; LLVM IR from devparthgarg/Data-Structures-and-Algorithms :: 10. Strings/13 Reverse Words in String (13b Reverse Words in String)

; 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
declare dso_local void @_Z7reverseRNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEii(ptr noundef nonnull align 8 dereferenceable(32), i32 noundef, i32 noundef) #0

; 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) #1 align 2

; Function Attrs: mustprogress uwtable
define dso_local void @_Z12reverseWordsRNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef nonnull align 8 dereferenceable(32) %0) #0 {
  %2 = alloca ptr, align 8
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #3
  %6 = load ptr, ptr %2, align 8, !tbaa !5
  %7 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %6) #3
  %8 = trunc i64 %7 to i32
  store i32 %8, ptr %3, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #3
  store i32 0, ptr %4, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  store i32 0, ptr %5, align 4, !tbaa !9
  br label %9

9:                                                ; preds = %30, %1
  %10 = load i32, ptr %5, align 4, !tbaa !9
  %11 = load i32, ptr %3, align 4, !tbaa !9
  %12 = icmp slt i32 %10, %11
  br i1 %12, label %14, label %13

13:                                               ; preds = %9
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  br label %33

14:                                               ; preds = %9
  %15 = load ptr, ptr %2, align 8, !tbaa !5
  %16 = load i32, ptr %5, align 4, !tbaa !9
  %17 = sext i32 %16 to i64
  %18 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %15, i64 noundef %17)
  %19 = load i8, ptr %18, align 1, !tbaa !11
  %20 = sext i8 %19 to i32
  %21 = icmp eq i32 %20, 32
  br i1 %21, label %22, label %29

22:                                               ; preds = %14
  %23 = load ptr, ptr %2, align 8, !tbaa !5
  %24 = load i32, ptr %4, align 4, !tbaa !9
  %25 = load i32, ptr %5, align 4, !tbaa !9
  %26 = sub nsw i32 %25, 1
  call void @_Z7reverseRNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEii(ptr noundef nonnull align 8 dereferenceable(32) %23, i32 noundef %24, i32 noundef %26)
  %27 = load i32, ptr %5, align 4, !tbaa !9
  %28 = add nsw i32 %27, 1
  store i32 %28, ptr %4, align 4, !tbaa !9
  br label %29

29:                                               ; preds = %22, %14
  br label %30

30:                                               ; preds = %29
  %31 = load i32, ptr %5, align 4, !tbaa !9
  %32 = add nsw i32 %31, 1
  store i32 %32, ptr %5, align 4, !tbaa !9
  br label %9, !llvm.loop !12

33:                                               ; preds = %13
  %34 = load ptr, ptr %2, align 8, !tbaa !5
  %35 = load i32, ptr %4, align 4, !tbaa !9
  %36 = load i32, ptr %3, align 4, !tbaa !9
  %37 = sub nsw i32 %36, 1
  call void @_Z7reverseRNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEii(ptr noundef nonnull align 8 dereferenceable(32) %34, i32 noundef %35, i32 noundef %37)
  %38 = load ptr, ptr %2, align 8, !tbaa !5
  %39 = load i32, ptr %3, align 4, !tbaa !9
  %40 = sub nsw i32 %39, 1
  call void @_Z7reverseRNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEii(ptr noundef nonnull align 8 dereferenceable(32) %38, i32 noundef 0, i32 noundef %40)
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #3
  ret void
}

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

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z7reverseRNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEii(ptr noundef nonnull align 8 dereferenceable(32), i32 noundef, i32 noundef) local_unnamed_addr #0

; 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
define dso_local void @_Z12reverseWordsRNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef nonnull align 8 dereferenceable(32) %0) local_unnamed_addr #0 {
  %2 = tail call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %0) #2
  %3 = trunc i64 %2 to i32
  %4 = icmp sgt i32 %3, 0
  br i1 %4, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %1
  %wide.trip.count = and i64 %2, 2147483647
  br label %.lr.ph

._crit_edge:                                      ; preds = %14, %1
  %.014.lcssa = phi i32 [ 0, %1 ], [ %.1, %14 ]
  %5 = add nsw i32 %3, -1
  tail call void @_Z7reverseRNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEii(ptr noundef nonnull align 8 dereferenceable(32) %0, i32 noundef %.014.lcssa, i32 noundef %5)
  tail call void @_Z7reverseRNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEii(ptr noundef nonnull align 8 dereferenceable(32) %0, i32 noundef 0, i32 noundef %5)
  ret void

.lr.ph:                                           ; preds = %.lr.ph.preheader, %14
  %indvars.iv = phi i64 [ 0, %.lr.ph.preheader ], [ %indvars.iv.next.pre-phi, %14 ]
  %.01416 = phi i32 [ 0, %.lr.ph.preheader ], [ %.1, %14 ]
  %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 = icmp eq i8 %7, 32
  br i1 %8, label %9, label %.lr.ph._crit_edge

.lr.ph._crit_edge:                                ; preds = %.lr.ph
  %.pre = add nuw nsw i64 %indvars.iv, 1
  br label %14

9:                                                ; preds = %.lr.ph
  %10 = trunc i64 %indvars.iv to i32
  %11 = add i32 %10, -1
  tail call void @_Z7reverseRNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEii(ptr noundef nonnull align 8 dereferenceable(32) %0, i32 noundef %.01416, i32 noundef %11)
  %12 = add nuw nsw i64 %indvars.iv, 1
  %13 = trunc nuw nsw i64 %12 to i32
  br label %14

14:                                               ; preds = %.lr.ph._crit_edge, %9
  %indvars.iv.next.pre-phi = phi i64 [ %.pre, %.lr.ph._crit_edge ], [ %12, %9 ]
  %.1 = phi i32 [ %.01416, %.lr.ph._crit_edge ], [ %13, %9 ]
  %exitcond.not = icmp eq i64 %indvars.iv.next.pre-phi, %wide.trip.count
  br i1 %exitcond.not, label %._crit_edge, label %.lr.ph, !llvm.loop !8
}

; 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

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,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass,TailCallElimPass