; LLVM IR from sbshah97/DS-Algo-Handbook :: labs/lab2/Fibonacci/fibonacii_rec.ll (Z3fibi)

; 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: mustprogress uwtable
define dso_local noundef i32 @_Z3fibi(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  %4 = load i32, ptr %3, align 4, !tbaa !5
  %5 = icmp eq i32 %4, 0
  br i1 %5, label %9, label %6

6:                                                ; preds = %1
  %7 = load i32, ptr %3, align 4, !tbaa !5
  %8 = icmp eq i32 %7, 1
  br i1 %8, label %9, label %10

9:                                                ; preds = %6, %1
  store i32 1, ptr %2, align 4
  br label %18

10:                                               ; preds = %6
  %11 = load i32, ptr %3, align 4, !tbaa !5
  %12 = sub nsw i32 %11, 1
  %13 = call noundef i32 @_Z3fibi(i32 noundef %12)
  %14 = load i32, ptr %3, align 4, !tbaa !5
  %15 = sub nsw i32 %14, 2
  %16 = call noundef i32 @_Z3fibi(i32 noundef %15)
  %17 = add nsw i32 %13, %16
  store i32 %17, ptr %2, align 4
  br label %18

18:                                               ; preds = %10, %9
  %19 = load i32, ptr %2, align 4
  ret i32 %19
}

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" }

!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"}


; 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: mustprogress nofree nosync nounwind willreturn memory(none) uwtable
define dso_local noundef i32 @_Z3fibi(i32 noundef %0) local_unnamed_addr #0 {
  %or.cond7 = icmp ult i32 %0, 2
  br i1 %or.cond7, label %tailrecurse._crit_edge, label %tailrecurse

tailrecurse:                                      ; preds = %1, %tailrecurse
  %.tr9 = phi i32 [ %4, %tailrecurse ], [ %0, %1 ]
  %accumulator.tr8 = phi i32 [ %5, %tailrecurse ], [ 0, %1 ]
  %2 = add nsw i32 %.tr9, -1
  %3 = tail call noundef i32 @_Z3fibi(i32 noundef %2)
  %4 = add nsw i32 %.tr9, -2
  %5 = add nsw i32 %3, %accumulator.tr8
  %or.cond = icmp ult i32 %4, 2
  br i1 %or.cond, label %tailrecurse._crit_edge.loopexit, label %tailrecurse

tailrecurse._crit_edge.loopexit:                  ; preds = %tailrecurse
  %6 = add nsw i32 %5, 1
  br label %tailrecurse._crit_edge

tailrecurse._crit_edge:                           ; preds = %tailrecurse._crit_edge.loopexit, %1
  %accumulator.tr.lcssa = phi i32 [ 1, %1 ], [ %6, %tailrecurse._crit_edge.loopexit ]
  ret i32 %accumulator.tr.lcssa
}

attributes #0 = { mustprogress nofree 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" }

!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)"}


; Effective O3 passes: GVNPass,GlobalOptPass,IPSCCPPass,InstCombinePass,InstSimplifyPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass