; LLVM IR from chachaxw/data-structure-and-algorithm :: leetcode/dynamic_programming/integer_break.ll (ZN8Solution13integerBreak1Ei)

; 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 noundef i32 @_ZN8Solution13integerBreak1Ei(ptr noundef nonnull align 1 dereferenceable(1) %0, i32 noundef %1) #1 align 2 {
  %3 = alloca i32, align 4
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  %7 = load ptr, ptr %4, align 8
  %8 = load i32, ptr %5, align 4, !tbaa !9
  %9 = icmp eq i32 %8, 2
  br i1 %9, label %10, label %11

10:                                               ; preds = %2
  store i32 1, ptr %3, align 4
  br label %33

11:                                               ; preds = %2
  %12 = load i32, ptr %5, align 4, !tbaa !9
  %13 = icmp eq i32 %12, 3
  br i1 %13, label %14, label %15

14:                                               ; preds = %11
  store i32 2, ptr %3, align 4
  br label %33

15:                                               ; preds = %11
  %16 = load i32, ptr %5, align 4, !tbaa !9
  %17 = icmp eq i32 %16, 4
  br i1 %17, label %18, label %19

18:                                               ; preds = %15
  store i32 4, ptr %3, align 4
  br label %33

19:                                               ; preds = %15
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #2
  store i32 1, ptr %6, align 4, !tbaa !9
  br label %20

20:                                               ; preds = %23, %19
  %21 = load i32, ptr %5, align 4, !tbaa !9
  %22 = icmp sgt i32 %21, 4
  br i1 %22, label %23, label %28

23:                                               ; preds = %20
  %24 = load i32, ptr %6, align 4, !tbaa !9
  %25 = mul nsw i32 %24, 3
  store i32 %25, ptr %6, align 4, !tbaa !9
  %26 = load i32, ptr %5, align 4, !tbaa !9
  %27 = sub nsw i32 %26, 3
  store i32 %27, ptr %5, align 4, !tbaa !9
  br label %20, !llvm.loop !11

28:                                               ; preds = %20
  %29 = load i32, ptr %5, align 4, !tbaa !9
  %30 = load i32, ptr %6, align 4, !tbaa !9
  %31 = mul nsw i32 %30, %29
  store i32 %31, ptr %6, align 4, !tbaa !9
  %32 = load i32, ptr %6, align 4, !tbaa !9
  store i32 %32, ptr %3, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  br label %33

33:                                               ; preds = %28, %18, %14, %10
  %34 = load i32, ptr %3, align 4
  ret i32 %34
}

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 = { 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"}


; 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"

@switch.table._ZN8Solution13integerBreak1Ei = private unnamed_addr constant [3 x i32] [i32 1, i32 2, i32 4], align 4

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none) uwtable
define dso_local noundef i32 @_ZN8Solution13integerBreak1Ei(ptr nocapture noundef nonnull readnone align 1 dereferenceable(1) %0, i32 noundef %1) local_unnamed_addr #0 align 2 {
  %switch.tableidx = add i32 %1, -2
  %3 = icmp ult i32 %switch.tableidx, 3
  br i1 %3, label %switch.lookup, label %.preheader

.preheader:                                       ; preds = %2
  %4 = icmp sgt i32 %1, 4
  br i1 %4, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %.preheader
  %5 = add nsw i32 %1, -5
  %6 = udiv i32 %5, 3
  %7 = add nuw nsw i32 %6, 1
  %min.iters.check = icmp ult i32 %5, 21
  br i1 %min.iters.check, label %.lr.ph.preheader20, label %vector.ph

vector.ph:                                        ; preds = %.lr.ph.preheader
  %n.vec = and i32 %7, 2147483640
  %8 = mul i32 %n.vec, -3
  %ind.end = add i32 %8, %1
  br label %vector.body

vector.body:                                      ; preds = %vector.body, %vector.ph
  %index = phi i32 [ 0, %vector.ph ], [ %index.next, %vector.body ]
  %vec.phi = phi <4 x i32> [ <i32 1, i32 1, i32 1, i32 1>, %vector.ph ], [ %9, %vector.body ]
  %vec.phi19 = phi <4 x i32> [ <i32 1, i32 1, i32 1, i32 1>, %vector.ph ], [ %10, %vector.body ]
  %9 = mul <4 x i32> %vec.phi, <i32 3, i32 3, i32 3, i32 3>
  %10 = mul <4 x i32> %vec.phi19, <i32 3, i32 3, i32 3, i32 3>
  %index.next = add nuw i32 %index, 8
  %11 = icmp eq i32 %index.next, %n.vec
  br i1 %11, label %middle.block, label %vector.body, !llvm.loop !5

middle.block:                                     ; preds = %vector.body
  %bin.rdx = mul <4 x i32> %10, %9
  %12 = tail call i32 @llvm.vector.reduce.mul.v4i32(<4 x i32> %bin.rdx)
  %cmp.n = icmp eq i32 %7, %n.vec
  br i1 %cmp.n, label %._crit_edge, label %.lr.ph.preheader20

.lr.ph.preheader20:                               ; preds = %middle.block, %.lr.ph.preheader
  %.014.ph = phi i32 [ 1, %.lr.ph.preheader ], [ %12, %middle.block ]
  %.01013.ph = phi i32 [ %1, %.lr.ph.preheader ], [ %ind.end, %middle.block ]
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader20, %.lr.ph
  %.014 = phi i32 [ %13, %.lr.ph ], [ %.014.ph, %.lr.ph.preheader20 ]
  %.01013 = phi i32 [ %14, %.lr.ph ], [ %.01013.ph, %.lr.ph.preheader20 ]
  %13 = mul nuw nsw i32 %.014, 3
  %14 = add nsw i32 %.01013, -3
  %15 = icmp ugt i32 %.01013, 7
  br i1 %15, label %.lr.ph, label %._crit_edge, !llvm.loop !9

._crit_edge:                                      ; preds = %.lr.ph, %middle.block, %.preheader
  %.010.lcssa = phi i32 [ %1, %.preheader ], [ %ind.end, %middle.block ], [ %14, %.lr.ph ]
  %.0.lcssa = phi i32 [ 1, %.preheader ], [ %12, %middle.block ], [ %13, %.lr.ph ]
  %16 = mul nsw i32 %.0.lcssa, %.010.lcssa
  br label %18

switch.lookup:                                    ; preds = %2
  %17 = zext nneg i32 %switch.tableidx to i64
  %switch.gep = getelementptr inbounds [3 x i32], ptr @switch.table._ZN8Solution13integerBreak1Ei, i64 0, i64 %17
  %switch.load = load i32, ptr %switch.gep, align 4
  br label %18

18:                                               ; preds = %switch.lookup, %._crit_edge
  %.011 = phi i32 [ %16, %._crit_edge ], [ %switch.load, %switch.lookup ]
  ret i32 %.011
}

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

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(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 = distinct !{!5, !6, !7, !8}
!6 = !{!"llvm.loop.mustprogress"}
!7 = !{!"llvm.loop.isvectorized", i32 1}
!8 = !{!"llvm.loop.unroll.runtime.disable"}
!9 = distinct !{!9, !6, !8, !7}


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