; LLVM IR from Leet-Us-Code/DSA-A-Z-Practice :: Sid's Levels/Level - 2/Stacks, Queue and Dequeue.cpp/BFS.ll (ZN7MyStack3popEv)

; 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"

%class.MyStack = type { [1000 x i32], i32 }

; 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 i32 @_ZN7MyStack3popEv(ptr noundef nonnull align 4 dereferenceable(4004) %0) #1 align 2 {
  %2 = alloca i32, align 4
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  %5 = load ptr, ptr %3, align 8
  %6 = getelementptr inbounds %class.MyStack, ptr %5, i32 0, i32 1
  %7 = load i32, ptr %6, align 4, !tbaa !9
  %8 = icmp slt i32 %7, 0
  br i1 %8, label %9, label %10

9:                                                ; preds = %1
  store i32 -1, ptr %2, align 4
  br label %21

10:                                               ; preds = %1
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  %11 = getelementptr inbounds %class.MyStack, ptr %5, i32 0, i32 1
  %12 = load i32, ptr %11, align 4, !tbaa !9
  store i32 %12, ptr %4, align 4, !tbaa !12
  %13 = getelementptr inbounds %class.MyStack, ptr %5, i32 0, i32 1
  %14 = load i32, ptr %13, align 4, !tbaa !9
  %15 = add nsw i32 %14, -1
  store i32 %15, ptr %13, align 4, !tbaa !9
  %16 = getelementptr inbounds %class.MyStack, ptr %5, i32 0, i32 0
  %17 = load i32, ptr %4, align 4, !tbaa !12
  %18 = sext i32 %17 to i64
  %19 = getelementptr inbounds [1000 x i32], ptr %16, i64 0, i64 %18
  %20 = load i32, ptr %19, align 4, !tbaa !12
  store i32 %20, ptr %2, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  br label %21

21:                                               ; preds = %10, %9
  %22 = load i32, ptr %2, align 4
  ret i32 %22
}

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 }

!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 4000}
!10 = !{!"_ZTS7MyStack", !7, i64 0, !11, i64 4000}
!11 = !{!"int", !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: mustprogress nofree norecurse nosync nounwind willreturn memory(argmem: readwrite) uwtable
define dso_local noundef i32 @_ZN7MyStack3popEv(ptr nocapture noundef nonnull align 4 dereferenceable(4004) %0) local_unnamed_addr #0 align 2 {
  %2 = getelementptr inbounds i8, ptr %0, i64 4000
  %3 = load i32, ptr %2, align 4, !tbaa !5
  %4 = icmp slt i32 %3, 0
  br i1 %4, label %10, label %5

5:                                                ; preds = %1
  %6 = add nsw i32 %3, -1
  store i32 %6, ptr %2, align 4, !tbaa !5
  %7 = zext nneg i32 %3 to i64
  %8 = getelementptr inbounds [1000 x i32], ptr %0, i64 0, i64 %7
  %9 = load i32, ptr %8, align 4, !tbaa !10
  br label %10

10:                                               ; preds = %1, %5
  %.0 = phi i32 [ %9, %5 ], [ -1, %1 ]
  ret i32 %.0
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(argmem: readwrite) 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, !9, i64 4000}
!6 = !{!"_ZTS7MyStack", !7, i64 0, !9, i64 4000}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!"int", !7, i64 0}
!10 = !{!9, !9, i64 0}


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