; LLVM IR from lolosssss/leetcode :: c (342_power_of_four)

; 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 zeroext i1 @isPowerOfFour(i32 noundef %0) #0 {
  %2 = alloca i1, align 1
  %3 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  br label %4

4:                                                ; preds = %16, %1
  %5 = load i32, ptr %3, align 4, !tbaa !5
  %6 = icmp ne i32 %5, 0
  br i1 %6, label %7, label %19

7:                                                ; preds = %4
  %8 = load i32, ptr %3, align 4, !tbaa !5
  %9 = icmp eq i32 %8, 1
  br i1 %9, label %10, label %11

10:                                               ; preds = %7
  store i1 true, ptr %2, align 1
  br label %19

11:                                               ; preds = %7
  %12 = load i32, ptr %3, align 4, !tbaa !5
  %13 = srem i32 %12, 4
  %14 = icmp ne i32 %13, 0
  br i1 %14, label %15, label %16

15:                                               ; preds = %11
  store i1 false, ptr %2, align 1
  br label %19

16:                                               ; preds = %11
  %17 = load i32, ptr %3, align 4, !tbaa !5
  %18 = sdiv i32 %17, 4
  store i32 %18, ptr %3, align 4, !tbaa !5
  br label %4, !llvm.loop !9

19:                                               ; preds = %15, %10, %4
  %20 = load i1, ptr %2, align 1
  ret i1 %20
}

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" }

!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 zeroext i1 @isPowerOfFour(i32 noundef %0) local_unnamed_addr #0 {
  br label %2

2:                                                ; preds = %2, %1
  %.0 = phi i32 [ %0, %1 ], [ %4, %2 ]
  %switch = icmp ult i32 %.0, 2
  %3 = and i32 %.0, 3
  %.not5 = icmp ne i32 %3, 0
  %or.cond.not = or i1 %.not5, %switch
  %4 = ashr exact i32 %.0, 2
  br i1 %or.cond.not, label %5, label %2, !llvm.loop !5

5:                                                ; preds = %2
  ret i1 %switch
}

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,InstCombinePass,InstSimplifyPass,LCSSAPass,LoopRotatePass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass