; LLVM IR from AllenDowney/ExercisesInC :: exercises/ex12 (beer)

; 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"

%union.pthread_mutex_t = type { %struct.__pthread_mutex_s }
%struct.__pthread_mutex_s = type { i32, i32, i32, i32, i32, i16, i16, %struct.__pthread_internal_list }
%struct.__pthread_internal_list = type { ptr, ptr }

@beers = external dso_local global i32, align 4
@.str.1 = external hidden unnamed_addr constant [12 x i8], align 1
@beers_lock = external dso_local global %union.pthread_mutex_t, align 8

; 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

declare i32 @printf(ptr noundef, ...) #1

; Function Attrs: nounwind uwtable
define dso_local ptr @drink_safely() #2 {
  %1 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %1) #4
  store i32 0, ptr %1, align 4, !tbaa !5
  br label %2

2:                                                ; preds = %11, %0
  %3 = load i32, ptr %1, align 4, !tbaa !5
  %4 = icmp slt i32 %3, 100000
  br i1 %4, label %6, label %5

5:                                                ; preds = %2
  call void @llvm.lifetime.end.p0(i64 4, ptr %1) #4
  br label %14

6:                                                ; preds = %2
  %7 = call i32 @pthread_mutex_lock(ptr noundef @beers_lock) #4
  %8 = load i32, ptr @beers, align 4, !tbaa !5
  %9 = sub nsw i32 %8, 1
  store i32 %9, ptr @beers, align 4, !tbaa !5
  %10 = call i32 @pthread_mutex_unlock(ptr noundef @beers_lock) #4
  br label %11

11:                                               ; preds = %6
  %12 = load i32, ptr %1, align 4, !tbaa !5
  %13 = add nsw i32 %12, 1
  store i32 %13, ptr %1, align 4, !tbaa !5
  br label %2, !llvm.loop !9

14:                                               ; preds = %5
  %15 = load i32, ptr @beers, align 4, !tbaa !5
  %16 = call i32 (ptr, ...) @printf(ptr noundef @.str.1, i32 noundef %15)
  ret ptr null
}

; Function Attrs: nounwind
declare i32 @pthread_mutex_lock(ptr noundef) #3

; Function Attrs: nounwind
declare i32 @pthread_mutex_unlock(ptr noundef) #3

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { "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 "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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"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"

%union.pthread_mutex_t = type { %struct.__pthread_mutex_s }
%struct.__pthread_mutex_s = type { i32, i32, i32, i32, i32, i16, i16, %struct.__pthread_internal_list }
%struct.__pthread_internal_list = type { ptr, ptr }

@beers = external dso_local local_unnamed_addr global i32, align 4
@.str.1 = external hidden unnamed_addr constant [12 x i8], align 1
@beers_lock = external dso_local global %union.pthread_mutex_t, align 8

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local noalias noundef ptr @drink_safely() local_unnamed_addr #1 {
  br label %4

1:                                                ; preds = %4
  %2 = load i32, ptr @beers, align 4, !tbaa !5
  %3 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.1, i32 noundef %2)
  ret ptr null

4:                                                ; preds = %0, %4
  %.02 = phi i32 [ 0, %0 ], [ %9, %4 ]
  %5 = tail call i32 @pthread_mutex_lock(ptr noundef nonnull @beers_lock) #3
  %6 = load i32, ptr @beers, align 4, !tbaa !5
  %7 = add nsw i32 %6, -1
  store i32 %7, ptr @beers, align 4, !tbaa !5
  %8 = tail call i32 @pthread_mutex_unlock(ptr noundef nonnull @beers_lock) #3
  %9 = add nuw nsw i32 %.02, 1
  %exitcond.not = icmp eq i32 %9, 100000
  br i1 %exitcond.not, label %1, label %4, !llvm.loop !9
}

; Function Attrs: nounwind
declare i32 @pthread_mutex_lock(ptr noundef) local_unnamed_addr #2

; Function Attrs: nounwind
declare i32 @pthread_mutex_unlock(ptr noundef) local_unnamed_addr #2

attributes #0 = { 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 #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 = { 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 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,LoopRotatePass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass