1 // Copyright 2015 The Gemmlowp Authors. All Rights Reserved. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 // bit_depth.h: defines the settins controlling LHS/RHS bit depth 16 17 #ifndef GEMMLOWP_PUBLIC_BIT_DEPTH_H_ 18 #define GEMMLOWP_PUBLIC_BIT_DEPTH_H_ 19 20 namespace gemmlowp { 21 22 // The range of allowed values for an operand. 23 template <int tMinValue, int tMaxValue> 24 struct OperandRange { 25 static const int kMinValue = tMinValue; 26 static const int kMaxValue = tMaxValue; 27 static_assert(0 <= kMinValue, ""); 28 static_assert(kMinValue < kMaxValue, ""); 29 static_assert(kMaxValue <= 255, ""); 30 }; 31 32 using Uint8Range = OperandRange<0, 255>; 33 using Uint8RangeExcludingZero = OperandRange<1, 255>; 34 35 template <typename tLhsRange, typename tRhsRange> 36 struct BitDepthParams { 37 using LhsRange = tLhsRange; 38 using RhsRange = tRhsRange; 39 }; 40 41 // Default: LHS and RHS are 8bit. 42 using DefaultL8R8BitDepthParams = BitDepthParams<Uint8Range, Uint8Range>; 43 44 // Variant: LHS may not take the value 0. This allows using 45 // faster kernels using signed arithmetic, see 46 // NEON_64bit_GEMM_Int8Operands_Int32Accumulators_AccumTwoWithin16Bits 47 using L8R8WithLhsNonzeroBitDepthParams = 48 BitDepthParams<Uint8RangeExcludingZero, Uint8Range>; 49 50 // Deprecated: when gemmlowp used to allow requantizing 8bit 51 // inputs to less-than-8-bit depths, the public setting allowing 52 // that was DefaultL7R5BitDepthParams. That requantization 53 // feature has been removed, but as the whole point of that 54 // requantization was to make less-than-8-bit an internal 55 // optimization without any impact on the API (other than lowering 56 // accuracy), we can temporarily support users who were using it 57 // by mapping it to the default 8bit behavior. 58 using DefaultL7R5BitDepthParams = DefaultL8R8BitDepthParams; 59 60 } // namespace gemmlowp 61 62 #endif // GEMMLOWP_PUBLIC_BIT_DEPTH_H_ 63