; LLVM IR from xing1357/SimpleOS :: src (kheap)

; 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"

@g_kheap_start_addr = external dso_local global ptr, align 8
@g_total_size = external dso_local global i64, align 8
@g_total_used_size = external dso_local global i64, align 8

; Function Attrs: nounwind uwtable
define dso_local ptr @kbrk(i32 noundef %0) #0 {
  %2 = alloca ptr, align 8
  %3 = alloca i32, align 4
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  store ptr null, ptr %4, align 8, !tbaa !9
  %6 = load i32, ptr %3, align 4, !tbaa !5
  %7 = icmp sle i32 %6, 0
  br i1 %7, label %8, label %9

8:                                                ; preds = %1
  store ptr null, ptr %2, align 8
  store i32 1, ptr %5, align 4
  br label %31

9:                                                ; preds = %1
  %10 = load i64, ptr @g_total_size, align 8, !tbaa !11
  %11 = load i64, ptr @g_total_used_size, align 8, !tbaa !11
  %12 = sub i64 %10, %11
  %13 = trunc i64 %12 to i32
  %14 = load i32, ptr %3, align 4, !tbaa !5
  %15 = icmp sle i32 %13, %14
  br i1 %15, label %16, label %17

16:                                               ; preds = %9
  store ptr null, ptr %2, align 8
  store i32 1, ptr %5, align 4
  br label %31

17:                                               ; preds = %9
  %18 = load ptr, ptr @g_kheap_start_addr, align 8, !tbaa !9
  %19 = load i64, ptr @g_total_used_size, align 8, !tbaa !11
  %20 = getelementptr inbounds i8, ptr %18, i64 %19
  %21 = load i32, ptr %3, align 4, !tbaa !5
  %22 = sext i32 %21 to i64
  %23 = getelementptr inbounds i8, ptr %20, i64 %22
  %24 = getelementptr inbounds i8, ptr %23, i64 8
  store ptr %24, ptr %4, align 8, !tbaa !9
  %25 = load i32, ptr %3, align 4, !tbaa !5
  %26 = sext i32 %25 to i64
  %27 = add i64 %26, 8
  %28 = load i64, ptr @g_total_used_size, align 8, !tbaa !11
  %29 = add i64 %28, %27
  store i64 %29, ptr @g_total_used_size, align 8, !tbaa !11
  %30 = load ptr, ptr %4, align 8, !tbaa !9
  store ptr %30, ptr %2, align 8
  store i32 1, ptr %5, align 4
  br label %31

31:                                               ; preds = %17, %16, %8
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  %32 = load ptr, ptr %2, align 8
  ret ptr %32
}

; 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 = { 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 = !{!"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}


; 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"

@g_kheap_start_addr = external dso_local local_unnamed_addr global ptr, align 8
@g_total_size = external dso_local local_unnamed_addr global i64, align 8
@g_total_used_size = external dso_local local_unnamed_addr global i64, align 8

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(readwrite, argmem: none, inaccessiblemem: none) uwtable
define dso_local ptr @kbrk(i32 noundef %0) local_unnamed_addr #0 {
  %2 = icmp slt i32 %0, 1
  br i1 %2, label %16, label %3

3:                                                ; preds = %1
  %4 = load i64, ptr @g_total_size, align 8, !tbaa !5
  %5 = load i64, ptr @g_total_used_size, align 8, !tbaa !5
  %6 = sub i64 %4, %5
  %7 = trunc i64 %6 to i32
  %.not = icmp sgt i32 %7, %0
  br i1 %.not, label %8, label %16

8:                                                ; preds = %3
  %9 = load ptr, ptr @g_kheap_start_addr, align 8, !tbaa !9
  %10 = getelementptr inbounds i8, ptr %9, i64 %5
  %11 = zext nneg i32 %0 to i64
  %12 = getelementptr inbounds i8, ptr %10, i64 %11
  %13 = getelementptr inbounds i8, ptr %12, i64 8
  %14 = add nuw nsw i64 %11, 8
  %15 = add i64 %14, %5
  store i64 %15, ptr @g_total_used_size, align 8, !tbaa !5
  br label %16

16:                                               ; preds = %3, %1, %8
  %.0 = phi ptr [ %13, %8 ], [ null, %1 ], [ null, %3 ]
  ret ptr %.0
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(readwrite, 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", !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}


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