; LLVM IR from upupming/algorithm :: acwing/算法竞赛进阶指南/0x41-并查集/237. 程序自动分析.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 [1000010 x i32], align 16
@sz = external dso_local global [1000010 x i32], align 16

; 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 = %14, %0
  %3 = load i32, ptr %1, align 4, !tbaa !5
  %4 = icmp sle i32 %3, 1000010
  br i1 %4, label %6, label %5

5:                                                ; preds = %2
  call void @llvm.lifetime.end.p0(i64 4, ptr %1) #2
  br label %17

6:                                                ; preds = %2
  %7 = load i32, ptr %1, align 4, !tbaa !5
  %8 = load i32, ptr %1, align 4, !tbaa !5
  %9 = sext i32 %8 to i64
  %10 = getelementptr inbounds [1000010 x i32], ptr @fa, i64 0, i64 %9
  store i32 %7, ptr %10, align 4, !tbaa !5
  %11 = load i32, ptr %1, align 4, !tbaa !5
  %12 = sext i32 %11 to i64
  %13 = getelementptr inbounds [1000010 x i32], ptr @sz, i64 0, i64 %12
  store i32 1, ptr %13, align 4, !tbaa !5
  br label %14

14:                                               ; preds = %6
  %15 = load i32, ptr %1, align 4, !tbaa !5
  %16 = add nsw i32 %15, 1
  store i32 %16, ptr %1, align 4, !tbaa !5
  br label %2, !llvm.loop !9

17:                                               ; preds = %5
  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 [1000010 x i32], align 16
@sz = external dso_local local_unnamed_addr global [1000010 x i32], align 16

; Function Attrs: mustprogress nofree norecurse nosync nounwind memory(write, argmem: none, inaccessiblemem: none) uwtable
define dso_local void @_Z4initv() local_unnamed_addr #0 {
vector.ph:
  br label %vector.body

vector.body:                                      ; preds = %vector.body.1, %vector.ph
  %index = phi i64 [ 0, %vector.ph ], [ %index.next.1, %vector.body.1 ]
  %vec.ind = phi <4 x i32> [ <i32 1, i32 2, i32 3, i32 4>, %vector.ph ], [ %vec.ind.next.1, %vector.body.1 ]
  %step.add = add <4 x i32> %vec.ind, <i32 4, i32 4, i32 4, i32 4>
  %offset.idx = or disjoint i64 %index, 1
  %0 = getelementptr inbounds [1000010 x i32], ptr @fa, i64 0, i64 %offset.idx
  %1 = getelementptr inbounds i8, ptr %0, i64 16
  store <4 x i32> %vec.ind, ptr %0, align 4, !tbaa !5
  store <4 x i32> %step.add, ptr %1, align 4, !tbaa !5
  %2 = getelementptr inbounds [1000010 x i32], ptr @sz, i64 0, i64 %offset.idx
  %3 = getelementptr inbounds i8, ptr %2, i64 16
  store <4 x i32> <i32 1, i32 1, i32 1, i32 1>, ptr %2, align 4, !tbaa !5
  store <4 x i32> <i32 1, i32 1, i32 1, i32 1>, ptr %3, align 4, !tbaa !5
  %4 = icmp eq i64 %index, 1000000
  br i1 %4, label %scalar.ph, label %vector.body.1, !llvm.loop !9

vector.body.1:                                    ; preds = %vector.body
  %vec.ind.next = add <4 x i32> %vec.ind, <i32 8, i32 8, i32 8, i32 8>
  %step.add.1 = add <4 x i32> %vec.ind, <i32 12, i32 12, i32 12, i32 12>
  %offset.idx.1 = or disjoint i64 %index, 9
  %5 = getelementptr inbounds [1000010 x i32], ptr @fa, i64 0, i64 %offset.idx.1
  %6 = getelementptr inbounds i8, ptr %5, i64 16
  store <4 x i32> %vec.ind.next, ptr %5, align 4, !tbaa !5
  store <4 x i32> %step.add.1, ptr %6, align 4, !tbaa !5
  %7 = getelementptr inbounds [1000010 x i32], ptr @sz, i64 0, i64 %offset.idx.1
  %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.1 = add nuw nsw i64 %index, 16
  %vec.ind.next.1 = add <4 x i32> %vec.ind, <i32 16, i32 16, i32 16, i32 16>
  br label %vector.body

scalar.ph:                                        ; preds = %vector.body
  store i32 1000009, ptr getelementptr inbounds (i8, ptr @fa, i64 4000036), align 4, !tbaa !5
  store i32 1, ptr getelementptr inbounds (i8, ptr @sz, i64 4000036), align 4, !tbaa !5
  store i32 1000010, ptr getelementptr inbounds (i8, ptr @fa, i64 4000040), align 8, !tbaa !5
  store i32 1, ptr getelementptr inbounds (i8, ptr @sz, i64 4000040), align 8, !tbaa !5
  ret void
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind memory(write, 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" }

!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"}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,IndVarSimplifyPass,InferAlignmentPass,InferFunctionAttrsPass,InstCombinePass,LoopLoadEliminationPass,LoopRotatePass,LoopUnrollPass,LoopVectorizePass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass