; LLVM IR from simonaertssen/MIT-6.172-Performance-Engineering-of-Software-Systems :: Week 2 Bentleys rules and bit hacks/homework (sort_a)

; 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 [2 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [155 x i8], align 1
@__PRETTY_FUNCTION__.sort_a = external hidden unnamed_addr constant [32 x i8], align 1

; Function Attrs: nounwind uwtable
define dso_local void @sort_a(ptr noundef %0, i32 noundef %1, i32 noundef %2) #0 {
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  store i32 %2, ptr %6, align 4, !tbaa !9
  %8 = load ptr, ptr %4, align 8, !tbaa !5
  %9 = icmp ne ptr %8, null
  br i1 %9, label %10, label %11

10:                                               ; preds = %3
  br label %12

11:                                               ; preds = %3
  call void @__assert_fail(ptr noundef @.str, ptr noundef @.str.1, i32 noundef 32, ptr noundef @__PRETTY_FUNCTION__.sort_a) #3
  unreachable

12:                                               ; preds = %10
  %13 = load i32, ptr %5, align 4, !tbaa !9
  %14 = load i32, ptr %6, align 4, !tbaa !9
  %15 = icmp slt i32 %13, %14
  br i1 %15, label %16, label %32

16:                                               ; preds = %12
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #4
  %17 = load i32, ptr %5, align 4, !tbaa !9
  %18 = load i32, ptr %6, align 4, !tbaa !9
  %19 = add nsw i32 %17, %18
  %20 = sdiv i32 %19, 2
  store i32 %20, ptr %7, align 4, !tbaa !9
  %21 = load ptr, ptr %4, align 8, !tbaa !5
  %22 = load i32, ptr %5, align 4, !tbaa !9
  %23 = load i32, ptr %7, align 4, !tbaa !9
  call void @sort_a(ptr noundef %21, i32 noundef %22, i32 noundef %23)
  %24 = load ptr, ptr %4, align 8, !tbaa !5
  %25 = load i32, ptr %7, align 4, !tbaa !9
  %26 = add nsw i32 %25, 1
  %27 = load i32, ptr %6, align 4, !tbaa !9
  call void @sort_a(ptr noundef %24, i32 noundef %26, i32 noundef %27)
  %28 = load ptr, ptr %4, align 8, !tbaa !5
  %29 = load i32, ptr %5, align 4, !tbaa !9
  %30 = load i32, ptr %7, align 4, !tbaa !9
  %31 = load i32, ptr %6, align 4, !tbaa !9
  call void @merge_a(ptr noundef %28, i32 noundef %29, i32 noundef %30, i32 noundef %31)
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #4
  br label %32

32:                                               ; preds = %16, %12
  ret void
}

; Function Attrs: noreturn nounwind
declare void @__assert_fail(ptr noundef, ptr noundef, i32 noundef, ptr noundef) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: nounwind uwtable
declare hidden void @merge_a(ptr noundef, i32 noundef, i32 noundef, i32 noundef) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #2

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 = { noreturn 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 #2 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #3 = { noreturn nounwind }
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, !10, i64 0}
!10 = !{!"int", !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"

@.str = external hidden unnamed_addr constant [2 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [155 x i8], align 1
@__PRETTY_FUNCTION__.sort_a = external hidden unnamed_addr constant [32 x i8], align 1

; Function Attrs: nounwind uwtable
define dso_local void @sort_a(ptr noundef %0, i32 noundef %1, i32 noundef %2) local_unnamed_addr #0 {
  %.not = icmp eq ptr %0, null
  br i1 %.not, label %4, label %5

4:                                                ; preds = %3
  tail call void @__assert_fail(ptr noundef nonnull @.str, ptr noundef nonnull @.str.1, i32 noundef 32, ptr noundef nonnull @__PRETTY_FUNCTION__.sort_a) #2
  unreachable

5:                                                ; preds = %3
  %6 = icmp slt i32 %1, %2
  br i1 %6, label %7, label %common.ret16

common.ret16:                                     ; preds = %5, %7
  ret void

7:                                                ; preds = %5
  %8 = add nsw i32 %2, %1
  %9 = sdiv i32 %8, 2
  tail call void @sort_a(ptr noundef nonnull %0, i32 noundef %1, i32 noundef %9)
  %10 = add nsw i32 %9, 1
  tail call void @sort_a(ptr noundef nonnull %0, i32 noundef %10, i32 noundef %2)
  tail call void @merge_a(ptr noundef nonnull %0, i32 noundef %1, i32 noundef %9, i32 noundef %2)
  br label %common.ret16
}

; Function Attrs: noreturn nounwind
declare void @__assert_fail(ptr noundef, ptr noundef, i32 noundef, ptr noundef) local_unnamed_addr #1

; Function Attrs: nounwind uwtable
declare hidden void @merge_a(ptr noundef, i32 noundef, i32 noundef, i32 noundef) local_unnamed_addr #0

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 = { noreturn 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 #2 = { noreturn 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)"}


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