; LLVM IR from wuzhouhui/leetcode :: second (17_letter_comb)

; 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 [4 x i8], align 1

; Function Attrs: nounwind uwtable
declare dso_local ptr @letterCombinations(ptr noundef, ptr noundef) #0

; Function Attrs: nounwind uwtable
define dso_local i32 @main(i32 noundef %0, ptr noundef %1) #0 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  %7 = alloca ptr, align 8
  store i32 0, ptr %3, align 4
  store i32 %0, ptr %4, align 4, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #3
  %8 = load ptr, ptr %5, align 8, !tbaa !9
  %9 = getelementptr inbounds ptr, ptr %8, i64 1
  %10 = load ptr, ptr %9, align 8, !tbaa !9
  %11 = call ptr @letterCombinations(ptr noundef %10, ptr noundef %6)
  store ptr %11, ptr %7, align 8, !tbaa !9
  br label %12

12:                                               ; preds = %16, %2
  %13 = load i32, ptr %6, align 4, !tbaa !5
  %14 = add nsw i32 %13, -1
  store i32 %14, ptr %6, align 4, !tbaa !5
  %15 = icmp sgt i32 %13, 0
  br i1 %15, label %16, label %23

16:                                               ; preds = %12
  %17 = load ptr, ptr %7, align 8, !tbaa !9
  %18 = load i32, ptr %6, align 4, !tbaa !5
  %19 = sext i32 %18 to i64
  %20 = getelementptr inbounds ptr, ptr %17, i64 %19
  %21 = load ptr, ptr %20, align 8, !tbaa !9
  %22 = call i32 (ptr, ...) @printf(ptr noundef @.str, ptr noundef %21)
  br label %12, !llvm.loop !11

23:                                               ; preds = %12
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #3
  %24 = load i32, ptr %3, align 4
  ret i32 %24
}

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

declare i32 @printf(ptr noundef, ...) #2

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

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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { "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/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"

@.str = external hidden unnamed_addr constant [4 x i8], align 1

; Function Attrs: nounwind uwtable
declare dso_local ptr @letterCombinations(ptr noundef, ptr noundef) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local noundef i32 @main(i32 noundef %0, ptr nocapture noundef readonly %1) local_unnamed_addr #0 {
  %3 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %3) #3
  %4 = getelementptr inbounds i8, ptr %1, i64 8
  %5 = load ptr, ptr %4, align 8, !tbaa !5
  %6 = call ptr @letterCombinations(ptr noundef %5, ptr noundef nonnull %3)
  %7 = load i32, ptr %3, align 4, !tbaa !9
  %8 = add nsw i32 %7, -1
  store i32 %8, ptr %3, align 4, !tbaa !9
  %9 = icmp sgt i32 %7, 0
  br i1 %9, label %.lr.ph, label %._crit_edge

.lr.ph:                                           ; preds = %2, %.lr.ph
  %10 = phi i32 [ %16, %.lr.ph ], [ %8, %2 ]
  %11 = zext nneg i32 %10 to i64
  %12 = getelementptr inbounds ptr, ptr %6, i64 %11
  %13 = load ptr, ptr %12, align 8, !tbaa !5
  %14 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str, ptr noundef %13)
  %15 = load i32, ptr %3, align 4, !tbaa !9
  %16 = add nsw i32 %15, -1
  store i32 %16, ptr %3, align 4, !tbaa !9
  %17 = icmp sgt i32 %15, 0
  br i1 %17, label %.lr.ph, label %._crit_edge, !llvm.loop !11

._crit_edge:                                      ; preds = %.lr.ph, %2
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %3) #3
  ret i32 0
}

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

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) 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 = { 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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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" }
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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


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