reverse xpu adamw to the combination of ops version. (#35286)

Author: zhaoyinglia

python/paddle/optimizer/adamw.py

@@ -162,6 +162,7 @@ def __init__(self,
         self._params_name = set()
         self._apply_decay_param_fun = apply_decay_param_fun
         self._coeff = coeff
+        self._lr_to_coeff = dict()
 
         super(AdamW, self).__init__(
             learning_rate=learning_rate,
@@ -177,6 +178,9 @@ def __init__(self,
 
         self.type = "adamw"
 
+        if core.is_compiled_with_xpu():
+            self.type = "adam"
+
         # Use _auxiliary_vars together with _set_auxiliary_var/_get_auxiliary_var to achieve that.
         self._auxiliary_vars = dict()
 
@@ -189,7 +193,63 @@ def _get_auxiliary_var(self, key):
         else:
             return None
 
+    def _append_decoupled_weight_decay(self, block, param_and_grad):
+        """
+        Add decoupled weight decay op.
+            parameter = parameter - parameter * coeff * lr
+        Args:
+            block: block in which variable is to be created
+            param_and_grad: (parameters, gradients) pairs,
+                the parameters need to decay.
+        Raises:
+            Exception: The type of coeff and parameter is not consistent.
+        """
+        if isinstance(param_and_grad, dict):
+            param_and_grad = self._update_param_group(param_and_grad)
+        param, grad = param_and_grad
+
+        if self._apply_decay_param_fun is not None \
+                and not self._apply_decay_param_fun(param.name):
+            return
+
+        if isinstance(self._learning_rate, float):
+            learning_rate = self._learning_rate
+        else:
+            # NOTE. We add this function to the _append_optimize_op(),
+            # for we must make sure _create_param_lr() be called after
+            # optimizer._create_global_learning_rate().
+            learning_rate = self._create_param_lr(param_and_grad)
+
+        with block.program._optimized_guard(
+            [param, grad]), framework.name_scope('weight decay'):
+            self._params_name.add(param.name)
+
+            # If it has been calculated, the result will be reused.
+            # NOTE(wangxi): In dygraph mode, apply_gradient will be executed
+            # every step, so need clear _lr_to_coeff every step,
+            # we do this in _create_optimization_pass
+            decay_coeff = self._lr_to_coeff.get(learning_rate, None)
+            if decay_coeff is None:
+                # NOTE(wangxi): for pipeline to set device:all
+                with paddle.static.device_guard(None):
+                    decay_coeff = 1.0 - learning_rate * self._coeff
+                self._lr_to_coeff[learning_rate] = decay_coeff
+
+            find_master = (self._multi_precision and
+                           param.dtype == core.VarDesc.VarType.FP16)
+            if find_master:
+                master_weight = self._master_weights[param.name]
+                scaled_param = master_weight * decay_coeff
+                paddle.fluid.layers.assign(
+                    input=scaled_param, output=master_weight)
+            else:
+                scaled_param = param * decay_coeff
+                paddle.fluid.layers.assign(input=scaled_param, output=param)
+
     def _append_optimize_op(self, block, param_and_grad):
+        if paddle.is_compiled_with_xpu():
+            self._append_decoupled_weight_decay(block, param_and_grad)
+            return super(AdamW, self)._append_optimize_op(block, param_and_grad)
 
         assert isinstance(block, framework.Block)
         if isinstance(param_and_grad, dict):
@@ -201,8 +261,6 @@ def _append_optimize_op(self, block, param_and_grad):
         if self._apply_decay_param_fun is not None \
                 and not self._apply_decay_param_fun(param.name):
             with_decay = False
-        else:
-            self._params_name.add(param.name)
 
         moment1 = self._get_accumulator(self._moment1_acc_str,
                                         param_and_grad[0])
@@ -291,6 +349,13 @@ def _append_optimize_op(self, block, param_and_grad):
 
         return adamw_op
 
+    def _create_optimization_pass(self, parameters_and_grads):
+        optimize_ops = super(
+            AdamW, self)._create_optimization_pass(parameters_and_grads)
+        # In dygraph mode, clear _lr_to_coeff after applied gradient
+        self._lr_to_coeff = dict()
+        return optimize_ops
+
     def __str__(self):
         return " ".join(["Weight Decay, params:", ",".join(self._params_name)])