; LLVM IR from Lakhankumawat/LearnCPP :: A-Array/Reversingofarray.ll (Z8reverse1Pii)

; 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: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z8reverse1Pii(ptr noundef %0, i32 noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca i64, align 8
  %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
  %9 = load i32, ptr %4, align 4, !tbaa !9
  %10 = zext i32 %9 to i64
  %11 = call ptr @llvm.stacksave.p0()
  store ptr %11, ptr %5, align 8
  %12 = alloca i32, i64 %10, align 16
  store i64 %10, ptr %6, align 8
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #3
  store i32 0, ptr %7, align 4, !tbaa !9
  br label %13

13:                                               ; preds = %30, %2
  %14 = load i32, ptr %7, align 4, !tbaa !9
  %15 = load i32, ptr %4, align 4, !tbaa !9
  %16 = icmp slt i32 %14, %15
  br i1 %16, label %18, label %17

17:                                               ; preds = %13
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #3
  br label %33

18:                                               ; preds = %13
  %19 = load ptr, ptr %3, align 8, !tbaa !5
  %20 = load i32, ptr %7, align 4, !tbaa !9
  %21 = sext i32 %20 to i64
  %22 = getelementptr inbounds i32, ptr %19, i64 %21
  %23 = load i32, ptr %22, align 4, !tbaa !9
  %24 = load i32, ptr %4, align 4, !tbaa !9
  %25 = sub nsw i32 %24, 1
  %26 = load i32, ptr %7, align 4, !tbaa !9
  %27 = sub nsw i32 %25, %26
  %28 = sext i32 %27 to i64
  %29 = getelementptr inbounds i32, ptr %12, i64 %28
  store i32 %23, ptr %29, align 4, !tbaa !9
  br label %30

30:                                               ; preds = %18
  %31 = load i32, ptr %7, align 4, !tbaa !9
  %32 = add nsw i32 %31, 1
  store i32 %32, ptr %7, align 4, !tbaa !9
  br label %13, !llvm.loop !11

33:                                               ; preds = %17
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #3
  store i32 0, ptr %8, align 4, !tbaa !9
  br label %34

34:                                               ; preds = %48, %33
  %35 = load i32, ptr %8, align 4, !tbaa !9
  %36 = load i32, ptr %4, align 4, !tbaa !9
  %37 = icmp slt i32 %35, %36
  br i1 %37, label %39, label %38

38:                                               ; preds = %34
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #3
  br label %51

39:                                               ; preds = %34
  %40 = load i32, ptr %8, align 4, !tbaa !9
  %41 = sext i32 %40 to i64
  %42 = getelementptr inbounds i32, ptr %12, i64 %41
  %43 = load i32, ptr %42, align 4, !tbaa !9
  %44 = load ptr, ptr %3, align 8, !tbaa !5
  %45 = load i32, ptr %8, align 4, !tbaa !9
  %46 = sext i32 %45 to i64
  %47 = getelementptr inbounds i32, ptr %44, i64 %46
  store i32 %43, ptr %47, align 4, !tbaa !9
  br label %48

48:                                               ; preds = %39
  %49 = load i32, ptr %8, align 4, !tbaa !9
  %50 = add nsw i32 %49, 1
  store i32 %50, ptr %8, align 4, !tbaa !9
  br label %34, !llvm.loop !13

51:                                               ; preds = %38
  %52 = load ptr, ptr %5, align 8
  call void @llvm.stackrestore.p0(ptr %52)
  ret void
}

; Function Attrs: nocallback nofree nosync nounwind willreturn
declare ptr @llvm.stacksave.p0() #2

; Function Attrs: nocallback nofree nosync nounwind willreturn
declare void @llvm.stackrestore.p0(ptr) #2

