| //===- FakeQuantSupport.h - Support utilities for FakeQuant ops -*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines support utilities for interoperating with FakeQuant* based |
| // QAT (Quantized Aware Training) computations, as implemented by TFLite. Note |
| // that FakeQuant* operators mix multiple concerns specific to how TFLite |
| // originally implemented quantization. As such, utilities here enforce |
| // opinions taken by that codebase (vs providing any amount of genericity). |
| // |
| // Specifically, it combines the following concerns, each of which would be |
| // independent variables in a more generic setup: |
| // - numBits and isSigned imply storage data type (uint8, int8, int16) |
| // - numBits < 8 is promoted to uint8 or int8 |
| // - "narrow_range" narrows the lower bound of the storage type's range by |
| // 1 |
| // - the specified min/max values are "nudged" so that the result has a zero |
| // that can be exactly expressed |
| // - min=max=0 implies scale=0 and zero_point=0 |
| // |
| // With the above assumptions applied, every conforming specified FakeQuant op |
| // can be represented by a UniformQuantizedType. This scheme is not expected to |
| // be generalized further in the future and should be considered to be a |
| // legacy set of rules. |
| // |
| // As canonically used in TensorFlow graphs, the presence of a FakeQuant node |
| // is a hint that the specific math represented here has been simulated at |
| // training time. As such, it is usually not advised to arbitrarily change |
| // quantization parameters derived from FakeQuant. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef MLIR_DIALECT_QUANT_FAKEQUANTSUPPORT_H_ |
| #define MLIR_DIALECT_QUANT_FAKEQUANTSUPPORT_H_ |
| |
| #include "mlir/Dialect/Quant/QuantTypes.h" |
| |
| namespace mlir { |
| namespace quant { |
| |
| /// Converts per-layer FakeQuant attributes to the corresponding type. |
| /// In the event that the parameters cannot be converted, returns a nullptr |
| /// convertible Type and issues an appropriate error. |
| /// Note that there are multiple variants of a per-layer FakeQuant op, so |
| /// this function takes the attributes discretely vs taking a reference to the |
| /// originating op. |
| UniformQuantizedType fakeQuantAttrsToType(Location loc, unsigned numBits, |
| double rmin, double rmax, |
| bool narrowRange, Type expressedType, |
| bool isSigned = false); |
| |
| /// Converts per-channel FakeQuant attributes to the corresponding type. |
| /// In the event that the parameters cannot be converted, returns a nullptr |
| /// convertible Type and issues an appropriate error. |
| UniformQuantizedPerAxisType |
| fakeQuantAttrsToType(Location loc, unsigned numBits, int32_t quantizedDimension, |
| ArrayRef<double> rmins, ArrayRef<double> rmax, |
| bool narrowRange, Type expressedType, |
| bool isSigned = false); |
| } // namespace quant |
| } // namespace mlir |
| |
| #endif // MLIR_DIALECT_QUANT_FAKEQUANTSUPPORT_H_ |
