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Merged
IlyasRidhuan merged 1 commit into from
Aug 29, 2025
Merged

fix(avm)!: handle zero copy size #16567

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32 changes: 20 additions & 12 deletions barretenberg/cpp/pil/vm2/data_copy.pil
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Original file line number Diff line number Diff line change
Expand Up @@ -118,9 +118,6 @@ namespace data_copy;
pol commit sel_rd_copy;
sel_rd_copy * (1 - sel_rd_copy) = 0;

// Two varieties depending of if we gate by error
pol SEL_NO_ERR = SEL * (1 - err);

pol commit clk;

// Things are range checked to 32 bits
Expand Down Expand Up @@ -226,11 +223,21 @@ namespace data_copy;
#[START_AFTER_END]
(sel_cd_copy' + sel_rd_copy') * sel_end * (sel_start' - 1) = 0;

pol commit sel_write_count_is_zero;
pol commit write_count_zero_inv; // Could optimise by using the existing write_count_minus_on_inv
// sel_write_count_is_zero = 1 IFF copy_size = 0 && sel_start = 1 (and there are no errors)
#[ZERO_SIZED_WRITE]
sel_start_no_err * (copy_size * (sel_write_count_is_zero * (1 - write_count_zero_inv) + write_count_zero_inv) - 1 + sel_write_count_is_zero) = 0;
#[END_IF_WRITE_IS_ZERO]
sel_start_no_err * sel_write_count_is_zero * (sel_end - 1) = 0;

pol SEL_PERFORM_COPY = SEL * (1 - err) * (1 - sel_write_count_is_zero);

pol WRITE_COUNT_MINUS_ONE = copy_size - 1;
pol commit write_count_minus_one_inv;
// sel_end = 1 IFF copy_size - 1 = 0;
#[END_WRITE_CONDITION]
SEL_NO_ERR * (WRITE_COUNT_MINUS_ONE * (sel_end * (1 - write_count_minus_one_inv) + write_count_minus_one_inv) - 1 + sel_end) = 0;
SEL_PERFORM_COPY * (WRITE_COUNT_MINUS_ONE * (sel_end * (1 - write_count_minus_one_inv) + write_count_minus_one_inv) - 1 + sel_end) = 0;

#[END_ON_ERR] // sel_end = 1 if error
err * (sel_end - 1) = 0;
Expand All @@ -248,15 +255,15 @@ namespace data_copy;
// If sel_offset_gt_max_read = 1 (i.e. when offset > MAX_READ_INDEX, reads_left = 0)
// otherwise, reads_left = MAX_READ_INDEX - offset
#[INIT_READS_LEFT]
sel_start_no_err * ( reads_left - (max_read_index - offset) * (1 - offset_gt_max_read_index)) = 0;
sel_start_no_err * (1 - sel_write_count_is_zero) * (reads_left - (max_read_index - offset) * (1 - offset_gt_max_read_index)) = 0;

//////////////////////////////
// Execute Data Copy
//////////////////////////////
// Most of these relations are either gated explicitly by an err or by sel_end (which is 1 when err = 1)
// ===== Writing to dst_context_id =====
pol commit sel_mem_write;
sel_mem_write = SEL_NO_ERR; // We write if there is no error
sel_mem_write = SEL_PERFORM_COPY; // We write if there is no error and copy_size != 0
// Data copy size decrements for each row until we end
#[DECR_COPY_SIZE]
SEL * (1 - sel_end) * (copy_size' - copy_size + 1) = 0;
Expand All @@ -271,8 +278,8 @@ namespace data_copy;

// ===== Reading for nested call =====
pol commit read_addr; // The addr to start reading the data from: src_addr + offset;
#[INIT_READ_ADDR]
SEL * sel_start_no_err * (read_addr - src_addr - offset) = 0;
#[INIT_READ_ADDR] // Only occurs at the start if we have not errored
sel_start_no_err * (1 - sel_write_count_is_zero) * (read_addr - src_addr - offset) = 0;
// Subsequent read addrs are incremented by 1 unless this is a padding row
#[INCR_READ_ADDR]
SEL * (1 - padding) * (1 - sel_end) * (read_addr' - read_addr - 1) = 0;
Expand All @@ -283,16 +290,16 @@ namespace data_copy;
pol commit padding; // Padding = 1 if reads_left = 0
pol commit reads_left_inv;
#[PADDING_CONDITION]
SEL_NO_ERR * (reads_left * (padding * (1 - reads_left_inv) + reads_left_inv) - 1 + padding) = 0;
SEL_PERFORM_COPY * (reads_left * (padding * (1 - reads_left_inv) + reads_left_inv) - 1 + padding) = 0;

// Read from memory if we are not the top level call and not a padding row
pol commit sel_mem_read; // If the current row is a memory op read
sel_mem_read = SEL_NO_ERR * (1 - is_top_level) * (1 - padding);
sel_mem_read = SEL_PERFORM_COPY * (1 - is_top_level) * (1 - padding);

// === Value Padding ===
pol commit value;
#[PAD_VALUE]
SEL_NO_ERR * padding * value = 0;
SEL_PERFORM_COPY * padding * value = 0;

#[MEM_READ]
sel_mem_read { clk, read_addr, value, /*mem_tag=*/precomputed.zero/*FF*/, /*rw=*/precomputed.zero/*(read)*/, src_context_id }
Expand All @@ -305,7 +312,7 @@ namespace data_copy;
// After calldata hashing
pol commit cd_copy_col_read;
#[CD_COPY_COLUMN]
cd_copy_col_read = SEL_NO_ERR * (1 - padding) * is_top_level * sel_cd_copy;
cd_copy_col_read = SEL_PERFORM_COPY * (1 - padding) * is_top_level * sel_cd_copy;

#[COL_READ]
cd_copy_col_read { value, dst_context_id, read_addr }
Expand Down Expand Up @@ -357,3 +364,4 @@ namespace data_copy;
src_addr, src_data_size,
sel_rd_copy, err
};

82 changes: 82 additions & 0 deletions barretenberg/cpp/src/barretenberg/vm2/constraining/relations/data_copy.test.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -74,6 +74,29 @@ class NestedCdConstrainingBuilderTest : public DataCopyConstrainingBuilderTest {
}
};

TEST_F(NestedCdConstrainingBuilderTest, CdZeroCopy)
{
uint32_t copy_size = 0;
uint32_t cd_offset = 0; // Offset into calldata

EXPECT_CALL(context, get_calldata(cd_offset, copy_size)).WillOnce(::testing::Return(std::vector<FF>{}));

copy_data.cd_copy(context, copy_size, cd_offset, dst_addr);

tracegen::DataCopyTraceBuilder builder;
builder.process(event_emitter.dump_events(), trace);

tracegen::GreaterThanTraceBuilder gt_builder;
gt_builder.process(gt_event_emitter.dump_events(), trace);

check_relation<data_copy>(trace);
check_interaction<DataCopyTraceBuilder,
lookup_data_copy_max_read_index_gt_settings,
lookup_data_copy_offset_gt_max_read_index_settings,
lookup_data_copy_check_src_addr_in_range_settings,
lookup_data_copy_check_dst_addr_in_range_settings>(trace);
}

TEST_F(NestedCdConstrainingBuilderTest, SimpleNestedCdCopy)
{
uint32_t copy_size = static_cast<uint32_t>(data.size());
Expand Down Expand Up @@ -194,6 +217,29 @@ class EnqueuedCdConstrainingBuilderTest : public DataCopyConstrainingBuilderTest
}
};

TEST_F(EnqueuedCdConstrainingBuilderTest, CdZeroCopy)
{
uint32_t copy_size = 0;
uint32_t cd_offset = 0; // Offset into calldata

EXPECT_CALL(context, get_calldata(cd_offset, copy_size)).WillOnce(::testing::Return(std::vector<FF>{}));

copy_data.cd_copy(context, copy_size, cd_offset, dst_addr);

tracegen::DataCopyTraceBuilder builder;
builder.process(event_emitter.dump_events(), trace);

tracegen::GreaterThanTraceBuilder gt_builder;
gt_builder.process(gt_event_emitter.dump_events(), trace);

check_relation<data_copy>(trace);
check_interaction<DataCopyTraceBuilder,
lookup_data_copy_max_read_index_gt_settings,
lookup_data_copy_offset_gt_max_read_index_settings,
lookup_data_copy_check_src_addr_in_range_settings,
lookup_data_copy_check_dst_addr_in_range_settings>(trace);
}

TEST_F(EnqueuedCdConstrainingBuilderTest, SimpleEnqueuedCdCopy)
{
auto copy_size = static_cast<uint32_t>(data.size());
Expand Down Expand Up @@ -343,6 +389,42 @@ TEST(DataCopyWithExecutionPerm, CdCopy)
perm_data_copy_dispatch_rd_copy_settings>(trace);
}

class NestedRdConstrainingBuilderTest : public DataCopyConstrainingBuilderTest {
protected:
NestedRdConstrainingBuilderTest()
{
// Set up parent context
EXPECT_CALL(context, has_parent).WillRepeatedly(Return(true));
EXPECT_CALL(context, get_last_child_id).WillRepeatedly(Return(2));
EXPECT_CALL(context, get_context_id).WillRepeatedly(Return(2));
EXPECT_CALL(context, get_last_rd_size).WillRepeatedly(Return(data.size()));
EXPECT_CALL(context, get_last_rd_addr).WillRepeatedly(Return(0));
}
};

TEST_F(NestedRdConstrainingBuilderTest, RdZeroCopy)
{
uint32_t copy_size = 0;
uint32_t rd_offset = 0; // Offset into calldata

EXPECT_CALL(context, get_returndata(rd_offset, copy_size)).WillOnce(::testing::Return(std::vector<FF>{}));

copy_data.rd_copy(context, copy_size, rd_offset, dst_addr);

tracegen::DataCopyTraceBuilder builder;
builder.process(event_emitter.dump_events(), trace);

tracegen::GreaterThanTraceBuilder gt_builder;
gt_builder.process(gt_event_emitter.dump_events(), trace);

check_relation<data_copy>(trace);
check_interaction<DataCopyTraceBuilder,
lookup_data_copy_max_read_index_gt_settings,
lookup_data_copy_offset_gt_max_read_index_settings,
lookup_data_copy_check_src_addr_in_range_settings,
lookup_data_copy_check_dst_addr_in_range_settings>(trace);
}

TEST(DataCopyWithExecutionPerm, RdCopy)
{
// Current Context
Expand Down
6 changes: 3 additions & 3 deletions barretenberg/cpp/src/barretenberg/vm2/generated/columns.hpp
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4 changes: 2 additions & 2 deletions barretenberg/cpp/src/barretenberg/vm2/generated/flavor_variables.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -133,10 +133,10 @@ namespace bb::avm2 {

struct AvmFlavorVariables {
static constexpr size_t NUM_PRECOMPUTED_ENTITIES = 133;
static constexpr size_t NUM_WITNESS_ENTITIES = 2934;
static constexpr size_t NUM_WITNESS_ENTITIES = 2936;
static constexpr size_t NUM_SHIFTED_ENTITIES = 316;
static constexpr size_t NUM_WIRES = NUM_WITNESS_ENTITIES + NUM_PRECOMPUTED_ENTITIES;
static constexpr size_t NUM_ALL_ENTITIES = 3383;
static constexpr size_t NUM_ALL_ENTITIES = 3385;

// Need to be templated for recursive verifier
template <typename FF_>
Expand Down
54 changes: 30 additions & 24 deletions barretenberg/cpp/src/barretenberg/vm2/generated/relations/data_copy.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -14,9 +14,9 @@ template <typename FF_> class data_copyImpl {
public:
using FF = FF_;

static constexpr std::array<size_t, 33> SUBRELATION_PARTIAL_LENGTHS = { 3, 3, 3, 3, 3, 3, 5, 3, 4, 3, 3,
3, 3, 3, 3, 3, 3, 4, 6, 3, 4, 3,
4, 5, 4, 5, 5, 6, 5, 5, 6, 3, 3 };
static constexpr std::array<size_t, 35> SUBRELATION_PARTIAL_LENGTHS = { 3, 3, 3, 3, 3, 3, 5, 3, 4, 3, 3, 3,
3, 3, 3, 3, 3, 4, 5, 4, 7, 3, 5, 4,
4, 5, 4, 5, 5, 7, 6, 6, 7, 3, 3 };

template <typename AllEntities> inline static bool skip(const AllEntities& in)
{
Expand Down Expand Up @@ -46,26 +46,30 @@ template <typename FF> class data_copy : public Relation<data_copyImpl<FF>> {
case 17:
return "START_AFTER_END";
case 18:
return "END_WRITE_CONDITION";
return "ZERO_SIZED_WRITE";
case 19:
return "END_ON_ERR";
return "END_IF_WRITE_IS_ZERO";
case 20:
return "INIT_READS_LEFT";
return "END_WRITE_CONDITION";
case 21:
return "END_ON_ERR";
case 22:
return "INIT_READS_LEFT";
case 24:
return "DECR_COPY_SIZE";
case 23:
case 25:
return "INCR_WRITE_ADDR";
case 24:
case 26:
return "INIT_READ_ADDR";
case 25:
case 27:
return "INCR_READ_ADDR";
case 26:
case 28:
return "DECR_READ_COUNT";
case 27:
return "PADDING_CONDITION";
case 29:
return "PADDING_CONDITION";
case 31:
return "PAD_VALUE";
case 30:
case 32:
return "CD_COPY_COLUMN";
}
return std::to_string(index);
Expand All @@ -74,17 +78,19 @@ template <typename FF> class data_copy : public Relation<data_copyImpl<FF>> {
// Subrelation indices constants, to be used in tests.
static constexpr size_t SR_TOP_LEVEL_COND = 6;
static constexpr size_t SR_START_AFTER_END = 17;
static constexpr size_t SR_END_WRITE_CONDITION = 18;
static constexpr size_t SR_END_ON_ERR = 19;
static constexpr size_t SR_INIT_READS_LEFT = 20;
static constexpr size_t SR_DECR_COPY_SIZE = 22;
static constexpr size_t SR_INCR_WRITE_ADDR = 23;
static constexpr size_t SR_INIT_READ_ADDR = 24;
static constexpr size_t SR_INCR_READ_ADDR = 25;
static constexpr size_t SR_DECR_READ_COUNT = 26;
static constexpr size_t SR_PADDING_CONDITION = 27;
static constexpr size_t SR_PAD_VALUE = 29;
static constexpr size_t SR_CD_COPY_COLUMN = 30;
static constexpr size_t SR_ZERO_SIZED_WRITE = 18;
static constexpr size_t SR_END_IF_WRITE_IS_ZERO = 19;
static constexpr size_t SR_END_WRITE_CONDITION = 20;
static constexpr size_t SR_END_ON_ERR = 21;
static constexpr size_t SR_INIT_READS_LEFT = 22;
static constexpr size_t SR_DECR_COPY_SIZE = 24;
static constexpr size_t SR_INCR_WRITE_ADDR = 25;
static constexpr size_t SR_INIT_READ_ADDR = 26;
static constexpr size_t SR_INCR_READ_ADDR = 27;
static constexpr size_t SR_DECR_READ_COUNT = 28;
static constexpr size_t SR_PADDING_CONDITION = 29;
static constexpr size_t SR_PAD_VALUE = 31;
static constexpr size_t SR_CD_COPY_COLUMN = 32;
};

} // namespace bb::avm2
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