; LLVM IR from Hunterdii/GeeksforGeeks-POTD :: September 2024 GFG SOLUTION (September-05)

; 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: nounwind uwtable
define dso_local i32 @missingNumber(i32 noundef %0, ptr noundef %1) #0 {
  %3 = alloca i32, align 4
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  store ptr %1, ptr %4, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  store i32 0, ptr %5, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #2
  store i32 0, ptr %6, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  store i32 1, ptr %7, align 4, !tbaa !5
  br label %9

9:                                                ; preds = %18, %2
  %10 = load i32, ptr %7, align 4, !tbaa !5
  %11 = load i32, ptr %3, align 4, !tbaa !5
  %12 = icmp sle i32 %10, %11
  br i1 %12, label %14, label %13

13:                                               ; preds = %9
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  br label %21

14:                                               ; preds = %9
  %15 = load i32, ptr %7, align 4, !tbaa !5
  %16 = load i32, ptr %5, align 4, !tbaa !5
  %17 = xor i32 %16, %15
  store i32 %17, ptr %5, align 4, !tbaa !5
  br label %18

18:                                               ; preds = %14
  %19 = load i32, ptr %7, align 4, !tbaa !5
  %20 = add nsw i32 %19, 1
  store i32 %20, ptr %7, align 4, !tbaa !5
  br label %9, !llvm.loop !11

21:                                               ; preds = %13
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #2
  store i32 0, ptr %8, align 4, !tbaa !5
  br label %22

22:                                               ; preds = %36, %21
  %23 = load i32, ptr %8, align 4, !tbaa !5
  %24 = load i32, ptr %3, align 4, !tbaa !5
  %25 = sub nsw i32 %24, 1
  %26 = icmp slt i32 %23, %25
  br i1 %26, label %28, label %27

27:                                               ; preds = %22
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #2
  br label %39

28:                                               ; preds = %22
  %29 = load ptr, ptr %4, align 8, !tbaa !9
  %30 = load i32, ptr %8, align 4, !tbaa !5
  %31 = sext i32 %30 to i64
  %32 = getelementptr inbounds i32, ptr %29, i64 %31
  %33 = load i32, ptr %32, align 4, !tbaa !5
  %34 = load i32, ptr %6, align 4, !tbaa !5
  %35 = xor i32 %34, %33
  store i32 %35, ptr %6, align 4, !tbaa !5
  br label %36

36:                                               ; preds = %28
  %37 = load i32, ptr %8, align 4, !tbaa !5
  %38 = add nsw i32 %37, 1
  store i32 %38, ptr %8, align 4, !tbaa !5
  br label %22, !llvm.loop !13

39:                                               ; preds = %27
  %40 = load i32, ptr %5, align 4, !tbaa !5
  %41 = load i32, ptr %6, align 4, !tbaa !5
  %42 = xor i32 %40, %41
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  ret i32 %42
}

; 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 = { 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/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = distinct !{!13, !12}


; 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: read) uwtable
define dso_local i32 @missingNumber(i32 noundef %0, ptr nocapture noundef readonly %1) local_unnamed_addr #0 {
  %.not16 = icmp slt i32 %0, 1
  br i1 %.not16, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %2
  %min.iters.check = icmp ult i32 %0, 8
  br i1 %min.iters.check, label %.lr.ph.preheader51, label %vector.ph

.lr.ph.preheader51:                               ; preds = %middle.block, %.lr.ph.preheader
  %.01218.ph = phi i32 [ 1, %.lr.ph.preheader ], [ %ind.end, %middle.block ]
  %.01417.ph = phi i32 [ 0, %.lr.ph.preheader ], [ %6, %middle.block ]
  br label %.lr.ph

vector.ph:                                        ; preds = %.lr.ph.preheader
  %n.vec = and i32 %0, 2147483640
  %ind.end = or disjoint i32 %n.vec, 1
  br label %vector.body

vector.body:                                      ; preds = %vector.body, %vector.ph
  %index = phi i32 [ 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 ]
  %vec.phi = phi <4 x i32> [ zeroinitializer, %vector.ph ], [ %3, %vector.body ]
  %vec.phi31 = phi <4 x i32> [ zeroinitializer, %vector.ph ], [ %4, %vector.body ]
  %step.add = add <4 x i32> %vec.ind, <i32 4, i32 4, i32 4, i32 4>
  %3 = xor <4 x i32> %vec.ind, %vec.phi
  %4 = xor <4 x i32> %step.add, %vec.phi31
  %index.next = add nuw i32 %index, 8
  %vec.ind.next = add <4 x i32> %vec.ind, <i32 8, i32 8, i32 8, i32 8>
  %5 = icmp eq i32 %index.next, %n.vec
  br i1 %5, label %middle.block, label %vector.body, !llvm.loop !5

middle.block:                                     ; preds = %vector.body
  %bin.rdx = xor <4 x i32> %4, %3
  %6 = tail call i32 @llvm.vector.reduce.xor.v4i32(<4 x i32> %bin.rdx)
  %cmp.n = icmp eq i32 %n.vec, %0
  br i1 %cmp.n, label %.preheader, label %.lr.ph.preheader51

.preheader:                                       ; preds = %.lr.ph, %middle.block
  %.lcssa29 = phi i32 [ %6, %middle.block ], [ %14, %.lr.ph ]
  %.not = icmp eq i32 %0, 1
  br i1 %.not, label %._crit_edge, label %.lr.ph21.preheader

.lr.ph21.preheader:                               ; preds = %.preheader
  %7 = add nsw i32 %0, -1
  %wide.trip.count = zext nneg i32 %7 to i64
  %min.iters.check34 = icmp ult i32 %0, 9
  br i1 %min.iters.check34, label %.lr.ph21.preheader48, label %vector.ph35

.lr.ph21.preheader48:                             ; preds = %middle.block32, %.lr.ph21.preheader
  %indvars.iv.ph = phi i64 [ 0, %.lr.ph21.preheader ], [ %n.vec37, %middle.block32 ]
  %.01319.ph = phi i32 [ 0, %.lr.ph21.preheader ], [ %13, %middle.block32 ]
  br label %.lr.ph21

vector.ph35:                                      ; preds = %.lr.ph21.preheader
  %n.vec37 = and i64 %wide.trip.count, 2147483640
  br label %vector.body39

vector.body39:                                    ; preds = %vector.body39, %vector.ph35
  %index40 = phi i64 [ 0, %vector.ph35 ], [ %index.next44, %vector.body39 ]
  %vec.phi41 = phi <4 x i32> [ zeroinitializer, %vector.ph35 ], [ %10, %vector.body39 ]
  %vec.phi42 = phi <4 x i32> [ zeroinitializer, %vector.ph35 ], [ %11, %vector.body39 ]
  %8 = getelementptr inbounds i32, ptr %1, i64 %index40
  %9 = getelementptr inbounds i8, ptr %8, i64 16
  %wide.load = load <4 x i32>, ptr %8, align 4, !tbaa !9
  %wide.load43 = load <4 x i32>, ptr %9, align 4, !tbaa !9
  %10 = xor <4 x i32> %wide.load, %vec.phi41
  %11 = xor <4 x i32> %wide.load43, %vec.phi42
  %index.next44 = add nuw i64 %index40, 8
  %12 = icmp eq i64 %index.next44, %n.vec37
  br i1 %12, label %middle.block32, label %vector.body39, !llvm.loop !13

middle.block32:                                   ; preds = %vector.body39
  %bin.rdx45 = xor <4 x i32> %11, %10
  %13 = tail call i32 @llvm.vector.reduce.xor.v4i32(<4 x i32> %bin.rdx45)
  %cmp.n46 = icmp eq i64 %n.vec37, %wide.trip.count
  br i1 %cmp.n46, label %._crit_edge, label %.lr.ph21.preheader48

.lr.ph:                                           ; preds = %.lr.ph.preheader51, %.lr.ph
  %.01218 = phi i32 [ %15, %.lr.ph ], [ %.01218.ph, %.lr.ph.preheader51 ]
  %.01417 = phi i32 [ %14, %.lr.ph ], [ %.01417.ph, %.lr.ph.preheader51 ]
  %14 = xor i32 %.01218, %.01417
  %15 = add nuw i32 %.01218, 1
  %exitcond.not = icmp eq i32 %.01218, %0
  br i1 %exitcond.not, label %.preheader, label %.lr.ph, !llvm.loop !14

._crit_edge:                                      ; preds = %.lr.ph21, %middle.block32, %2, %.preheader
  %.014.lcssa27 = phi i32 [ %.lcssa29, %.preheader ], [ 0, %2 ], [ %.lcssa29, %middle.block32 ], [ %.lcssa29, %.lr.ph21 ]
  %.013.lcssa = phi i32 [ 0, %.preheader ], [ 0, %2 ], [ %13, %middle.block32 ], [ %19, %.lr.ph21 ]
  %16 = xor i32 %.013.lcssa, %.014.lcssa27
  ret i32 %16

.lr.ph21:                                         ; preds = %.lr.ph21.preheader48, %.lr.ph21
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph21 ], [ %indvars.iv.ph, %.lr.ph21.preheader48 ]
  %.01319 = phi i32 [ %19, %.lr.ph21 ], [ %.01319.ph, %.lr.ph21.preheader48 ]
  %17 = getelementptr inbounds i32, ptr %1, i64 %indvars.iv
  %18 = load i32, ptr %17, align 4, !tbaa !9
  %19 = xor i32 %18, %.01319
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond25.not = icmp eq i64 %indvars.iv.next, %wide.trip.count
  br i1 %exitcond25.not, label %._crit_edge, label %.lr.ph21, !llvm.loop !15
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.vector.reduce.xor.v4i32(<4 x i32>) #1

attributes #0 = { nofree norecurse nosync nounwind memory(argmem: read) 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 = distinct !{!5, !6, !7, !8}
!6 = !{!"llvm.loop.mustprogress"}
!7 = !{!"llvm.loop.isvectorized", i32 1}
!8 = !{!"llvm.loop.unroll.runtime.disable"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !11, i64 0}
!11 = !{!"omnipotent char", !12, i64 0}
!12 = !{!"Simple C/C++ TBAA"}
!13 = distinct !{!13, !6, !7, !8}
!14 = distinct !{!14, !6, !8, !7}
!15 = distinct !{!15, !6, !8, !7}


; Effective O3 passes: CorrelatedValuePropagationPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LICMPass,LoopLoadEliminationPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,LoopVectorizePass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass