; LLVM IR from kaynewbie/algorithm :: algorithm/CodingInterviews (fibonacci)

; 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"

@.str = external hidden unnamed_addr constant [4 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [2 x i8], align 1

; Function Attrs: nounwind uwtable
define dso_local void @fibonacciLoop(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
  store i32 %0, ptr %2, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #3
  store i32 0, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #3
  store i32 1, ptr %4, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  store i32 0, ptr %5, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #3
  store i32 0, ptr %6, align 4, !tbaa !5
  br label %7

7:                                                ; preds = %26, %1
  %8 = load i32, ptr %6, align 4, !tbaa !5
  %9 = load i32, ptr %2, align 4, !tbaa !5
  %10 = icmp slt i32 %8, %9
  br i1 %10, label %12, label %11

11:                                               ; preds = %7
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #3
  br label %29

12:                                               ; preds = %7
  %13 = load i32, ptr %6, align 4, !tbaa !5
  %14 = icmp sle i32 %13, 1
  br i1 %14, label %15, label %17

15:                                               ; preds = %12
  %16 = load i32, ptr %6, align 4, !tbaa !5
  store i32 %16, ptr %5, align 4, !tbaa !5
  br label %23

17:                                               ; preds = %12
  %18 = load i32, ptr %3, align 4, !tbaa !5
  %19 = load i32, ptr %4, align 4, !tbaa !5
  %20 = add nsw i32 %18, %19
  store i32 %20, ptr %5, align 4, !tbaa !5
  %21 = load i32, ptr %4, align 4, !tbaa !5
  store i32 %21, ptr %3, align 4, !tbaa !5
  %22 = load i32, ptr %5, align 4, !tbaa !5
  store i32 %22, ptr %4, align 4, !tbaa !5
  br label %23

23:                                               ; preds = %17, %15
  %24 = load i32, ptr %5, align 4, !tbaa !5
  %25 = call i32 (ptr, ...) @printf(ptr noundef @.str, i32 noundef %24)
  br label %26

26:                                               ; preds = %23
  %27 = load i32, ptr %6, align 4, !tbaa !5
  %28 = add nsw i32 %27, 1
  store i32 %28, ptr %6, align 4, !tbaa !5
  br label %7, !llvm.loop !9

29:                                               ; preds = %11
  %30 = call i32 (ptr, ...) @printf(ptr noundef @.str.1)
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #3
  ret void
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

declare i32 @printf(ptr noundef, ...) #2

; 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 = { "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 = { 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"

@.str = external hidden unnamed_addr constant [4 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [2 x i8], align 1

; Function Attrs: nofree nounwind uwtable
define dso_local void @fibonacciLoop(i32 noundef %0) local_unnamed_addr #0 {
  %2 = icmp sgt i32 %0, 0
  br i1 %2, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %1
  %3 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str, i32 noundef 0)
  %exitcond.peel.not = icmp eq i32 %0, 1
  br i1 %exitcond.peel.not, label %._crit_edge, label %.lr.ph.peel.next

.lr.ph.peel.next:                                 ; preds = %.lr.ph.preheader
  %4 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str, i32 noundef 1)
  %exitcond.peel22.not = icmp eq i32 %0, 2
  br i1 %exitcond.peel22.not, label %._crit_edge, label %.lr.ph

._crit_edge:                                      ; preds = %.lr.ph, %.lr.ph.preheader, %.lr.ph.peel.next, %1
  %5 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.1)
  ret void

.lr.ph:                                           ; preds = %.lr.ph.peel.next, %.lr.ph
  %.016 = phi i32 [ %8, %.lr.ph ], [ 2, %.lr.ph.peel.next ]
  %.01115 = phi i32 [ %6, %.lr.ph ], [ 1, %.lr.ph.peel.next ]
  %.01214 = phi i32 [ %.01115, %.lr.ph ], [ 0, %.lr.ph.peel.next ]
  %6 = add nsw i32 %.01115, %.01214
  %7 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str, i32 noundef %6)
  %8 = add nuw nsw i32 %.016, 1
  %exitcond.not = icmp eq i32 %8, %0
  br i1 %exitcond.not, label %._crit_edge, label %.lr.ph, !llvm.loop !5
}

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #1

attributes #0 = { nofree 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 = { nofree 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" }

!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}
!6 = !{!"llvm.loop.mustprogress"}
!7 = !{!"llvm.loop.peeled.count", i32 2}


; Effective O3 passes: GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopFullUnrollPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass