; LLVM IR from Lakhankumawat/LearnCPP :: S-Strings (LongestWordInSentence)

; 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 @_Z12longest_wordNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef %1) #0 {
  %3 = alloca ptr, align 8
  %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
  %9 = alloca i32, align 4
  %10 = alloca i32, align 4
  store ptr %0, ptr %3, align 8
  store ptr %1, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  %11 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  %12 = trunc i64 %11 to i32
  store i32 %12, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #3
  store i32 0, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #3
  store i32 0, ptr %7, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #3
  store i32 0, ptr %8, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %9) #3
  store i32 0, ptr %9, align 4, !tbaa !9
  br label %13

13:                                               ; preds = %45, %2
  %14 = load i32, ptr %7, align 4, !tbaa !9
  %15 = load i32, ptr %5, align 4, !tbaa !9
  %16 = icmp sle i32 %14, %15
  br i1 %16, label %17, label %46

17:                                               ; preds = %13
  %18 = load i32, ptr %7, align 4, !tbaa !9
  %19 = load i32, ptr %5, align 4, !tbaa !9
  %20 = icmp slt i32 %18, %19
  br i1 %20, label %21, label %31

21:                                               ; preds = %17
  %22 = load i32, ptr %7, align 4, !tbaa !9
  %23 = sext i32 %22 to i64
  %24 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %23)
  %25 = load i8, ptr %24, align 1, !tbaa !11
  %26 = sext i8 %25 to i32
  %27 = icmp ne i32 %26, 32
  br i1 %27, label %28, label %31

28:                                               ; preds = %21
  %29 = load i32, ptr %7, align 4, !tbaa !9
  %30 = add nsw i32 %29, 1
  store i32 %30, ptr %7, align 4, !tbaa !9
  br label %45

31:                                               ; preds = %21, %17
  call void @llvm.lifetime.start.p0(i64 4, ptr %10) #3
  %32 = load i32, ptr %7, align 4, !tbaa !9
  %33 = load i32, ptr %6, align 4, !tbaa !9
  %34 = sub nsw i32 %32, %33
  store i32 %34, ptr %10, align 4, !tbaa !9
  %35 = load i32, ptr %10, align 4, !tbaa !9
  %36 = load i32, ptr %8, align 4, !tbaa !9
  %37 = icmp sgt i32 %35, %36
  br i1 %37, label %38, label %41

38:                                               ; preds = %31
  %39 = load i32, ptr %10, align 4, !tbaa !9
  store i32 %39, ptr %8, align 4, !tbaa !9
  %40 = load i32, ptr %6, align 4, !tbaa !9
  store i32 %40, ptr %9, align 4, !tbaa !9
  br label %41

41:                                               ; preds = %38, %31
  %42 = load i32, ptr %7, align 4, !tbaa !9
  %43 = add nsw i32 %42, 1
  store i32 %43, ptr %7, align 4, !tbaa !9
  %44 = load i32, ptr %7, align 4, !tbaa !9
  store i32 %44, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %10) #3
  br label %45

45:                                               ; preds = %41, %28
  br label %13, !llvm.loop !12

46:                                               ; preds = %13
  %47 = load i32, ptr %9, align 4, !tbaa !9
  %48 = sext i32 %47 to i64
  %49 = load i32, ptr %8, align 4, !tbaa !9
  %50 = sext i32 %49 to i64
  call void @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6substrEmm(ptr dead_on_unwind writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %48, i64 noundef %50)
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  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: 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

; Function Attrs: mustprogress uwtable
declare void @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6substrEmm(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8, ptr noundef nonnull align 8 dereferenceable(32), i64 noundef, i64 noundef) #0 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 = { 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"}


; 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 @_Z12longest_wordNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef nonnull %1) local_unnamed_addr #0 {
  %3 = tail call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  %4 = trunc i64 %3 to i32
  %.not27 = icmp slt i32 %4, 0
  br i1 %.not27, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %2, %16
  %.031 = phi i32 [ %.1, %16 ], [ 0, %2 ]
  %.01630 = phi i32 [ %.2, %16 ], [ 0, %2 ]
  %.01829 = phi i32 [ %.220, %16 ], [ 0, %2 ]
  %.02128 = phi i32 [ %.122, %16 ], [ 0, %2 ]
  %5 = icmp slt i32 %.02128, %4
  br i1 %5, label %6, label %12

6:                                                ; preds = %.lr.ph
  %7 = sext i32 %.02128 to i64
  %8 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %7)
  %9 = load i8, ptr %8, align 1, !tbaa !5
  %.not25 = icmp eq i8 %9, 32
  br i1 %.not25, label %12, label %10

10:                                               ; preds = %6
  %11 = add nsw i32 %.02128, 1
  br label %16

12:                                               ; preds = %6, %.lr.ph
  %13 = sub nsw i32 %.02128, %.031
  %14 = icmp sgt i32 %13, %.01829
  %spec.select = tail call i32 @llvm.smax.i32(i32 %13, i32 %.01829)
  %spec.select26 = select i1 %14, i32 %.031, i32 %.01630
  %15 = add nsw i32 %.02128, 1
  br label %16

16:                                               ; preds = %12, %10
  %.122 = phi i32 [ %11, %10 ], [ %15, %12 ]
  %.220 = phi i32 [ %.01829, %10 ], [ %spec.select, %12 ]
  %.2 = phi i32 [ %.01630, %10 ], [ %spec.select26, %12 ]
  %.1 = phi i32 [ %.031, %10 ], [ %15, %12 ]
  %.not = icmp sgt i32 %.122, %4
  br i1 %.not, label %._crit_edge.loopexit, label %.lr.ph, !llvm.loop !8

._crit_edge.loopexit:                             ; preds = %16
  %17 = sext i32 %.2 to i64
  %18 = zext nneg i32 %.220 to i64
  br label %._crit_edge

._crit_edge:                                      ; preds = %._crit_edge.loopexit, %2
  %.018.lcssa = phi i64 [ 0, %2 ], [ %18, %._crit_edge.loopexit ]
  %.016.lcssa = phi i64 [ 0, %2 ], [ %17, %._crit_edge.loopexit ]
  tail call void @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6substrEmm(ptr dead_on_unwind writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %.016.lcssa, i64 noundef %.018.lcssa)
  ret void
}

; 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 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 #1 align 2

; Function Attrs: mustprogress uwtable
declare void @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6substrEmm(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8, ptr noundef nonnull align 8 dereferenceable(32), i64 noundef, i64 noundef) local_unnamed_addr #0 align 2

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.smax.i32(i32, i32) #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 speculatable willreturn memory(none) }
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 = distinct !{!8, !9}
!9 = !{!"llvm.loop.mustprogress"}


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