; LLVM IR from Lakhankumawat/LearnCPP :: S-Strings/StringReverse.ll (Z7reversePcii)

; 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 void @_Z7reversePcii(ptr noundef %0, i32 noundef %1, i32 noundef %2) #0 {
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i8, align 1
  %8 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  store i32 %2, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 1, ptr %7) #2
  %9 = load i32, ptr %5, align 4, !tbaa !9
  %10 = load i32, ptr %6, align 4, !tbaa !9
  %11 = icmp sge i32 %9, %10
  br i1 %11, label %12, label %13

12:                                               ; preds = %3
  store i32 1, ptr %8, align 4
  br label %38

13:                                               ; preds = %3
  %14 = load ptr, ptr %4, align 8, !tbaa !5
  %15 = load i32, ptr %5, align 4, !tbaa !9
  %16 = sext i32 %15 to i64
  %17 = getelementptr inbounds i8, ptr %14, i64 %16
  %18 = load i8, ptr %17, align 1, !tbaa !11
  store i8 %18, ptr %7, align 1, !tbaa !11
  %19 = load ptr, ptr %4, align 8, !tbaa !5
  %20 = load i32, ptr %6, align 4, !tbaa !9
  %21 = sext i32 %20 to i64
  %22 = getelementptr inbounds i8, ptr %19, i64 %21
  %23 = load i8, ptr %22, align 1, !tbaa !11
  %24 = load ptr, ptr %4, align 8, !tbaa !5
  %25 = load i32, ptr %5, align 4, !tbaa !9
  %26 = sext i32 %25 to i64
  %27 = getelementptr inbounds i8, ptr %24, i64 %26
  store i8 %23, ptr %27, align 1, !tbaa !11
  %28 = load i8, ptr %7, align 1, !tbaa !11
  %29 = load ptr, ptr %4, align 8, !tbaa !5
  %30 = load i32, ptr %6, align 4, !tbaa !9
  %31 = sext i32 %30 to i64
  %32 = getelementptr inbounds i8, ptr %29, i64 %31
  store i8 %28, ptr %32, align 1, !tbaa !11
  %33 = load ptr, ptr %4, align 8, !tbaa !5
  %34 = load i32, ptr %5, align 4, !tbaa !9
  %35 = add nsw i32 %34, 1
  store i32 %35, ptr %5, align 4, !tbaa !9
  %36 = load i32, ptr %6, align 4, !tbaa !9
  %37 = add nsw i32 %36, -1
  store i32 %37, ptr %6, align 4, !tbaa !9
  call void @_Z7reversePcii(ptr noundef %33, i32 noundef %35, i32 noundef %37)
  store i32 0, ptr %8, align 4
  br label %38

38:                                               ; preds = %13, %12
  call void @llvm.lifetime.end.p0(i64 1, ptr %7) #2
  %39 = load i32, ptr %8, align 4
  switch i32 %39, label %41 [
    i32 0, label %40
    i32 1, label %40
  ]

40:                                               ; preds = %38, %38
  ret void

41:                                               ; preds = %38
  unreachable
}

; 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 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 = { 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}


; 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 nofree norecurse nosync nounwind memory(argmem: readwrite) uwtable
define dso_local void @_Z7reversePcii(ptr nocapture noundef %0, i32 noundef %1, i32 noundef %2) local_unnamed_addr #0 {
  %.not16 = icmp slt i32 %1, %2
  br i1 %.not16, label %tailrecurse.preheader, label %tailrecurse._crit_edge

tailrecurse.preheader:                            ; preds = %3
  %4 = sext i32 %2 to i64
  %5 = sext i32 %1 to i64
  br label %tailrecurse

tailrecurse:                                      ; preds = %tailrecurse.preheader, %tailrecurse
  %indvars.iv19 = phi i64 [ %5, %tailrecurse.preheader ], [ %indvars.iv.next20, %tailrecurse ]
  %indvars.iv = phi i64 [ %4, %tailrecurse.preheader ], [ %indvars.iv.next, %tailrecurse ]
  %6 = getelementptr inbounds i8, ptr %0, i64 %indvars.iv19
  %7 = load i8, ptr %6, align 1, !tbaa !5
  %8 = getelementptr inbounds i8, ptr %0, i64 %indvars.iv
  %9 = load i8, ptr %8, align 1, !tbaa !5
  store i8 %9, ptr %6, align 1, !tbaa !5
  store i8 %7, ptr %8, align 1, !tbaa !5
  %indvars.iv.next20 = add nsw i64 %indvars.iv19, 1
  %indvars.iv.next = add nsw i64 %indvars.iv, -1
  %.not = icmp slt i64 %indvars.iv.next20, %indvars.iv.next
  br i1 %.not, label %tailrecurse, label %tailrecurse._crit_edge

tailrecurse._crit_edge:                           ; preds = %tailrecurse, %3
  ret void
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind memory(argmem: readwrite) 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" }

!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"}


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