commit 880e73543120648f08886365a45e8b2ce32d5ff1
author Fredrik Svedberg <fredrik.svedberg@arm.com> Tue Aug 25 11:31:47 2020 +0200
committer Fredrik Svedberg <fredrik.svedberg@arm.com> Thu Aug 27 16:39:29 2020 +0200
tree 420627fb8e7e5000f23f82c52ba6569f4a696813
parent a41cd4de2af1e43b76a2a33d78eeb2d90a88b757

[MLBEDSW-2846] Do not use NHCWB16 for reduce_sum int32

Added checks for not using NHCWB16 for reduce_sum int32 which makes
int8/uint8 softmax work.

Also enabled softmax graph rewrite by default and fixed a saturation
problem.

Change-Id: Ic01bd9ece7e5c3edb2900b7915cc747efe9e5760
Signed-off-by: Fredrik Svedberg <fredrik.svedberg@arm.com>

ethosu/vela/softmax.py

diff --git a/ethosu/vela/softmax.py b/ethosu/vela/softmax.py
index eb97c79..7c23f47 100644
--- a/ethosu/vela/softmax.py
+++ b/ethosu/vela/softmax.py
@@ -391,7 +391,9 @@
         F2_one = create_const_tensor(
             "F2_one_const", [1, 1, 1, 1], DataType.int32, [(1 << 29)], np.int32, quantization=no_scale_quant
         )
-        two = create_const_tensor("two_const", [1, 1, 1, 1], DataType.int32, [2], np.int32, quantization=no_scale_quant)
+        four = create_const_tensor(
+            "four_const", [1, 1, 1, 1], DataType.int32, [4], np.int32, quantization=no_scale_quant
+        )
         for i in range(3):
             # PASS 13, 18, 23 - MUL
             mul_op = Operation("MulAct", self.op.name + "_mul%d" % (13 + i * 5))
@@ -416,10 +418,10 @@
             to_rescale.quantization = one_scale_quant.clone()
             to_rescale.quantization.scale_f32 = 2.0
             mul_op.set_output_tensor(to_rescale)
-            # PASS 16, 21, 26 - SHL
-            shl_op = Operation("SHL", self.op.name + "_shl%d" % (16 + i * 5))
+            # PASS 16, 21, 26 - MUL
+            shl_op = Operation("MulAct", self.op.name + "_mul%d" % (16 + i * 5))
             shl_op.add_input_tensor(to_rescale)
-            shl_op.add_input_tensor(two)
+            shl_op.add_input_tensor(four)
             to_add = Tensor(reduce_sum_shape, DataType.int32, shl_op.name + "_0")
             to_add.quantization = no_scale_quant
             shl_op.set_output_tensor(to_add)
@@ -431,13 +433,15 @@
             nr_x.quantization = one_scale_quant
             add_op.set_output_tensor(nr_x)
 
-        # PASS 28 - SHL
-        shl28_op = Operation("SHL", self.op.name + "_shl28")
-        shl28_op.add_input_tensor(nr_x)
-        shl28_op.add_input_tensor(one)
-        scale_factor = Tensor(reduce_sum_shape, DataType.int32, shl28_op.name + "_0")
+        # PASS 28 - Multiply
+        mul28_op = Operation("MulAct", self.op.name + "_mul28")
+        mul28_op.add_input_tensor(nr_x)
+        mul28_op.add_input_tensor(
+            create_const_tensor("two_const", [1, 1, 1, 1], DataType.int32, [2], np.int32, quantization=no_scale_quant)
+        )
+        scale_factor = Tensor(reduce_sum_shape, DataType.int32, mul28_op.name + "_0")
         scale_factor.quantization = one_scale_quant
-        shl28_op.set_output_tensor(scale_factor)
+        mul28_op.set_output_tensor(scale_factor)
 
         # PASS 29 - Multiply
         mul_op = Operation("MulAct", self.op.name + "_mul29")