; LLVM IR from sbshah97/DS-Algo-Handbook :: labs/lab3/max_subArrayDivAndConq.ll (Z11maxSubArrayii)

; 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"

@arr = external dso_local global [100 x i32], align 16

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i32 @_Z3maxiii(i32 noundef, i32 noundef, i32 noundef) #0

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i32 @_Z14maxCrossingSumiii(i32 noundef, i32 noundef, i32 noundef) #0

; 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

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_Z11maxSubArrayii(i32 noundef %0, i32 noundef %1) #2 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  store i32 %0, ptr %4, align 4, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !5
  %7 = load i32, ptr %4, align 4, !tbaa !5
  %8 = load i32, ptr %5, align 4, !tbaa !5
  %9 = icmp eq i32 %7, %8
  br i1 %9, label %10, label %15

10:                                               ; preds = %2
  %11 = load i32, ptr %4, align 4, !tbaa !5
  %12 = sext i32 %11 to i64
  %13 = getelementptr inbounds [100 x i32], ptr @arr, i64 0, i64 %12
  %14 = load i32, ptr %13, align 4, !tbaa !5
  store i32 %14, ptr %3, align 4
  br label %32

15:                                               ; preds = %2
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #3
  %16 = load i32, ptr %4, align 4, !tbaa !5
  %17 = load i32, ptr %5, align 4, !tbaa !5
  %18 = add nsw i32 %16, %17
  %19 = sdiv i32 %18, 2
  store i32 %19, ptr %6, align 4, !tbaa !5
  %20 = load i32, ptr %4, align 4, !tbaa !5
  %21 = load i32, ptr %6, align 4, !tbaa !5
  %22 = call noundef i32 @_Z11maxSubArrayii(i32 noundef %20, i32 noundef %21)
  %23 = load i32, ptr %6, align 4, !tbaa !5
  %24 = add nsw i32 %23, 1
  %25 = load i32, ptr %5, align 4, !tbaa !5
  %26 = call noundef i32 @_Z11maxSubArrayii(i32 noundef %24, i32 noundef %25)
  %27 = load i32, ptr %4, align 4, !tbaa !5
  %28 = load i32, ptr %6, align 4, !tbaa !5
  %29 = load i32, ptr %5, align 4, !tbaa !5
  %30 = call noundef i32 @_Z14maxCrossingSumiii(i32 noundef %27, i32 noundef %28, i32 noundef %29)
  %31 = call noundef i32 @_Z3maxiii(i32 noundef %22, i32 noundef %26, i32 noundef %30)
  store i32 %31, ptr %3, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #3
  br label %32

32:                                               ; preds = %15, %10
  %33 = load i32, ptr %3, align 4
  ret i32 %33
}

attributes #0 = { 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 #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { mustprogress 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 }

!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++ TBAA"}


; 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"

@arr = external dso_local local_unnamed_addr global [100 x i32], align 16

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i32 @_Z3maxiii(i32 noundef, i32 noundef, i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i32 @_Z14maxCrossingSumiii(i32 noundef, i32 noundef, i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z11maxSubArrayii(i32 noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = icmp eq i32 %0, %1
  br i1 %3, label %common.ret, label %7

common.ret:                                       ; preds = %2
  %4 = sext i32 %0 to i64
  %5 = getelementptr inbounds [100 x i32], ptr @arr, i64 0, i64 %4
  %6 = load i32, ptr %5, align 4, !tbaa !5
  br label %common.ret15

common.ret15:                                     ; preds = %7, %common.ret
  %common.ret15.op = phi i32 [ %6, %common.ret ], [ %14, %7 ]
  ret i32 %common.ret15.op

7:                                                ; preds = %2
  %8 = add nsw i32 %1, %0
  %9 = sdiv i32 %8, 2
  %10 = tail call noundef i32 @_Z11maxSubArrayii(i32 noundef %0, i32 noundef %9)
  %11 = add nsw i32 %9, 1
  %12 = tail call noundef i32 @_Z11maxSubArrayii(i32 noundef %11, i32 noundef %1)
  %13 = tail call noundef i32 @_Z14maxCrossingSumiii(i32 noundef %0, i32 noundef %9, i32 noundef %1)
  %14 = tail call noundef i32 @_Z3maxiii(i32 noundef %10, i32 noundef %12, i32 noundef %13)
  br label %common.ret15
}

attributes #0 = { 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" }

!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++ TBAA"}


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