; LLVM IR from lolosssss/leetcode :: c (52_n_queens_ii)

; 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: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nounwind uwtable
declare dso_local void @dfs(i32 noundef, ptr noundef, ptr noundef, ptr noundef, i32 noundef) #1

; Function Attrs: nounwind uwtable
define dso_local i32 @totalNQueens(i32 noundef %0) #1 {
  %2 = alloca i32, align 4
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #3
  %7 = load i32, ptr %2, align 4, !tbaa !5
  %8 = sext i32 %7 to i64
  %9 = mul i64 4, %8
  %10 = call noalias ptr @malloc(i64 noundef %9) #4
  store ptr %10, ptr %3, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #3
  %11 = load i32, ptr %2, align 4, !tbaa !5
  %12 = sext i32 %11 to i64
  %13 = mul i64 4, %12
  %14 = call noalias ptr @malloc(i64 noundef %13) #4
  store ptr %14, ptr %4, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  store i32 0, ptr %5, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #3
  store i32 0, ptr %6, align 4, !tbaa !5
  br label %15

15:                                               ; preds = %25, %1
  %16 = load i32, ptr %6, align 4, !tbaa !5
  %17 = load i32, ptr %2, align 4, !tbaa !5
  %18 = icmp slt i32 %16, %17
  br i1 %18, label %20, label %19

19:                                               ; preds = %15
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #3
  br label %28

20:                                               ; preds = %15
  %21 = load ptr, ptr %4, align 8, !tbaa !9
  %22 = load i32, ptr %6, align 4, !tbaa !5
  %23 = sext i32 %22 to i64
  %24 = getelementptr inbounds i32, ptr %21, i64 %23
  store i32 1, ptr %24, align 4, !tbaa !5
  br label %25

25:                                               ; preds = %20
  %26 = load i32, ptr %6, align 4, !tbaa !5
  %27 = add nsw i32 %26, 1
  store i32 %27, ptr %6, align 4, !tbaa !5
  br label %15, !llvm.loop !11

28:                                               ; preds = %19
  %29 = load i32, ptr %2, align 4, !tbaa !5
  %30 = load ptr, ptr %3, align 8, !tbaa !9
  %31 = load ptr, ptr %4, align 8, !tbaa !9
  call void @dfs(i32 noundef %29, ptr noundef %30, ptr noundef %31, ptr noundef %5, i32 noundef 0)
  %32 = load i32, ptr %5, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #3
  ret i32 %32
}

; Function Attrs: nounwind allocsize(0)
declare noalias ptr @malloc(i64 noundef) #2

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #2 = { nounwind allocsize(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 }
attributes #4 = { nounwind allocsize(0) }

!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 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !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"

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nounwind uwtable
declare dso_local void @dfs(i32 noundef, ptr noundef, ptr noundef, ptr noundef, i32 noundef) local_unnamed_addr #1

; Function Attrs: nounwind uwtable
define dso_local i32 @totalNQueens(i32 noundef %0) local_unnamed_addr #1 {
  %2 = alloca i32, align 4
  %3 = sext i32 %0 to i64
  %4 = shl nsw i64 %3, 2
  %5 = tail call noalias ptr @malloc(i64 noundef %4) #3
  %6 = tail call noalias ptr @malloc(i64 noundef %4) #3
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #4
  store i32 0, ptr %2, align 4, !tbaa !5
  %7 = icmp sgt i32 %0, 0
  br i1 %7, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %1
  %wide.trip.count = zext nneg i32 %0 to i64
  %min.iters.check = icmp ult i32 %0, 8
  br i1 %min.iters.check, label %.lr.ph.preheader12, label %vector.ph

.lr.ph.preheader12:                               ; preds = %middle.block, %.lr.ph.preheader
  %indvars.iv.ph = phi i64 [ 0, %.lr.ph.preheader ], [ %n.vec, %middle.block ]
  br label %.lr.ph

vector.ph:                                        ; preds = %.lr.ph.preheader
  %n.vec = and i64 %wide.trip.count, 2147483640
  br label %vector.body

vector.body:                                      ; preds = %vector.body, %vector.ph
  %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
  %8 = getelementptr inbounds i32, ptr %6, i64 %index
  %9 = getelementptr inbounds i8, ptr %8, i64 16
  store <4 x i32> <i32 1, i32 1, i32 1, i32 1>, ptr %8, align 4, !tbaa !5
  store <4 x i32> <i32 1, i32 1, i32 1, i32 1>, ptr %9, align 4, !tbaa !5
  %index.next = add nuw i64 %index, 8
  %10 = icmp eq i64 %index.next, %n.vec
  br i1 %10, label %middle.block, label %vector.body, !llvm.loop !9

middle.block:                                     ; preds = %vector.body
  %cmp.n = icmp eq i64 %n.vec, %wide.trip.count
  br i1 %cmp.n, label %._crit_edge, label %.lr.ph.preheader12

._crit_edge:                                      ; preds = %.lr.ph, %middle.block, %1
  call void @dfs(i32 noundef %0, ptr noundef %5, ptr noundef %6, ptr noundef nonnull %2, i32 noundef 0)
  %11 = load i32, ptr %2, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #4
  ret i32 %11

.lr.ph:                                           ; preds = %.lr.ph.preheader12, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ %indvars.iv.ph, %.lr.ph.preheader12 ]
  %12 = getelementptr inbounds i32, ptr %6, i64 %indvars.iv
  store i32 1, ptr %12, align 4, !tbaa !5
  %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 !13
}

; Function Attrs: mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite)
declare noalias noundef ptr @malloc(i64 noundef) local_unnamed_addr #2

attributes #0 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #2 = { mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite) "alloc-family"="malloc" "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 allocsize(0) }
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/C++ TBAA"}
!9 = distinct !{!9, !10, !11, !12}
!10 = !{!"llvm.loop.mustprogress"}
!11 = !{!"llvm.loop.isvectorized", i32 1}
!12 = !{!"llvm.loop.unroll.runtime.disable"}
!13 = distinct !{!13, !10, !12, !11}


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