1 /* 2 * Copyright 2015 Advanced Micro Devices, Inc. 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice shall be included in 12 * all copies or substantial portions of the Software. 13 * 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR 18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 20 * OTHER DEALINGS IN THE SOFTWARE. 21 * 22 * Authors: AMD 23 * 24 */ 25 #include "dm_services.h" 26 #include "bw_fixed.h" 27 28 29 #define MIN_I64 \ 30 (int64_t)(-(1LL << 63)) 31 32 #define MAX_I64 \ 33 (int64_t)((1ULL << 63) - 1) 34 35 #define FRACTIONAL_PART_MASK \ 36 ((1ULL << BW_FIXED_BITS_PER_FRACTIONAL_PART) - 1) 37 38 #define GET_FRACTIONAL_PART(x) \ 39 (FRACTIONAL_PART_MASK & (x)) 40 41 static uint64_t abs_i64(int64_t arg) 42 { 43 if (arg >= 0) 44 return (uint64_t)(arg); 45 else 46 return (uint64_t)(-arg); 47 } 48 49 struct bw_fixed bw_int_to_fixed_nonconst(int64_t value) 50 { 51 struct bw_fixed res; 52 ASSERT(value < BW_FIXED_MAX_I32 && value > BW_FIXED_MIN_I32); 53 res.value = value << BW_FIXED_BITS_PER_FRACTIONAL_PART; 54 return res; 55 } 56 57 struct bw_fixed bw_frc_to_fixed(int64_t numerator, int64_t denominator) 58 { 59 struct bw_fixed res; 60 bool arg1_negative = numerator < 0; 61 bool arg2_negative = denominator < 0; 62 uint64_t arg1_value; 63 uint64_t arg2_value; 64 uint64_t remainder; 65 66 /* determine integer part */ 67 uint64_t res_value; 68 69 ASSERT(denominator != 0); 70 71 arg1_value = abs_i64(numerator); 72 arg2_value = abs_i64(denominator); 73 /* XXX: int64_t* -> u64* conversion! */ 74 res_value = div64_u64_rem(arg1_value, arg2_value, (u64 *)&remainder); 75 76 ASSERT(res_value <= BW_FIXED_MAX_I32); 77 78 /* determine fractional part */ 79 { 80 uint32_t i = BW_FIXED_BITS_PER_FRACTIONAL_PART; 81 82 do 83 { 84 remainder <<= 1; 85 86 res_value <<= 1; 87 88 if (remainder >= arg2_value) 89 { 90 res_value |= 1; 91 remainder -= arg2_value; 92 } 93 } while (--i != 0); 94 } 95 96 /* round up LSB */ 97 { 98 uint64_t summand = (remainder << 1) >= arg2_value; 99 100 ASSERT(res_value <= MAX_I64 - summand); 101 102 res_value += summand; 103 } 104 105 res.value = (int64_t)(res_value); 106 107 if (arg1_negative ^ arg2_negative) 108 res.value = -res.value; 109 return res; 110 } 111 112 struct bw_fixed bw_floor2( 113 const struct bw_fixed arg, 114 const struct bw_fixed significance) 115 { 116 struct bw_fixed result; 117 int64_t multiplicand; 118 119 multiplicand = div64_s64(arg.value, abs_i64(significance.value)); 120 result.value = abs_i64(significance.value) * multiplicand; 121 ASSERT(abs_i64(result.value) <= abs_i64(arg.value)); 122 return result; 123 } 124 125 struct bw_fixed bw_ceil2( 126 const struct bw_fixed arg, 127 const struct bw_fixed significance) 128 { 129 struct bw_fixed result; 130 int64_t multiplicand; 131 132 multiplicand = div64_s64(arg.value, abs_i64(significance.value)); 133 result.value = abs_i64(significance.value) * multiplicand; 134 if (abs_i64(result.value) < abs_i64(arg.value)) { 135 if (arg.value < 0) 136 result.value -= abs_i64(significance.value); 137 else 138 result.value += abs_i64(significance.value); 139 } 140 return result; 141 } 142 143 struct bw_fixed bw_mul(const struct bw_fixed arg1, const struct bw_fixed arg2) 144 { 145 struct bw_fixed res; 146 147 bool arg1_negative = arg1.value < 0; 148 bool arg2_negative = arg2.value < 0; 149 150 uint64_t arg1_value = abs_i64(arg1.value); 151 uint64_t arg2_value = abs_i64(arg2.value); 152 153 uint64_t arg1_int = BW_FIXED_GET_INTEGER_PART(arg1_value); 154 uint64_t arg2_int = BW_FIXED_GET_INTEGER_PART(arg2_value); 155 156 uint64_t arg1_fra = GET_FRACTIONAL_PART(arg1_value); 157 uint64_t arg2_fra = GET_FRACTIONAL_PART(arg2_value); 158 159 uint64_t tmp; 160 161 res.value = arg1_int * arg2_int; 162 163 ASSERT(res.value <= BW_FIXED_MAX_I32); 164 165 res.value <<= BW_FIXED_BITS_PER_FRACTIONAL_PART; 166 167 tmp = arg1_int * arg2_fra; 168 169 ASSERT(tmp <= (uint64_t)(MAX_I64 - res.value)); 170 171 res.value += tmp; 172 173 tmp = arg2_int * arg1_fra; 174 175 ASSERT(tmp <= (uint64_t)(MAX_I64 - res.value)); 176 177 res.value += tmp; 178 179 tmp = arg1_fra * arg2_fra; 180 181 tmp = (tmp >> BW_FIXED_BITS_PER_FRACTIONAL_PART) + 182 (tmp >= (uint64_t)(bw_frc_to_fixed(1, 2).value)); 183 184 ASSERT(tmp <= (uint64_t)(MAX_I64 - res.value)); 185 186 res.value += tmp; 187 188 if (arg1_negative ^ arg2_negative) 189 res.value = -res.value; 190 return res; 191 } 192 193