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Public Member Functions | Private Attributes | List of all members
cluster_linearize::SFLDefaultCostModel Class Reference

A default cost model for SFL for SetType=BitSet<64>, based on benchmarks. More...

#include <cluster_linearize.h>

Public Member Functions

void InitializeBegin () noexcept
void InitializeEnd (int num_txns, int num_deps) noexcept
void GetLinearizationBegin () noexcept
void GetLinearizationEnd (int num_txns, int num_deps) noexcept
void MakeTopologicalBegin () noexcept
void MakeTopologicalEnd (int num_chunks, int num_steps) noexcept
void StartOptimizingBegin () noexcept
void StartOptimizingEnd (int num_chunks) noexcept
void ActivateBegin () noexcept
void ActivateEnd (int num_deps) noexcept
void DeactivateBegin () noexcept
void DeactivateEnd (int num_deps) noexcept
void MergeChunksBegin () noexcept
void MergeChunksMid (int num_txns) noexcept
void MergeChunksEnd (int num_steps) noexcept
void PickMergeCandidateBegin () noexcept
void PickMergeCandidateEnd (int num_steps) noexcept
void PickChunkToOptimizeBegin () noexcept
void PickChunkToOptimizeEnd (int num_steps) noexcept
void PickDependencyToSplitBegin () noexcept
void PickDependencyToSplitEnd (int num_txns) noexcept
void StartMinimizingBegin () noexcept
void StartMinimizingEnd (int num_chunks) noexcept
void MinimizeStepBegin () noexcept
void MinimizeStepMid (int num_txns) noexcept
void MinimizeStepEnd (bool split) noexcept
uint64_t GetCost () const noexcept

Private Attributes

uint64_t m_cost {0}

Detailed Description

A default cost model for SFL for SetType=BitSet<64>, based on benchmarks.

The numbers here were obtained in February 2026 by:

  • For a variety of machines:
    • Running a fixed collection of ~385000 clusters found through random generation and fuzzing, optimizing for difficulty of linearization.
      • Linearize each ~3000 times, with different random seeds. Sometimes without input linearization, sometimes with a bad one.
        • Gather cycle counts for each of the operations included in this cost model, broken down by their parameters.
    • Correct the data by subtracting the runtime of obtaining the cycle count.
    • Drop the 5% top and bottom samples from each cycle count dataset, and compute the average of the remaining samples.
    • For each operation, fit a least-squares linear function approximation through the samples.
  • Rescale all machine expressions to make their total time match, as we only care about relative cost of each operation.
  • Take the per-operation average of operation expressions across all machines, to construct expressions for an average machine.
  • Approximate the result with integer coefficients. Each cost unit corresponds to somewhere between 0.5 ns and 2.5 ns, depending on the hardware.

Definition at line 496 of file cluster_linearize.h.

Member Function Documentation

◆ ActivateBegin()

void cluster_linearize::SFLDefaultCostModel::ActivateBegin ( )
inlinenoexcept

Definition at line 524 of file cluster_linearize.h.

◆ ActivateEnd()

void cluster_linearize::SFLDefaultCostModel::ActivateEnd ( int num_deps)
inlinenoexcept

Definition at line 525 of file cluster_linearize.h.

◆ DeactivateBegin()

void cluster_linearize::SFLDefaultCostModel::DeactivateBegin ( )
inlinenoexcept

Definition at line 526 of file cluster_linearize.h.

◆ DeactivateEnd()

void cluster_linearize::SFLDefaultCostModel::DeactivateEnd ( int num_deps)
inlinenoexcept

Definition at line 527 of file cluster_linearize.h.

◆ GetCost()

uint64_t cluster_linearize::SFLDefaultCostModel::GetCost ( ) const
inlinenoexcept

Definition at line 543 of file cluster_linearize.h.

◆ GetLinearizationBegin()

void cluster_linearize::SFLDefaultCostModel::GetLinearizationBegin ( )
inlinenoexcept

Definition at line 509 of file cluster_linearize.h.

◆ GetLinearizationEnd()

void cluster_linearize::SFLDefaultCostModel::GetLinearizationEnd ( int num_txns,
int num_deps )
inlinenoexcept

Definition at line 510 of file cluster_linearize.h.

◆ InitializeBegin()

void cluster_linearize::SFLDefaultCostModel::InitializeBegin ( )
inlinenoexcept

Definition at line 501 of file cluster_linearize.h.

◆ InitializeEnd()

void cluster_linearize::SFLDefaultCostModel::InitializeEnd ( int num_txns,
int num_deps )
inlinenoexcept

Definition at line 502 of file cluster_linearize.h.

◆ MakeTopologicalBegin()

void cluster_linearize::SFLDefaultCostModel::MakeTopologicalBegin ( )
inlinenoexcept

Definition at line 517 of file cluster_linearize.h.

◆ MakeTopologicalEnd()

void cluster_linearize::SFLDefaultCostModel::MakeTopologicalEnd ( int num_chunks,
int num_steps )
inlinenoexcept

Definition at line 518 of file cluster_linearize.h.

◆ MergeChunksBegin()

void cluster_linearize::SFLDefaultCostModel::MergeChunksBegin ( )
inlinenoexcept

Definition at line 528 of file cluster_linearize.h.

◆ MergeChunksEnd()

void cluster_linearize::SFLDefaultCostModel::MergeChunksEnd ( int num_steps)
inlinenoexcept

Definition at line 530 of file cluster_linearize.h.

◆ MergeChunksMid()

void cluster_linearize::SFLDefaultCostModel::MergeChunksMid ( int num_txns)
inlinenoexcept

Definition at line 529 of file cluster_linearize.h.

◆ MinimizeStepBegin()

void cluster_linearize::SFLDefaultCostModel::MinimizeStepBegin ( )
inlinenoexcept

Definition at line 539 of file cluster_linearize.h.

◆ MinimizeStepEnd()

void cluster_linearize::SFLDefaultCostModel::MinimizeStepEnd ( bool split)
inlinenoexcept

Definition at line 541 of file cluster_linearize.h.

◆ MinimizeStepMid()

void cluster_linearize::SFLDefaultCostModel::MinimizeStepMid ( int num_txns)
inlinenoexcept

Definition at line 540 of file cluster_linearize.h.

◆ PickChunkToOptimizeBegin()

void cluster_linearize::SFLDefaultCostModel::PickChunkToOptimizeBegin ( )
inlinenoexcept

Definition at line 533 of file cluster_linearize.h.

◆ PickChunkToOptimizeEnd()

void cluster_linearize::SFLDefaultCostModel::PickChunkToOptimizeEnd ( int num_steps)
inlinenoexcept

Definition at line 534 of file cluster_linearize.h.

◆ PickDependencyToSplitBegin()

void cluster_linearize::SFLDefaultCostModel::PickDependencyToSplitBegin ( )
inlinenoexcept

Definition at line 535 of file cluster_linearize.h.

◆ PickDependencyToSplitEnd()

void cluster_linearize::SFLDefaultCostModel::PickDependencyToSplitEnd ( int num_txns)
inlinenoexcept

Definition at line 536 of file cluster_linearize.h.

◆ PickMergeCandidateBegin()

void cluster_linearize::SFLDefaultCostModel::PickMergeCandidateBegin ( )
inlinenoexcept

Definition at line 531 of file cluster_linearize.h.

◆ PickMergeCandidateEnd()

void cluster_linearize::SFLDefaultCostModel::PickMergeCandidateEnd ( int num_steps)
inlinenoexcept

Definition at line 532 of file cluster_linearize.h.

◆ StartMinimizingBegin()

void cluster_linearize::SFLDefaultCostModel::StartMinimizingBegin ( )
inlinenoexcept

Definition at line 537 of file cluster_linearize.h.

◆ StartMinimizingEnd()

void cluster_linearize::SFLDefaultCostModel::StartMinimizingEnd ( int num_chunks)
inlinenoexcept

Definition at line 538 of file cluster_linearize.h.

◆ StartOptimizingBegin()

void cluster_linearize::SFLDefaultCostModel::StartOptimizingBegin ( )
inlinenoexcept

Definition at line 522 of file cluster_linearize.h.

◆ StartOptimizingEnd()

void cluster_linearize::SFLDefaultCostModel::StartOptimizingEnd ( int num_chunks)
inlinenoexcept

Definition at line 523 of file cluster_linearize.h.

Member Data Documentation

◆ m_cost

uint64_t cluster_linearize::SFLDefaultCostModel::m_cost {0}
private

Definition at line 498 of file cluster_linearize.h.

The documentation for this class was generated from the following file:
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