add back get_global_scale

Signed-off-by: Kyle Sayers <[email protected]>

Author: kylesayrs

src/llmcompressor/observers/base.py

@@ -7,7 +7,7 @@
 from compressed_tensors.quantization.quant_args import (
     QuantizationArgs,
 )
-from compressed_tensors.quantization.utils import calculate_qparams
+from compressed_tensors.quantization.utils import calculate_qparams, generate_gparam
 from compressed_tensors.registry.registry import RegistryMixin
 
 from llmcompressor.observers.helpers import flatten_for_calibration
@@ -75,6 +75,19 @@ def forward(self, observed: torch.Tensor) -> Tuple[torch.Tensor, torch.Tensor]:
             global_scale=global_scale,
         )
 
+    def get_global_scale(self, observed: torch.Tensor) -> torch.nn.Parameter:
+        """
+        Calculates updated global scale from observed value
+
+        :param observed: value being observed
+        :return: calibrated global parameter
+        """
+        observed = observed.reshape((1, 1, -1))  # per tensor reshape
+        min_vals, max_vals = self.get_min_max(observed)
+        global_scale = generate_gparam(min_vals, max_vals)
+
+        return global_scale
+
     def _get_module_param(self, name: str) -> Optional[torch.nn.Parameter]:
         if self.module is None:
             return None