[quant] Add per block quantization primitives (pytorch#159)

Summary:
We want to use this to replace all q/dq/choose_qparams ops in https://github.com/pytorch-labs/ao/blob/main/torchao/quantization/quant_primitives.py and https://github.com/pytorch/pytorch/blob/main/torch/ao/quantization/fx/_decomposed.py

Test Plan:
python test/quantization/test_quant_primitives.py

Reviewers:

Subscribers:

Tasks:

Tags:

test/quantization/test_quant_primitives.py

@@ -8,8 +8,21 @@
 # This test takes a long time to run
 import unittest
 import torch
-from torchao.quantization.quant_primitives import get_group_qparams_symmetric
-from torchao.quantization.utils import TORCH_VERSION_AFTER_2_3
+from torchao.quantization.quant_primitives import (
+    get_group_qparams_symmetric,
+    quantize_affine,
+    dequantize_affine,
+    choose_qparams_affine,
+    MappingType,
+)
+
+from torchao.quantization.utils import (
+    TORCH_VERSION_AFTER_2_3,
+    TORCH_VERSION_AFTER_2_4,
+)
+
+_SEED = 1234
+torch.manual_seed(_SEED)
 
 class TestQuantPrimitives(unittest.TestCase):
     SEED = 123
@@ -46,5 +59,176 @@ def test_get_group_qparams_symmetric(self):
         (scale_ao, _) = get_group_qparams_symmetric(weight, n_bit, groupsize)
         torch.testing.assert_allclose(scale_obs, scale_ao, rtol=0, atol=0)
 
