; LLVM IR from devparthgarg/Data-Structures-and-Algorithms :: 10. Strings/11 Leftmost Repeating Character (11b Leftmost Repeating Character)

; 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"

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_Z17leftMostRepeatingNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca ptr, align 8
  %4 = alloca [256 x i32], align 16
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 1024, ptr %4) #4
  call void @llvm.memset.p0.i64(ptr align 16 %4, i8 0, i64 1024, i1 false)
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #4
  %9 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %0) #4
  %10 = trunc i64 %9 to i32
  store i32 %10, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #4
  store i32 0, ptr %6, align 4, !tbaa !9
  br label %11

11:                                               ; preds = %25, %1
  %12 = load i32, ptr %6, align 4, !tbaa !9
  %13 = load i32, ptr %5, align 4, !tbaa !9
  %14 = icmp slt i32 %12, %13
  br i1 %14, label %16, label %15

15:                                               ; preds = %11
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #4
  br label %28

16:                                               ; preds = %11
  %17 = load i32, ptr %6, align 4, !tbaa !9
  %18 = sext i32 %17 to i64
  %19 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %18)
  %20 = load i8, ptr %19, align 1, !tbaa !11
  %21 = sext i8 %20 to i64
  %22 = getelementptr inbounds [256 x i32], ptr %4, i64 0, i64 %21
  %23 = load i32, ptr %22, align 4, !tbaa !9
  %24 = add nsw i32 %23, 1
  store i32 %24, ptr %22, align 4, !tbaa !9
  br label %25

25:                                               ; preds = %16
  %26 = load i32, ptr %6, align 4, !tbaa !9
  %27 = add nsw i32 %26, 1
  store i32 %27, ptr %6, align 4, !tbaa !9
  br label %11, !llvm.loop !12

28:                                               ; preds = %15
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #4
  store i32 0, ptr %7, align 4, !tbaa !9
  br label %29

29:                                               ; preds = %46, %28
  %30 = load i32, ptr %7, align 4, !tbaa !9
  %31 = load i32, ptr %5, align 4, !tbaa !9
  %32 = icmp slt i32 %30, %31
  br i1 %32, label %34, label %33

33:                                               ; preds = %29
  store i32 5, ptr %8, align 4
  br label %49

34:                                               ; preds = %29
  %35 = load i32, ptr %7, align 4, !tbaa !9
  %36 = sext i32 %35 to i64
  %37 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %36)
  %38 = load i8, ptr %37, align 1, !tbaa !11
  %39 = sext i8 %38 to i64
  %40 = getelementptr inbounds [256 x i32], ptr %4, i64 0, i64 %39
  %41 = load i32, ptr %40, align 4, !tbaa !9
  %42 = icmp sgt i32 %41, 1
  br i1 %42, label %43, label %45

43:                                               ; preds = %34
  %44 = load i32, ptr %7, align 4, !tbaa !9
  store i32 %44, ptr %2, align 4
  store i32 1, ptr %8, align 4
  br label %49

45:                                               ; preds = %34
  br label %46

46:                                               ; preds = %45
  %47 = load i32, ptr %7, align 4, !tbaa !9
  %48 = add nsw i32 %47, 1
  store i32 %48, ptr %7, align 4, !tbaa !9
  br label %29, !llvm.loop !14

49:                                               ; preds = %43, %33
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #4
  %50 = load i32, ptr %8, align 4
  switch i32 %50, label %52 [
    i32 5, label %51
  ]

51:                                               ; preds = %49
  store i32 -1, ptr %2, align 4
  store i32 1, ptr %8, align 4
  br label %52

52:                                               ; preds = %51, %49
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #4
  call void @llvm.lifetime.end.p0(i64 1024, ptr %4) #4
  %53 = load i32, ptr %2, align 4
  ret i32 %53
}

; 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 nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #2

; Function Attrs: mustprogress nounwind uwtable
declare noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32)) #3 align 2

; Function Attrs: mustprogress nounwind uwtable
declare noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32), i64 noundef) #3 align 2

