; LLVM IR from imteekay/algorithms :: computer_science/algorithms/recursion (regua)

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

; Function Attrs: nounwind uwtable
define dso_local void @regua(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  %4 = load i32, ptr %2, align 4, !tbaa !5
  %5 = icmp eq i32 %4, 1
  br i1 %5, label %6, label %8

6:                                                ; preds = %1
  %7 = call i32 (ptr, ...) @printf(ptr noundef @.str)
  br label %24

8:                                                ; preds = %1
  %9 = load i32, ptr %2, align 4, !tbaa !5
  %10 = sub nsw i32 %9, 1
  call void @regua(i32 noundef %10)
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #3
  store i32 0, ptr %3, align 4, !tbaa !5
  br label %11

11:                                               ; preds = %17, %8
  %12 = load i32, ptr %3, align 4, !tbaa !5
  %13 = load i32, ptr %2, align 4, !tbaa !5
  %14 = icmp slt i32 %12, %13
  br i1 %14, label %15, label %20

15:                                               ; preds = %11
  %16 = call i32 (ptr, ...) @printf(ptr noundef @.str.1)
  br label %17

17:                                               ; preds = %15
  %18 = load i32, ptr %3, align 4, !tbaa !5
  %19 = add nsw i32 %18, 1
  store i32 %19, ptr %3, align 4, !tbaa !5
  br label %11, !llvm.loop !9

20:                                               ; preds = %11
  %21 = call i32 (ptr, ...) @printf(ptr noundef @.str.2)
  %22 = load i32, ptr %2, align 4, !tbaa !5
  %23 = sub nsw i32 %22, 1
  call void @regua(i32 noundef %23)
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #3
  br label %24

24:                                               ; preds = %20, %6
  ret void
}

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

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"

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

; Function Attrs: nofree nounwind uwtable
define dso_local void @regua(i32 noundef %0) local_unnamed_addr #0 {
  %2 = icmp eq i32 %0, 1
  br i1 %2, label %tailrecurse._crit_edge, label %.lr.ph10

tailrecurse._crit_edge:                           ; preds = %tailrecurse, %1
  %3 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str)
  ret void

.lr.ph10:                                         ; preds = %1, %tailrecurse
  %.tr8 = phi i32 [ %4, %tailrecurse ], [ %0, %1 ]
  %4 = add nsw i32 %.tr8, -1
  tail call void @regua(i32 noundef %4)
  %5 = icmp sgt i32 %.tr8, 0
  br i1 %5, label %.lr.ph, label %tailrecurse

.lr.ph:                                           ; preds = %.lr.ph10, %.lr.ph
  %.07 = phi i32 [ %7, %.lr.ph ], [ 0, %.lr.ph10 ]
  %6 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.1)
  %7 = add nuw nsw i32 %.07, 1
  %exitcond.not = icmp eq i32 %7, %.tr8
  br i1 %exitcond.not, label %tailrecurse, label %.lr.ph, !llvm.loop !5

tailrecurse:                                      ; preds = %.lr.ph, %.lr.ph10
  %8 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.2)
  %9 = icmp eq i32 %4, 1
  br i1 %9, label %tailrecurse._crit_edge, label %.lr.ph10
}

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

attributes #0 = { nofree 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 = distinct !{!5, !6}
!6 = !{!"llvm.loop.mustprogress"}


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