+    def test_choose_qparams_group_sym(self):
+        """Note: groupwise asymmetric quant is using a different way of computing zero_points, so
+        we don't include it here. We may just replace it with per block quant
+        """
+        input = torch.randn(10, 10)
+        mapping_type = MappingType.SYMMETRIC
+        dtype = torch.int8
+        block_size = (1, 2)
+        scale, zero_point = choose_qparams_affine(input, mapping_type, block_size, dtype, eps=torch.finfo(torch.float32).eps)
+
+        scale_ref, zp_ref = get_group_qparams_symmetric(input, n_bit=8, groupsize=2)
+
+        self.assertTrue(torch.equal(scale, scale_ref))
+        self.assertTrue(torch.equal(zero_point, zp_ref))
+
+    @unittest.skipIf(not TORCH_VERSION_AFTER_2_3, "skipping when torch verion is 2.3 or lower")
+    def test_choose_qparams_token_asym(self):
+        input = torch.randn(10, 10)
+        mapping_type = MappingType.ASYMMETRIC
+        dtype = torch.int8
+        block_size = (1, 10)
+        scale, zero_point = choose_qparams_affine(input, mapping_type, block_size, dtype, eps=torch.finfo(torch.float32).eps)
+
+        scale_ref, zp_ref = torch.ops.quantized_decomposed.choose_qparams_per_token_asymmetric(input, dtype)
+        scale_ref = scale_ref.squeeze()
+        zp_ref = zp_ref.squeeze()
+
+        torch.testing.assert_allclose(scale, scale_ref, atol=10e-3, rtol=10e-3)
+        self.assertTrue(torch.equal(zero_point, zp_ref))
+
+    def test_choose_qparams_tensor_asym(self):
+        input = torch.randn(10, 10)
+        mapping_type = MappingType.ASYMMETRIC
+        dtype = torch.int8
+        block_size = (10, 10)
+        eps = torch.finfo(torch.float32).eps
+        scale, zero_point = choose_qparams_affine(input, mapping_type, block_size, dtype, eps=eps)
+
+
+        quant_min = -128
+        quant_max = 127
+        scale_ref, zp_ref = torch.ops.quantized_decomposed.choose_qparams(input, quant_min, quant_max, eps, dtype)
+        scale_ref = scale_ref.squeeze()
+        zp_ref = zp_ref.squeeze()
+
+        self.assertTrue(torch.equal(scale, scale_ref))
+        self.assertTrue(torch.equal(zero_point, zp_ref))
+
+    def test_choose_qparams_tensor_sym(self):
+        input = torch.randn(10, 10)
+        mapping_type = MappingType.SYMMETRIC
+        dtype = torch.int8
+        block_size = (10, 10)
+        eps = torch.finfo(torch.float32).eps
+        scale, zero_point = choose_qparams_affine(input, mapping_type, block_size, dtype, eps=eps)
+
+        quant_min = -128
+        quant_max = 127
+        scale_ref, zp_ref = torch.ops.quantized_decomposed.choose_qparams_symmetric(input, quant_min, quant_max, eps, dtype)
+        scale_ref = scale_ref.squeeze()
+        zp_ref = zp_ref.squeeze()
+
+        self.assertTrue(torch.equal(scale, scale_ref))
+        self.assertTrue(torch.equal(zero_point, zp_ref))
+
+
+    @unittest.skipIf(not TORCH_VERSION_AFTER_2_3, "skipping when torch verion is 2.3 or lower")
+    def test_quantize_dequantize_group_sym(self):
+        input = torch.randn(10, 10)
+        mapping_type = MappingType.SYMMETRIC
+        dtype = torch.int8
+        block_size = (1, 2)
+        scale, zero_point = choose_qparams_affine(input, mapping_type, block_size, dtype, eps=torch.finfo(torch.float32).eps)
+
+        quantized = quantize_affine(input, block_size, scale, zero_point, dtype)
+        dequantized = dequantize_affine(quantized, block_size, scale, zero_point, dtype, output_dtype=torch.float32)
+
+        group_size = 2
+        quant_min = -128
+        quant_max = 127
+        quantized_ref = torch.ops.quantized_decomposed.quantize_per_channel_group(
+            input, scale, zero_point, quant_min, quant_max, torch.int8, group_size
+        )
+        dequantized_ref = torch.ops.quantized_decomposed.dequantize_per_channel_group(
+            quantized_ref, scale, zero_point, quant_min, quant_max, torch.int8, group_size, output_dtype=torch.float32
+        )
+
+        self.assertTrue(torch.equal(quantized, quantized_ref))
+        self.assertTrue(torch.equal(dequantized, dequantized_ref))
+
+    @unittest.skipIf(not TORCH_VERSION_AFTER_2_4, "skipping when torch verion is 2.4 or lower")
+    def test_quantize_dequantize_channel_asym(self):
+        input = torch.randn(10, 10)
+        mapping_type = MappingType.ASYMMETRIC
+        dtype = torch.int8
+        block_size = (10, 1)
+        scale, zero_point = choose_qparams_affine(input, mapping_type, block_size, dtype, eps=torch.finfo(torch.float32).eps)
+        output_dtype = torch.float32
+        quantized = quantize_affine(input, block_size, scale, zero_point, dtype)
+        dequantized = dequantize_affine(quantized, block_size, scale, zero_point, dtype, output_dtype=output_dtype)
+
+        axis = 1
+        quant_min = -128
+        quant_max = 127
+        quantized_ref = torch.ops.quantized_decomposed.quantize_per_channel(
+            input, scale, zero_point, axis, quant_min, quant_max, torch.int8
+        )
+        dequantized_ref = torch.ops.quantized_decomposed.dequantize_per_channel(
+            quantized_ref, scale, zero_point, axis, quant_min, quant_max, torch.int8, out_dtype=output_dtype
+        )
+        self.assertTrue(torch.equal(quantized, quantized_ref))
+        self.assertTrue(torch.equal(dequantized, dequantized_ref))
+
+    @unittest.skipIf(not TORCH_VERSION_AFTER_2_4, "skipping when torch verion is 2.4 or lower")
+    def test_quantize_dequantize_tensor_asym(self):
+        input = torch.randn(10, 10)
+        mapping_type = MappingType.ASYMMETRIC
+        dtype = torch.int8
+        block_size = (10, 10)
+        output_dtype = torch.float32
+        scale, zero_point = choose_qparams_affine(input, mapping_type, block_size, dtype, eps=torch.finfo(torch.float32).eps)
+        quantized = quantize_affine(input, block_size, scale, zero_point, dtype)
+        dequantized = dequantize_affine(quantized, block_size, scale, zero_point, dtype, output_dtype=output_dtype)
+
+        axis = 1
+        quant_min = -128
+        quant_max = 127
+        quantized_ref = torch.ops.quantized_decomposed.quantize_per_tensor(
+            input, scale, zero_point, quant_min, quant_max, torch.int8
+        )
+        dequantized_ref = torch.ops.quantized_decomposed.dequantize_per_tensor(
+            quantized_ref, scale, zero_point, quant_min, quant_max, torch.int8, out_dtype=output_dtype
+        )
+        self.assertTrue(torch.equal(quantized, quantized_ref))
+        self.assertTrue(torch.equal(dequantized, dequantized_ref))
+
+    @unittest.skipIf(not TORCH_VERSION_AFTER_2_4, "skipping when torch verion is 2.4 or lower")
+    def test_quantize_dequantize_channel_asym_4d(self):
+        input = torch.randn(3, 3, 10, 10)
+        mapping_type = MappingType.ASYMMETRIC
+        dtype = torch.int8
+        block_size = (3, 3, 1, 10)
+        scale, zero_point = choose_qparams_affine(input, mapping_type, block_size, dtype, eps=torch.finfo(torch.float32).eps)
+        quantized = quantize_affine(input, block_size, scale, zero_point, dtype)
+        dequantized = dequantize_affine(quantized, block_size, scale, zero_point, dtype, output_dtype=torch.float32)
+
+        axis = 2
+        quant_min = -128
+        quant_max = 127
+        quantized_ref = torch.ops.quantized_decomposed.quantize_per_channel(
+            input, scale, zero_point, axis, quant_min, quant_max, torch.int8
+        )
+        dequantized_ref = torch.ops.quantized_decomposed.dequantize_per_channel(
+            quantized_ref, scale, zero_point, axis, quant_min, quant_max, torch.int8, out_dtype=torch.float32
+        )
+        self.assertTrue(torch.equal(quantized, quantized_ref))
+        self.assertTrue(torch.equal(dequantized, dequantized_ref))
+
+    @unittest.skipIf(not TORCH_VERSION_AFTER_2_3, "skipping when torch verion is 2.3 or lower")
+    def test_quantize_dequantize_channel_asym_4d_multi_dim_reduction(self):
+        input = torch.randn(3, 3, 10, 10)
+        mapping_type = MappingType.ASYMMETRIC
+        dtype = torch.int8
+        block_size = (3, 3, 2, 2)
+        scale, zero_point = choose_qparams_affine(input, mapping_type, block_size, dtype, eps=torch.finfo(torch.float32).eps)
+        quantized = quantize_affine(input, block_size, scale, zero_point, dtype)
+        dequantized = dequantize_affine(quantized, block_size, scale, zero_point, dtype, output_dtype=torch.float32)
+        # we don't have corresponding ops in existing primitives, so just make sure it runs and it's close to float
+        torch.testing.assert_allclose(dequantized, input, rtol=2, atol=0.02)
+
+
 if __name__ == "__main__":
     unittest.main()

torchao/quantization/autoquant.py

@@ -391,4 +391,3 @@ def autoquant(model, example_input, qtensor_class_list=DEFAULT_CLASS_LIST, filte
     model(*example_input)
     change_autoquantizable_to_quantized(model, **kwargs)
     return model
-