; LLVM IR from wrnlb666/yet-another-string-library-in-c :: yasli (str_append)

; 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"

%struct.string_t = type { i64, i64, [1 x i8] }

; 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: inlinehint nounwind uwtable
declare hidden zeroext i1 @str_resize(ptr noundef, i64 noundef) #1

; Function Attrs: nounwind
declare ptr @strcpy(ptr noundef, ptr noundef) #2

; Function Attrs: nounwind uwtable
define dso_local ptr @str_append(ptr noundef %0, ptr noundef %1) #3 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca i64, align 8
  %7 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #4
  %8 = load ptr, ptr %4, align 8, !tbaa !5
  %9 = load ptr, ptr %8, align 8, !tbaa !5
  %10 = getelementptr inbounds %struct.string_t, ptr %9, i32 0, i32 0
  %11 = load i64, ptr %10, align 8, !tbaa !9
  store i64 %11, ptr %6, align 8, !tbaa !12
  %12 = load ptr, ptr %4, align 8, !tbaa !5
  %13 = load ptr, ptr %4, align 8, !tbaa !5
  %14 = load ptr, ptr %13, align 8, !tbaa !5
  %15 = getelementptr inbounds %struct.string_t, ptr %14, i32 0, i32 0
  %16 = load i64, ptr %15, align 8, !tbaa !9
  %17 = load ptr, ptr %5, align 8, !tbaa !5
  %18 = getelementptr inbounds %struct.string_t, ptr %17, i32 0, i32 0
  %19 = load i64, ptr %18, align 8, !tbaa !9
  %20 = add i64 %16, %19
  %21 = call zeroext i1 @str_resize(ptr noundef %12, i64 noundef %20)
  br i1 %21, label %22, label %35

22:                                               ; preds = %2
  %23 = load ptr, ptr %4, align 8, !tbaa !5
  %24 = load ptr, ptr %23, align 8, !tbaa !5
  %25 = getelementptr inbounds %struct.string_t, ptr %24, i32 0, i32 2
  %26 = getelementptr inbounds [1 x i8], ptr %25, i64 0, i64 0
  %27 = load i64, ptr %6, align 8, !tbaa !12
  %28 = getelementptr inbounds i8, ptr %26, i64 %27
  %29 = load ptr, ptr %5, align 8, !tbaa !5
  %30 = getelementptr inbounds %struct.string_t, ptr %29, i32 0, i32 2
  %31 = getelementptr inbounds [1 x i8], ptr %30, i64 0, i64 0
  %32 = call ptr @strcpy(ptr noundef %28, ptr noundef %31) #4
  %33 = load ptr, ptr %4, align 8, !tbaa !5
  %34 = load ptr, ptr %33, align 8, !tbaa !5
  store ptr %34, ptr %3, align 8
  store i32 1, ptr %7, align 4
  br label %36

35:                                               ; preds = %2
  store ptr null, ptr %3, align 8
  store i32 1, ptr %7, align 4
  br label %36

36:                                               ; preds = %35, %22
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #4
  %37 = load ptr, ptr %3, align 8
  ret ptr %37
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { inlinehint 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 = { 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 #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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !11, i64 0}
!10 = !{!"string_t", !11, i64 0, !11, i64 8, !7, i64 16}
!11 = !{!"long", !7, i64 0}
!12 = !{!11, !11, i64 0}


; 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: inlinehint nounwind uwtable
declare hidden zeroext i1 @str_resize(ptr noundef, i64 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nofree nounwind willreturn memory(argmem: readwrite)
declare ptr @strcpy(ptr noalias noundef returned writeonly, ptr noalias nocapture noundef readonly) local_unnamed_addr #1

; Function Attrs: nounwind uwtable
define dso_local ptr @str_append(ptr noundef %0, ptr nocapture noundef readonly %1) local_unnamed_addr #2 {
  %3 = load ptr, ptr %0, align 8, !tbaa !5
  %4 = load i64, ptr %3, align 8, !tbaa !9
  %5 = load i64, ptr %1, align 8, !tbaa !9
  %6 = add i64 %5, %4
  %7 = tail call zeroext i1 @str_resize(ptr noundef nonnull %0, i64 noundef %6)
  br i1 %7, label %8, label %15

8:                                                ; preds = %2
  %9 = load ptr, ptr %0, align 8, !tbaa !5
  %10 = getelementptr inbounds i8, ptr %9, i64 16
  %11 = getelementptr inbounds i8, ptr %10, i64 %4
  %12 = getelementptr inbounds i8, ptr %1, i64 16
  %13 = tail call ptr @strcpy(ptr noundef nonnull dereferenceable(1) %11, ptr noundef nonnull dereferenceable(1) %12) #3
  %14 = load ptr, ptr %0, align 8, !tbaa !5
  br label %15

15:                                               ; preds = %2, %8
  %.0 = phi ptr [ %14, %8 ], [ null, %2 ]
  ret ptr %.0
}

attributes #0 = { inlinehint 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 nofree nounwind willreturn memory(argmem: readwrite) "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 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 #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, !11, i64 0}
!10 = !{!"string_t", !11, i64 0, !11, i64 8, !7, i64 16}
!11 = !{!"long", !7, i64 0}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass