; LLVM IR from Chasmiccoder/Algos-for-Amigos :: Mathematics/Series/p02_N_Bonacci_Numbers.ll (Z13fib_iterativei)

; 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"

%"class.std::basic_ostream" = type { ptr, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }

@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str = external hidden unnamed_addr constant [52 x i8], align 1

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_Z13fib_iterativei(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
  store i32 %0, ptr %3, align 4, !tbaa !5
  %8 = load i32, ptr %3, align 4, !tbaa !5
  %9 = icmp slt i32 %8, 0
  br i1 %9, label %10, label %12

10:                                               ; preds = %1
  %11 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef @.str)
  call void @exit(i32 noundef -1) #4
  unreachable

12:                                               ; preds = %1
  %13 = load i32, ptr %3, align 4, !tbaa !5
  %14 = icmp eq i32 %13, 0
  br i1 %14, label %18, label %15

15:                                               ; preds = %12
  %16 = load i32, ptr %3, align 4, !tbaa !5
  %17 = icmp eq i32 %16, 1
  br i1 %17, label %18, label %20

18:                                               ; preds = %15, %12
  %19 = load i32, ptr %3, align 4, !tbaa !5
  store i32 %19, ptr %2, align 4
  br label %37

20:                                               ; preds = %15
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #5
  store i32 0, ptr %4, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #5
  store i32 1, ptr %5, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #5
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #5
  store i32 2, ptr %7, align 4, !tbaa !5
  br label %21

21:                                               ; preds = %32, %20
  %22 = load i32, ptr %7, align 4, !tbaa !5
  %23 = load i32, ptr %3, align 4, !tbaa !5
  %24 = icmp sle i32 %22, %23
  br i1 %24, label %26, label %25

25:                                               ; preds = %21
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #5
  br label %35

26:                                               ; preds = %21
  %27 = load i32, ptr %4, align 4, !tbaa !5
  %28 = load i32, ptr %5, align 4, !tbaa !5
  %29 = add nsw i32 %27, %28
  store i32 %29, ptr %6, align 4, !tbaa !5
  %30 = load i32, ptr %5, align 4, !tbaa !5
  store i32 %30, ptr %4, align 4, !tbaa !5
  %31 = load i32, ptr %6, align 4, !tbaa !5
  store i32 %31, ptr %5, align 4, !tbaa !5
  br label %32

32:                                               ; preds = %26
  %33 = load i32, ptr %7, align 4, !tbaa !5
  %34 = add nsw i32 %33, 1
  store i32 %34, ptr %7, align 4, !tbaa !5
  br label %21, !llvm.loop !9

35:                                               ; preds = %25
  %36 = load i32, ptr %6, align 4, !tbaa !5
  store i32 %36, ptr %2, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #5
  br label %37

37:                                               ; preds = %35, %18
  %38 = load i32, ptr %2, align 4
  ret i32 %38
}

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #1

; Function Attrs: noreturn nounwind
declare void @exit(i32 noundef) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #3

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #3

attributes #0 = { mustprogress 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 = { inlinehint mustprogress 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 = { noreturn nounwind "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 #3 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #4 = { noreturn nounwind }
attributes #5 = { 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++ 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"

%"class.std::basic_ostream" = type { ptr, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }

@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str = external hidden unnamed_addr constant [52 x i8], align 1

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_Z13fib_iterativei(i32 noundef %0) local_unnamed_addr #0 {
  %2 = icmp slt i32 %0, 0
  br i1 %2, label %3, label %5

3:                                                ; preds = %1
  %4 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef nonnull @.str)
  tail call void @exit(i32 noundef -1) #3
  unreachable

5:                                                ; preds = %1
  %or.cond = icmp ult i32 %0, 2
  br i1 %or.cond, label %.loopexit, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %5
  %6 = add nsw i32 %0, -1
  %7 = add nsw i32 %0, -2
  %xtraiter = and i32 %6, 7
  %8 = icmp ult i32 %7, 7
  br i1 %8, label %.loopexit.loopexit.unr-lcssa, label %.lr.ph.preheader.new

.lr.ph.preheader.new:                             ; preds = %.lr.ph.preheader
  %unroll_iter = and i32 %6, -8
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph, %.lr.ph.preheader.new
  %.01521 = phi i32 [ 1, %.lr.ph.preheader.new ], [ %16, %.lr.ph ]
  %.01620 = phi i32 [ 0, %.lr.ph.preheader.new ], [ %15, %.lr.ph ]
  %niter = phi i32 [ 0, %.lr.ph.preheader.new ], [ %niter.next.7, %.lr.ph ]
  %9 = add nsw i32 %.01521, %.01620
  %10 = add nsw i32 %9, %.01521
  %11 = add nsw i32 %10, %9
  %12 = add nsw i32 %11, %10
  %13 = add nsw i32 %12, %11
  %14 = add nsw i32 %13, %12
  %15 = add nsw i32 %14, %13
  %16 = add nsw i32 %15, %14
  %niter.next.7 = add i32 %niter, 8
  %niter.ncmp.7 = icmp eq i32 %niter.next.7, %unroll_iter
  br i1 %niter.ncmp.7, label %.loopexit.loopexit.unr-lcssa, label %.lr.ph, !llvm.loop !5

.loopexit.loopexit.unr-lcssa:                     ; preds = %.lr.ph, %.lr.ph.preheader
  %.lcssa.ph = phi i32 [ poison, %.lr.ph.preheader ], [ %16, %.lr.ph ]
  %.01521.unr = phi i32 [ 1, %.lr.ph.preheader ], [ %16, %.lr.ph ]
  %.01620.unr = phi i32 [ 0, %.lr.ph.preheader ], [ %15, %.lr.ph ]
  %lcmp.mod.not = icmp eq i32 %xtraiter, 0
  br i1 %lcmp.mod.not, label %.loopexit, label %.lr.ph.epil

.lr.ph.epil:                                      ; preds = %.loopexit.loopexit.unr-lcssa, %.lr.ph.epil
  %.01521.epil = phi i32 [ %17, %.lr.ph.epil ], [ %.01521.unr, %.loopexit.loopexit.unr-lcssa ]
  %.01620.epil = phi i32 [ %.01521.epil, %.lr.ph.epil ], [ %.01620.unr, %.loopexit.loopexit.unr-lcssa ]
  %epil.iter = phi i32 [ %epil.iter.next, %.lr.ph.epil ], [ 0, %.loopexit.loopexit.unr-lcssa ]
  %17 = add nsw i32 %.01521.epil, %.01620.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 %.loopexit, label %.lr.ph.epil, !llvm.loop !7

.loopexit:                                        ; preds = %.loopexit.loopexit.unr-lcssa, %.lr.ph.epil, %5
  %.017 = phi i32 [ %0, %5 ], [ %.lcssa.ph, %.loopexit.loopexit.unr-lcssa ], [ %17, %.lr.ph.epil ]
  ret i32 %.017
}

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) local_unnamed_addr #1

; Function Attrs: noreturn nounwind
declare void @exit(i32 noundef) local_unnamed_addr #2

attributes #0 = { mustprogress 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 = { inlinehint mustprogress 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 = { noreturn nounwind "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 #3 = { noreturn 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 = distinct !{!5, !6}
!6 = !{!"llvm.loop.mustprogress"}
!7 = distinct !{!7, !8}
!8 = !{!"llvm.loop.unroll.disable"}


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