; LLVM IR from 6leetcode/6leetcode :: questions/Algorithms/0017. Letter Combinations of a Phone Number (Solution)

; 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"

@__const.main.input = external hidden unnamed_addr constant [3 x i8], align 1
@.str.8 = external hidden unnamed_addr constant [12 x i8], align 1
@.str.9 = external hidden unnamed_addr constant [12 x i8], align 1
@.str.10 = external hidden unnamed_addr constant [4 x i8], align 1
@.str.11 = external hidden unnamed_addr constant [2 x i8], align 1

; 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 ptr @letterCombinations(ptr noundef, ptr noundef) #1

; Function Attrs: nounwind
declare void @free(ptr noundef) #2

; Function Attrs: nounwind uwtable
define dso_local i32 @main(i32 noundef %0, ptr noundef %1) #1 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca [3 x i8], align 1
  %7 = alloca i32, align 4
  %8 = alloca ptr, align 8
  %9 = alloca i64, 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 3, ptr %6) #5
  call void @llvm.memcpy.p0.p0.i64(ptr align 1 %6, ptr align 1 @__const.main.input, i64 3, i1 false)
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #5
  store i32 0, ptr %7, align 4, !tbaa !5
  %10 = getelementptr inbounds [3 x i8], ptr %6, i64 0, i64 0
  %11 = call i32 (ptr, ...) @printf(ptr noundef @.str.8, ptr noundef %10)
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #5
  %12 = getelementptr inbounds [3 x i8], ptr %6, i64 0, i64 0
  %13 = call ptr @letterCombinations(ptr noundef %12, ptr noundef %7)
  store ptr %13, ptr %8, align 8, !tbaa !9
  %14 = load ptr, ptr %8, align 8, !tbaa !9
  %15 = getelementptr inbounds ptr, ptr %14, i64 0
  %16 = load ptr, ptr %15, align 8, !tbaa !9
  %17 = call i32 (ptr, ...) @printf(ptr noundef @.str.9, ptr noundef %16)
  %18 = load ptr, ptr %8, align 8, !tbaa !9
  %19 = getelementptr inbounds ptr, ptr %18, i64 0
  %20 = load ptr, ptr %19, align 8, !tbaa !9
  call void @free(ptr noundef %20) #5
  call void @llvm.lifetime.start.p0(i64 8, ptr %9) #5
  store i64 1, ptr %9, align 8, !tbaa !11
  br label %21

21:                                               ; preds = %37, %2
  %22 = load i64, ptr %9, align 8, !tbaa !11
  %23 = load i32, ptr %7, align 4, !tbaa !5
  %24 = sext i32 %23 to i64
  %25 = icmp ult i64 %22, %24
  br i1 %25, label %27, label %26

26:                                               ; preds = %21
  call void @llvm.lifetime.end.p0(i64 8, ptr %9) #5
  br label %40

27:                                               ; preds = %21
  %28 = load ptr, ptr %8, align 8, !tbaa !9
  %29 = load i64, ptr %9, align 8, !tbaa !11
  %30 = getelementptr inbounds ptr, ptr %28, i64 %29
  %31 = load ptr, ptr %30, align 8, !tbaa !9
  %32 = call i32 (ptr, ...) @printf(ptr noundef @.str.10, ptr noundef %31)
  %33 = load ptr, ptr %8, align 8, !tbaa !9
  %34 = load i64, ptr %9, align 8, !tbaa !11
  %35 = getelementptr inbounds ptr, ptr %33, i64 %34
  %36 = load ptr, ptr %35, align 8, !tbaa !9
  call void @free(ptr noundef %36) #5
  br label %37

37:                                               ; preds = %27
  %38 = load i64, ptr %9, align 8, !tbaa !11
  %39 = add i64 %38, 1
  store i64 %39, ptr %9, align 8, !tbaa !11
  br label %21, !llvm.loop !13

40:                                               ; preds = %26
  %41 = call i32 (ptr, ...) @printf(ptr noundef @.str.11)
  %42 = load ptr, ptr %8, align 8, !tbaa !9
  call void @free(ptr noundef %42) #5
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #5
  call void @llvm.lifetime.end.p0(i64 3, ptr %6) #5
  ret i32 0
}

; 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) #3

declare i32 @printf(ptr noundef, ...) #4

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 "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 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
attributes #4 = { "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 #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/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = !{!12, !12, i64 0}
!12 = !{!"long", !7, i64 0}
!13 = distinct !{!13, !14}
!14 = !{!"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"

@__const.main.input = external hidden unnamed_addr constant [3 x i8], align 1
@.str.8 = external hidden unnamed_addr constant [12 x i8], align 1
@.str.9 = external hidden unnamed_addr constant [12 x i8], align 1
@.str.10 = external hidden unnamed_addr constant [4 x i8], align 1
@.str.11 = external hidden unnamed_addr constant [2 x i8], align 1

; 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 ptr @letterCombinations(ptr noundef, ptr noundef) local_unnamed_addr #1

; Function Attrs: mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite)
declare void @free(ptr allocptr nocapture noundef) local_unnamed_addr #2

; Function Attrs: nounwind uwtable
define dso_local noundef i32 @main(i32 noundef %0, ptr nocapture noundef readnone %1) local_unnamed_addr #1 {
  %3 = alloca [3 x i8], align 1
  %4 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 3, ptr nonnull %3) #5
  call void @llvm.memcpy.p0.p0.i64(ptr noundef nonnull align 1 dereferenceable(3) %3, ptr noundef nonnull align 1 dereferenceable(3) @__const.main.input, i64 3, i1 false)
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %4) #5
  store i32 0, ptr %4, align 4, !tbaa !5
  %5 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.8, ptr noundef nonnull %3)
  %6 = call ptr @letterCombinations(ptr noundef nonnull %3, ptr noundef nonnull %4)
  %7 = load ptr, ptr %6, align 8, !tbaa !9
  %8 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.9, ptr noundef %7)
  %9 = load ptr, ptr %6, align 8, !tbaa !9
  call void @free(ptr noundef %9) #5
  %10 = load i32, ptr %4, align 4, !tbaa !5
  %11 = icmp ugt i32 %10, 1
  br i1 %11, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph, %2
  %12 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.11)
  call void @free(ptr noundef nonnull %6) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %4) #5
  call void @llvm.lifetime.end.p0(i64 3, ptr nonnull %3) #5
  ret i32 0

.lr.ph:                                           ; preds = %2, %.lr.ph
  %.08 = phi i64 [ %17, %.lr.ph ], [ 1, %2 ]
  %13 = getelementptr inbounds ptr, ptr %6, i64 %.08
  %14 = load ptr, ptr %13, align 8, !tbaa !9
  %15 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.10, ptr noundef %14)
  %16 = load ptr, ptr %13, align 8, !tbaa !9
  call void @free(ptr noundef %16) #5
  %17 = add nuw i64 %.08, 1
  %18 = load i32, ptr %4, align 4, !tbaa !5
  %19 = sext i32 %18 to i64
  %20 = icmp ult i64 %17, %19
  br i1 %20, label %.lr.ph, label %._crit_edge, !llvm.loop !11
}

; Function Attrs: mustprogress 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) #3

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #4

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 nounwind willreturn allockind("free") memory(argmem: readwrite, 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 = { mustprogress nocallback nofree nounwind willreturn memory(argmem: readwrite) }
attributes #4 = { 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 #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/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


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