chromium/third_party/gemmlowp/src/public/bit_depth.h

// Copyright 2015 The Gemmlowp Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// bit_depth.h: defines the settins controlling LHS/RHS bit depth

#ifndef GEMMLOWP_PUBLIC_BIT_DEPTH_H_
#define GEMMLOWP_PUBLIC_BIT_DEPTH_H_

namespace gemmlowp {

// The range of allowed values for an operand.
template <int tMinValue, int tMaxValue>
struct OperandRange { … };

Uint8Range;
Uint8RangeExcludingZero;

Int8Range;
Int8RangeExcludingLow;

template <typename tLhsRange, typename tRhsRange>
struct BitDepthParams { … };

// Default: LHS and RHS are 8bit.
DefaultL8R8BitDepthParams;

// Variant: LHS may not take the value 0. This allows using
// faster kernels using signed arithmetic, see
// NEON_64bit_GEMM_Int8Operands_Int32Accumulators_AccumTwoWithin16Bits
L8R8WithLhsNonzeroBitDepthParams;

// Signed Variant: This allows using faster kernels using signed arithmetic, see
// NEON_64bit_GEMM_Int8Operands_Int32Accumulators_AccumTwoWithin16Bits
SignedL8R8WithLhsNonzeroBitDepthParams;

// Deprecated: when gemmlowp used to allow requantizing 8bit
// inputs to less-than-8-bit depths, the public setting allowing
// that was DefaultL7R5BitDepthParams. That requantization
// feature has been removed, but as the whole point of that
// requantization was to make less-than-8-bit an internal
// optimization without any impact on the API (other than lowering
// accuracy), we can temporarily support users who were using it
// by mapping it to the default 8bit behavior.
DefaultL7R5BitDepthParams;

}  // namespace gemmlowp

#endif  // GEMMLOWP_PUBLIC_BIT_DEPTH_H_