; LLVM IR from DimitrisJim/leetcode_solutions :: C/Algorithms (136)

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

6:                                                ; preds = %10, %2
  %7 = load i32, ptr %4, align 4, !tbaa !9
  %8 = add nsw i32 %7, -1
  store i32 %8, ptr %4, align 4, !tbaa !9
  %9 = icmp ne i32 %7, 0
  br i1 %9, label %10, label %16

10:                                               ; preds = %6
  %11 = load ptr, ptr %3, align 8, !tbaa !5
  %12 = getelementptr inbounds i32, ptr %11, i32 1
  store ptr %12, ptr %3, align 8, !tbaa !5
  %13 = load i32, ptr %11, align 4, !tbaa !9
  %14 = load i32, ptr %5, align 4, !tbaa !9
  %15 = xor i32 %14, %13
  store i32 %15, ptr %5, align 4, !tbaa !9
  br label %6, !llvm.loop !11

16:                                               ; preds = %6
  %17 = load i32, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  ret i32 %17
}

; 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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"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"

; Function Attrs: nofree norecurse nosync nounwind memory(read, inaccessiblemem: none) uwtable
define dso_local i32 @singleNumber(ptr nocapture noundef readonly %0, i32 noundef %1) local_unnamed_addr #0 {
  %.not5 = icmp eq i32 %1, 0
  br i1 %.not5, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %2
  %3 = zext i32 %1 to i64
  %min.iters.check = icmp ult i32 %1, 8
  br i1 %min.iters.check, label %.lr.ph.preheader14, label %vector.ph

vector.ph:                                        ; preds = %.lr.ph.preheader
  %n.vec = and i64 %3, 4294967288
  %.cast = trunc nuw i64 %n.vec to i32
  %ind.end = sub i32 %1, %.cast
  %4 = shl nuw nsw i64 %n.vec, 2
  %ind.end9 = getelementptr i8, ptr %0, i64 %4
  br label %vector.body

vector.body:                                      ; preds = %vector.body, %vector.ph
  %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
  %vec.phi = phi <4 x i32> [ zeroinitializer, %vector.ph ], [ %6, %vector.body ]
  %vec.phi11 = phi <4 x i32> [ zeroinitializer, %vector.ph ], [ %7, %vector.body ]
  %offset.idx = shl i64 %index, 2
  %next.gep = getelementptr i8, ptr %0, i64 %offset.idx
  %5 = getelementptr i8, ptr %next.gep, i64 16
  %wide.load = load <4 x i32>, ptr %next.gep, align 4, !tbaa !5
  %wide.load13 = load <4 x i32>, ptr %5, align 4, !tbaa !5
  %6 = xor <4 x i32> %wide.load, %vec.phi
  %7 = xor <4 x i32> %wide.load13, %vec.phi11
  %index.next = add nuw i64 %index, 8
  %8 = icmp eq i64 %index.next, %n.vec
  br i1 %8, label %middle.block, label %vector.body, !llvm.loop !9

middle.block:                                     ; preds = %vector.body
  %bin.rdx = xor <4 x i32> %7, %6
  %9 = tail call i32 @llvm.vector.reduce.xor.v4i32(<4 x i32> %bin.rdx)
  %cmp.n = icmp eq i64 %n.vec, %3
  br i1 %cmp.n, label %._crit_edge, label %.lr.ph.preheader14

.lr.ph.preheader14:                               ; preds = %middle.block, %.lr.ph.preheader
  %.08.ph = phi i32 [ 0, %.lr.ph.preheader ], [ %9, %middle.block ]
  %.037.ph = phi i32 [ %1, %.lr.ph.preheader ], [ %ind.end, %middle.block ]
  %.046.ph = phi ptr [ %0, %.lr.ph.preheader ], [ %ind.end9, %middle.block ]
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader14, %.lr.ph
  %.08 = phi i32 [ %13, %.lr.ph ], [ %.08.ph, %.lr.ph.preheader14 ]
  %.037 = phi i32 [ %10, %.lr.ph ], [ %.037.ph, %.lr.ph.preheader14 ]
  %.046 = phi ptr [ %11, %.lr.ph ], [ %.046.ph, %.lr.ph.preheader14 ]
  %10 = add nsw i32 %.037, -1
  %11 = getelementptr inbounds i8, ptr %.046, i64 4
  %12 = load i32, ptr %.046, align 4, !tbaa !5
  %13 = xor i32 %12, %.08
  %.not = icmp eq i32 %10, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !13

._crit_edge:                                      ; preds = %.lr.ph, %middle.block, %2
  %.0.lcssa = phi i32 [ 0, %2 ], [ %9, %middle.block ], [ %13, %.lr.ph ]
  ret i32 %.0.lcssa
}

; 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(read, 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/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: GVNPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopLoadEliminationPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,LoopVectorizePass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass