; LLVM IR from sbshah97/DS-Algo-Handbook :: Algorithms/Sort_Algorithms/Radix_Sort (radixinc)

; 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 @largest(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
  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
  %7 = load ptr, ptr %3, align 8, !tbaa !5
  %8 = getelementptr inbounds i32, ptr %7, i64 0
  %9 = load i32, ptr %8, align 4, !tbaa !9
  store i32 %9, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #2
  store i32 1, ptr %6, align 4, !tbaa !9
  br label %10

10:                                               ; preds = %29, %2
  %11 = load i32, ptr %6, align 4, !tbaa !9
  %12 = load i32, ptr %4, align 4, !tbaa !9
  %13 = icmp slt i32 %11, %12
  br i1 %13, label %14, label %32

14:                                               ; preds = %10
  %15 = load i32, ptr %5, align 4, !tbaa !9
  %16 = load ptr, ptr %3, align 8, !tbaa !5
  %17 = load i32, ptr %6, align 4, !tbaa !9
  %18 = sext i32 %17 to i64
  %19 = getelementptr inbounds i32, ptr %16, i64 %18
  %20 = load i32, ptr %19, align 4, !tbaa !9
  %21 = icmp slt i32 %15, %20
  br i1 %21, label %22, label %28

22:                                               ; preds = %14
  %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
  store i32 %27, ptr %5, align 4, !tbaa !9
  br label %28

28:                                               ; preds = %22, %14
  br label %29

29:                                               ; preds = %28
  %30 = load i32, ptr %6, align 4, !tbaa !9
  %31 = add nsw i32 %30, 1
  store i32 %31, ptr %6, align 4, !tbaa !9
  br label %10, !llvm.loop !11

32:                                               ; preds = %10
  %33 = load i32, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  ret i32 %33
}

; 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(argmem: read) uwtable
define dso_local i32 @largest(ptr nocapture noundef readonly %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = load i32, ptr %0, align 4, !tbaa !5
  %4 = icmp sgt i32 %1, 1
  br i1 %4, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %2
  %wide.trip.count = zext nneg i32 %1 to i64
  %5 = add nsw i64 %wide.trip.count, -1
  %min.iters.check = icmp ult i32 %1, 9
  br i1 %min.iters.check, label %.lr.ph.preheader16, label %vector.ph

vector.ph:                                        ; preds = %.lr.ph.preheader
  %n.vec = and i64 %5, -8
  %ind.end = or disjoint i64 %n.vec, 1
  %minmax.ident.splatinsert = insertelement <4 x i32> poison, i32 %3, i64 0
  %minmax.ident.splat = shufflevector <4 x i32> %minmax.ident.splatinsert, <4 x i32> poison, <4 x i32> zeroinitializer
  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> [ %minmax.ident.splat, %vector.ph ], [ %8, %vector.body ]
  %vec.phi14 = phi <4 x i32> [ %minmax.ident.splat, %vector.ph ], [ %9, %vector.body ]
  %offset.idx = or disjoint i64 %index, 1
  %6 = getelementptr inbounds i32, ptr %0, i64 %offset.idx
  %7 = getelementptr inbounds i8, ptr %6, i64 16
  %wide.load = load <4 x i32>, ptr %6, align 4, !tbaa !5
  %wide.load15 = load <4 x i32>, ptr %7, align 4, !tbaa !5
  %8 = tail call <4 x i32> @llvm.smax.v4i32(<4 x i32> %vec.phi, <4 x i32> %wide.load)
  %9 = tail call <4 x i32> @llvm.smax.v4i32(<4 x i32> %vec.phi14, <4 x i32> %wide.load15)
  %index.next = add nuw i64 %index, 8
  %10 = icmp eq i64 %index.next, %n.vec
  br i1 %10, label %middle.block, label %vector.body, !llvm.loop !9

middle.block:                                     ; preds = %vector.body
  %rdx.minmax = tail call <4 x i32> @llvm.smax.v4i32(<4 x i32> %8, <4 x i32> %9)
  %11 = tail call i32 @llvm.vector.reduce.smax.v4i32(<4 x i32> %rdx.minmax)
  %cmp.n = icmp eq i64 %5, %n.vec
  br i1 %cmp.n, label %._crit_edge, label %.lr.ph.preheader16

.lr.ph.preheader16:                               ; preds = %middle.block, %.lr.ph.preheader
  %indvars.iv.ph = phi i64 [ 1, %.lr.ph.preheader ], [ %ind.end, %middle.block ]
  %.0911.ph = phi i32 [ %3, %.lr.ph.preheader ], [ %11, %middle.block ]
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader16, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ %indvars.iv.ph, %.lr.ph.preheader16 ]
  %.0911 = phi i32 [ %spec.select, %.lr.ph ], [ %.0911.ph, %.lr.ph.preheader16 ]
  %12 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv
  %13 = load i32, ptr %12, align 4, !tbaa !5
  %spec.select = tail call i32 @llvm.smax.i32(i32 %.0911, i32 %13)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %wide.trip.count
  br i1 %exitcond.not, label %._crit_edge, label %.lr.ph, !llvm.loop !13

._crit_edge:                                      ; preds = %.lr.ph, %middle.block, %2
  %.09.lcssa = phi i32 [ %3, %2 ], [ %11, %middle.block ], [ %spec.select, %.lr.ph ]
  ret i32 %.09.lcssa
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.smax.i32(i32, i32) #1

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

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.vector.reduce.smax.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 = !{!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: EarlyCSEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopLoadEliminationPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,LoopVectorizePass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass