; LLVM IR from ritikbanger/Hacktoberfest2022-DSA :: 09. String (ReverseStringUsingStack)

; 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"

@.str = external hidden unnamed_addr constant [30 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [9 x i8], align 1
@.str.2 = external hidden unnamed_addr constant [3 x i8], align 1

; Function Attrs: nounwind uwtable
declare dso_local void @push(i8 noundef signext) #0

; Function Attrs: nounwind uwtable
declare dso_local signext i8 @topEle() #0

; Function Attrs: nounwind uwtable
declare dso_local void @pop() #0

; Function Attrs: nounwind uwtable
define dso_local i32 @main() #0 {
  %1 = alloca i32, align 4
  %2 = alloca [100 x i8], align 16
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 100, ptr %2) #4
  %5 = call i32 (ptr, ...) @printf(ptr noundef @.str)
  %6 = getelementptr inbounds [100 x i8], ptr %2, i64 0, i64 0
  %7 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str.1, ptr noundef %6)
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #4
  store i32 0, ptr %3, align 4, !tbaa !5
  br label %8

8:                                                ; preds = %20, %0
  %9 = load i32, ptr %3, align 4, !tbaa !5
  %10 = sext i32 %9 to i64
  %11 = getelementptr inbounds [100 x i8], ptr %2, i64 0, i64 0
  %12 = call i64 @strlen(ptr noundef %11) #5
  %13 = icmp ult i64 %10, %12
  br i1 %13, label %15, label %14

14:                                               ; preds = %8
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #4
  br label %23

15:                                               ; preds = %8
  %16 = load i32, ptr %3, align 4, !tbaa !5
  %17 = sext i32 %16 to i64
  %18 = getelementptr inbounds [100 x i8], ptr %2, i64 0, i64 %17
  %19 = load i8, ptr %18, align 1, !tbaa !9
  call void @push(i8 noundef signext %19)
  br label %20

20:                                               ; preds = %15
  %21 = load i32, ptr %3, align 4, !tbaa !5
  %22 = add nsw i32 %21, 1
  store i32 %22, ptr %3, align 4, !tbaa !5
  br label %8, !llvm.loop !10

23:                                               ; preds = %14
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #4
  store i32 0, ptr %4, align 4, !tbaa !5
  br label %24

24:                                               ; preds = %35, %23
  %25 = load i32, ptr %4, align 4, !tbaa !5
  %26 = sext i32 %25 to i64
  %27 = getelementptr inbounds [100 x i8], ptr %2, i64 0, i64 0
  %28 = call i64 @strlen(ptr noundef %27) #5
  %29 = icmp ult i64 %26, %28
  br i1 %29, label %31, label %30

30:                                               ; preds = %24
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #4
  br label %38

31:                                               ; preds = %24
  %32 = call signext i8 @topEle()
  %33 = sext i8 %32 to i32
  %34 = call i32 (ptr, ...) @printf(ptr noundef @.str.2, i32 noundef %33)
  call void @pop()
  br label %35

35:                                               ; preds = %31
  %36 = load i32, ptr %4, align 4, !tbaa !5
  %37 = add nsw i32 %36, 1
  store i32 %37, ptr %4, align 4, !tbaa !5
  br label %24, !llvm.loop !12

38:                                               ; preds = %30
  call void @llvm.lifetime.end.p0(i64 100, ptr %2) #4
  ret i32 0
}

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

declare i32 @printf(ptr noundef, ...) #2

declare i32 @__isoc99_scanf(ptr noundef, ...) #2

; Function Attrs: nounwind willreturn memory(read)
declare i64 @strlen(ptr noundef) #3

; 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 = { "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 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 #4 = { nounwind }
attributes #5 = { 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 = !{!"int", !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"}
!12 = distinct !{!12, !11}


; 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"

@.str = external hidden unnamed_addr constant [30 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [9 x i8], align 1
@.str.2 = external hidden unnamed_addr constant [3 x i8], align 1

; Function Attrs: nounwind uwtable
declare dso_local void @push(i8 noundef signext) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
declare dso_local signext i8 @topEle() local_unnamed_addr #0

; Function Attrs: nounwind uwtable
declare dso_local void @pop() local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local noundef i32 @main() local_unnamed_addr #0 {
  %1 = alloca [100 x i8], align 16
  call void @llvm.lifetime.start.p0(i64 100, ptr nonnull %1) #4
  %2 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str)
  %3 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str.1, ptr noundef nonnull %1)
  %char0 = load i8, ptr %1, align 16
  %.not = icmp eq i8 %char0, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph

.preheader:                                       ; preds = %.lr.ph
  %char010.pre = load i8, ptr %1, align 16
  %4 = icmp eq i8 %char010.pre, 0
  br i1 %4, label %._crit_edge, label %.lr.ph9

.lr.ph:                                           ; preds = %0, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %0 ]
  %5 = getelementptr inbounds [100 x i8], ptr %1, i64 0, i64 %indvars.iv
  %6 = load i8, ptr %5, align 1, !tbaa !5
  call void @push(i8 noundef signext %6)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %7 = call i64 @strlen(ptr noundef nonnull dereferenceable(1) %1) #5
  %8 = icmp ugt i64 %7, %indvars.iv.next
  br i1 %8, label %.lr.ph, label %.preheader, !llvm.loop !8

._crit_edge:                                      ; preds = %.lr.ph9, %0, %.preheader
  call void @llvm.lifetime.end.p0(i64 100, ptr nonnull %1) #4
  ret i32 0

.lr.ph9:                                          ; preds = %.preheader, %.lr.ph9
  %indvars.iv13 = phi i64 [ %indvars.iv.next14, %.lr.ph9 ], [ 0, %.preheader ]
  %9 = call signext i8 @topEle()
  %10 = sext i8 %9 to i32
  %11 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.2, i32 noundef %10)
  call void @pop()
  %indvars.iv.next14 = add nuw nsw i64 %indvars.iv13, 1
  %12 = call i64 @strlen(ptr noundef nonnull dereferenceable(1) %1) #5
  %13 = icmp ugt i64 %12, %indvars.iv.next14
  br i1 %13, label %.lr.ph9, label %._crit_edge, !llvm.loop !10
}

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

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #2

; Function Attrs: nofree nounwind
declare noundef i32 @__isoc99_scanf(ptr nocapture noundef readonly, ...) local_unnamed_addr #2

; Function Attrs: mustprogress nofree nounwind willreturn memory(argmem: read)
declare i64 @strlen(ptr nocapture noundef) local_unnamed_addr #3

; Function Attrs: mustprogress 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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { nofree nounwind "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 = { 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 #4 = { nounwind }
attributes #5 = { 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"}
!10 = distinct !{!10, !9}


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