; LLVM IR from HarshCasper/NeoAlgo :: C-Plus-Plus/cp (length_of_last_word)

; 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 @_Z16lengthOfLastWordNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef %0) #0 {
  %2 = alloca ptr, align 8
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #3
  store i32 0, ptr %3, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #3
  %5 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %0) #3
  %6 = sub i64 %5, 1
  %7 = trunc i64 %6 to i32
  store i32 %7, ptr %4, align 4, !tbaa !9
  br label %8

8:                                                ; preds = %20, %1
  %9 = load i32, ptr %4, align 4, !tbaa !9
  %10 = icmp sge i32 %9, 0
  br i1 %10, label %11, label %18

11:                                               ; preds = %8
  %12 = load i32, ptr %4, align 4, !tbaa !9
  %13 = sext i32 %12 to i64
  %14 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %13)
  %15 = load i8, ptr %14, align 1, !tbaa !11
  %16 = sext i8 %15 to i32
  %17 = icmp eq i32 %16, 32
  br label %18

18:                                               ; preds = %11, %8
  %19 = phi i1 [ false, %8 ], [ %17, %11 ]
  br i1 %19, label %20, label %23

20:                                               ; preds = %18
  %21 = load i32, ptr %4, align 4, !tbaa !9
  %22 = add nsw i32 %21, -1
  store i32 %22, ptr %4, align 4, !tbaa !9
  br label %8, !llvm.loop !12

23:                                               ; preds = %18
  br label %24

24:                                               ; preds = %36, %23
  %25 = load i32, ptr %4, align 4, !tbaa !9
  %26 = icmp sge i32 %25, 0
  br i1 %26, label %27, label %34

27:                                               ; preds = %24
  %28 = load i32, ptr %4, align 4, !tbaa !9
  %29 = sext i32 %28 to i64
  %30 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %29)
  %31 = load i8, ptr %30, align 1, !tbaa !11
  %32 = sext i8 %31 to i32
  %33 = icmp ne i32 %32, 32
  br label %34

34:                                               ; preds = %27, %24
  %35 = phi i1 [ false, %24 ], [ %33, %27 ]
  br i1 %35, label %36, label %41

36:                                               ; preds = %34
  %37 = load i32, ptr %3, align 4, !tbaa !9
  %38 = add nsw i32 %37, 1
  store i32 %38, ptr %3, align 4, !tbaa !9
  %39 = load i32, ptr %4, align 4, !tbaa !9
  %40 = add nsw i32 %39, -1
  store i32 %40, ptr %4, align 4, !tbaa !9
  br label %24, !llvm.loop !14

41:                                               ; preds = %34
  %42 = load i32, ptr %3, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #3
  ret i32 %42
}

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

; Function Attrs: mustprogress nounwind uwtable
declare noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32)) #2 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) #2 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 = { 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 #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"}
!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 @_Z16lengthOfLastWordNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef nonnull %0) local_unnamed_addr #0 {
  %2 = tail call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %0) #1
  %3 = trunc i64 %2 to i32
  %4 = and i64 %2, 4294967295
  br label %5

5:                                                ; preds = %8, %1
  %indvars.iv20 = phi i32 [ %indvars.iv.next21, %8 ], [ %3, %1 ]
  %indvars.iv16.in = phi i32 [ %indvars.iv16, %8 ], [ %3, %1 ]
  %indvars.iv = phi i64 [ %indvars.iv.next, %8 ], [ %4, %1 ]
  %indvars.iv.next = add nsw i64 %indvars.iv, -1
  %6 = and i64 %indvars.iv.next, 2147483648
  %7 = icmp eq i64 %6, 0
  br i1 %7, label %8, label %.critedge2

8:                                                ; preds = %5
  %indvars.iv16 = add i32 %indvars.iv16.in, -1
  %9 = and i64 %indvars.iv.next, 2147483647
  %10 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %9)
  %11 = load i8, ptr %10, align 1, !tbaa !5
  %12 = icmp eq i8 %11, 32
  %indvars.iv.next21 = add i32 %indvars.iv20, -1
  br i1 %12, label %5, label %.lr.ph.preheader, !llvm.loop !8

.lr.ph.preheader:                                 ; preds = %8
  %13 = zext i32 %indvars.iv16 to i64
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader, %16
  %indvars.iv18 = phi i64 [ %13, %.lr.ph.preheader ], [ %indvars.iv.next19, %16 ]
  %.01011 = phi i32 [ 0, %.lr.ph.preheader ], [ %17, %16 ]
  %14 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %indvars.iv18)
  %15 = load i8, ptr %14, align 1, !tbaa !5
  %.not = icmp eq i8 %15, 32
  br i1 %.not, label %.critedge2, label %16

16:                                               ; preds = %.lr.ph
  %17 = add nuw i32 %.01011, 1
  %indvars.iv.next19 = add nsw i64 %indvars.iv18, -1
  %exitcond.not = icmp eq i32 %17, %indvars.iv20
  br i1 %exitcond.not, label %.critedge2, label %.lr.ph, !llvm.loop !10

.critedge2:                                       ; preds = %5, %.lr.ph, %16
  %.010.lcssa = phi i32 [ %indvars.iv20, %16 ], [ %.01011, %.lr.ph ], [ 0, %5 ]
  ret i32 %.010.lcssa
}

; 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

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 = { 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"}
!10 = distinct !{!10, !9}


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