Fix bug in fake_quantize_op and add more unit testing (#15912)

paddle/fluid/operators/fake_quantize_op.cc

@@ -31,7 +31,7 @@ template <typename T>
 struct FindAbsMaxFunctor<platform::CPUDeviceContext, T> {
   void operator()(const platform::CPUDeviceContext& ctx, const T* in,
                   const int num, T* out) {
-    *out = *(std::max_element(in + 0, in + num, Compare<T>()));
+    *out = std::abs(*(std::max_element(in + 0, in + num, Compare<T>())));
   }
 };
 
@@ -46,10 +46,8 @@ struct ClipAndFakeQuantFunctor<platform::CPUDeviceContext, T> {
     platform::Transform<platform::CPUDeviceContext> trans;
     trans(ctx, in.data<T>(), in.data<T>() + in.numel(),
           out->mutable_data<T>(ctx.GetPlace()), ClipFunctor<T>(-s, s));
-    auto in_e = framework::EigenVector<T>::Flatten(in);
     auto out_e = framework::EigenVector<T>::Flatten(*out);
-
-    out_e.device(*ctx.eigen_device()) = (bin_cnt / s * in_e).round();
+    out_e.device(*ctx.eigen_device()) = (bin_cnt / s * out_e).round();
   }
 };
 

python/paddle/fluid/tests/unittests/test_fake_quantize_op.py

@@ -35,7 +35,7 @@ class TestFakeQuantizeOp(OpTest):
         self.check_output()
 
 
-class TestFakeQuantizeOp(OpTest):
+class TestFakeQuantizeRangeAbsMaxOp(OpTest):
     def setUp(self):
         self.op_type = "fake_quantize_range_abs_max"
         self.attrs = {
@@ -43,8 +43,10 @@ class TestFakeQuantizeOp(OpTest):
             'window_size': int(1),
             'is_test': False
         }
+        x = (np.random.random((8, 16, 7, 7)) - 0.5) * 10
+        x = x.astype("float32")
         self.inputs = {
-            'X': np.random.random((8, 16, 7, 7)).astype("float32"),
+            'X': x,
             'Iter': np.zeros(1).astype("int64"),
             'InScale': np.zeros(1).astype("float32")
         }
@@ -62,5 +64,36 @@ class TestFakeQuantizeOp(OpTest):
         self.check_output()
 
 
+class TestFakeQuantizeRangeAbsMaxOp2(OpTest):
+    def setUp(self):
+        self.op_type = "fake_quantize_range_abs_max"
+        self.attrs = {
+            'bit_length': int(8),
+            'window_size': int(1),
+            'is_test': True
+        }
+        x = (np.random.random((8, 16, 7, 7)) - 0.5) * 10
+        x = x.astype("float32")
+        scale = np.max(np.abs(x)).astype("float32") - 1.0
+        out_scales = np.zeros(self.attrs['window_size']).astype("float32")
+        out_scales[0] = scale
+
+        self.inputs = {
+            'X': x,
+            'Iter': np.zeros(1).astype("int64"),
+            'InScale': scale.astype("float32")
+        }
+        xs = np.clip(x, -scale, scale)
+        qs = np.round(xs / scale * ((1 << (self.attrs['bit_length'] - 1)) - 1))
+        self.outputs = {
+            'Out': qs,
+            'OutScale': scale.astype("float32"),
+            'OutScales': out_scales,
+        }
+
+    def test_check_output(self):
+        self.check_output(no_check_set=set(['OutScale', 'OutScales']))
+
+
 if __name__ == "__main__":
     unittest.main()