; LLVM IR from JessonYue/LeetCodeLearning :: Array/zhuqiguang/c (ReversalStr)

; 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: nounwind uwtable
define dso_local void @reverse(ptr noundef %0) #0 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i8, align 1
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #3
  %6 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %6, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #3
  %7 = load ptr, ptr %2, align 8, !tbaa !5
  %8 = call i64 @strlen(ptr noundef %7) #4
  %9 = load ptr, ptr %2, align 8, !tbaa !5
  %10 = getelementptr inbounds i8, ptr %9, i64 %8
  %11 = getelementptr inbounds i8, ptr %10, i64 -1
  store ptr %11, ptr %4, align 8, !tbaa !5
  br label %12

12:                                               ; preds = %16, %1
  %13 = load ptr, ptr %3, align 8, !tbaa !5
  %14 = load ptr, ptr %4, align 8, !tbaa !5
  %15 = icmp ult ptr %13, %14
  br i1 %15, label %16, label %28

16:                                               ; preds = %12
  call void @llvm.lifetime.start.p0(i64 1, ptr %5) #3
  %17 = load ptr, ptr %3, align 8, !tbaa !5
  %18 = load i8, ptr %17, align 1, !tbaa !9
  store i8 %18, ptr %5, align 1, !tbaa !9
  %19 = load ptr, ptr %4, align 8, !tbaa !5
  %20 = load i8, ptr %19, align 1, !tbaa !9
  %21 = load ptr, ptr %3, align 8, !tbaa !5
  store i8 %20, ptr %21, align 1, !tbaa !9
  %22 = load i8, ptr %5, align 1, !tbaa !9
  %23 = load ptr, ptr %4, align 8, !tbaa !5
  store i8 %22, ptr %23, align 1, !tbaa !9
  %24 = load ptr, ptr %3, align 8, !tbaa !5
  %25 = getelementptr inbounds i8, ptr %24, i32 1
  store ptr %25, ptr %3, align 8, !tbaa !5
  %26 = load ptr, ptr %4, align 8, !tbaa !5
  %27 = getelementptr inbounds i8, ptr %26, i32 -1
  store ptr %27, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 1, ptr %5) #3
  br label %12, !llvm.loop !10

28:                                               ; preds = %12
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 8, 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) #1

; Function Attrs: nounwind willreturn memory(read)
declare i64 @strlen(ptr noundef) #2

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

attributes #0 = { 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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { nounwind willreturn memory(read) "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 }
attributes #4 = { nounwind willreturn memory(read) }

!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/C++ TBAA"}
!9 = !{!7, !7, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"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: nofree nounwind memory(readwrite, inaccessiblemem: none) uwtable
define dso_local void @reverse(ptr noundef %0) local_unnamed_addr #0 {
  %2 = tail call i64 @strlen(ptr noundef nonnull dereferenceable(1) %0) #2
  %3 = getelementptr inbounds i8, ptr %0, i64 %2
  %.01112 = getelementptr inbounds i8, ptr %3, i64 -1
  %4 = icmp ugt ptr %.01112, %0
  br i1 %4, label %.lr.ph, label %._crit_edge

.lr.ph:                                           ; preds = %1, %.lr.ph
  %.01114 = phi ptr [ %.011, %.lr.ph ], [ %.01112, %1 ]
  %.013 = phi ptr [ %7, %.lr.ph ], [ %0, %1 ]
  %5 = load i8, ptr %.013, align 1, !tbaa !5
  %6 = load i8, ptr %.01114, align 1, !tbaa !5
  store i8 %6, ptr %.013, align 1, !tbaa !5
  store i8 %5, ptr %.01114, align 1, !tbaa !5
  %7 = getelementptr inbounds i8, ptr %.013, i64 1
  %.011 = getelementptr inbounds i8, ptr %.01114, i64 -1
  %8 = icmp ult ptr %7, %.011
  br i1 %8, label %.lr.ph, label %._crit_edge, !llvm.loop !8

._crit_edge:                                      ; preds = %.lr.ph, %1
  ret void
}

; Function Attrs: mustprogress nofree nounwind willreturn memory(argmem: read)
declare i64 @strlen(ptr nocapture noundef) local_unnamed_addr #1

attributes #0 = { nofree nounwind memory(readwrite, inaccessiblemem: none) 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 nofree nounwind willreturn memory(argmem: read) "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 willreturn memory(read) }

!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/C++ TBAA"}
!8 = distinct !{!8, !9}
!9 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass