; LLVM IR from VAR-solutions/Algorithms :: Bit Manipulation/next power of 2/cpp/nextPowerof2.ll (Z12nextPowerOf2j)

; 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: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z12nextPowerOf2j(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  store i32 1, ptr %4, align 4, !tbaa !5
  %6 = load i32, ptr %3, align 4, !tbaa !5
  %7 = icmp ne i32 %6, 0
  br i1 %7, label %8, label %16

8:                                                ; preds = %1
  %9 = load i32, ptr %3, align 4, !tbaa !5
  %10 = load i32, ptr %3, align 4, !tbaa !5
  %11 = sub i32 %10, 1
  %12 = and i32 %9, %11
  %13 = icmp ne i32 %12, 0
  br i1 %13, label %16, label %14

14:                                               ; preds = %8
  %15 = load i32, ptr %3, align 4, !tbaa !5
  store i32 %15, ptr %2, align 4
  store i32 1, ptr %5, align 4
  br label %26

16:                                               ; preds = %8, %1
  br label %17

17:                                               ; preds = %21, %16
  %18 = load i32, ptr %4, align 4, !tbaa !5
  %19 = load i32, ptr %3, align 4, !tbaa !5
  %20 = icmp ult i32 %18, %19
  br i1 %20, label %21, label %24

21:                                               ; preds = %17
  %22 = load i32, ptr %4, align 4, !tbaa !5
  %23 = shl i32 %22, 1
  store i32 %23, ptr %4, align 4, !tbaa !5
  br label %17, !llvm.loop !9

24:                                               ; preds = %17
  %25 = load i32, ptr %4, align 4, !tbaa !5
  store i32 %25, ptr %2, align 4
  store i32 1, ptr %5, align 4
  br label %26

26:                                               ; preds = %24, %14
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  %27 = load i32, ptr %2, align 4
  ret i32 %27
}

; 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 = { 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 = { 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"}
!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: mustprogress nofree norecurse nosync nounwind willreturn memory(none) uwtable
define dso_local noundef i32 @_Z12nextPowerOf2j(i32 noundef %0) local_unnamed_addr #0 {
  %2 = tail call range(i32 0, 33) i32 @llvm.ctpop.i32(i32 %0)
  %or.cond = icmp eq i32 %2, 1
  br i1 %or.cond, label %.loopexit, label %.preheader

.preheader:                                       ; preds = %1, %.preheader
  %.0 = phi i32 [ %4, %.preheader ], [ 1, %1 ]
  %3 = icmp ult i32 %.0, %0
  %4 = shl i32 %.0, 1
  br i1 %3, label %.preheader, label %.loopexit, !llvm.loop !5

.loopexit:                                        ; preds = %.preheader, %1
  %.09 = phi i32 [ %0, %1 ], [ %.0, %.preheader ]
  ret i32 %.09
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.ctpop.i32(i32) #1

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn 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" }
attributes #1 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }

!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,IPSCCPPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass