; LLVM IR from AllenDowney/ExercisesInC :: exercises/ex02.5 (recurse)

; 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 [37 x i8], align 1

declare i32 @printf(ptr noundef, ...) #0

; 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

; Function Attrs: nounwind uwtable
define dso_local i32 @fibonacci(i32 noundef %0) #2 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  %6 = load i32, ptr %3, align 4, !tbaa !5
  %7 = call i32 (ptr, ...) @printf(ptr noundef @.str, ptr noundef %3, i32 noundef %6)
  %8 = load i32, ptr %3, align 4, !tbaa !5
  %9 = icmp sle i32 %8, 1
  br i1 %9, label %10, label %12

10:                                               ; preds = %1
  %11 = load i32, ptr %3, align 4, !tbaa !5
  store i32 %11, ptr %2, align 4
  br label %22

12:                                               ; preds = %1
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #3
  %13 = load i32, ptr %3, align 4, !tbaa !5
  %14 = sub nsw i32 %13, 1
  %15 = call i32 @fibonacci(i32 noundef %14)
  store i32 %15, ptr %4, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  %16 = load i32, ptr %3, align 4, !tbaa !5
  %17 = sub nsw i32 %16, 2
  %18 = call i32 @fibonacci(i32 noundef %17)
  store i32 %18, ptr %5, align 4, !tbaa !5
  %19 = load i32, ptr %4, align 4, !tbaa !5
  %20 = load i32, ptr %5, align 4, !tbaa !5
  %21 = add nsw i32 %19, %20
  store i32 %21, ptr %2, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #3
  br label %22

22:                                               ; preds = %12, %10
  %23 = load i32, ptr %2, align 4
  ret i32 %23
}

attributes #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 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 #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"}


; 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 [37 x i8], align 1

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #0

; Function Attrs: nofree nounwind uwtable
define dso_local i32 @fibonacci(i32 noundef %0) local_unnamed_addr #1 {
  %2 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  %3 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str, ptr noundef nonnull %2, i32 noundef %0)
  %4 = load i32, ptr %2, align 4, !tbaa !5
  %5 = icmp slt i32 %4, 2
  br i1 %5, label %13, label %6

6:                                                ; preds = %1
  %7 = add nsw i32 %4, -1
  %8 = call i32 @fibonacci(i32 noundef %7)
  %9 = load i32, ptr %2, align 4, !tbaa !5
  %10 = add nsw i32 %9, -2
  %11 = call i32 @fibonacci(i32 noundef %10)
  %12 = add nsw i32 %11, %8
  br label %13

13:                                               ; preds = %1, %6
  %.0 = phi i32 [ %12, %6 ], [ %4, %1 ]
  ret i32 %.0
}

attributes #0 = { 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" }
attributes #1 = { 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" }

!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"}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,IPSCCPPass,InferFunctionAttrsPass,InstCombinePass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass