; LLVM IR from Dovyski/opengl-demos :: libs/glm-0.9.9.3/test/core/core_func_integer_find_lsb.ll (Z4ntz3j)

; 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 @_Z4ntz3j(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
  %6 = load i32, ptr %3, align 4, !tbaa !5
  %7 = icmp eq i32 %6, 0
  br i1 %7, label %8, label %9

8:                                                ; preds = %1
  store i32 32, ptr %2, align 4
  store i32 1, ptr %5, align 4
  br label %50

9:                                                ; preds = %1
  store i32 1, ptr %4, align 4, !tbaa !5
  %10 = load i32, ptr %3, align 4, !tbaa !5
  %11 = and i32 %10, 65535
  %12 = icmp eq i32 %11, 0
  br i1 %12, label %13, label %18

13:                                               ; preds = %9
  %14 = load i32, ptr %4, align 4, !tbaa !5
  %15 = add nsw i32 %14, 16
  store i32 %15, ptr %4, align 4, !tbaa !5
  %16 = load i32, ptr %3, align 4, !tbaa !5
  %17 = lshr i32 %16, 16
  store i32 %17, ptr %3, align 4, !tbaa !5
  br label %18

18:                                               ; preds = %13, %9
  %19 = load i32, ptr %3, align 4, !tbaa !5
  %20 = and i32 %19, 255
  %21 = icmp eq i32 %20, 0
  br i1 %21, label %22, label %27

22:                                               ; preds = %18
  %23 = load i32, ptr %4, align 4, !tbaa !5
  %24 = add nsw i32 %23, 8
  store i32 %24, ptr %4, align 4, !tbaa !5
  %25 = load i32, ptr %3, align 4, !tbaa !5
  %26 = lshr i32 %25, 8
  store i32 %26, ptr %3, align 4, !tbaa !5
  br label %27

27:                                               ; preds = %22, %18
  %28 = load i32, ptr %3, align 4, !tbaa !5
  %29 = and i32 %28, 15
  %30 = icmp eq i32 %29, 0
  br i1 %30, label %31, label %36

31:                                               ; preds = %27
  %32 = load i32, ptr %4, align 4, !tbaa !5
  %33 = add nsw i32 %32, 4
  store i32 %33, ptr %4, align 4, !tbaa !5
  %34 = load i32, ptr %3, align 4, !tbaa !5
  %35 = lshr i32 %34, 4
  store i32 %35, ptr %3, align 4, !tbaa !5
  br label %36

36:                                               ; preds = %31, %27
  %37 = load i32, ptr %3, align 4, !tbaa !5
  %38 = and i32 %37, 3
  %39 = icmp eq i32 %38, 0
  br i1 %39, label %40, label %45

40:                                               ; preds = %36
  %41 = load i32, ptr %4, align 4, !tbaa !5
  %42 = add nsw i32 %41, 2
  store i32 %42, ptr %4, align 4, !tbaa !5
  %43 = load i32, ptr %3, align 4, !tbaa !5
  %44 = lshr i32 %43, 2
  store i32 %44, ptr %3, align 4, !tbaa !5
  br label %45

45:                                               ; preds = %40, %36
  %46 = load i32, ptr %4, align 4, !tbaa !5
  %47 = load i32, ptr %3, align 4, !tbaa !5
  %48 = and i32 %47, 1
  %49 = sub i32 %46, %48
  store i32 %49, ptr %2, align 4
  store i32 1, ptr %5, align 4
  br label %50

50:                                               ; preds = %45, %8
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  %51 = load i32, ptr %2, align 4
  ret i32 %51
}

; 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"}


; 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 @_Z4ntz3j(i32 noundef %0) local_unnamed_addr #0 {
  %2 = icmp eq i32 %0, 0
  br i1 %2, label %21, label %3

3:                                                ; preds = %1
  %4 = and i32 %0, 65535
  %5 = icmp eq i32 %4, 0
  %6 = lshr exact i32 %0, 16
  %spec.select = select i1 %5, i32 %6, i32 %0
  %spec.select22 = select i1 %5, i32 17, i32 1
  %7 = and i32 %spec.select, 255
  %8 = icmp eq i32 %7, 0
  %9 = or disjoint i32 %spec.select22, 8
  %10 = lshr exact i32 %spec.select, 8
  %.117 = select i1 %8, i32 %10, i32 %spec.select
  %.1 = select i1 %8, i32 %9, i32 %spec.select22
  %11 = and i32 %.117, 15
  %12 = icmp eq i32 %11, 0
  %13 = or disjoint i32 %.1, 4
  %14 = lshr exact i32 %.117, 4
  %.218 = select i1 %12, i32 %14, i32 %.117
  %.2 = select i1 %12, i32 %13, i32 %.1
  %15 = and i32 %.218, 3
  %16 = icmp eq i32 %15, 0
  %17 = or disjoint i32 %.2, 2
  %18 = lshr exact i32 %.218, 2
  %.319 = select i1 %16, i32 %18, i32 %.218
  %.3 = select i1 %16, i32 %17, i32 %.2
  %19 = and i32 %.319, 1
  %20 = sub nuw nsw i32 %.3, %19
  br label %21

21:                                               ; preds = %1, %3
  %.020 = phi i32 [ %20, %3 ], [ 32, %1 ]
  ret i32 %.020
}

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" }

!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)"}


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