[AWQ] Allow for activation quantization

src/llmcompressor/modifiers/awq/base.py

@@ -1,4 +1,5 @@
 import inspect
+import warnings
 from typing import Dict, List, Optional, Tuple, Union
 
 import torch
@@ -181,25 +182,20 @@ def validate_model_after(model: "AWQModifier") -> "AWQModifier":
 
         model._group_size = next(iter(group_size_set))
 
-        in_num_bits_set = set(
-            group.input_activations.num_bits
+        num_bits_set = {
+            act.num_bits
             for group in config.config_groups.values()
-            if group.input_activations is not None
-        )
-        assert len(in_num_bits_set) == 0 or in_num_bits_set == {16}, (
-            "AWQ activations must be 16-bit precision, "
-            f"input activations {in_num_bits_set} not allowed"
-        )
-
-        out_num_bits_set = set(
-            group.output_activations.num_bits
-            for group in config.config_groups.values()
-            if group.output_activations is not None
-        )
-        assert len(out_num_bits_set) == 0 or out_num_bits_set == {16}, (
-            "AWQ activations must be 16-bit precision, "
-            f"output activations {out_num_bits_set} not allowed"
-        )
+            for act in (group.input_activations, group.output_activations)
+            if act is not None
+        }
+        if not (len(num_bits_set) == 0 or num_bits_set == {16}):
+            warnings.warn(
+                "A strategy including activation quantization was detected. "
+                "AWQ was originally intended for weight-only quantization. "
+                "Lower-precision activations are an experimental feature, and "
+                "overall performance may be poor. If it is, consider using "
+                "`W4A16` or `W4A16_ASYM` quantization schemes instead."
+            )
 
         return model
 

tests/llmcompressor/modifiers/awq/test_base.py

@@ -114,9 +114,6 @@ def test_set_resolved_mappings():
 
 @pytest.mark.unit
 def test_validate():
-    with pytest.raises(ValidationError):
-        AWQModifier(scheme="W8A8")
-
     with pytest.raises(ValidationError):
         AWQModifier(
             config_groups={