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #2 = { nocallback nofree nosync nounwind willreturn }
attributes #3 = { 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 memory(argmem: readwrite) uwtable
define dso_local void @_Z8reverse1Pii(ptr nocapture noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = zext i32 %1 to i64
  %4 = alloca i32, i64 %3, align 16
  %5 = icmp sgt i32 %1, 0
  br i1 %5, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %2
  %6 = zext nneg i32 %1 to i64
  %invariant.gep = getelementptr i32, ptr %4, i64 %6
  %min.iters.check = icmp ult i32 %1, 8
  br i1 %min.iters.check, label %.lr.ph.preheader25, label %vector.ph

.lr.ph.preheader25:                               ; preds = %middle.block, %.lr.ph.preheader
  %indvars.iv.ph = phi i64 [ 0, %.lr.ph.preheader ], [ %n.vec, %middle.block ]
  br label %.lr.ph

vector.ph:                                        ; preds = %.lr.ph.preheader
  %n.vec = and i64 %3, 2147483640
  br label %vector.body

vector.body:                                      ; preds = %vector.body, %vector.ph
  %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
  %7 = getelementptr inbounds i32, ptr %0, i64 %index
  %8 = getelementptr inbounds i8, ptr %7, i64 16
  %wide.load = load <4 x i32>, ptr %7, align 4, !tbaa !5
  %wide.load23 = load <4 x i32>, ptr %8, align 4, !tbaa !5
  %9 = xor i64 %index, -1
  %10 = getelementptr i32, ptr %invariant.gep, i64 %9
  %11 = getelementptr i8, ptr %10, i64 -12
  %12 = getelementptr i8, ptr %10, i64 -28
  %reverse = shufflevector <4 x i32> %wide.load, <4 x i32> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
  store <4 x i32> %reverse, ptr %11, align 4, !tbaa !5
  %reverse24 = shufflevector <4 x i32> %wide.load23, <4 x i32> poison, <4 x i32> <i32 3, i32 2, i32 1, i32 0>
  store <4 x i32> %reverse24, ptr %12, align 4, !tbaa !5
  %index.next = add nuw i64 %index, 8
  %13 = icmp eq i64 %index.next, %n.vec
  br i1 %13, label %middle.block, label %vector.body, !llvm.loop !9

middle.block:                                     ; preds = %vector.body
  %cmp.n = icmp eq i64 %n.vec, %3
  br i1 %cmp.n, label %.preheader, label %.lr.ph.preheader25

.preheader:                                       ; preds = %.lr.ph, %middle.block
  br i1 %5, label %.lr.ph18.preheader, label %._crit_edge

.lr.ph18.preheader:                               ; preds = %.preheader
  %14 = shl nuw nsw i64 %3, 2
  call void @llvm.memcpy.p0.p0.i64(ptr nonnull align 4 %0, ptr nonnull align 16 %4, i64 %14, i1 false), !tbaa !5
  br label %._crit_edge

.lr.ph:                                           ; preds = %.lr.ph.preheader25, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ %indvars.iv.ph, %.lr.ph.preheader25 ]
  %15 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv
  %16 = load i32, ptr %15, align 4, !tbaa !5
  %17 = xor i64 %indvars.iv, -1
  %gep = getelementptr i32, ptr %invariant.gep, i64 %17
  store i32 %16, ptr %gep, align 4, !tbaa !5
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %3
  br i1 %exitcond.not, label %.preheader, label %.lr.ph, !llvm.loop !13

._crit_edge:                                      ; preds = %2, %.lr.ph18.preheader, %.preheader
  ret void
}

; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
declare void @llvm.memcpy.p0.p0.i64(ptr noalias nocapture writeonly, ptr noalias nocapture readonly, i64, i1 immarg) #1

attributes #0 = { mustprogress nofree norecurse nosync nounwind memory(argmem: readwrite) 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 nounwind willreturn memory(argmem: readwrite) }

!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, !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: CorrelatedValuePropagationPass,EarlyCSEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LICMPass,LoopIdiomRecognizePass,LoopLoadEliminationPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,LoopVectorizePass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass