; LLVM IR from ritikbanger/Hacktoberfest2022-DSA :: 11. Stack (stack-using-array)

; 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"

@top = external dso_local global i32, align 4
@arr = external dso_local global [4 x i32], align 16
@.str.2 = external hidden unnamed_addr constant [17 x i8], align 1
@.str.3 = external hidden unnamed_addr constant [3 x i8], align 1
@.str.4 = external hidden unnamed_addr constant [2 x i8], align 1

; Function Attrs: nounwind uwtable
declare dso_local i32 @isEmpty() #0

declare i32 @printf(ptr noundef, ...) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: nounwind uwtable
define dso_local i32 @print() #0 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = call i32 @isEmpty()
  %4 = icmp ne i32 %3, 0
  br i1 %4, label %5, label %7

5:                                                ; preds = %0
  %6 = call i32 (ptr, ...) @printf(ptr noundef @.str.2)
  br label %24

7:                                                ; preds = %0
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #3
  %8 = load i32, ptr @top, align 4, !tbaa !5
  store i32 %8, ptr %2, align 4, !tbaa !5
  br label %9

9:                                                ; preds = %20, %7
  %10 = load i32, ptr %2, align 4, !tbaa !5
  %11 = icmp sge i32 %10, 0
  br i1 %11, label %13, label %12

12:                                               ; preds = %9
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #3
  br label %23

13:                                               ; preds = %9
  %14 = load i32, ptr %2, align 4, !tbaa !5
  %15 = sext i32 %14 to i64
  %16 = getelementptr inbounds [4 x i32], ptr @arr, i64 0, i64 %15
  %17 = load i32, ptr %16, align 4, !tbaa !5
  %18 = call i32 (ptr, ...) @printf(ptr noundef @.str.3, i32 noundef %17)
  %19 = call i32 (ptr, ...) @printf(ptr noundef @.str.4)
  br label %20

20:                                               ; preds = %13
  %21 = load i32, ptr %2, align 4, !tbaa !5
  %22 = add nsw i32 %21, -1
  store i32 %22, ptr %2, align 4, !tbaa !5
  br label %9, !llvm.loop !9

23:                                               ; preds = %12
  br label %24

24:                                               ; preds = %23, %5
  %25 = load i32, ptr %1, align 4
  ret i32 %25
}

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 = { "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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"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"

@top = external dso_local local_unnamed_addr global i32, align 4
@arr = external dso_local local_unnamed_addr global [4 x i32], align 16
@.str.2 = external hidden unnamed_addr constant [17 x i8], align 1
@.str.3 = external hidden unnamed_addr constant [3 x i8], align 1
@.str.4 = external hidden unnamed_addr constant [2 x i8], align 1

; Function Attrs: nounwind uwtable
declare dso_local i32 @isEmpty() local_unnamed_addr #0

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #1

; Function Attrs: nounwind uwtable
define dso_local i32 @print() local_unnamed_addr #0 {
  %1 = tail call i32 @isEmpty()
  %.not = icmp eq i32 %1, 0
  br i1 %.not, label %4, label %2

2:                                                ; preds = %0
  %3 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.2)
  br label %.loopexit

4:                                                ; preds = %0
  %5 = load i32, ptr @top, align 4, !tbaa !5
  %6 = icmp sgt i32 %5, -1
  br i1 %6, label %.lr.ph.preheader, label %.loopexit

.lr.ph.preheader:                                 ; preds = %4
  %7 = zext nneg i32 %5 to i64
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader, %.lr.ph
  %indvars.iv = phi i64 [ %7, %.lr.ph.preheader ], [ %indvars.iv.next, %.lr.ph ]
  %8 = getelementptr inbounds [4 x i32], ptr @arr, i64 0, i64 %indvars.iv
  %9 = load i32, ptr %8, align 4, !tbaa !5
  %10 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.3, i32 noundef %9)
  %11 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.4)
  %indvars.iv.next = add nsw i64 %indvars.iv, -1
  %.not6 = icmp eq i64 %indvars.iv, 0
  br i1 %.not6, label %.loopexit, label %.lr.ph, !llvm.loop !9

.loopexit:                                        ; preds = %.lr.ph, %4, %2
  ret i32 undef
}

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 = { 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" }

!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 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


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