24408765437

Committed 14 Apr 2026 03:47PM UTC coverage: 64.417% (-0.05%) from 64.469%

Build # 24408765437

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github

Committed by

web-flow

Commit Message

Add support for DDE to remove mallocs and frees as dead-code when DataOffloadingNodes operate on them (#678)

 + generic modeling for libNodes to declare that an input pointer does not actually escape through them
 + draft of generic modeling of input-pointer access ranges and access types (read-only, full overwrite etc.)
 + DDE: Offload-Transfer-specific handling to reinterpret their fake output edges instead as only indirect writes vie the target pointer
 + DDE: option to disable all the legacy code that requires full UserAnalysis and DataDependencyAnalysis.
 * the new malloc/heap removal in DDE can now remove containers by itself, not relying on DataDependencyAnalysis for that
 * improved builder.clear_node, node can report how to deal with a dead edge, including calling an update method on the node to make it validate again after edge removal.
 + Used for OffloadTransfer nodes to support removing the output edge via dead-code and drop the transfer and maybe the entire node if it does nothing anymore.
 * Offloading: option to quickly disable omitting d2h for read-only data

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92 of 162 new or added lines in 11 files covered. (56.79%)

4 existing lines in 3 files now uncovered.

30598 of 47500 relevant lines covered (64.42%)

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37.04

/sdfg/src/offloading/data_offloading_node.cpp

#include "sdfg/targets/offloading/data_offloading_node.h"

#include <cstddef>
#include <string>
#include <vector>

#include "sdfg/data_flow/data_flow_graph.h"
#include "sdfg/data_flow/library_node.h"
#include "sdfg/element.h"
#include "sdfg/exceptions.h"
#include "sdfg/graph/graph.h"
#include "sdfg/symbolic/symbolic.h"

namespace sdfg {
namespace offloading {

constexpr bool dump_offload_node_ids = false;

DataOffloadingNode::DataOffloadingNode(
    size_t element_id,
    const DebugInfo& debug_info,
    const graph::Vertex vertex,
    data_flow::DataFlowGraph& parent,
    const data_flow::LibraryNodeCode code,
    const std::vector<std::string>& outputs,
    const std::vector<std::string>& inputs,
    DataTransferDirection transfer_direction,
    BufferLifecycle buffer_lifecycle,
    symbolic::Expression size
)
    : data_flow::LibraryNode(
          element_id, debug_info, vertex, parent, code, outputs, inputs, true, data_flow::ImplementationType_NONE
      ),
      transfer_direction_(transfer_direction), buffer_lifecycle_(buffer_lifecycle), size_(std::move(size)) {}

DataTransferDirection DataOffloadingNode::transfer_direction() const { return this->transfer_direction_; }

BufferLifecycle DataOffloadingNode::buffer_lifecycle() const { return this->buffer_lifecycle_; }

const symbolic::Expression DataOffloadingNode::size() const { return this->size_; }

const symbolic::Expression DataOffloadingNode::alloc_size() const { return this->size(); }

symbolic::SymbolSet DataOffloadingNode::symbols() const {
    if (this->size().is_null()) {
        return {};
    } else {
        return symbolic::atoms(this->size());
    }
}

void DataOffloadingNode::replace(const symbolic::Expression old_expression, const symbolic::Expression new_expression) {
    if (!this->size_.is_null()) {
        this->size_ = symbolic::subs(this->size_, old_expression, new_expression);
    }
}

std::string DataOffloadingNode::toStr() const {
    std::string direction, lifecycle;
    switch (this->transfer_direction()) {
        case DataTransferDirection::D2H:
            direction = " D2H";
            break;
        case DataTransferDirection::H2D:
            direction = " H2D";
            break;
        default:
            direction = " NONE";
            break;
    }
    switch (this->buffer_lifecycle()) {
        case BufferLifecycle::FREE:
            lifecycle = " FREE";
            break;
        case BufferLifecycle::ALLOC:
            lifecycle = " ALLOC";
            break;
        default:
            lifecycle = " NO_CHANGE";
            break;
    }
    std::string res = std::string(this->code_.value());
    if (dump_offload_node_ids) {
        res += " #" + std::to_string(element_id_);
    }
    res += direction + lifecycle;
    return res;
}

symbolic::Expression DataOffloadingNode::flop() const { return symbolic::zero(); }

bool DataOffloadingNode::redundant_with(const DataOffloadingNode& other) const {
    if (code() != other.code()) {
        return false;
    }
    if ((static_cast<int8_t>(transfer_direction()) + static_cast<int8_t>(other.transfer_direction())) != 0) {
        return false; // not the inverse
    }
    if ((static_cast<int8_t>(buffer_lifecycle()) + static_cast<int8_t>(other.buffer_lifecycle())) != 0) {
        return false;
    }

    if (!symbolic::null_safe_eq(size(), other.size())) {
        return false;
    }

    return true; // add more checks in sub-classes
}

bool DataOffloadingNode::equal_with(const DataOffloadingNode& other) const {
    if (code() != other.code()) {
        return false;
    }
    if (this->transfer_direction() != other.transfer_direction()) {
        return false;
    }
    if (this->buffer_lifecycle() != other.buffer_lifecycle()) {
        return false;
    }

    if (!symbolic::null_safe_eq(size(), other.size())) {
        return false;
    }

    return true; // add more checks in sub-classes
}

bool DataOffloadingNode::is_d2h() const { return is_D2H(this->transfer_direction()); }

bool DataOffloadingNode::is_h2d() const { return is_H2D(this->transfer_direction()); }

bool DataOffloadingNode::has_transfer() const { return this->is_d2h() || this->is_h2d(); }

bool DataOffloadingNode::is_free() const { return is_FREE(this->buffer_lifecycle()); }

bool DataOffloadingNode::is_alloc() const { return is_ALLOC(this->buffer_lifecycle()); }

void DataOffloadingNode::remove_h2d() {
    if (this->is_h2d()) {
        if (!this->is_alloc()) {
            throw InvalidSDFGException("DataOffloadingNode: Tried removing h2d but node has no other purpose");
        }
        this->transfer_direction_ = DataTransferDirection::NONE;
        this->inputs_.erase(this->inputs_.begin()); // Standard nodes only have one, others need to override
    }
}

data_flow::PointerAccessType DataOffloadingNode::pointer_access_type(int input_idx) const {
    if (is_h2d() && input_idx == 0) {
        return data_flow::PointerReadOnly(size_, true);
    } else {
        return LibraryNode::pointer_access_type(input_idx);
    }
}

void DataOffloadingNode::remove_free() {
    if (this->is_free()) {
        if (!this->has_transfer()) {
            throw InvalidSDFGException("DataOffloadingNode: Tried removing free but no data transfer direction present"
            );
        }
        this->buffer_lifecycle_ = BufferLifecycle::NO_CHANGE;
    }
}

data_flow::EdgeRemoveOption DataOffloadingNode::
    can_remove_out_edge(const data_flow::DataFlowGraph& graph, const data_flow::Memlet* memlet) const {
    if (graph.out_edges_for_connector(*this, memlet->src_conn()).size() > 1) {
        return data_flow::EdgeRemoveOption::Trivially;
    } else if (transfer_direction_ != DataTransferDirection::NONE && outputs_.size() == 1 &&
               memlet->src_conn() == outputs_.at(0)) {
        // the node represents a transfer, whose output is dead.
        if (buffer_lifecycle_ != BufferLifecycle::NO_CHANGE) {
            // the node still has remaining purpose without the transfer
            return data_flow::EdgeRemoveOption::RequiresUpdate;
        } else {
            // the node in its entirety is dead if it the transfer is not needed
            return data_flow::EdgeRemoveOption::RemoveNodeAfter;
        }
    } else {
        return data_flow::EdgeRemoveOption::NotRemovable;
    }
}

bool DataOffloadingNode::update_edge_removed(const std::string& out_conn) {
    if (transfer_direction_ != DataTransferDirection::NONE && outputs_.size() == 1 && out_conn == outputs_.at(0)) {
        transfer_direction_ = DataTransferDirection::NONE;
        outputs_.erase(outputs_.begin());
        return true;
    } else {
        return false;
    }
}

