bb::avm2::tracegen::FieldGreaterThanTraceBuilder Class Reference

#include <field_gt_trace.hpp>

Public Member Functions
void	process (const simulation::EventEmitterInterface< simulation::FieldGreaterThanEvent >::Container &events, TraceContainer &trace)
	Processes FieldGreaterThanEvent events and generates trace rows for the ff_gt gadget.

Static Public Attributes
static const InteractionDefinition	interactions

Detailed Description

Definition at line 11 of file field_gt_trace.hpp.

Member Function Documentation

process()

void bb::avm2::tracegen::FieldGreaterThanTraceBuilder::process	(	const simulation::EventEmitterInterface< simulation::FieldGreaterThanEvent >::Container &	events,
		TraceContainer &	trace
	)

Processes FieldGreaterThanEvent events and generates trace rows for the ff_gt gadget.

This function handles two flavors of FieldGreaterThanEvent:

1. GT Operation (operation == GREATER_THAN):
   • Generates 5 rows total (1 initial + 4 shift rows)
   • First row: Sets sel_gt=1, populates all fields (a, b, result, decompositions, witnesses)
   • Rows 2-5: Shift rows with sel_shift_rng=1, performing pairwise range checks via shifting
   • All event fields are populated (a_limbs, b_limbs, p_sub_a_witness, p_sub_b_witness, res_witness)
   • cmp_rng_ctr initialized to 4 and decrements to 0
2. Canonical Decomposition (operation == CANONICAL_DECOMPOSITION):
   • Generates 2 rows total (1 initial + 1 shift row)
   • First row: Sets sel_dec=1, populates a-related fields (a, a_limbs, p_sub_a_witness)
   • Row 2: Shift row with sel_shift_rng=1, performs remaining range checks
   • Only a-related fields are meaningful; b-related and result fields have default values
   • cmp_rng_ctr initialized to 1 and decrements to 0

The shifting mechanism ensures all 128-bit limbs are range-checked:

• Each row performs 2 x 128-bit range checks on a_lo and a_hi columns
• Values shift left across columns: p_sub_a → a, b → p_sub_a, p_sub_b → b, res → p_sub_b
• After all shifts, all 10 limbs (GT) or 4 limbs (decomp) have been range-checked

Parameters

events	Container of FieldGreaterThanEvent to process.
trace	The trace container to populate with generated rows.

Note

Row indices start at 1 (row 0 is always empty when there are shifts).

The sel column is set to 1 for all rows in a gadget block (initial + shift rows).

Selectors sel_gt and sel_dec are only set on the first row of each gadget invocation.

Definition at line 44 of file field_gt_trace.cpp.

Member Data Documentation

interactions

const InteractionDefinition bb::avm2::tracegen::FieldGreaterThanTraceBuilder::interactions

static

Initial value:

=
    InteractionDefinition()
        .add<lookup_ff_gt_a_lo_range_settings, InteractionType::LookupGeneric>()
        .add<lookup_ff_gt_a_hi_range_settings, InteractionType::LookupGeneric>()

Definition at line 16 of file field_gt_trace.hpp.

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

• src/barretenberg/vm2/tracegen/field_gt_trace.hpp
• src/barretenberg/vm2/tracegen/field_gt_trace.cpp