; LLVM IR from upupming/algorithm :: acwing/算法竞赛进阶指南/0x41-并查集/240. 食物链.ll (Z4initv)

; 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"

@fa = external dso_local global [150010 x i32], align 16
@sz = external dso_local global [150010 x i32], align 16
@n = external dso_local global i32, align 4

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z4initv() #0 {
  %1 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %1) #2
  store i32 1, ptr %1, align 4, !tbaa !5
  br label %2

2:                                                ; preds = %16, %0
  %3 = load i32, ptr %1, align 4, !tbaa !5
  %4 = load i32, ptr @n, align 4, !tbaa !5
  %5 = mul nsw i32 3, %4
  %6 = icmp sle i32 %3, %5
  br i1 %6, label %8, label %7

7:                                                ; preds = %2
  call void @llvm.lifetime.end.p0(i64 4, ptr %1) #2
  br label %19

8:                                                ; preds = %2
  %9 = load i32, ptr %1, align 4, !tbaa !5
  %10 = load i32, ptr %1, align 4, !tbaa !5
  %11 = sext i32 %10 to i64
  %12 = getelementptr inbounds [150010 x i32], ptr @fa, i64 0, i64 %11
  store i32 %9, ptr %12, align 4, !tbaa !5
  %13 = load i32, ptr %1, align 4, !tbaa !5
  %14 = sext i32 %13 to i64
  %15 = getelementptr inbounds [150010 x i32], ptr @sz, i64 0, i64 %14
  store i32 1, ptr %15, align 4, !tbaa !5
  br label %16

16:                                               ; preds = %8
  %17 = load i32, ptr %1, align 4, !tbaa !5
  %18 = add nsw i32 %17, 1
  store i32 %18, ptr %1, align 4, !tbaa !5
  br label %2, !llvm.loop !9

19:                                               ; preds = %7
  ret void
}

; 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"

@fa = external dso_local local_unnamed_addr global [150010 x i32], align 16
@sz = external dso_local local_unnamed_addr global [150010 x i32], align 16
@n = external dso_local local_unnamed_addr global i32, align 4

; Function Attrs: mustprogress nofree norecurse nosync nounwind memory(readwrite, argmem: none, inaccessiblemem: none) uwtable
define dso_local void @_Z4initv() local_unnamed_addr #0 {
  %1 = load i32, ptr @n, align 4, !tbaa !5
  %.not5 = icmp slt i32 %1, 1
  br i1 %.not5, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %0
  %2 = mul i32 %1, 3
  %smax = tail call i32 @llvm.smax.i32(i32 %2, i32 1)
  %3 = add nuw i32 %smax, 1
  %wide.trip.count = zext i32 %3 to i64
  %4 = zext nneg i32 %smax to i64
  %min.iters.check = icmp slt i32 %2, 8
  br i1 %min.iters.check, label %.lr.ph.preheader9, label %vector.ph

.lr.ph.preheader9:                                ; preds = %middle.block, %.lr.ph.preheader
  %indvars.iv.ph = phi i64 [ 1, %.lr.ph.preheader ], [ %ind.end, %middle.block ]
  br label %.lr.ph

vector.ph:                                        ; preds = %.lr.ph.preheader
  %n.vec = and i64 %4, 2147483640
  %ind.end = or disjoint i64 %n.vec, 1
  br label %vector.body

vector.body:                                      ; preds = %vector.body, %vector.ph
  %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
  %vec.ind = phi <4 x i32> [ <i32 1, i32 2, i32 3, i32 4>, %vector.ph ], [ %vec.ind.next, %vector.body ]
  %step.add = add <4 x i32> %vec.ind, <i32 4, i32 4, i32 4, i32 4>
  %offset.idx = or disjoint i64 %index, 1
  %5 = getelementptr inbounds [150010 x i32], ptr @fa, i64 0, i64 %offset.idx
  %6 = getelementptr inbounds i8, ptr %5, i64 16
  store <4 x i32> %vec.ind, ptr %5, align 4, !tbaa !5
  store <4 x i32> %step.add, ptr %6, align 4, !tbaa !5
  %7 = getelementptr inbounds [150010 x i32], ptr @sz, i64 0, i64 %offset.idx
  %8 = getelementptr inbounds i8, ptr %7, i64 16
  store <4 x i32> <i32 1, i32 1, i32 1, i32 1>, ptr %7, align 4, !tbaa !5
  store <4 x i32> <i32 1, i32 1, i32 1, i32 1>, ptr %8, align 4, !tbaa !5
  %index.next = add nuw i64 %index, 8
  %vec.ind.next = add <4 x i32> %vec.ind, <i32 8, i32 8, i32 8, i32 8>
  %9 = icmp eq i64 %index.next, %n.vec
  br i1 %9, label %middle.block, label %vector.body, !llvm.loop !9

middle.block:                                     ; preds = %vector.body
  %cmp.n = icmp eq i64 %n.vec, %4
  br i1 %cmp.n, label %._crit_edge, label %.lr.ph.preheader9

._crit_edge:                                      ; preds = %.lr.ph, %middle.block, %0
  ret void

.lr.ph:                                           ; preds = %.lr.ph.preheader9, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ %indvars.iv.ph, %.lr.ph.preheader9 ]
  %10 = getelementptr inbounds [150010 x i32], ptr @fa, i64 0, i64 %indvars.iv
  %11 = trunc nuw nsw i64 %indvars.iv to i32
  store i32 %11, ptr %10, align 4, !tbaa !5
  %12 = getelementptr inbounds [150010 x i32], ptr @sz, i64 0, i64 %indvars.iv
  store i32 1, ptr %12, align 4, !tbaa !5
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %wide.trip.count
  br i1 %exitcond.not, label %._crit_edge, label %.lr.ph, !llvm.loop !13
}

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

attributes #0 = { mustprogress nofree norecurse nosync nounwind memory(readwrite, argmem: none, inaccessiblemem: 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 = !{!6, !6, i64 0}
!6 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10, !11, !12}
!10 = !{!"llvm.loop.mustprogress"}
!11 = !{!"llvm.loop.isvectorized", i32 1}
!12 = !{!"llvm.loop.unroll.runtime.disable"}
!13 = distinct !{!13, !10, !12, !11}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LICMPass,LoopLoadEliminationPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,LoopVectorizePass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass