; LLVM IR from upupming/algorithm :: acwing/算法基础课/第三讲 搜索与图论/染色法判定二分图/860. 染色法判定二分图.ll (Z11isBipartitev)

; 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"

@n = external dso_local global i32, align 4
@v = external dso_local global [100010 x i32], align 16

; Function Attrs: mustprogress uwtable
declare dso_local noundef zeroext i1 @_Z3dfsii(i32 noundef, i32 noundef) #0

; 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

; Function Attrs: mustprogress uwtable
define dso_local noundef zeroext i1 @_Z11isBipartitev() #0 {
  %1 = alloca i1, align 1
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #2
  store i32 1, ptr %2, align 4, !tbaa !5
  br label %4

4:                                                ; preds = %21, %0
  %5 = load i32, ptr %2, align 4, !tbaa !5
  %6 = load i32, ptr @n, align 4, !tbaa !5
  %7 = icmp sle i32 %5, %6
  br i1 %7, label %9, label %8

8:                                                ; preds = %4
  store i32 2, ptr %3, align 4
  br label %24

9:                                                ; preds = %4
  %10 = load i32, ptr %2, align 4, !tbaa !5
  %11 = sext i32 %10 to i64
  %12 = getelementptr inbounds [100010 x i32], ptr @v, i64 0, i64 %11
  %13 = load i32, ptr %12, align 4, !tbaa !5
  %14 = icmp ne i32 %13, 0
  br i1 %14, label %20, label %15

15:                                               ; preds = %9
  %16 = load i32, ptr %2, align 4, !tbaa !5
  %17 = call noundef zeroext i1 @_Z3dfsii(i32 noundef %16, i32 noundef 1)
  br i1 %17, label %19, label %18

18:                                               ; preds = %15
  store i1 false, ptr %1, align 1
  store i32 1, ptr %3, align 4
  br label %24

19:                                               ; preds = %15
  br label %20

20:                                               ; preds = %19, %9
  br label %21

21:                                               ; preds = %20
  %22 = load i32, ptr %2, align 4, !tbaa !5
  %23 = add nsw i32 %22, 1
  store i32 %23, ptr %2, align 4, !tbaa !5
  br label %4, !llvm.loop !9

24:                                               ; preds = %18, %8
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #2
  %25 = load i32, ptr %3, align 4
  switch i32 %25, label %29 [
    i32 2, label %26
    i32 1, label %27
  ]

26:                                               ; preds = %24
  store i1 true, ptr %1, align 1
  br label %27

27:                                               ; preds = %26, %24
  %28 = load i1, ptr %1, align 1
  ret i1 %28

29:                                               ; preds = %24
  unreachable
}

attributes #0 = { mustprogress 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"

@n = external dso_local local_unnamed_addr global i32, align 4
@v = external dso_local local_unnamed_addr global [100010 x i32], align 16

; Function Attrs: mustprogress uwtable
declare dso_local noundef zeroext i1 @_Z3dfsii(i32 noundef, i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
define dso_local noundef zeroext i1 @_Z11isBipartitev() local_unnamed_addr #0 {
  %1 = load i32, ptr @n, align 4, !tbaa !5
  %.not8 = icmp slt i32 %1, 1
  br i1 %.not8, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %0, %8
  %2 = phi i32 [ %9, %8 ], [ %1, %0 ]
  %indvars.iv = phi i64 [ %indvars.iv.next, %8 ], [ 1, %0 ]
  %3 = getelementptr inbounds [100010 x i32], ptr @v, i64 0, i64 %indvars.iv
  %4 = load i32, ptr %3, align 4, !tbaa !5
  %.not7 = icmp eq i32 %4, 0
  br i1 %.not7, label %5, label %8

5:                                                ; preds = %.lr.ph
  %6 = trunc nuw nsw i64 %indvars.iv to i32
  %7 = tail call noundef zeroext i1 @_Z3dfsii(i32 noundef %6, i32 noundef 1)
  br i1 %7, label %._crit_edge13, label %._crit_edge

._crit_edge13:                                    ; preds = %5
  %.pre = load i32, ptr @n, align 4, !tbaa !5
  br label %8

8:                                                ; preds = %._crit_edge13, %.lr.ph
  %9 = phi i32 [ %.pre, %._crit_edge13 ], [ %2, %.lr.ph ]
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %10 = sext i32 %9 to i64
  %.not.not = icmp slt i64 %indvars.iv, %10
  br i1 %.not.not, label %.lr.ph, label %._crit_edge, !llvm.loop !9

._crit_edge:                                      ; preds = %8, %5, %0
  %.not.lcssa = phi i1 [ true, %0 ], [ false, %5 ], [ true, %8 ]
  ret i1 %.not.lcssa
}

attributes #0 = { mustprogress 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}
!10 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: CorrelatedValuePropagationPass,EarlyCSEPass,GVNPass,GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass,TailCallElimPass