; LLVM IR from JessonYue/LeetCodeLearning :: Array/majiyao/爬楼梯/main.ll (Z11climbStairsi)

; 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"

%"class.std::basic_ostream" = type { ptr, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }

@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@__const._Z11climbStairsi.num = external hidden unnamed_addr constant [2 x i32], align 4
@.str.2 = external hidden unnamed_addr constant [16 x i8], align 1

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #0

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #1 align 2

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_(ptr noundef nonnull align 8 dereferenceable(8)) #0

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

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_Z11climbStairsi(i32 noundef %0) #1 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca [2 x i32], align 4
  %5 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  %6 = load i32, ptr %3, align 4, !tbaa !5
  %7 = icmp eq i32 %6, 0
  br i1 %7, label %14, label %8

8:                                                ; preds = %1
  %9 = load i32, ptr %3, align 4, !tbaa !5
  %10 = icmp eq i32 %9, 1
  br i1 %10, label %14, label %11

11:                                               ; preds = %8
  %12 = load i32, ptr %3, align 4, !tbaa !5
  %13 = icmp eq i32 %12, 2
  br i1 %13, label %14, label %16

14:                                               ; preds = %11, %8, %1
  %15 = load i32, ptr %3, align 4, !tbaa !5
  store i32 %15, ptr %2, align 4
  br label %53

16:                                               ; preds = %11
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #5
  call void @llvm.memcpy.p0.p0.i64(ptr align 4 %4, ptr align 4 @__const._Z11climbStairsi.num, i64 8, i1 false)
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #5
  store i32 2, ptr %5, align 4, !tbaa !5
  br label %17

17:                                               ; preds = %44, %16
  %18 = load i32, ptr %5, align 4, !tbaa !5
  %19 = load i32, ptr %3, align 4, !tbaa !5
  %20 = icmp slt i32 %18, %19
  br i1 %20, label %22, label %21

21:                                               ; preds = %17
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #5
  br label %47

22:                                               ; preds = %17
  %23 = load i32, ptr %5, align 4, !tbaa !5
  %24 = sub nsw i32 %23, 1
  %25 = sext i32 %24 to i64
  %26 = getelementptr inbounds [2 x i32], ptr %4, i64 0, i64 %25
  %27 = load i32, ptr %26, align 4, !tbaa !5
  %28 = load i32, ptr %5, align 4, !tbaa !5
  %29 = sub nsw i32 %28, 2
  %30 = sext i32 %29 to i64
  %31 = getelementptr inbounds [2 x i32], ptr %4, i64 0, i64 %30
  %32 = load i32, ptr %31, align 4, !tbaa !5
  %33 = add nsw i32 %27, %32
  %34 = load i32, ptr %5, align 4, !tbaa !5
  %35 = sext i32 %34 to i64
  %36 = getelementptr inbounds [2 x i32], ptr %4, i64 0, i64 %35
  store i32 %33, ptr %36, align 4, !tbaa !5
  %37 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef @.str.2)
  %38 = load i32, ptr %5, align 4, !tbaa !5
  %39 = sext i32 %38 to i64
  %40 = getelementptr inbounds [2 x i32], ptr %4, i64 0, i64 %39
  %41 = load i32, ptr %40, align 4, !tbaa !5
  %42 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) %37, i32 noundef %41)
  %43 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) %42, ptr noundef @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  br label %44

44:                                               ; preds = %22
  %45 = load i32, ptr %5, align 4, !tbaa !5
  %46 = add nsw i32 %45, 1
  store i32 %46, ptr %5, align 4, !tbaa !5
  br label %17, !llvm.loop !9

47:                                               ; preds = %21
  %48 = load i32, ptr %3, align 4, !tbaa !5
  %49 = sub nsw i32 %48, 1
  %50 = sext i32 %49 to i64
  %51 = getelementptr inbounds [2 x i32], ptr %4, i64 0, i64 %50
  %52 = load i32, ptr %51, align 4, !tbaa !5
  store i32 %52, ptr %2, align 4
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #5
  br label %53

53:                                               ; preds = %47, %14
  %54 = load i32, ptr %2, align 4
  ret i32 %54
}

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) #3

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

; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
declare void @llvm.memcpy.p0.p0.i64(ptr noalias nocapture writeonly, ptr noalias nocapture readonly, i64, i1 immarg) #4

attributes #0 = { inlinehint 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 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 #2 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #3 = { "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 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
attributes #5 = { 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"

%"class.std::basic_ostream" = type { ptr, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }

@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@__const._Z11climbStairsi.num = external hidden unnamed_addr constant [2 x i32], align 4
@.str.2 = external hidden unnamed_addr constant [16 x i8], align 1

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) local_unnamed_addr #1 align 2

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_(ptr noundef nonnull align 8 dereferenceable(8)) #0

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

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_Z11climbStairsi(i32 noundef %0) local_unnamed_addr #1 {
  %2 = alloca [2 x i32], align 8
  %or.cond3 = icmp ult i32 %0, 3
  br i1 %or.cond3, label %21, label %3

3:                                                ; preds = %1
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %2) #4
  %4 = load i64, ptr @__const._Z11climbStairsi.num, align 4
  store i64 %4, ptr %2, align 8
  %5 = icmp sgt i32 %0, 2
  br i1 %5, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %3
  %6 = lshr i64 %4, 32
  %7 = trunc nuw i64 %6 to i32
  %wide.trip.count = zext nneg i32 %0 to i64
  br label %.lr.ph

._crit_edge:                                      ; preds = %.lr.ph, %3
  %8 = add nsw i32 %0, -1
  %9 = sext i32 %8 to i64
  %10 = getelementptr inbounds [2 x i32], ptr %2, i64 0, i64 %9
  %11 = load i32, ptr %10, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %2) #4
  br label %21

.lr.ph:                                           ; preds = %.lr.ph.preheader, %.lr.ph
  %12 = phi i32 [ %7, %.lr.ph.preheader ], [ %16, %.lr.ph ]
  %indvars.iv = phi i64 [ 2, %.lr.ph.preheader ], [ %indvars.iv.next, %.lr.ph ]
  %13 = add nsw i64 %indvars.iv, -2
  %14 = getelementptr inbounds [2 x i32], ptr %2, i64 0, i64 %13
  %15 = load i32, ptr %14, align 4, !tbaa !5
  %16 = add nsw i32 %15, %12
  %17 = getelementptr inbounds [2 x i32], ptr %2, i64 0, i64 %indvars.iv
  store i32 %16, ptr %17, align 4, !tbaa !5
  %18 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef nonnull @.str.2)
  %19 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) %18, i32 noundef %16)
  %20 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) %19, ptr noundef nonnull @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %wide.trip.count
  br i1 %exitcond.not, label %._crit_edge, label %.lr.ph, !llvm.loop !9

21:                                               ; preds = %1, %._crit_edge
  %.016 = phi i32 [ %11, %._crit_edge ], [ %0, %1 ]
  ret i32 %.016
}

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 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) #2

attributes #0 = { inlinehint 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 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 #2 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #3 = { "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 }

!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: BDCEPass,EarlyCSEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferAlignmentPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,ReassociatePass,SCCPPass,SROAPass,SimplifyCFGPass,TailCallElimPass