; preds = %23, %2
  %10 = load i32, ptr %6, align 4, !tbaa !9
  %11 = sext i32 %10 to i64
  %12 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  %13 = icmp ult i64 %11, %12
  br i1 %13, label %15, label %14

14:                                               ; preds = %9
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #3
  br label %30

15:                                               ; preds = %9
  %16 = load i32, ptr %6, align 4, !tbaa !9
  %17 = sext i32 %16 to i64
  %18 = invoke noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE2atEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %17)
          to label %19 unwind label %26

19:                                               ; preds = %15
  %20 = load i8, ptr %18, align 1, !tbaa !11
  %21 = invoke noundef nonnull align 8 dereferenceable(32) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEpLEc(ptr noundef nonnull align 8 dereferenceable(32) %0, i8 noundef signext %20)
          to label %22 unwind label %26

22:                                               ; preds = %19
  br label %23

23:                                               ; preds = %22
  %24 = load i32, ptr %6, align 4, !tbaa !9
  %25 = add nsw i32 %24, 2
  store i32 %25, ptr %6, align 4, !tbaa !9
  br label %9, !llvm.loop !12

26:                                               ; preds = %19, %15
  %27 = landingpad { ptr, i32 }
          cleanup
  %28 = extractvalue { ptr, i32 } %27, 0
  store ptr %28, ptr %7, align 8
  %29 = extractvalue { ptr, i32 } %27, 1
  store i32 %29, ptr %8, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #3
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %0) #3
  br label %34

30:                                               ; preds = %14
  store i1 true, ptr %5, align 1
  %31 = load i1, ptr %5, align 1
  br i1 %31, label %33, label %32

32:                                               ; preds = %30
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %0) #3
  br label %33

33:                                               ; preds = %32, %30
  ret void

34:                                               ; preds = %26
  %35 = load ptr, ptr %7, align 8
  %36 = load i32, ptr %8, align 4
  %37 = insertvalue { ptr, i32 } poison, ptr %35, 0
  %38 = insertvalue { ptr, i32 } %37, i32 %36, 1
  resume { ptr, i32 } %38
}

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #1 align 2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #2

; 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 uwtable
declare noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE2atEm(ptr noundef nonnull align 8 dereferenceable(32), i64 noundef) #0 align 2

declare i32 @__gxx_personality_v0(...)

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(32) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEpLEc(ptr noundef nonnull align 8 dereferenceable(32), i8 noundef signext) #0 align 2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #1 align 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 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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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::__cxx11::basic_string" = type { %"struct.std::__cxx11::basic_string<char>::_Alloc_hider", i64, %union.anon }
%"struct.std::__cxx11::basic_string<char>::_Alloc_hider" = type { ptr }
%union.anon = type { i64, [8 x i8] }

; Function Attrs: mustprogress uwtable
define dso_local void @_Z12delAlternateNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr dead_on_unwind noalias nonnull writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef %1) local_unnamed_addr #0 personality ptr @__gxx_personality_v0 {
  tail call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32) %0) #2
  %3 = tail call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #2
  %.not = icmp eq i64 %3, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %2, %8
  %indvars.iv = phi i64 [ %indvars.iv.next, %8 ], [ 0, %2 ]
  %4 = invoke noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE2atEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %indvars.iv)
          to label %5 unwind label %11

5:                                                ; preds = %.lr.ph
  %6 = load i8, ptr %4, align 1, !tbaa !5
  %7 = invoke noundef nonnull align 8 dereferenceable(32) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEpLEc(ptr noundef nonnull align 8 dereferenceable(32) %0, i8 noundef signext %6)
          to label %8 unwind label %11

8:                                                ; preds = %5
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 2
  %9 = tail call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #2
  %10 = icmp ugt i64 %9, %indvars.iv.next
  br i1 %10, label %.lr.ph, label %._crit_edge, !llvm.loop !8

11:                                               ; preds = %5, %.lr.ph
  %12 = landingpad { ptr, i32 }
          cleanup
  tail call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %0) #2
  resume { ptr, i32 } %12

._crit_edge:                                      ; preds = %8, %2
  ret void
}

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #1 align 2

; Function Attrs: mustprogress nounwind uwtable
declare noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32)) local_unnamed_addr #1 align 2

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE2atEm(ptr noundef nonnull align 8 dereferenceable(32), i64 noundef) local_unnamed_addr #0 align 2

declare i32 @__gxx_personality_v0(...)

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(32) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEpLEc(ptr noundef nonnull align 8 dereferenceable(32), i8 noundef signext) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #1 align 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 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 = { 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,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass