; LLVM IR from nonstriater/Learn-Algorithms :: 9 Algorithms Job Interview/codes/4 numer (isSquare)

; 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"

; Function Attrs: nounwind uwtable
define dso_local i32 @isSquare(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  %7 = load i32, ptr %3, align 4, !tbaa !5
  %8 = icmp eq i32 %7, 1
  br i1 %8, label %12, label %9

9:                                                ; preds = %1
  %10 = load i32, ptr %3, align 4, !tbaa !5
  %11 = icmp eq i32 %10, 0
  br i1 %11, label %12, label %14

12:                                               ; preds = %9, %1
  %13 = load i32, ptr %3, align 4, !tbaa !5
  store i32 %13, ptr %2, align 4
  br label %36

14:                                               ; preds = %9
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  store i32 2, ptr %4, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  %15 = load i32, ptr %3, align 4, !tbaa !5
  %16 = load i32, ptr %4, align 4, !tbaa !5
  %17 = udiv i32 %15, %16
  store i32 %17, ptr %5, align 4, !tbaa !5
  br label %18

18:                                               ; preds = %22, %14
  %19 = load i32, ptr %5, align 4, !tbaa !5
  %20 = load i32, ptr %4, align 4, !tbaa !5
  %21 = icmp sgt i32 %19, %20
  br i1 %21, label %22, label %28

22:                                               ; preds = %18
  %23 = load i32, ptr %4, align 4, !tbaa !5
  %24 = add nsw i32 %23, 1
  store i32 %24, ptr %4, align 4, !tbaa !5
  %25 = load i32, ptr %3, align 4, !tbaa !5
  %26 = load i32, ptr %4, align 4, !tbaa !5
  %27 = udiv i32 %25, %26
  store i32 %27, ptr %5, align 4, !tbaa !5
  br label %18, !llvm.loop !9

28:                                               ; preds = %18
  %29 = load i32, ptr %5, align 4, !tbaa !5
  %30 = load i32, ptr %4, align 4, !tbaa !5
  %31 = icmp ne i32 %29, %30
  br i1 %31, label %32, label %33

32:                                               ; preds = %28
  store i32 -1, ptr %2, align 4
  store i32 1, ptr %6, align 4
  br label %35

33:                                               ; preds = %28
  %34 = load i32, ptr %5, align 4, !tbaa !5
  store i32 %34, ptr %2, align 4
  store i32 1, ptr %6, align 4
  br label %35

35:                                               ; preds = %33, %32
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  br label %36

36:                                               ; preds = %35, %12
  %37 = load i32, ptr %2, align 4
  ret i32 %37
}

; 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

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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = !{!"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"

; Function Attrs: nofree norecurse nosync nounwind memory(none) uwtable
define dso_local i32 @isSquare(i32 noundef %0) local_unnamed_addr #0 {
  %or.cond = icmp ult i32 %0, 2
  br i1 %or.cond, label %8, label %2

2:                                                ; preds = %1
  %3 = lshr i32 %0, 1
  %4 = icmp ugt i32 %0, 5
  br i1 %4, label %.lr.ph, label %._crit_edge

.lr.ph:                                           ; preds = %2, %.lr.ph
  %.01518 = phi i32 [ %5, %.lr.ph ], [ 2, %2 ]
  %5 = add nuw nsw i32 %.01518, 1
  %6 = udiv i32 %0, %5
  %7 = icmp ugt i32 %6, %5
  br i1 %7, label %.lr.ph, label %._crit_edge, !llvm.loop !5

._crit_edge:                                      ; preds = %.lr.ph, %2
  %.015.lcssa = phi i32 [ 2, %2 ], [ %5, %.lr.ph ]
  %.0.lcssa = phi i32 [ %3, %2 ], [ %6, %.lr.ph ]
  %.not = icmp eq i32 %.0.lcssa, %.015.lcssa
  %.0. = select i1 %.not, i32 %.0.lcssa, i32 -1
  br label %8

8:                                                ; preds = %1, %._crit_edge
  %.1 = phi i32 [ %.0., %._crit_edge ], [ %0, %1 ]
  ret i32 %.1
}

attributes #0 = { nofree norecurse nosync nounwind memory(none) 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 = distinct !{!5, !6}
!6 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass