Compute Library
 21.08
UtilsQuantizedAsymm.h
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1 /*
2  * Copyright (c) 2017-2021 Arm Limited.
3  *
4  * SPDX-License-Identifier: MIT
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24 #ifndef ARM_COMPUTE_TEST_VALIDATION_UTILS_QUANTIZED_ASYMM_H
25 #define ARM_COMPUTE_TEST_VALIDATION_UTILS_QUANTIZED_ASYMM_H
26 
27 #include <cstdint>
28 
29 namespace arm_compute
30 {
31 namespace test
32 {
33 namespace validation
34 {
35 /** Rounded to nearest division by a power-of-two. */
36 inline int32_t asymm_rounding_divide_by_pow2(int32_t x, int exponent)
37 {
38  const int32_t mask = (1 << exponent) - 1;
39  const int32_t threshold = (mask >> 1) + (x < 0 ? 1 : 0);
40  return (x >> exponent) + ((x & mask) > threshold ? 1 : 0);
41 }
42 
43 /** Multiplication of two integers. The same as ARMv7 Arm® Neon™ VQRDMULH instruction. */
44 inline int32_t asymm_int_mult(int32_t a, int32_t b)
45 {
46  bool overflow = a == b && a == std::numeric_limits<int32_t>::min();
47  int64_t a_64(a);
48  int64_t b_64(b);
49  int64_t ab_64 = a_64 * b_64;
50  int32_t nudge = ab_64 >= 0 ? (1 << 30) : (1 - (1 << 30));
51  int32_t ab_x2_high32 = static_cast<int32_t>((ab_64 + nudge) / (1ll << 31));
52  return overflow ? std::numeric_limits<int32_t>::max() : ab_x2_high32;
53 }
54 
55 /** Quantize down the input value in range [min, max]. */
56 inline int32_t quantize_down_scale_by_fixedpoint(int32_t val, int32_t result_mult_int, int32_t result_shift,
57  int32_t result_offset_after_shift, int32_t min, int32_t max)
58 {
59  int32_t res = 0;
60  if(result_shift < 0)
61  {
62  res = asymm_int_mult(val * (1 << (-result_shift)), result_mult_int);
63  }
64  else
65  {
66  res = asymm_rounding_divide_by_pow2(asymm_int_mult(val, result_mult_int), result_shift);
67  }
68  res += result_offset_after_shift;
69  res = utility::clamp<int32_t>(res, min, max);
70  return res;
71 }
72 } // namespace validation
73 } // namespace test
74 } // namespace arm_compute
75 #endif /* ARM_COMPUTE_TEST_VALIDATION_UTILS_QUANTIZED_ASYMM_H */
int32_t asymm_rounding_divide_by_pow2(int32_t x, int exponent)
Rounded to nearest division by a power-of-two.
SimpleTensor< float > b
Definition: DFT.cpp:157
Copyright (c) 2017-2021 Arm Limited.
int32_t asymm_int_mult(int32_t a, int32_t b)
Multiplication of two integers.
int32_t quantize_down_scale_by_fixedpoint(int32_t val, int32_t result_mult_int, int32_t result_shift, int32_t result_offset_after_shift, int32_t min, int32_t max)
Quantize down the input value in range [min, max].