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/*
* Copyright 2015 Advanced Micro Devices, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* Authors: AMD
*
*/
#include "dm_services.h"
#include "bw_fixed.h"
#define MIN_I64 \
(int64_t)(-(1LL << 63))
#define MAX_I64 \
(int64_t)((1ULL << 63) - 1)
#define FRACTIONAL_PART_MASK \
((1ULL << BW_FIXED_BITS_PER_FRACTIONAL_PART) - 1)
#define GET_FRACTIONAL_PART(x) \
(FRACTIONAL_PART_MASK & (x))
static uint64_t abs_i64(int64_t arg)
{
if (arg >= 0)
return (uint64_t)(arg);
else
return (uint64_t)(-arg);
}
struct bw_fixed bw_int_to_fixed_nonconst(int64_t value)
{
struct bw_fixed res;
ASSERT(value < BW_FIXED_MAX_I32 && value > BW_FIXED_MIN_I32);
res.value = value << BW_FIXED_BITS_PER_FRACTIONAL_PART;
return res;
}
struct bw_fixed bw_frc_to_fixed(int64_t numerator, int64_t denominator)
{
struct bw_fixed res;
bool arg1_negative = numerator < 0;
bool arg2_negative = denominator < 0;
uint64_t arg1_value;
uint64_t arg2_value;
uint64_t remainder;
/* determine integer part */
uint64_t res_value;
ASSERT(denominator != 0);
arg1_value = abs_i64(numerator);
arg2_value = abs_i64(denominator);
res_value = div64_u64_rem(arg1_value, arg2_value, &remainder);
ASSERT(res_value <= BW_FIXED_MAX_I32);
/* determine fractional part */
{
uint32_t i = BW_FIXED_BITS_PER_FRACTIONAL_PART;
do
{
remainder <<= 1;
res_value <<= 1;
if (remainder >= arg2_value)
{
res_value |= 1;
remainder -= arg2_value;
}
} while (--i != 0);
}
/* round up LSB */
{
uint64_t summand = (remainder << 1) >= arg2_value;
ASSERT(res_value <= MAX_I64 - summand);
res_value += summand;
}
res.value = (int64_t)(res_value);
if (arg1_negative ^ arg2_negative)
res.value = -res.value;
return res;
}
struct bw_fixed bw_floor2(
const struct bw_fixed arg,
const struct bw_fixed significance)
{
struct bw_fixed result;
int64_t multiplicand;
multiplicand = div64_s64(arg.value, abs_i64(significance.value));
result.value = abs_i64(significance.value) * multiplicand;
ASSERT(abs_i64(result.value) <= abs_i64(arg.value));
return result;
}
struct bw_fixed bw_ceil2(
const struct bw_fixed arg,
const struct bw_fixed significance)
{
struct bw_fixed result;
int64_t multiplicand;
multiplicand = div64_s64(arg.value, abs_i64(significance.value));
result.value = abs_i64(significance.value) * multiplicand;
if (abs_i64(result.value) < abs_i64(arg.value)) {
if (arg.value < 0)
result.value -= abs_i64(significance.value);
else
result.value += abs_i64(significance.value);
}
return result;
}
struct bw_fixed bw_mul(const struct bw_fixed arg1, const struct bw_fixed arg2)
{
struct bw_fixed res;
bool arg1_negative = arg1.value < 0;
bool arg2_negative = arg2.value < 0;
uint64_t arg1_value = abs_i64(arg1.value);
uint64_t arg2_value = abs_i64(arg2.value);
uint64_t arg1_int = BW_FIXED_GET_INTEGER_PART(arg1_value);
uint64_t arg2_int = BW_FIXED_GET_INTEGER_PART(arg2_value);
uint64_t arg1_fra = GET_FRACTIONAL_PART(arg1_value);
uint64_t arg2_fra = GET_FRACTIONAL_PART(arg2_value);
uint64_t tmp;
res.value = arg1_int * arg2_int;
ASSERT(res.value <= BW_FIXED_MAX_I32);
res.value <<= BW_FIXED_BITS_PER_FRACTIONAL_PART;
tmp = arg1_int * arg2_fra;
ASSERT(tmp <= (uint64_t)(MAX_I64 - res.value));
res.value += tmp;
tmp = arg2_int * arg1_fra;
ASSERT(tmp <= (uint64_t)(MAX_I64 - res.value));
res.value += tmp;
tmp = arg1_fra * arg2_fra;
tmp = (tmp >> BW_FIXED_BITS_PER_FRACTIONAL_PART) +
(tmp >= (uint64_t)(bw_frc_to_fixed(1, 2).value));
ASSERT(tmp <= (uint64_t)(MAX_I64 - res.value));
res.value += tmp;
if (arg1_negative ^ arg2_negative)
res.value = -res.value;
return res;
}
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