; LLVM IR from Lakhankumawat/LearnCPP :: S-Stack/stackADTUsingLL.ll (Z8popStackP5STACK)

; 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.STACK = type { i32, ptr }
%struct.node = type { ptr, ptr }

; 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: mustprogress nounwind uwtable
define dso_local noundef ptr @_Z8popStackP5STACK(ptr noundef %0) #1 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #3
  %5 = load ptr, ptr %2, align 8, !tbaa !5
  %6 = getelementptr inbounds %struct.STACK, ptr %5, i32 0, i32 0
  %7 = load i32, ptr %6, align 8, !tbaa !9
  %8 = icmp eq i32 %7, 0
  br i1 %8, label %9, label %10

9:                                                ; preds = %1
  store ptr null, ptr %3, align 8, !tbaa !5
  br label %31

10:                                               ; preds = %1
  %11 = load ptr, ptr %2, align 8, !tbaa !5
  %12 = getelementptr inbounds %struct.STACK, ptr %11, i32 0, i32 1
  %13 = load ptr, ptr %12, align 8, !tbaa !12
  store ptr %13, ptr %4, align 8, !tbaa !5
  %14 = load ptr, ptr %2, align 8, !tbaa !5
  %15 = getelementptr inbounds %struct.STACK, ptr %14, i32 0, i32 1
  %16 = load ptr, ptr %15, align 8, !tbaa !12
  %17 = getelementptr inbounds %struct.node, ptr %16, i32 0, i32 0
  %18 = load ptr, ptr %17, align 8, !tbaa !13
  store ptr %18, ptr %3, align 8, !tbaa !5
  %19 = load ptr, ptr %2, align 8, !tbaa !5
  %20 = getelementptr inbounds %struct.STACK, ptr %19, i32 0, i32 1
  %21 = load ptr, ptr %20, align 8, !tbaa !12
  %22 = getelementptr inbounds %struct.node, ptr %21, i32 0, i32 1
  %23 = load ptr, ptr %22, align 8, !tbaa !15
  %24 = load ptr, ptr %2, align 8, !tbaa !5
  %25 = getelementptr inbounds %struct.STACK, ptr %24, i32 0, i32 1
  store ptr %23, ptr %25, align 8, !tbaa !12
  %26 = load ptr, ptr %4, align 8, !tbaa !5
  call void @free(ptr noundef %26) #3
  %27 = load ptr, ptr %2, align 8, !tbaa !5
  %28 = getelementptr inbounds %struct.STACK, ptr %27, i32 0, i32 0
  %29 = load i32, ptr %28, align 8, !tbaa !9
  %30 = add nsw i32 %29, -1
  store i32 %30, ptr %28, align 8, !tbaa !9
  br label %31

31:                                               ; preds = %10, %9
  %32 = load ptr, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #3
  ret ptr %32
}

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

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { mustprogress 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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !11, i64 0}
!10 = !{!"_ZTS5STACK", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 8}
!13 = !{!14, !6, i64 0}
!14 = !{!"_ZTS4node", !6, i64 0, !6, i64 8}
!15 = !{!14, !6, i64 8}


; 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: mustprogress nounwind willreturn uwtable
define dso_local noundef ptr @_Z8popStackP5STACK(ptr nocapture noundef %0) local_unnamed_addr #0 {
  %2 = load i32, ptr %0, align 8, !tbaa !5
  %3 = icmp eq i32 %2, 0
  br i1 %3, label %12, label %4

4:                                                ; preds = %1
  %5 = getelementptr inbounds i8, ptr %0, i64 8
  %6 = load ptr, ptr %5, align 8, !tbaa !11
  %7 = load ptr, ptr %6, align 8, !tbaa !12
  %8 = getelementptr inbounds i8, ptr %6, i64 8
  %9 = load ptr, ptr %8, align 8, !tbaa !14
  store ptr %9, ptr %5, align 8, !tbaa !11
  tail call void @free(ptr noundef %6) #2
  %10 = load i32, ptr %0, align 8, !tbaa !5
  %11 = add nsw i32 %10, -1
  store i32 %11, ptr %0, align 8, !tbaa !5
  br label %12

12:                                               ; preds = %1, %4
  %.0 = phi ptr [ %7, %4 ], [ null, %1 ]
  ret ptr %.0
}

; Function Attrs: mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite)
declare void @free(ptr allocptr nocapture noundef) local_unnamed_addr #1

attributes #0 = { mustprogress nounwind willreturn 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 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 #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, !7, i64 0}
!6 = !{!"_ZTS5STACK", !7, i64 0, !10, i64 8}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = !{!6, !10, i64 8}
!12 = !{!13, !10, i64 0}
!13 = !{!"_ZTS4node", !10, i64 0, !10, i64 8}
!14 = !{!13, !10, i64 8}


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