; LLVM IR from sgtlaugh/algovault :: code_library/misc (bit_twiddling)

; 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: nounwind uwtable
define dso_local i32 @iterate(i64 noundef %0, ptr noundef %1) #1 {
  %3 = alloca i64, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  store i64 %0, ptr %3, align 8, !tbaa !5
  store ptr %1, ptr %4, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  store i32 0, ptr %5, align 4, !tbaa !11
  br label %6

6:                                                ; preds = %9, %2
  %7 = load i64, ptr %3, align 8, !tbaa !5
  %8 = icmp ne i64 %7, 0
  br i1 %8, label %9, label %24

9:                                                ; preds = %6
  %10 = load i64, ptr %3, align 8, !tbaa !5
  %11 = call i64 @llvm.cttz.i64(i64 %10, i1 true)
  %12 = trunc i64 %11 to i32
  %13 = load ptr, ptr %4, align 8, !tbaa !9
  %14 = load i32, ptr %5, align 4, !tbaa !11
  %15 = add nsw i32 %14, 1
  store i32 %15, ptr %5, align 4, !tbaa !11
  %16 = sext i32 %14 to i64
  %17 = getelementptr inbounds i32, ptr %13, i64 %16
  store i32 %12, ptr %17, align 4, !tbaa !11
  %18 = load i64, ptr %3, align 8, !tbaa !5
  %19 = sub i64 0, %18
  %20 = load i64, ptr %3, align 8, !tbaa !5
  %21 = and i64 %19, %20
  %22 = load i64, ptr %3, align 8, !tbaa !5
  %23 = xor i64 %22, %21
  store i64 %23, ptr %3, align 8, !tbaa !5
  br label %6, !llvm.loop !13

24:                                               ; preds = %6
  %25 = load i32, ptr %5, align 4, !tbaa !11
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  ret i32 %25
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i64 @llvm.cttz.i64(i64, i1 immarg) #2

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
attributes #3 = { 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 = !{!"long long", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = !{!12, !12, i64 0}
!12 = !{!"int", !7, i64 0}
!13 = distinct !{!13, !14}
!14 = !{!"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(argmem: write) uwtable
define dso_local i32 @iterate(i64 noundef %0, ptr nocapture noundef writeonly %1) local_unnamed_addr #0 {
  %.not8 = icmp eq i64 %0, 0
  br i1 %.not8, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %2, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %2 ]
  %.079 = phi i64 [ %7, %.lr.ph ], [ %0, %2 ]
  %3 = tail call range(i64 0, 65) i64 @llvm.cttz.i64(i64 %.079, i1 true)
  %4 = trunc nuw nsw i64 %3 to i32
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %5 = getelementptr inbounds i32, ptr %1, i64 %indvars.iv
  store i32 %4, ptr %5, align 4, !tbaa !5
  %6 = add i64 %.079, -1
  %7 = and i64 %6, %.079
  %.not = icmp eq i64 %7, 0
  br i1 %.not, label %._crit_edge.loopexit, label %.lr.ph, !llvm.loop !9

._crit_edge.loopexit:                             ; preds = %.lr.ph
  %8 = trunc nuw i64 %indvars.iv.next to i32
  br label %._crit_edge

._crit_edge:                                      ; preds = %._crit_edge.loopexit, %2
  %.0.lcssa = phi i32 [ 0, %2 ], [ %8, %._crit_edge.loopexit ]
  ret i32 %.0.lcssa
}

; Function Attrs: mustprogress nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i64 @llvm.cttz.i64(i64, i1 immarg) #1

attributes #0 = { nofree norecurse nosync nounwind memory(argmem: write) 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 = { mustprogress 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 = !{!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"}


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