; LLVM IR from lzyrapx/Competitive-Programming :: Retired_code/Guass (洛谷 P3389（高斯消元）)

; 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"

%"class.std::basic_istream" = type { ptr, i64, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }
%"class.std::basic_ostream" = type { ptr, %"class.std::basic_ios" }

@n = external dso_local global i32, align 4
@a = external dso_local global [1234 x [1234 x double]], align 16
@_ZSt3cin = external global %"class.std::basic_istream", align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str = external hidden unnamed_addr constant [12 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [7 x i8], align 1

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef zeroext i1 @_Z5Gaussv() #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 norecurse uwtable
define dso_local noundef i32 @main(i32 noundef %0, ptr noundef %1) #2 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  %9 = alloca i32, align 4
  %10 = alloca i32, align 4
  store i32 0, ptr %3, align 4
  store i32 %0, ptr %4, align 4, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !9
  %11 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) @n)
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #5
  store i32 0, ptr %6, align 4, !tbaa !5
  br label %12

12:                                               ; preds = %37, %2
  %13 = load i32, ptr %6, align 4, !tbaa !5
  %14 = load i32, ptr @n, align 4, !tbaa !5
  %15 = icmp slt i32 %13, %14
  br i1 %15, label %17, label %16

16:                                               ; preds = %12
  store i32 2, ptr %7, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #5
  br label %40

17:                                               ; preds = %12
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #5
  store i32 0, ptr %8, align 4, !tbaa !5
  br label %18

18:                                               ; preds = %33, %17
  %19 = load i32, ptr %8, align 4, !tbaa !5
  %20 = load i32, ptr @n, align 4, !tbaa !5
  %21 = icmp sle i32 %19, %20
  br i1 %21, label %23, label %22

22:                                               ; preds = %18
  store i32 5, ptr %7, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #5
  br label %36

23:                                               ; preds = %18
  call void @llvm.lifetime.start.p0(i64 4, ptr %9) #5
  %24 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %9)
  %25 = load i32, ptr %9, align 4, !tbaa !5
  %26 = sitofp i32 %25 to double
  %27 = load i32, ptr %6, align 4, !tbaa !5
  %28 = sext i32 %27 to i64
  %29 = getelementptr inbounds [1234 x [1234 x double]], ptr @a, i64 0, i64 %28
  %30 = load i32, ptr %8, align 4, !tbaa !5
  %31 = sext i32 %30 to i64
  %32 = getelementptr inbounds [1234 x double], ptr %29, i64 0, i64 %31
  store double %26, ptr %32, align 8, !tbaa !11
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #5
  br label %33

33:                                               ; preds = %23
  %34 = load i32, ptr %8, align 4, !tbaa !5
  %35 = add nsw i32 %34, 1
  store i32 %35, ptr %8, align 4, !tbaa !5
  br label %18, !llvm.loop !13

36:                                               ; preds = %22
  br label %37

37:                                               ; preds = %36
  %38 = load i32, ptr %6, align 4, !tbaa !5
  %39 = add nsw i32 %38, 1
  store i32 %39, ptr %6, align 4, !tbaa !5
  br label %12, !llvm.loop !15

40:                                               ; preds = %16
  %41 = call noundef zeroext i1 @_Z5Gaussv()
  %42 = zext i1 %41 to i32
  %43 = icmp eq i32 %42, 0
  br i1 %43, label %44, label %47

44:                                               ; preds = %40
  %45 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef @.str)
  %46 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8) %45, i8 noundef signext 10)
  br label %66

47:                                               ; preds = %40
  call void @llvm.lifetime.start.p0(i64 4, ptr %10) #5
  store i32 0, ptr %10, align 4, !tbaa !5
  br label %48

48:                                               ; preds = %62, %47
  %49 = load i32, ptr %10, align 4, !tbaa !5
  %50 = load i32, ptr @n, align 4, !tbaa !5
  %51 = icmp slt i32 %49, %50
  br i1 %51, label %53, label %52

52:                                               ; preds = %48
  store i32 8, ptr %7, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %10) #5
  br label %65

53:                                               ; preds = %48
  %54 = load i32, ptr %10, align 4, !tbaa !5
  %55 = sext i32 %54 to i64
  %56 = getelementptr inbounds [1234 x [1234 x double]], ptr @a, i64 0, i64 %55
  %57 = load i32, ptr @n, align 4, !tbaa !5
  %58 = sext i32 %57 to i64
  %59 = getelementptr inbounds [1234 x double], ptr %56, i64 0, i64 %58
  %60 = load double, ptr %59, align 8, !tbaa !11
  %61 = call i32 (ptr, ...) @printf(ptr noundef @.str.1, double noundef %60)
  br label %62

62:                                               ; preds = %53
  %63 = load i32, ptr %10, align 4, !tbaa !5
  %64 = add nsw i32 %63, 1
  store i32 %64, ptr %10, align 4, !tbaa !5
  br label %48, !llvm.loop !16

65:                                               ; preds = %52
  br label %66

66:                                               ; preds = %65, %44
  ret i32 0
}

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 4 dereferenceable(4)) #3

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8), i8 noundef signext) #4

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #4

declare i32 @printf(ptr noundef, ...) #3

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 = { mustprogress norecurse 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 #3 = { "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 #4 = { inlinehint 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 #5 = { 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 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = !{!12, !12, i64 0}
!12 = !{!"double", !7, i64 0}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}
!15 = distinct !{!15, !14}
!16 = distinct !{!16, !14}


