; LLVM IR from devparthgarg/Data-Structures-and-Algorithms :: 07. Sorting/10 Count Inversions in Array (10a count inversions in array)

; 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: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z15countInversionsPii(ptr noundef %0, i32 noundef %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = 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
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #2
  store i32 0, ptr %6, align 4, !tbaa !9
  br label %9

9:                                                ; preds = %42, %2
  %10 = load i32, ptr %6, align 4, !tbaa !9
  %11 = load i32, ptr %4, align 4, !tbaa !9
  %12 = icmp slt i32 %10, %11
  br i1 %12, label %14, label %13

13:                                               ; preds = %9
  store i32 2, ptr %7, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  br label %45

14:                                               ; preds = %9
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #2
  %15 = load i32, ptr %6, align 4, !tbaa !9
  %16 = add nsw i32 %15, 1
  store i32 %16, ptr %8, align 4, !tbaa !9
  br label %17

17:                                               ; preds = %38, %14
  %18 = load i32, ptr %8, align 4, !tbaa !9
  %19 = load i32, ptr %4, align 4, !tbaa !9
  %20 = icmp slt i32 %18, %19
  br i1 %20, label %22, label %21

21:                                               ; preds = %17
  store i32 5, ptr %7, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #2
  br label %41

22:                                               ; preds = %17
  %23 = load ptr, ptr %3, align 8, !tbaa !5
  %24 = load i32, ptr %6, align 4, !tbaa !9
  %25 = sext i32 %24 to i64
  %26 = getelementptr inbounds i32, ptr %23, i64 %25
  %27 = load i32, ptr %26, align 4, !tbaa !9
  %28 = load ptr, ptr %3, align 8, !tbaa !5
  %29 = load i32, ptr %8, align 4, !tbaa !9
  %30 = sext i32 %29 to i64
  %31 = getelementptr inbounds i32, ptr %28, i64 %30
  %32 = load i32, ptr %31, align 4, !tbaa !9
  %33 = icmp sgt i32 %27, %32
  br i1 %33, label %34, label %37

34:                                               ; preds = %22
  %35 = load i32, ptr %5, align 4, !tbaa !9
  %36 = add nsw i32 %35, 1
  store i32 %36, ptr %5, align 4, !tbaa !9
  br label %37

37:                                               ; preds = %34, %22
  br label %38

38:                                               ; preds = %37
  %39 = load i32, ptr %8, align 4, !tbaa !9
  %40 = add nsw i32 %39, 1
  store i32 %40, ptr %8, align 4, !tbaa !9
  br label %17, !llvm.loop !11

41:                                               ; preds = %21
  br label %42

42:                                               ; preds = %41
  %43 = load i32, ptr %6, align 4, !tbaa !9
  %44 = add nsw i32 %43, 1
  store i32 %44, ptr %6, align 4, !tbaa !9
  br label %9, !llvm.loop !13

45:                                               ; preds = %13
  %46 = load i32, ptr %5, align 4, !tbaa !9
  store i32 1, ptr %7, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  ret i32 %46
}

; 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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !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: mustprogress nofree norecurse nosync nounwind willreturn memory(argmem: read) uwtable
define dso_local noundef i32 @_Z15countInversionsPii(ptr nocapture noundef readonly %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = icmp sgt i32 %1, 0
  br i1 %3, label %.lr.ph19.preheader, label %._crit_edge

.lr.ph19.preheader:                               ; preds = %2
  %4 = zext nneg i32 %1 to i64
  %wide.trip.count27 = zext nneg i32 %1 to i64
  br label %.lr.ph19

.loopexit:                                        ; preds = %scalar.ph, %middle.block, %.lr.ph19
  %.1.lcssa = phi i32 [ %.01317, %.lr.ph19 ], [ %21, %middle.block ], [ %spec.select, %scalar.ph ]
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond28.not = icmp eq i64 %indvars.iv.next25, %wide.trip.count27
  br i1 %exitcond28.not, label %._crit_edge, label %.lr.ph19, !llvm.loop !5

._crit_edge:                                      ; preds = %.loopexit, %2
  %.013.lcssa = phi i32 [ 0, %2 ], [ %.1.lcssa, %.loopexit ]
  ret i32 %.013.lcssa

.lr.ph19:                                         ; preds = %.lr.ph19.preheader, %.loopexit
  %indvars.iv24 = phi i64 [ 0, %.lr.ph19.preheader ], [ %indvars.iv.next25, %.loopexit ]
  %indvars.iv = phi i64 [ 1, %.lr.ph19.preheader ], [ %indvars.iv.next, %.loopexit ]
  %.01317 = phi i32 [ 0, %.lr.ph19.preheader ], [ %.1.lcssa, %.loopexit ]
  %5 = xor i64 %indvars.iv24, -1
  %6 = add nsw i64 %5, %wide.trip.count27
  %indvars.iv.next25 = add nuw nsw i64 %indvars.iv24, 1
  %7 = icmp ult i64 %indvars.iv.next25, %4
  br i1 %7, label %.lr.ph, label %.loopexit

.lr.ph:                                           ; preds = %.lr.ph19
  %8 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv24
  %9 = load i32, ptr %8, align 4, !tbaa !7
  %min.iters.check = icmp ult i64 %6, 8
  br i1 %min.iters.check, label %scalar.ph.preheader, label %vector.ph

vector.ph:                                        ; preds = %.lr.ph
  %n.vec = and i64 %6, -8
  %ind.end = add i64 %indvars.iv, %n.vec
  %10 = insertelement <4 x i32> <i32 poison, i32 0, i32 0, i32 0>, i32 %.01317, i64 0
  %broadcast.splatinsert = insertelement <4 x i32> poison, i32 %9, i64 0
  %broadcast.splat = shufflevector <4 x i32> %broadcast.splatinsert, <4 x i32> poison, <4 x i32> zeroinitializer
  %11 = getelementptr i32, ptr %0, i64 %indvars.iv
  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> [ %10, %vector.ph ], [ %18, %vector.body ]
  %vec.phi29 = phi <4 x i32> [ zeroinitializer, %vector.ph ], [ %19, %vector.body ]
  %12 = getelementptr i32, ptr %11, i64 %index
  %13 = getelementptr inbounds i8, ptr %12, i64 16
  %wide.load = load <4 x i32>, ptr %12, align 4, !tbaa !7
  %wide.load30 = load <4 x i32>, ptr %13, align 4, !tbaa !7
  %14 = icmp sgt <4 x i32> %broadcast.splat, %wide.load
  %15 = icmp sgt <4 x i32> %broadcast.splat, %wide.load30
  %16 = zext <4 x i1> %14 to <4 x i32>
  %17 = zext <4 x i1> %15 to <4 x i32>
  %18 = add <4 x i32> %vec.phi, %16
  %19 = add <4 x i32> %vec.phi29, %17
  %index.next = add nuw i64 %index, 8
  %20 = icmp eq i64 %index.next, %n.vec
  br i1 %20, label %middle.block, label %vector.body, !llvm.loop !11

middle.block:                                     ; preds = %vector.body
  %bin.rdx = add <4 x i32> %19, %18
  %21 = tail call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> %bin.rdx)
  %cmp.n = icmp eq i64 %6, %n.vec
  br i1 %cmp.n, label %.loopexit, label %scalar.ph.preheader

scalar.ph.preheader:                              ; preds = %middle.block, %.lr.ph
  %indvars.iv21.ph = phi i64 [ %indvars.iv, %.lr.ph ], [ %ind.end, %middle.block ]
  %.115.ph = phi i32 [ %.01317, %.lr.ph ], [ %21, %middle.block ]
  br label %scalar.ph

scalar.ph:                                        ; preds = %scalar.ph.preheader, %scalar.ph
  %indvars.iv21 = phi i64 [ %indvars.iv.next22, %scalar.ph ], [ %indvars.iv21.ph, %scalar.ph.preheader ]
  %.115 = phi i32 [ %spec.select, %scalar.ph ], [ %.115.ph, %scalar.ph.preheader ]
  %22 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv21
  %23 = load i32, ptr %22, align 4, !tbaa !7
  %24 = icmp sgt i32 %9, %23
  %25 = zext i1 %24 to i32
  %spec.select = add nsw i32 %.115, %25
  %indvars.iv.next22 = add nuw nsw i64 %indvars.iv21, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next22, %wide.trip.count27
  br i1 %exitcond.not, label %.loopexit, label %scalar.ph, !llvm.loop !14
}

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

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


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