; LLVM IR from DimitrisJim/leetcode_solutions :: C/Algorithms (1137)

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

9:                                                ; preds = %25, %1
  %10 = load i32, ptr %6, align 4, !tbaa !5
  %11 = load i32, ptr %2, align 4, !tbaa !5
  %12 = sub nsw i32 %11, 2
  %13 = icmp slt i32 %10, %12
  br i1 %13, label %15, label %14

14:                                               ; preds = %9
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  br label %28

15:                                               ; preds = %9
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  %16 = load i32, ptr %3, align 4, !tbaa !5
  store i32 %16, ptr %7, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #2
  %17 = load i32, ptr %4, align 4, !tbaa !5
  store i32 %17, ptr %8, align 4, !tbaa !5
  %18 = load i32, ptr %4, align 4, !tbaa !5
  store i32 %18, ptr %3, align 4, !tbaa !5
  %19 = load i32, ptr %5, align 4, !tbaa !5
  store i32 %19, ptr %4, align 4, !tbaa !5
  %20 = load i32, ptr %7, align 4, !tbaa !5
  %21 = load i32, ptr %8, align 4, !tbaa !5
  %22 = add nsw i32 %20, %21
  %23 = load i32, ptr %5, align 4, !tbaa !5
  %24 = add nsw i32 %22, %23
  store i32 %24, ptr %5, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  br label %25

25:                                               ; preds = %15
  %26 = load i32, ptr %6, align 4, !tbaa !5
  %27 = add nsw i32 %26, 1
  store i32 %27, ptr %6, align 4, !tbaa !5
  br label %9, !llvm.loop !9

28:                                               ; preds = %14
  %29 = load i32, ptr %2, align 4, !tbaa !5
  %30 = icmp ne i32 %29, 0
  br i1 %30, label %31, label %33

31:                                               ; preds = %28
  %32 = load i32, ptr %5, align 4, !tbaa !5
  br label %34

33:                                               ; preds = %28
  br label %34

34:                                               ; preds = %33, %31
  %35 = phi i32 [ %32, %31 ], [ 0, %33 ]
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #2
  ret i32 %35
}

; 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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"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(none) uwtable
define dso_local i32 @tribonacci(i32 noundef %0) local_unnamed_addr #0 {
  %2 = icmp sgt i32 %0, 2
  br i1 %2, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %1
  %3 = add nsw i32 %0, -3
  %4 = add nsw i32 %0, -2
  %xtraiter = and i32 %4, 7
  %5 = icmp ult i32 %3, 7
  br i1 %5, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph.preheader.new

.lr.ph.preheader.new:                             ; preds = %.lr.ph.preheader
  %unroll_iter = and i32 %4, -8
  br label %.lr.ph

._crit_edge.loopexit.unr-lcssa:                   ; preds = %.lr.ph, %.lr.ph.preheader
  %.lcssa.ph = phi i32 [ poison, %.lr.ph.preheader ], [ %24, %.lr.ph ]
  %.018.unr = phi i32 [ 0, %.lr.ph.preheader ], [ %20, %.lr.ph ]
  %.01217.unr = phi i32 [ 1, %.lr.ph.preheader ], [ %22, %.lr.ph ]
  %.01415.unr = phi i32 [ 1, %.lr.ph.preheader ], [ %24, %.lr.ph ]
  %lcmp.mod.not = icmp eq i32 %xtraiter, 0
  br i1 %lcmp.mod.not, label %._crit_edge, label %.lr.ph.epil

.lr.ph.epil:                                      ; preds = %._crit_edge.loopexit.unr-lcssa, %.lr.ph.epil
  %.018.epil = phi i32 [ %.01217.epil, %.lr.ph.epil ], [ %.018.unr, %._crit_edge.loopexit.unr-lcssa ]
  %.01217.epil = phi i32 [ %.01415.epil, %.lr.ph.epil ], [ %.01217.unr, %._crit_edge.loopexit.unr-lcssa ]
  %.01415.epil = phi i32 [ %7, %.lr.ph.epil ], [ %.01415.unr, %._crit_edge.loopexit.unr-lcssa ]
  %epil.iter = phi i32 [ %epil.iter.next, %.lr.ph.epil ], [ 0, %._crit_edge.loopexit.unr-lcssa ]
  %6 = add i32 %.01217.epil, %.01415.epil
  %7 = add i32 %6, %.018.epil
  %epil.iter.next = add i32 %epil.iter, 1
  %epil.iter.cmp.not = icmp eq i32 %epil.iter.next, %xtraiter
  br i1 %epil.iter.cmp.not, label %._crit_edge, label %.lr.ph.epil, !llvm.loop !5

._crit_edge:                                      ; preds = %._crit_edge.loopexit.unr-lcssa, %.lr.ph.epil, %1
  %.014.lcssa = phi i32 [ 1, %1 ], [ %.lcssa.ph, %._crit_edge.loopexit.unr-lcssa ], [ %7, %.lr.ph.epil ]
  %.not = icmp eq i32 %0, 0
  %8 = select i1 %.not, i32 0, i32 %.014.lcssa
  ret i32 %8

.lr.ph:                                           ; preds = %.lr.ph, %.lr.ph.preheader.new
  %.018 = phi i32 [ 0, %.lr.ph.preheader.new ], [ %20, %.lr.ph ]
  %.01217 = phi i32 [ 1, %.lr.ph.preheader.new ], [ %22, %.lr.ph ]
  %.01415 = phi i32 [ 1, %.lr.ph.preheader.new ], [ %24, %.lr.ph ]
  %niter = phi i32 [ 0, %.lr.ph.preheader.new ], [ %niter.next.7, %.lr.ph ]
  %9 = add i32 %.01217, %.01415
  %10 = add i32 %9, %.018
  %11 = add i32 %.01415, %10
  %12 = add i32 %11, %.01217
  %13 = add i32 %10, %12
  %14 = add i32 %13, %.01415
  %15 = add i32 %12, %14
  %16 = add i32 %15, %10
  %17 = add i32 %14, %16
  %18 = add i32 %17, %12
  %19 = add i32 %16, %18
  %20 = add i32 %19, %14
  %21 = add i32 %18, %20
  %22 = add i32 %21, %16
  %23 = add i32 %20, %22
  %24 = add i32 %23, %18
  %niter.next.7 = add i32 %niter, 8
  %niter.ncmp.7 = icmp eq i32 %niter.next.7, %unroll_iter
  br i1 %niter.ncmp.7, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph, !llvm.loop !7
}

attributes #0 = { nofree norecurse nosync nounwind 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" }

!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.unroll.disable"}
!7 = distinct !{!7, !8}
!8 = !{!"llvm.loop.mustprogress"}


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