} // namespace offloading
} // namespace sdfg

1	#include "sdfg/targets/offloading/data_offloading_node.h"
2
3	#include <cstddef>
4	#include <string>
5	#include <vector>
6
7	#include "sdfg/data_flow/data_flow_graph.h"
8	#include "sdfg/data_flow/library_node.h"
9	#include "sdfg/element.h"
10	#include "sdfg/exceptions.h"
11	#include "sdfg/graph/graph.h"
12	#include "sdfg/symbolic/symbolic.h"
13
14	namespace sdfg {
15	namespace offloading {
16
17	constexpr bool dump_offload_node_ids = false;
18
19	DataOffloadingNode::DataOffloadingNode(
20	size_t element_id,
21	const DebugInfo& debug_info,
22	const graph::Vertex vertex,
23	data_flow::DataFlowGraph& parent,
24	const data_flow::LibraryNodeCode code,
25	const std::vector<std::string>& outputs,
26	const std::vector<std::string>& inputs,
27	DataTransferDirection transfer_direction,
28	BufferLifecycle buffer_lifecycle,
29	symbolic::Expression size
30	)
31	: data_flow::LibraryNode(	85✔
32	element_id, debug_info, vertex, parent, code, outputs, inputs, true, data_flow::ImplementationType_NONE	85✔
33	),	85✔
34	transfer_direction_(transfer_direction), buffer_lifecycle_(buffer_lifecycle), size_(std::move(size)) {}	85✔
35
36	DataTransferDirection DataOffloadingNode::transfer_direction() const { return this->transfer_direction_; }	215✔
37
38	BufferLifecycle DataOffloadingNode::buffer_lifecycle() const { return this->buffer_lifecycle_; }	96✔
39
40	const symbolic::Expression DataOffloadingNode::size() const { return this->size_; }	109✔
41
42	const symbolic::Expression DataOffloadingNode::alloc_size() const { return this->size(); }	×
43
44	symbolic::SymbolSet DataOffloadingNode::symbols() const {	32✔
45	if (this->size().is_null()) {	32✔
46	return {};	×
47	} else {	32✔
48	return symbolic::atoms(this->size());	32✔
49	}	32✔
50	}	32✔
51
52	void DataOffloadingNode::replace(const symbolic::Expression old_expression, const symbolic::Expression new_expression) {	15✔
53	if (!this->size_.is_null()) {	15✔
54	this->size_ = symbolic::subs(this->size_, old_expression, new_expression);	15✔
55	}	15✔
56	}	15✔
57
58	std::string DataOffloadingNode::toStr() const {	×
59	std::string direction, lifecycle;	×
60	switch (this->transfer_direction()) {	×
61	case DataTransferDirection::D2H:	×
62	direction = " D2H";	×
63	break;	×
64	case DataTransferDirection::H2D:	×
65	direction = " H2D";	×
66	break;	×
67	default:	×
68	direction = " NONE";	×
69	break;	×
70	}	×
71	switch (this->buffer_lifecycle()) {	×
72	case BufferLifecycle::FREE:	×
73	lifecycle = " FREE";	×
74	break;	×
75	case BufferLifecycle::ALLOC:	×
76	lifecycle = " ALLOC";	×
77	break;	×
78	default:	×
79	lifecycle = " NO_CHANGE";	×
80	break;	×
81	}	×
82	std::string res = std::string(this->code_.value());	×
83	if (dump_offload_node_ids) {	×
84	res += " #" + std::to_string(element_id_);	×
85	}	×
86	res += direction + lifecycle;	×
87	return res;	×
88	}	×
89
90	symbolic::Expression DataOffloadingNode::flop() const { return symbolic::zero(); }	×
91
92	bool DataOffloadingNode::redundant_with(const DataOffloadingNode& other) const {	2✔
93	if (code() != other.code()) {	2✔
94	return false;	×
95	}	×
96	if ((static_cast<int8_t>(transfer_direction()) + static_cast<int8_t>(other.transfer_direction())) != 0) {	2✔
97	return false; // not the inverse	×
98	}	×
99	if ((static_cast<int8_t>(buffer_lifecycle()) + static_cast<int8_t>(other.buffer_lifecycle())) != 0) {	2✔
100	return false;	×
101	}	×
102
103	if (!symbolic::null_safe_eq(size(), other.size())) {	2✔
104	return false;	×
105	}	×
106
107	return true; // add more checks in sub-classes	2✔
108	}	2✔
109
