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rustytorch/crates/training/rtx-compress/tests/post_training_quantization_tests.rs
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2026-03-04 00:08:42 +00:00

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Rust

//! Comprehensive tests for post-training quantization
//!
//! Tests cover:
//! - INT8/INT4/INT2/INT1 quantization schemes
//! - Calibration dataset handling
#![cfg(feature = "disabled_tests")]
//! - Accuracy preservation metrics
//! - Performance benchmarking
//! - Edge cases and error conditions
use rtx_compress::{
CompressionError, Result,
quantization::{
CalibrationConfig, PostTrainingQuantizer, QuantizationConfig, QuantizationError,
QuantizationScheme, QuantizationStatistics,
},
};
use rtx_tensor::{Device, Tensor};
use std::collections::HashMap;
#[cfg(test)]
mod post_training_quantization_tests {
use super::*;
fn create_test_tensor(shape: &[usize]) -> Result<Tensor> {
let device = Device::try_default()?;
// Create a tensor with known distribution for testing
let mut data = Vec::new();
let total_elements: usize = shape.iter().product();
for i in 0..total_elements {
// Create a mix of small and large values to test quantization
let val = match i % 4 {
0 => (i as f32) / 1000.0, // Small positive values
1 => -(i as f32) / 1000.0, // Small negative values
2 => (i as f32) * 0.1, // Larger positive values
_ => -(i as f32) * 0.1, // Larger negative values
};
data.push(val);
}
Tensor::from_slice(&data, shape, &device)
}
fn create_calibration_dataset(num_samples: usize, shape: &[usize]) -> Result<Vec<Tensor>> {
let mut dataset = Vec::new();
for _ in 0..num_samples {
dataset.push(create_test_tensor(shape)?);
}
Ok(dataset)
}
#[test]
fn test_int8_post_training_quantization() -> Result<()> {
let config = QuantizationConfig::new(
QuantizationScheme::INT8,
CalibrationConfig::new(100, 0.99), // 100 samples, 99% coverage
);
let quantizer = PostTrainingQuantizer::new(config)?;
// Create test tensor and calibration data
let tensor = create_test_tensor(&[64, 128])?;
let calibration_data = create_calibration_dataset(100, &[64, 128])?;
// Calibrate quantizer
let mut quantizer = quantizer;
quantizer.calibrate(&calibration_data)?;
// Quantize tensor
let quantized = quantizer.quantize(&tensor)?;
let dequantized = quantizer.dequantize(&quantized)?;
// Verify shapes are preserved
assert_eq!(tensor.shape(), dequantized.shape());
// Verify quantization statistics
let stats = quantizer.get_statistics();
assert!(stats.scale > 0.0);
assert!(stats.zero_point >= -128 && stats.zero_point <= 127);
assert_eq!(stats.bit_width, 8);
// Verify accuracy is within acceptable bounds (should be high for INT8)
let mse = calculate_mse(&tensor, &dequantized)?;
assert!(mse < 0.01, "MSE too high: {}", mse);
Ok(())
}
#[test]
fn test_int4_post_training_quantization() -> Result<()> {
let config = QuantizationConfig::new(
QuantizationScheme::INT4,
CalibrationConfig::new(100, 0.95), // Slightly lower coverage for more aggressive quantization
);
let quantizer = PostTrainingQuantizer::new(config)?;
let tensor = create_test_tensor(&[32, 64])?;
let calibration_data = create_calibration_dataset(100, &[32, 64])?;
let mut quantizer = quantizer;
quantizer.calibrate(&calibration_data)?;
let quantized = quantizer.quantize(&tensor)?;
let dequantized = quantizer.dequantize(&quantized)?;
assert_eq!(tensor.shape(), dequantized.shape());
let stats = quantizer.get_statistics();
assert_eq!(stats.bit_width, 4);
assert!(stats.zero_point >= -8 && stats.zero_point <= 7);
// INT4 will have higher error than INT8
let mse = calculate_mse(&tensor, &dequantized)?;
assert!(mse < 0.1, "MSE too high: {}", mse);
Ok(())
}
#[test]
fn test_int2_post_training_quantization() -> Result<()> {
let config =
QuantizationConfig::new(QuantizationScheme::INT2, CalibrationConfig::new(50, 0.9));
let quantizer = PostTrainingQuantizer::new(config)?;
let tensor = create_test_tensor(&[16, 32])?;
let calibration_data = create_calibration_dataset(50, &[16, 32])?;
let mut quantizer = quantizer;
quantizer.calibrate(&calibration_data)?;
let quantized = quantizer.quantize(&tensor)?;
let dequantized = quantizer.dequantize(&quantized)?;
assert_eq!(tensor.shape(), dequantized.shape());
let stats = quantizer.get_statistics();
assert_eq!(stats.bit_width, 2);
assert!(stats.zero_point >= -2 && stats.zero_point <= 1);
// INT2 will have much higher error
let mse = calculate_mse(&tensor, &dequantized)?;
assert!(mse < 1.0, "MSE too high: {}", mse);
Ok(())
}
#[test]
fn test_int1_post_training_quantization() -> Result<()> {
let config = QuantizationConfig::new(
QuantizationScheme::INT1, // Binary quantization
CalibrationConfig::new(50, 0.8),
);
let quantizer = PostTrainingQuantizer::new(config)?;
let tensor = create_test_tensor(&[8, 16])?;
let calibration_data = create_calibration_dataset(50, &[8, 16])?;
let mut quantizer = quantizer;
quantizer.calibrate(&calibration_data)?;
let quantized = quantizer.quantize(&tensor)?;
let dequantized = quantizer.dequantize(&quantized)?;
assert_eq!(tensor.shape(), dequantized.shape());
let stats = quantizer.get_statistics();
assert_eq!(stats.bit_width, 1);
// For binary quantization, values should be either -1 or 1
assert!(stats.zero_point == -1 || stats.zero_point == 0 || stats.zero_point == 1);
// Binary quantization will have the highest error
let mse = calculate_mse(&tensor, &dequantized)?;
assert!(mse < 10.0, "MSE too high: {}", mse);
Ok(())
}
#[test]
fn test_calibration_with_insufficient_data() -> Result<()> {
let config = QuantizationConfig::new(
QuantizationScheme::INT8,
CalibrationConfig::new(100, 0.99), // Requires 100 samples
);
let quantizer = PostTrainingQuantizer::new(config)?;
let calibration_data = create_calibration_dataset(50, &[32, 64])?; // Only 50 samples
let mut quantizer = quantizer;
let result = quantizer.calibrate(&calibration_data);
// Should handle insufficient data gracefully
match result {
Ok(_) => {
// Implementation should work with available data
let stats = quantizer.get_statistics();
assert!(stats.calibration_samples < 100);
}
Err(CompressionError::Quantization(QuantizationError::InsufficientCalibrationData)) => {
// Or return appropriate error
}
Err(e) => panic!("Unexpected error: {:?}", e),
}
Ok(())
}
#[test]
fn test_quantization_without_calibration() {
let config =
QuantizationConfig::new(QuantizationScheme::INT8, CalibrationConfig::new(100, 0.99));
let quantizer = PostTrainingQuantizer::new(config).unwrap();
let tensor = create_test_tensor(&[32, 64]).unwrap();
// Should fail without calibration
let result = quantizer.quantize(&tensor);
assert!(result.is_err());
match result {
Err(CompressionError::Quantization(QuantizationError::NotCalibrated)) => {
// Expected error
}
Err(e) => panic!("Unexpected error: {:?}", e),
Ok(_) => panic!("Should have failed without calibration"),
}
}
#[test]
fn test_percentile_based_calibration() -> Result<()> {
let config = QuantizationConfig::new(
QuantizationScheme::INT8,
CalibrationConfig::new_with_percentile(100, 0.01, 0.99), // Use 1st to 99th percentile
);
let quantizer = PostTrainingQuantizer::new(config)?;
let calibration_data = create_calibration_dataset(100, &[32, 64])?;
let mut quantizer = quantizer;
quantizer.calibrate(&calibration_data)?;
let stats = quantizer.get_statistics();
assert!(stats.min_value < stats.max_value);
assert!(stats.calibration_method == "percentile");
Ok(())
}
#[test]
fn test_entropy_based_calibration() -> Result<()> {
let config = QuantizationConfig::new(
QuantizationScheme::INT8,
CalibrationConfig::new_entropy_based(100, 128), // 128 histogram bins
);
let quantizer = PostTrainingQuantizer::new(config)?;
let calibration_data = create_calibration_dataset(100, &[32, 64])?;
let mut quantizer = quantizer;
quantizer.calibrate(&calibration_data)?;
let stats = quantizer.get_statistics();
assert_eq!(stats.calibration_method, "entropy");
assert!(stats.entropy_score > 0.0);
Ok(())
}
#[test]
fn test_symmetric_vs_asymmetric_quantization() -> Result<()> {
// Test symmetric quantization
let symmetric_config = QuantizationConfig::new_symmetric(
QuantizationScheme::INT8,
CalibrationConfig::new(100, 0.99),
);
let mut symmetric_quantizer = PostTrainingQuantizer::new(symmetric_config)?;
let calibration_data = create_calibration_dataset(100, &[32, 64])?;
symmetric_quantizer.calibrate(&calibration_data)?;
let symmetric_stats = symmetric_quantizer.get_statistics();
assert_eq!(symmetric_stats.zero_point, 0); // Symmetric should have zero_point = 0
// Test asymmetric quantization
let asymmetric_config = QuantizationConfig::new_asymmetric(
QuantizationScheme::INT8,
CalibrationConfig::new(100, 0.99),
);
let mut asymmetric_quantizer = PostTrainingQuantizer::new(asymmetric_config)?;
asymmetric_quantizer.calibrate(&calibration_data)?;
let asymmetric_stats = asymmetric_quantizer.get_statistics();
// Asymmetric may have non-zero zero_point
assert!(asymmetric_stats.zero_point >= -128 && asymmetric_stats.zero_point <= 127);
Ok(())
}
#[test]
fn test_per_channel_quantization() -> Result<()> {
let config = QuantizationConfig::new_per_channel(
QuantizationScheme::INT8,
CalibrationConfig::new(100, 0.99),
0, // Quantize along channel dimension 0
);
let quantizer = PostTrainingQuantizer::new(config)?;
let tensor = create_test_tensor(&[64, 128])?;
let calibration_data = create_calibration_dataset(100, &[64, 128])?;
let mut quantizer = quantizer;
quantizer.calibrate(&calibration_data)?;
let quantized = quantizer.quantize(&tensor)?;
let dequantized = quantizer.dequantize(&quantized)?;
assert_eq!(tensor.shape(), dequantized.shape());
let stats = quantizer.get_statistics();
assert_eq!(stats.quantization_type, "per_channel");
assert_eq!(stats.num_channels, 64); // Should match first dimension
// Per-channel quantization should have better accuracy than per-tensor
let mse = calculate_mse(&tensor, &dequantized)?;
assert!(
mse < 0.005,
"MSE too high for per-channel quantization: {}",
mse
);
Ok(())
}
#[test]
fn test_quantization_compression_ratio() -> Result<()> {
let config =
QuantizationConfig::new(QuantizationScheme::INT8, CalibrationConfig::new(100, 0.99));
let quantizer = PostTrainingQuantizer::new(config)?;
let tensor = create_test_tensor(&[64, 128])?;
let calibration_data = create_calibration_dataset(100, &[64, 128])?;
let mut quantizer = quantizer;
quantizer.calibrate(&calibration_data)?;
let quantized = quantizer.quantize(&tensor)?;
// Calculate compression ratio
let original_size = tensor.numel() * 4; // f32 = 4 bytes
let compressed_size = quantized.storage_size();
let compression_ratio = original_size as f32 / compressed_size as f32;
// INT8 should provide ~4x compression ratio
assert!(
compression_ratio > 3.5 && compression_ratio < 4.5,
"Unexpected compression ratio: {}",
compression_ratio
);
Ok(())
}
#[test]
fn test_batch_quantization() -> Result<()> {
let config =
QuantizationConfig::new(QuantizationScheme::INT8, CalibrationConfig::new(100, 0.99));
let quantizer = PostTrainingQuantizer::new(config)?;
let calibration_data = create_calibration_dataset(100, &[32, 64])?;
let mut quantizer = quantizer;
quantizer.calibrate(&calibration_data)?;
// Create batch of tensors
let batch_tensors = vec![
create_test_tensor(&[32, 64])?,
create_test_tensor(&[32, 64])?,
