; LLVM IR from Hunterdii/GeeksforGeeks-POTD :: April 2025 GFG SOLUTION (April-26)

; 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"

%struct.Node = type { i32, ptr, ptr }

; Function Attrs: nounwind uwtable
define dso_local i32 @c(ptr noundef %0) #0 {
  %2 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  %3 = load ptr, ptr %2, align 8, !tbaa !5
  %4 = icmp ne ptr %3, null
  br i1 %4, label %5, label %16

5:                                                ; preds = %1
  %6 = load ptr, ptr %2, align 8, !tbaa !5
  %7 = getelementptr inbounds %struct.Node, ptr %6, i32 0, i32 1
  %8 = load ptr, ptr %7, align 8, !tbaa !9
  %9 = call i32 @c(ptr noundef %8)
  %10 = add nsw i32 1, %9
  %11 = load ptr, ptr %2, align 8, !tbaa !5
  %12 = getelementptr inbounds %struct.Node, ptr %11, i32 0, i32 2
  %13 = load ptr, ptr %12, align 8, !tbaa !12
  %14 = call i32 @c(ptr noundef %13)
  %15 = add nsw i32 %10, %14
  br label %17

16:                                               ; preds = %1
  br label %17

17:                                               ; preds = %16, %5
  %18 = phi i32 [ %15, %5 ], [ 0, %16 ]
  ret i32 %18
}

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" }

!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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !6, i64 8}
!10 = !{!"Node", !11, i64 0, !6, i64 8, !6, i64 16}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 16}


; 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 nosync nounwind memory(read, inaccessiblemem: none) uwtable
define dso_local i32 @c(ptr noundef readonly %0) local_unnamed_addr #0 {
  %.not3 = icmp eq ptr %0, null
  br i1 %.not3, label %tailrecurse._crit_edge, label %tailrecurse

tailrecurse:                                      ; preds = %1, %tailrecurse
  %.tr5 = phi ptr [ %6, %tailrecurse ], [ %0, %1 ]
  %accumulator.tr4 = phi i32 [ %8, %tailrecurse ], [ 0, %1 ]
  %2 = getelementptr inbounds i8, ptr %.tr5, i64 8
  %3 = load ptr, ptr %2, align 8, !tbaa !5
  %4 = tail call i32 @c(ptr noundef %3)
  %5 = getelementptr inbounds i8, ptr %.tr5, i64 16
  %6 = load ptr, ptr %5, align 8, !tbaa !11
  %7 = add i32 %accumulator.tr4, 1
  %8 = add i32 %7, %4
  %.not = icmp eq ptr %6, null
  br i1 %.not, label %tailrecurse._crit_edge, label %tailrecurse

tailrecurse._crit_edge:                           ; preds = %tailrecurse, %1
  %accumulator.tr.lcssa = phi i32 [ 0, %1 ], [ %8, %tailrecurse ]
  ret i32 %accumulator.tr.lcssa
}

attributes #0 = { nofree nosync nounwind memory(read, inaccessiblemem: 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 = !{!6, !10, i64 8}
!6 = !{!"Node", !7, i64 0, !10, i64 8, !10, i64 16}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = !{!6, !10, i64 16}


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