; LLVM IR from Dovyski/opengl-demos :: libs/glm-0.9.9.3/test/core/core_func_integer_find_msb.ll (Z4nlz3i)

; 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: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z4nlz3i(i32 noundef %0) #1 {
  %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
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  store i32 0, ptr %5, align 4, !tbaa !5
  %7 = load i32, ptr %3, align 4, !tbaa !5
  store i32 %7, ptr %4, align 4, !tbaa !5
  br label %8

8:                                                ; preds = %19, %1
  %9 = load i32, ptr %3, align 4, !tbaa !5
  %10 = icmp slt i32 %9, 0
  br i1 %10, label %11, label %13

11:                                               ; preds = %8
  %12 = load i32, ptr %5, align 4, !tbaa !5
  store i32 %12, ptr %2, align 4
  store i32 1, ptr %6, align 4
  br label %26

13:                                               ; preds = %8
  %14 = load i32, ptr %4, align 4, !tbaa !5
  %15 = icmp eq i32 %14, 0
  br i1 %15, label %16, label %19

16:                                               ; preds = %13
  %17 = load i32, ptr %5, align 4, !tbaa !5
  %18 = sub nsw i32 32, %17
  store i32 %18, ptr %2, align 4
  store i32 1, ptr %6, align 4
  br label %26

19:                                               ; preds = %13
  %20 = load i32, ptr %5, align 4, !tbaa !5
  %21 = add nsw i32 %20, 1
  store i32 %21, ptr %5, align 4, !tbaa !5
  %22 = load i32, ptr %3, align 4, !tbaa !5
  %23 = shl i32 %22, 1
  store i32 %23, ptr %3, align 4, !tbaa !5
  %24 = load i32, ptr %4, align 4, !tbaa !5
  %25 = ashr i32 %24, 1
  store i32 %25, ptr %4, align 4, !tbaa !5
  br label %8

26:                                               ; preds = %16, %11
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  %27 = load i32, ptr %2, align 4
  ret i32 %27
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #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 @_Z4nlz3i(i32 noundef %0) local_unnamed_addr #0 {
  %2 = icmp slt i32 %0, 0
  br i1 %2, label %.loopexit, label %.lr.ph

.lr.ph:                                           ; preds = %1, %6
  %.015 = phi i32 [ %7, %6 ], [ 0, %1 ]
  %.0914 = phi i32 [ %9, %6 ], [ %0, %1 ]
  %.01013 = phi i32 [ %8, %6 ], [ %0, %1 ]
  %3 = icmp eq i32 %.0914, 0
  br i1 %3, label %4, label %6

4:                                                ; preds = %.lr.ph
  %5 = sub nsw i32 32, %.015
  br label %.loopexit

6:                                                ; preds = %.lr.ph
  %7 = add nuw nsw i32 %.015, 1
  %8 = shl nuw i32 %.01013, 1
  %9 = lshr i32 %.0914, 1
  %10 = icmp slt i32 %8, 0
  br i1 %10, label %.loopexit, label %.lr.ph

.loopexit:                                        ; preds = %6, %1, %4
  %.011 = phi i32 [ %5, %4 ], [ 0, %1 ], [ %7, %6 ]
  ret i32 %.011
}

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: GVNPass,GlobalOptPass,IPSCCPPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass