; LLVM IR from upupming/algorithm :: acwing/算法竞赛进阶指南/0x02-递推与递归/96. 奇怪的汉诺塔.ll (Z7hanio_4i)

; 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
declare dso_local noundef i32 @_Z7hanio_3i(i32 noundef) #0

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_Z7hanio_4i(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  %7 = load i32, ptr %3, align 4, !tbaa !5
  %8 = icmp eq i32 %7, 1
  br i1 %8, label %9, label %10

9:                                                ; preds = %1
  store i32 1, ptr %2, align 4
  br label %32

10:                                               ; preds = %1
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #3
  store i32 2147483647, ptr %4, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  store i32 1, ptr %5, align 4, !tbaa !5
  br label %11

11:                                               ; preds = %27, %10
  %12 = load i32, ptr %5, align 4, !tbaa !5
  %13 = load i32, ptr %3, align 4, !tbaa !5
  %14 = icmp slt i32 %12, %13
  br i1 %14, label %16, label %15

15:                                               ; preds = %11
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  br label %30

16:                                               ; preds = %11
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #3
  %17 = load i32, ptr %5, align 4, !tbaa !5
  %18 = call noundef i32 @_Z7hanio_4i(i32 noundef %17)
  %19 = mul nsw i32 2, %18
  %20 = load i32, ptr %3, align 4, !tbaa !5
  %21 = load i32, ptr %5, align 4, !tbaa !5
  %22 = sub nsw i32 %20, %21
  %23 = call noundef i32 @_Z7hanio_3i(i32 noundef %22)
  %24 = add nsw i32 %19, %23
  store i32 %24, ptr %6, align 4, !tbaa !5
  %25 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3minIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4) %4, ptr noundef nonnull align 4 dereferenceable(4) %6)
  %26 = load i32, ptr %25, align 4, !tbaa !5
  store i32 %26, ptr %4, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #3
  br label %27

27:                                               ; preds = %16
  %28 = load i32, ptr %5, align 4, !tbaa !5
  %29 = add nsw i32 %28, 1
  store i32 %29, ptr %5, align 4, !tbaa !5
  br label %11, !llvm.loop !9

30:                                               ; preds = %15
  %31 = load i32, ptr %4, align 4, !tbaa !5
  store i32 %31, ptr %2, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #3
  br label %32

32:                                               ; preds = %30, %9
  %33 = load i32, ptr %2, align 4
  ret i32 %33
}

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

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3minIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) #2

; 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 = { inlinehint mustprogress 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 #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++ 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"

; Function Attrs: mustprogress uwtable
declare dso_local noundef i32 @_Z7hanio_3i(i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_Z7hanio_4i(i32 noundef %0) local_unnamed_addr #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = icmp eq i32 %0, 1
  br i1 %4, label %16, label %5

5:                                                ; preds = %1
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #3
  store i32 2147483647, ptr %2, align 4, !tbaa !5
  %6 = icmp sgt i32 %0, 1
  br i1 %6, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph, %5
  %7 = phi i32 [ 2147483647, %5 ], [ %14, %.lr.ph ]
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #3
  br label %16

.lr.ph:                                           ; preds = %5, %.lr.ph
  %.010 = phi i32 [ %15, %.lr.ph ], [ 1, %5 ]
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %3) #3
  %8 = call noundef i32 @_Z7hanio_4i(i32 noundef %.010)
  %9 = shl nsw i32 %8, 1
  %10 = sub nsw i32 %0, %.010
  %11 = call noundef i32 @_Z7hanio_3i(i32 noundef %10)
  %12 = add nsw i32 %9, %11
  store i32 %12, ptr %3, align 4, !tbaa !5
  %13 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3minIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4) %2, ptr noundef nonnull align 4 dereferenceable(4) %3)
  %14 = load i32, ptr %13, align 4, !tbaa !5
  store i32 %14, ptr %2, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %3) #3
  %15 = add nuw nsw i32 %.010, 1
  %exitcond.not = icmp eq i32 %15, %0
  br i1 %exitcond.not, label %._crit_edge, label %.lr.ph, !llvm.loop !9

16:                                               ; preds = %1, %._crit_edge
  %.08 = phi i32 [ %7, %._crit_edge ], [ 1, %1 ]
  ret i32 %.08
}

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

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3minIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #2

; Function Attrs: mustprogress 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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { inlinehint mustprogress 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 #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++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,ReassociatePass,SROAPass,SimplifyCFGPass