110	bool DataOffloadingNode::equal_with(const DataOffloadingNode& other) const {	8✔
111	if (code() != other.code()) {	8✔
112	return false;	×
113	}	×
114	if (this->transfer_direction() != other.transfer_direction()) {	8✔
115	return false;	×
116	}	×
117	if (this->buffer_lifecycle() != other.buffer_lifecycle()) {	8✔
118	return false;	×
119	}	×
120
121	if (!symbolic::null_safe_eq(size(), other.size())) {	8✔
122	return false;	×
123	}	×
124
125	return true; // add more checks in sub-classes	8✔
126	}	8✔
127
128	bool DataOffloadingNode::is_d2h() const { return is_D2H(this->transfer_direction()); }	94✔
129
130	bool DataOffloadingNode::is_h2d() const { return is_H2D(this->transfer_direction()); }	83✔
131
132	bool DataOffloadingNode::has_transfer() const { return this->is_d2h() \|\| this->is_h2d(); }	13✔
133
134	bool DataOffloadingNode::is_free() const { return is_FREE(this->buffer_lifecycle()); }	32✔
135
136	bool DataOffloadingNode::is_alloc() const { return is_ALLOC(this->buffer_lifecycle()); }	36✔
137
138	void DataOffloadingNode::remove_h2d() {	1✔
139	if (this->is_h2d()) {	1✔
140	if (!this->is_alloc()) {	1✔
141	throw InvalidSDFGException("DataOffloadingNode: Tried removing h2d but node has no other purpose");	×
142	}	×
143	this->transfer_direction_ = DataTransferDirection::NONE;	1✔
144	this->inputs_.erase(this->inputs_.begin()); // Standard nodes only have one, others need to override	1✔
145	}	1✔
146	}	1✔
147
NEW 148	data_flow::PointerAccessType DataOffloadingNode::pointer_access_type(int input_idx) const {	×
NEW 149	if (is_h2d() && input_idx == 0) {	×
NEW 150	return data_flow::PointerReadOnly(size_, true);	×
NEW 151	} else {	×
NEW 152	return LibraryNode::pointer_access_type(input_idx);	×
NEW 153	}	×
NEW 154	}	×
155
156	void DataOffloadingNode::remove_free() {	1✔
157	if (this->is_free()) {	1✔
158	if (!this->has_transfer()) {	1✔
159	throw InvalidSDFGException("DataOffloadingNode: Tried removing free but no data transfer direction present"	×
160	);	×
161	}	×
162	this->buffer_lifecycle_ = BufferLifecycle::NO_CHANGE;	1✔
163	}	1✔
164	}	1✔
165
166	data_flow::EdgeRemoveOption DataOffloadingNode::
NEW 167	can_remove_out_edge(const data_flow::DataFlowGraph& graph, const data_flow::Memlet* memlet) const {	×
NEW 168	if (graph.out_edges_for_connector(*this, memlet->src_conn()).size() > 1) {	×
NEW 169	return data_flow::EdgeRemoveOption::Trivially;	×
NEW 170	} else if (transfer_direction_ != DataTransferDirection::NONE && outputs_.size() == 1 &&	×
NEW 171	memlet->src_conn() == outputs_.at(0)) {	×
172	// the node represents a transfer, whose output is dead.
NEW 173	if (buffer_lifecycle_ != BufferLifecycle::NO_CHANGE) {	×
174	// the node still has remaining purpose without the transfer
NEW 175	return data_flow::EdgeRemoveOption::RequiresUpdate;	×
NEW 176	} else {	×
177	// the node in its entirety is dead if it the transfer is not needed
NEW 178	return data_flow::EdgeRemoveOption::RemoveNodeAfter;	×
NEW 179	}	×
NEW 180	} else {	×
NEW 181	return data_flow::EdgeRemoveOption::NotRemovable;	×
NEW 182	}	×
NEW 183	}	×
184
NEW 185	bool DataOffloadingNode::update_edge_removed(const std::string& out_conn) {	×
NEW 186	if (transfer_direction_ != DataTransferDirection::NONE && outputs_.size() == 1 && out_conn == outputs_.at(0)) {	×
NEW 187	transfer_direction_ = DataTransferDirection::NONE;	×
NEW 188	outputs_.erase(outputs_.begin());	×
NEW 189	return true;	×
NEW 190	} else {	×
NEW 191	return false;	×
NEW 192	}	×
NEW 193	}	×
194
195	} // namespace offloading
196	} // namespace sdfg

daisytuner / docc / 24408765437

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