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

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 = { nocallback nofree nounwind willreturn memory(argmem: write) }
attributes #3 = { 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 #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 = !{!7, !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}
!14 = distinct !{!14, !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"

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z17leftMostRepeatingNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef nonnull %0) local_unnamed_addr #0 {
  %2 = alloca [256 x i32], align 16
  call void @llvm.lifetime.start.p0(i64 1024, ptr nonnull %2) #3
  call void @llvm.memset.p0.i64(ptr noundef nonnull align 16 dereferenceable(1024) %2, i8 0, i64 1024, i1 false)
  %3 = tail call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %0) #3
  %4 = trunc i64 %3 to i32
  %5 = icmp sgt i32 %4, 0
  br i1 %5, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %1
  %wide.trip.count = and i64 %3, 2147483647
  br label %.lr.ph

.preheader:                                       ; preds = %.lr.ph
  br i1 %5, label %.lr.ph18.preheader, label %._crit_edge

.lr.ph18.preheader:                               ; preds = %.preheader
  %wide.trip.count25 = and i64 %3, 2147483647
  br label %.lr.ph18

.lr.ph:                                           ; preds = %.lr.ph.preheader, %.lr.ph
  %indvars.iv = phi i64 [ 0, %.lr.ph.preheader ], [ %indvars.iv.next, %.lr.ph ]
  %6 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %indvars.iv)
  %7 = load i8, ptr %6, align 1, !tbaa !5
  %8 = sext i8 %7 to i64
  %9 = getelementptr inbounds [256 x i32], ptr %2, i64 0, i64 %8
  %10 = load i32, ptr %9, align 4, !tbaa !8
  %11 = add nsw i32 %10, 1
  store i32 %11, ptr %9, align 4, !tbaa !8
  %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 %.preheader, label %.lr.ph, !llvm.loop !10

.lr.ph18:                                         ; preds = %.lr.ph18.preheader, %18
  %indvars.iv22 = phi i64 [ 0, %.lr.ph18.preheader ], [ %indvars.iv.next23, %18 ]
  %12 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %indvars.iv22)
  %13 = load i8, ptr %12, align 1, !tbaa !5
  %14 = sext i8 %13 to i64
  %15 = getelementptr inbounds [256 x i32], ptr %2, i64 0, i64 %14
  %16 = load i32, ptr %15, align 4, !tbaa !8
  %17 = icmp sgt i32 %16, 1
  br i1 %17, label %._crit_edge.loopexit.split.loop.exit, label %18

18:                                               ; preds = %.lr.ph18
  %indvars.iv.next23 = add nuw nsw i64 %indvars.iv22, 1
  %exitcond26.not = icmp eq i64 %indvars.iv.next23, %wide.trip.count25
  br i1 %exitcond26.not, label %._crit_edge, label %.lr.ph18, !llvm.loop !12

._crit_edge.loopexit.split.loop.exit:             ; preds = %.lr.ph18
  %19 = trunc nuw nsw i64 %indvars.iv22 to i32
  br label %._crit_edge

._crit_edge:                                      ; preds = %18, %._crit_edge.loopexit.split.loop.exit, %1, %.preheader
  %spec.select = phi i32 [ -1, %.preheader ], [ -1, %1 ], [ %19, %._crit_edge.loopexit.split.loop.exit ], [ -1, %18 ]
  call void @llvm.lifetime.end.p0(i64 1024, ptr nonnull %2) #3
  ret i32 %spec.select
}

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

; Function Attrs: mustprogress nocallback nofree nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #2

; Function Attrs: mustprogress nounwind uwtable
declare noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32), i64 noundef) local_unnamed_addr #0 align 2

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

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 nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { mustprogress nocallback nofree nounwind willreturn memory(argmem: write) }
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 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C++ TBAA"}
!8 = !{!9, !9, i64 0}
!9 = !{!"int", !6, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"llvm.loop.mustprogress"}
!12 = distinct !{!12, !11}


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