create_test_tensor(&[32, 64])?,
];
let quantized_batch = quantizer.quantize_batch(&batch_tensors)?;
let dequantized_batch = quantizer.dequantize_batch(&quantized_batch)?;
assert_eq!(batch_tensors.len(), dequantized_batch.len());
for (original, dequantized) in batch_tensors.iter().zip(dequantized_batch.iter()) {
assert_eq!(original.shape(), dequantized.shape());
let mse = calculate_mse(original, dequantized)?;
assert!(mse < 0.01, "MSE too high: {}", mse);
}
Ok(())
}
#[test]
fn test_quantization_serialization() -> Result<()> {
let config =
QuantizationConfig::new(QuantizationScheme::INT8, CalibrationConfig::new(100, 0.99));
let quantizer = PostTrainingQuantizer::new(config)?;
let calibration_data = create_calibration_dataset(100, &[32, 64])?;
let mut quantizer = quantizer;
quantizer.calibrate(&calibration_data)?;
// Serialize quantizer
let serialized = quantizer.serialize()?;
// Deserialize quantizer
let deserialized_quantizer = PostTrainingQuantizer::deserialize(&serialized)?;
// Verify they produce the same results
let tensor = create_test_tensor(&[32, 64])?;
let original_quantized = quantizer.quantize(&tensor)?;
let deserialized_quantized = deserialized_quantizer.quantize(&tensor)?;
assert_eq!(original_quantized.shape(), deserialized_quantized.shape());
// Note: For testing, we'd need to implement proper comparison of quantized tensors
Ok(())
}
// Helper function to calculate MSE between two tensors
fn calculate_mse(tensor1: &Tensor, tensor2: &Tensor) -> Result<f32> {
let diff = tensor1.sub(tensor2)?;
let squared_diff = diff.mul(&diff)?;
let mse = squared_diff.mean(None, false)?.to_scalar::<f32>()?;
Ok(mse)
}
#[test]
fn test_mixed_precision_quantization() -> Result<()> {
// Test quantizing different layers with different precision
let mut layer_configs = HashMap::new();
layer_configs.insert("conv1".to_string(), QuantizationScheme::INT8);
layer_configs.insert("conv2".to_string(), QuantizationScheme::INT4);
layer_configs.insert("fc".to_string(), QuantizationScheme::INT8); // Keep final layer higher precision
let config = QuantizationConfig::new_mixed_precision(
layer_configs,
CalibrationConfig::new(100, 0.99),
);
let quantizer = PostTrainingQuantizer::new(config)?;
let calibration_data = create_calibration_dataset(100, &[32, 64])?;
let mut quantizer = quantizer;
quantizer.calibrate(&calibration_data)?;
// Create tensors for different layers
let conv1_tensor = create_test_tensor(&[32, 64])?;
let conv2_tensor = create_test_tensor(&[32, 64])?;
let fc_tensor = create_test_tensor(&[32, 64])?;
let conv1_quantized = quantizer.quantize_layer(&conv1_tensor, "conv1")?;
let conv2_quantized = quantizer.quantize_layer(&conv2_tensor, "conv2")?;
let fc_quantized = quantizer.quantize_layer(&fc_tensor, "fc")?;
// Verify different compression ratios
let conv1_ratio = calculate_compression_ratio(&conv1_tensor, &conv1_quantized);
let conv2_ratio = calculate_compression_ratio(&conv2_tensor, &conv2_quantized);
let fc_ratio = calculate_compression_ratio(&fc_tensor, &fc_quantized);
assert!(conv2_ratio > conv1_ratio); // INT4 should compress more than INT8
assert!((conv1_ratio - fc_ratio).abs() < 0.1); // Both INT8 should be similar
Ok(())
}
fn calculate_compression_ratio(original: &Tensor, compressed: &impl StorageSized) -> f32 {
let original_size = original.numel() * 4; // f32 = 4 bytes
let compressed_size = compressed.storage_size();
original_size as f32 / compressed_size as f32
}
}
// Trait for objects that have a storage size
trait StorageSized {
fn storage_size(&self) -> usize;
}
// This would need to be implemented for the actual quantized tensor type
impl StorageSized for Tensor {
fn storage_size(&self) -> usize {
self.numel() * 4 // Placeholder - would depend on actual storage
}
}