!7183 fix symmetric bug in FakeQuantPerChannel op

Merge pull request !7183 from yuchaojie/quant2

mindspore/ops/_op_impl/_custom_op/fake_quant_perchannel.py

@@ -50,7 +50,7 @@ def _fake_quant_perchannel_tbe():
 
 
 @fusion_manager.register("fake_quant_perchannel")
-def fake_quant_perchannel_compute(x, min_val, max_val, y, quant_min, quant_max,
+def fake_quant_perchannel_compute(x, min_val, max_val, y, quant_min, quant_max, symmetric,
                                   kernel_name="fake_quant_perchannel"):
     """FakeQuantPerChannel"""
     x_shape = te.lang.cce.util.shape_to_list(x.shape)
@@ -59,6 +59,9 @@ def fake_quant_perchannel_compute(x, min_val, max_val, y, quant_min, quant_max,
     quant_max = tvm.const(quant_max, x.dtype)
     quant_min = te.lang.cce.broadcast(quant_min, minmax_shape, x.dtype)
     quant_max = te.lang.cce.broadcast(quant_max, minmax_shape, x.dtype)
+    if symmetric:
+        max_val = te.lang.cce.vmax(te.lang.cce.vmuls(min_val, -1.), max_val)
+        min_val = te.lang.cce.vmuls(max_val, -1.)
 
     scale = te.lang.cce.vdiv(te.lang.cce.vsub(
         max_val, min_val), te.lang.cce.vsub(quant_max, quant_min))
@@ -119,12 +122,8 @@ def fake_quant_perchannel(x, min_val, max_val, y,
     util.check_dtype_rule(min_dtype, check_list)
     util.check_dtype_rule(max_dtype, check_list)
 
-    if symmetric:
-        quant_min = 0 - 2 ** (num_bits - 1)
-        quant_max = 2 ** (num_bits - 1) - 1
-    else:
-        quant_min = 0
-        quant_max = 2 ** num_bits - 1
+    quant_min = 0
+    quant_max = 2 ** num_bits - 1
     if narrow_range:
         quant_min = quant_min + 1
 
@@ -136,7 +135,7 @@ def fake_quant_perchannel(x, min_val, max_val, y,
     min_data = tvm.placeholder(shape_c, name="min_val", dtype=x_dtype)
     max_data = tvm.placeholder(shape_c, name="max_val", dtype=x_dtype)
     res = fake_quant_perchannel_compute(input_data, min_data, max_data, y,
-                                        quant_min, quant_max, kernel_name)
+                                        quant_min, quant_max, symmetric, kernel_name)
 
     with tvm.target.cce():
         sch = generic.auto_schedule(res)