校准执行过程中提示“IfmrQuantCalibration with offset scale is illegal"或“ IfmrQuantCalibration without offset scale is illegal”

问题描述

在调用Caffe框架执行中间校准模型推理过程中，由于输入数据范围不合法，导致量化算法计算得到的scale不合理，从而校准过程失败，终止Caffe校准流程。

可能原因

1. 数据范围 [-inf , +inf]：

   因为昇腾模型压缩工具的量化算法需要强制过零点，所以计算出的scale也就是inf/255=inf，该情况下量化因子后续无法承载，因此量化算法会提示错误信息，不支持该数据范围。

   1. 场景1

      I0513 16:12:37.508546 80719 ifmr_layer.cu:58] Doing layer: "Convolution1" calibration, already store 1/1 data.
      I0513 16:12:37.508558 80719 ifmr_layer.cu:65] Start to do ifmr quant.
      [ERROR][ProcessScale][48] Not support scale is +inf.
      [ERROR][IfmrQuantCalibration][338] IfmrQuantCalibration with offset scale is illegal.
      [ERROR][IfmrQuantInternel][462] IfmrQuantInternel calibration failed.
      F0513 16:12:37.535028 80719 ifmr_layer.cu:70] Check failed: ret == 0 (-65519 vs. 0) Do IFMR calibration failed
      *** Check failure stack trace: ***
      Aborted

   2. 场景2

      I0513 16:14:48.173506 81053 ifmr_layer.cu:58] Doing layer: "Convolution1" calibration, already store 1/1 data.
      I0513 16:14:48.173519 81053 ifmr_layer.cu:65] Start to do ifmr quant.
      [ERROR][ProcessScale][48] Not support scale is +inf.
      [ERROR][IfmrQuantCalibration][359] IfmrQuantCalibration without offset scale is illegal.
      [ERROR][IfmrQuantInternel][462] IfmrQuantInternel calibration failed.
      F0513 16:14:48.199769 81053 ifmr_layer.cu:70] Check failed: ret == 0 (-65519 vs. 0) Do IFMR calibration failed
      *** Check failure stack trace: ***
      Aborted

2. 数据范围：（其中EPSILON包括DBL_EPSILON double类型，FLT_EPSILON float类型，当前使用的是FLT_EPSILON类型）

   昇腾模型压缩工具量化支持计算得到的最大，因为在昇腾AI处理器量化动作做的是乘法计算： ， 如果scale大于， 会小于FLT_EPSILON，此时量化后结果就不可信。因此昇腾模型压缩工具量化算法仅支持原始数据范围在内进行量化，否则会提示不支持并提示错误信息。

   2021-05-11 09:25:42,222 - INFO - [AMCT]:[WeightsCalibrationPass]: Do layer 'Convolution1[arq_quantize]' weights calibration success!
   2021-05-11 09:25:42,222 - INFO - [AMCT]:[Optimizer]: Do <class 'amct_caffe.optimizer.insert_ifmr_layer.InsertIFMRLayerPass'>
   2021-05-11 09:25:42,223 - INFO - [AMCT]:[Optimizer]: Do <class 'amct_caffe.optimizer.lstm_calibration_replace.LSTMCalibrationReplacePass'>
   2021-05-11 09:25:42,223 - INFO - [AMCT]:[Optimizer]: Do <class 'amct_caffe.optimizer.insert_searchn_layer.InsertSearchNLayerPass'>
   2021-05-11 09:25:42,223 - INFO - [AMCT]:[Graph]: Doing whole model dump...
   2021-05-11 09:25:42,225 - INFO - [AMCT]:[Utils]: The weights_file is saved in xx/data/AMCT15_CAFFE_GPU_GPU_FAQ_LEVEL1_TC_001/AMCT15_CAFFE_GPU_GPU_FAQ_LEVEL1_TC_001_tmp.caffemodel
   2021-05-11 09:25:42,226 - INFO - [AMCT]:[Utils]: The model_file is saved in xx/data/AMCT15_CAFFE_GPU_GPU_FAQ_LEVEL1_TC_001/AMCT15_CAFFE_GPU_GPU_FAQ_LEVEL1_TC_001_tmp.prototxt
   [ERROR][ProcessScale][52] Not support scale greater than 1 / FLT_EPSILON.
   [ERROR][IfmrQuantCalibration][338] IfmrQuantCalibration with offset scale is illegal.
   [ERROR][IfmrQuantInternel][462] IfmrQuantInternel calibration failed.
   WARNING: Logging before InitGoogleLogging() is written to STDERR
   F0511 09:25:42.292863 80432 ifmr_layer.cu:70] Check failed: ret == 0 (-65519 vs. 0) Do IFMR calibration failed
   *** Check failure stack trace: ***
   Aborted

处理建议

根据提示信息，跳过日志中的量化层，例如上述提示信息中的Convolution1层。