; LLVM IR from AdarshGaur/Competitive-Programming :: CSES/Dynamic Programming/Counting Towers.ll (Z3prev)

; 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"

@dp = external dso_local global [1000007 x [2 x i64]], align 16

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z3prev() #0 {
  %1 = alloca i32, align 4
  store i64 1, ptr getelementptr inbounds ([2 x i64], ptr getelementptr inbounds ([1000007 x [2 x i64]], ptr @dp, i64 0, i64 1), i64 0, i64 1), align 8, !tbaa !5
  store i64 1, ptr getelementptr inbounds ([1000007 x [2 x i64]], ptr @dp, i64 0, i64 1), align 16, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %1) #2
  store i32 2, ptr %1, align 4, !tbaa !9
  br label %2

2:                                                ; preds = %45, %0
  %3 = load i32, ptr %1, align 4, !tbaa !9
  %4 = icmp slt i32 %3, 1000007
  br i1 %4, label %6, label %5

5:                                                ; preds = %2
  call void @llvm.lifetime.end.p0(i64 4, ptr %1) #2
  br label %48

6:                                                ; preds = %2
  %7 = load i32, ptr %1, align 4, !tbaa !9
  %8 = sub nsw i32 %7, 1
  %9 = sext i32 %8 to i64
  %10 = getelementptr inbounds [1000007 x [2 x i64]], ptr @dp, i64 0, i64 %9
  %11 = getelementptr inbounds [2 x i64], ptr %10, i64 0, i64 0
  %12 = load i64, ptr %11, align 16, !tbaa !5
  %13 = mul nsw i64 %12, 4
  %14 = load i32, ptr %1, align 4, !tbaa !9
  %15 = sub nsw i32 %14, 1
  %16 = sext i32 %15 to i64
  %17 = getelementptr inbounds [1000007 x [2 x i64]], ptr @dp, i64 0, i64 %16
  %18 = getelementptr inbounds [2 x i64], ptr %17, i64 0, i64 1
  %19 = load i64, ptr %18, align 8, !tbaa !5
  %20 = add nsw i64 %13, %19
  %21 = srem i64 %20, 1000000007
  %22 = load i32, ptr %1, align 4, !tbaa !9
  %23 = sext i32 %22 to i64
  %24 = getelementptr inbounds [1000007 x [2 x i64]], ptr @dp, i64 0, i64 %23
  %25 = getelementptr inbounds [2 x i64], ptr %24, i64 0, i64 0
  store i64 %21, ptr %25, align 16, !tbaa !5
  %26 = load i32, ptr %1, align 4, !tbaa !9
  %27 = sub nsw i32 %26, 1
  %28 = sext i32 %27 to i64
  %29 = getelementptr inbounds [1000007 x [2 x i64]], ptr @dp, i64 0, i64 %28
  %30 = getelementptr inbounds [2 x i64], ptr %29, i64 0, i64 0
  %31 = load i64, ptr %30, align 16, !tbaa !5
  %32 = load i32, ptr %1, align 4, !tbaa !9
  %33 = sub nsw i32 %32, 1
  %34 = sext i32 %33 to i64
  %35 = getelementptr inbounds [1000007 x [2 x i64]], ptr @dp, i64 0, i64 %34
  %36 = getelementptr inbounds [2 x i64], ptr %35, i64 0, i64 1
  %37 = load i64, ptr %36, align 8, !tbaa !5
  %38 = mul nsw i64 %37, 2
  %39 = add nsw i64 %31, %38
  %40 = srem i64 %39, 1000000007
  %41 = load i32, ptr %1, align 4, !tbaa !9
  %42 = sext i32 %41 to i64
  %43 = getelementptr inbounds [1000007 x [2 x i64]], ptr @dp, i64 0, i64 %42
  %44 = getelementptr inbounds [2 x i64], ptr %43, i64 0, i64 1
  store i64 %40, ptr %44, align 8, !tbaa !5
  br label %45

45:                                               ; preds = %6
  %46 = load i32, ptr %1, align 4, !tbaa !9
  %47 = add nsw i32 %46, 1
  store i32 %47, ptr %1, align 4, !tbaa !9
  br label %2, !llvm.loop !11

48:                                               ; preds = %5
  ret void
}

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

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

attributes #0 = { 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 #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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 = !{!"long long", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"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"

@dp = external dso_local local_unnamed_addr global [1000007 x [2 x i64]], align 16

; Function Attrs: mustprogress nofree norecurse nosync nounwind memory(write, argmem: none, inaccessiblemem: none) uwtable
define dso_local void @_Z3prev() local_unnamed_addr #0 {
  store i64 1, ptr getelementptr inbounds (i8, ptr @dp, i64 24), align 8, !tbaa !5
  store i64 1, ptr getelementptr inbounds (i8, ptr @dp, i64 16), align 16, !tbaa !5
  br label %2

1:                                                ; preds = %2
  ret void

2:                                                ; preds = %0, %2
  %3 = phi i64 [ 1, %0 ], [ %11, %2 ]
  %4 = phi i64 [ 1, %0 ], [ %7, %2 ]
  %indvars.iv = phi i64 [ 2, %0 ], [ %indvars.iv.next, %2 ]
  %5 = shl nsw i64 %4, 2
  %6 = add nsw i64 %5, %3
  %7 = srem i64 %6, 1000000007
  %8 = getelementptr inbounds [1000007 x [2 x i64]], ptr @dp, i64 0, i64 %indvars.iv
  store i64 %7, ptr %8, align 16, !tbaa !5
  %9 = shl nsw i64 %3, 1
  %10 = add nsw i64 %9, %4
  %11 = srem i64 %10, 1000000007
  %12 = getelementptr inbounds i8, ptr %8, i64 8
  store i64 %11, ptr %12, align 8, !tbaa !5
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, 1000007
  br i1 %exitcond.not, label %1, label %2, !llvm.loop !9
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind memory(write, argmem: none, inaccessiblemem: none) 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" }

!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 = !{!"long long", !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,InferFunctionAttrsPass,InstCombinePass,LoopRotatePass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass