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Changed the random number generator in packer to deterministic vtr::irand #2871

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Merged
merged 4 commits into from
Jan 28, 2025
Merged

Changed the random number generator in packer to deterministic vtr::irand #2871

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53cd616
Changed the random number generator in packer to deterministic vtr::i…
haydar-c Jan 24, 2025
bf028ef
Revert "Changed the random number generator in packer to deterministi…
haydar-c Jan 24, 2025
71a4c20
Changed the rng initialization to be in GreedyCandidateSelector based…
haydar-c Jan 26, 2025
313753c
Made commenting in the header more general based on review.
haydar-c Jan 28, 2025
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19 changes: 8 additions & 11 deletions vpr/src/pack/greedy_candidate_selector.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -17,6 +17,7 @@
#include "vpr_context.h"
#include "vpr_types.h"
#include "vtr_assert.h"
#include "vtr_random.h"

/*
* @brief Get gain of packing molecule into current cluster.
Expand Down Expand Up @@ -518,7 +519,8 @@ t_pack_molecule* GreedyCandidateSelector::get_next_candidate_for_cluster(
LegalizationClusterId cluster_id,
const ClusterLegalizer& cluster_legalizer,
const Prepacker& prepacker,
AttractionInfo& attraction_groups) {
AttractionInfo& attraction_groups,
vtr::RngContainer& rng) {
/* Finds the block with the greatest gain that satisfies the
* input, clock and capacity constraints of a cluster that are
* passed in. If no suitable block is found it returns nullptr.
Expand Down Expand Up @@ -597,7 +599,8 @@ t_pack_molecule* GreedyCandidateSelector::get_next_candidate_for_cluster(
cluster_id,
prepacker,
cluster_legalizer,
attraction_groups);
attraction_groups,
rng);
}
/* Grab highest gain molecule */
// If this was a vector, this would just be a pop_back.
Expand Down Expand Up @@ -726,7 +729,8 @@ void GreedyCandidateSelector::add_cluster_molecule_candidates_by_attraction_grou
LegalizationClusterId legalization_cluster_id,
const Prepacker& prepacker,
const ClusterLegalizer& cluster_legalizer,
AttractionInfo& attraction_groups) {
AttractionInfo& attraction_groups,
vtr::RngContainer& rng) {
auto cluster_type = cluster_legalizer.get_cluster_type(legalization_cluster_id);

/*
Expand Down Expand Up @@ -779,17 +783,10 @@ void GreedyCandidateSelector::add_cluster_molecule_candidates_by_attraction_grou
return;
}

int min = 0;
int max = num_available_atoms - 1;

for (int j = 0; j < attraction_group_num_atoms_threshold_; j++) {
// FIXME: This is a non-deterministic random number generator and it is
// overkill to what this needs to be. Should use vtr::irand which
// would be faster.
std::random_device rd;
std::mt19937 gen(rd());
std::uniform_int_distribution<> distr(min, max);
int selected_atom = distr(gen);
int selected_atom = rng.irand(max);

AtomBlockId blk_id = available_atoms[selected_atom];

Expand Down
7 changes: 5 additions & 2 deletions vpr/src/pack/greedy_candidate_selector.h
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Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,7 @@
#include "cluster_legalizer.h"
#include "physical_types.h"
#include "vtr_vector.h"
#include "vtr_random.h"

// Forward declarations
class AtomNetlist;
Expand Down Expand Up @@ -301,7 +302,8 @@ class GreedyCandidateSelector {
LegalizationClusterId cluster_id,
const ClusterLegalizer& cluster_legalizer,
const Prepacker& prepacker,
AttractionInfo& attraction_groups);
AttractionInfo& attraction_groups,
vtr::RngContainer& rng);

/**
* @brief Finalize the creation of a cluster.
Expand Down Expand Up @@ -454,7 +456,8 @@ class GreedyCandidateSelector {
LegalizationClusterId legalization_cluster_id,
const Prepacker& prepacker,
const ClusterLegalizer& cluster_legalizer,
AttractionInfo& attraction_groups);
AttractionInfo& attraction_groups,
vtr::RngContainer& rng);

/**
* @brief Finds a molecule to propose which is unrelated but may be good to
Expand Down
18 changes: 13 additions & 5 deletions vpr/src/pack/greedy_clusterer.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -55,6 +55,7 @@
#include "vpr_context.h"
#include "vtr_math.h"
#include "vtr_vector.h"
#include "vtr_random.h"

namespace {

Expand Down Expand Up @@ -160,6 +161,8 @@ GreedyClusterer::do_clustering(ClusterLegalizer& cluster_legalizer,

print_pack_status_header();

vtr::RngContainer rng(0);
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I guess that the only user of this RngContainer object is GreedyCandidateSelector. If this is the case, I think it makes more sense to add it as a member variable to GreedyCandidateSelector and initilize it in its constructor instead of passing it down a deep function call hierarchy.

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I agree! That would make things much cleaner! Especially since it is an independent object!


// Continue clustering as long as a valid seed is returned from the seed
// selector.
while (seed_mol != nullptr) {
Expand All @@ -183,7 +186,8 @@ GreedyClusterer::do_clustering(ClusterLegalizer& cluster_legalizer,
balance_block_type_utilization,
attraction_groups,
num_used_type_instances,
mutable_device_ctx);
mutable_device_ctx,
rng);

if (!new_cluster_id.is_valid()) {
// If the previous strategy failed, try to grow the cluster again,
Expand All @@ -197,7 +201,8 @@ GreedyClusterer::do_clustering(ClusterLegalizer& cluster_legalizer,
balance_block_type_utilization,
attraction_groups,
num_used_type_instances,
mutable_device_ctx);
mutable_device_ctx,
rng);
}

// Ensure that the seed was packed successfully.
Expand Down Expand Up @@ -239,7 +244,8 @@ LegalizationClusterId GreedyClusterer::try_grow_cluster(
bool balance_block_type_utilization,
AttractionInfo& attraction_groups,
std::map<t_logical_block_type_ptr, size_t>& num_used_type_instances,
DeviceContext& mutable_device_ctx) {
DeviceContext& mutable_device_ctx,
vtr::RngContainer& rng) {

// Check to ensure that this molecule is unclustered.
VTR_ASSERT(!cluster_legalizer.is_mol_clustered(seed_mol));
Expand Down Expand Up @@ -267,7 +273,8 @@ LegalizationClusterId GreedyClusterer::try_grow_cluster(
legalization_cluster_id,
cluster_legalizer,
prepacker,
attraction_groups);
attraction_groups,
rng);

/*
* When attraction groups are created, the purpose is to pack more densely by adding more molecules
Expand Down Expand Up @@ -316,7 +323,8 @@ LegalizationClusterId GreedyClusterer::try_grow_cluster(
legalization_cluster_id,
cluster_legalizer,
prepacker,
attraction_groups);
attraction_groups,
rng);

// If the next candidate molecule is the same as the previous
// candidate molecule, increment the number of repeated
Expand Down
4 changes: 3 additions & 1 deletion vpr/src/pack/greedy_clusterer.h
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Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@
#include <vector>
#include "cluster_legalizer.h"
#include "physical_types.h"
#include "vtr_random.h"

// Forward declarations
class AtomNetId;
Expand Down Expand Up @@ -156,7 +157,8 @@ class GreedyClusterer {
bool balance_block_type_utilization,
AttractionInfo& attraction_groups,
std::map<t_logical_block_type_ptr, size_t>& num_used_type_instances,
DeviceContext& mutable_device_ctx);
DeviceContext& mutable_device_ctx,
vtr::RngContainer& rng);

/**
* @brief Given a seed molecule, starts a new cluster by trying to find a
Expand Down
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