; 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"

%"class.std::basic_istream" = type { ptr, i64, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }
%"class.std::basic_ostream" = type { ptr, %"class.std::basic_ios" }

@n = external dso_local global i32, align 4
@a = external dso_local local_unnamed_addr global [1234 x [1234 x double]], align 16
@_ZSt3cin = external global %"class.std::basic_istream", align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str = external hidden unnamed_addr constant [12 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [7 x i8], align 1

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef zeroext i1 @_Z5Gaussv() local_unnamed_addr #0

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main(i32 noundef %0, ptr nocapture noundef readnone %1) local_unnamed_addr #2 {
  %3 = alloca i32, align 4
  %4 = tail call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) @n)
  %5 = load i32, ptr @n, align 4, !tbaa !5
  %6 = icmp sgt i32 %5, 0
  br i1 %6, label %.preheader12, label %._crit_edge16

.preheader12:                                     ; preds = %2, %._crit_edge
  %7 = phi i32 [ %11, %._crit_edge ], [ %5, %2 ]
  %indvars.iv21 = phi i64 [ %indvars.iv.next22, %._crit_edge ], [ 0, %2 ]
  %.not13 = icmp slt i32 %7, 0
  br i1 %.not13, label %.preheader12.._crit_edge_crit_edge, label %.lr.ph

.preheader12.._crit_edge_crit_edge:               ; preds = %.preheader12
  %.pre = sext i32 %7 to i64
  br label %._crit_edge

._crit_edge16:                                    ; preds = %._crit_edge, %2
  %8 = call noundef zeroext i1 @_Z5Gaussv()
  br i1 %8, label %.preheader, label %19

.preheader:                                       ; preds = %._crit_edge16
  %9 = load i32, ptr @n, align 4, !tbaa !5
  %10 = icmp sgt i32 %9, 0
  br i1 %10, label %.lr.ph18, label %.loopexit

._crit_edge:                                      ; preds = %.lr.ph, %.preheader12.._crit_edge_crit_edge
  %.pre-phi = phi i64 [ %.pre, %.preheader12.._crit_edge_crit_edge ], [ %18, %.lr.ph ]
  %11 = phi i32 [ %7, %.preheader12.._crit_edge_crit_edge ], [ %17, %.lr.ph ]
  %indvars.iv.next22 = add nuw nsw i64 %indvars.iv21, 1
  %12 = icmp slt i64 %indvars.iv.next22, %.pre-phi
  br i1 %12, label %.preheader12, label %._crit_edge16, !llvm.loop !9

.lr.ph:                                           ; preds = %.preheader12, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %.preheader12 ]
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %3) #6
  %13 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %3)
  %14 = load i32, ptr %3, align 4, !tbaa !5
  %15 = sitofp i32 %14 to double
  %16 = getelementptr inbounds [1234 x [1234 x double]], ptr @a, i64 0, i64 %indvars.iv21, i64 %indvars.iv
  store double %15, ptr %16, align 8, !tbaa !12
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %3) #6
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %17 = load i32, ptr @n, align 4, !tbaa !5
  %18 = sext i32 %17 to i64
  %.not.not = icmp slt i64 %indvars.iv, %18
  br i1 %.not.not, label %.lr.ph, label %._crit_edge, !llvm.loop !14

19:                                               ; preds = %._crit_edge16
  %20 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef nonnull @.str)
  %21 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8) %20, i8 noundef signext 10)
  br label %.loopexit

.lr.ph18:                                         ; preds = %.preheader, %.lr.ph18
  %indvars.iv24 = phi i64 [ %indvars.iv.next25, %.lr.ph18 ], [ 0, %.preheader ]
  %22 = phi i32 [ %27, %.lr.ph18 ], [ %9, %.preheader ]
  %23 = sext i32 %22 to i64
  %24 = getelementptr inbounds [1234 x [1234 x double]], ptr @a, i64 0, i64 %indvars.iv24, i64 %23
  %25 = load double, ptr %24, align 8, !tbaa !12
  %26 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.1, double noundef %25)
  %indvars.iv.next25 = add nuw nsw i64 %indvars.iv24, 1
  %27 = load i32, ptr @n, align 4, !tbaa !5
  %28 = sext i32 %27 to i64
  %29 = icmp slt i64 %indvars.iv.next25, %28
  br i1 %29, label %.lr.ph18, label %.loopexit, !llvm.loop !15

.loopexit:                                        ; preds = %.lr.ph18, %.preheader, %19
  ret i32 0
}

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #3

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8), i8 noundef signext) local_unnamed_addr #4

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) local_unnamed_addr #4

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #5

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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { mustprogress norecurse 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 #3 = { "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 #4 = { inlinehint 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 #5 = { nofree nounwind "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 #6 = { 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, !11}
!10 = !{!"llvm.loop.mustprogress"}
!11 = !{!"llvm.loop.unswitch.partial.disable"}
!12 = !{!13, !13, i64 0}
!13 = !{!"double", !7, i64 0}
!14 = distinct !{!14, !10}
!15 = distinct !{!15, !10}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LICMPass,LoopRotatePass,LoopSimplifyCFGPass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SCCPPass,SROAPass,SimpleLoopUnswitchPass,SimplifyCFGPass,TailCallElimPass