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/*
* Copyright 2017 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 "custom_float.h"
static bool build_custom_float(
struct fixed31_32 value,
const struct custom_float_format *format,
bool *negative,
uint32_t *mantissa,
uint32_t *exponenta)
{
uint32_t exp_offset = (1 << (format->exponenta_bits - 1)) - 1;
const struct fixed31_32 mantissa_constant_plus_max_fraction =
dal_fixed31_32_from_fraction(
(1LL << (format->mantissa_bits + 1)) - 1,
1LL << format->mantissa_bits);
struct fixed31_32 mantiss;
if (dal_fixed31_32_eq(
value,
dal_fixed31_32_zero)) {
*negative = false;
*mantissa = 0;
*exponenta = 0;
return true;
}
if (dal_fixed31_32_lt(
value,
dal_fixed31_32_zero)) {
*negative = format->sign;
value = dal_fixed31_32_neg(value);
} else {
*negative = false;
}
if (dal_fixed31_32_lt(
value,
dal_fixed31_32_one)) {
uint32_t i = 1;
do {
value = dal_fixed31_32_shl(value, 1);
++i;
} while (dal_fixed31_32_lt(
value,
dal_fixed31_32_one));
--i;
if (exp_offset <= i) {
*mantissa = 0;
*exponenta = 0;
return true;
}
*exponenta = exp_offset - i;
} else if (dal_fixed31_32_le(
mantissa_constant_plus_max_fraction,
value)) {
uint32_t i = 1;
do {
value = dal_fixed31_32_shr(value, 1);
++i;
} while (dal_fixed31_32_lt(
mantissa_constant_plus_max_fraction,
value));
*exponenta = exp_offset + i - 1;
} else {
*exponenta = exp_offset;
}
mantiss = dal_fixed31_32_sub(
value,
dal_fixed31_32_one);
if (dal_fixed31_32_lt(
mantiss,
dal_fixed31_32_zero) ||
dal_fixed31_32_lt(
dal_fixed31_32_one,
mantiss))
mantiss = dal_fixed31_32_zero;
else
mantiss = dal_fixed31_32_shl(
mantiss,
format->mantissa_bits);
*mantissa = dal_fixed31_32_floor(mantiss);
return true;
}
static bool setup_custom_float(
const struct custom_float_format *format,
bool negative,
uint32_t mantissa,
uint32_t exponenta,
uint32_t *result)
{
uint32_t i = 0;
uint32_t j = 0;
uint32_t value = 0;
/* verification code:
* once calculation is ok we can remove it
*/
const uint32_t mantissa_mask =
(1 << (format->mantissa_bits + 1)) - 1;
const uint32_t exponenta_mask =
(1 << (format->exponenta_bits + 1)) - 1;
if (mantissa & ~mantissa_mask) {
BREAK_TO_DEBUGGER();
mantissa = mantissa_mask;
}
if (exponenta & ~exponenta_mask) {
BREAK_TO_DEBUGGER();
exponenta = exponenta_mask;
}
/* end of verification code */
while (i < format->mantissa_bits) {
uint32_t mask = 1 << i;
if (mantissa & mask)
value |= mask;
++i;
}
while (j < format->exponenta_bits) {
uint32_t mask = 1 << j;
if (exponenta & mask)
value |= mask << i;
++j;
}
if (negative && format->sign)
value |= 1 << (i + j);
*result = value;
return true;
}
bool convert_to_custom_float_format(
struct fixed31_32 value,
const struct custom_float_format *format,
uint32_t *result)
{
uint32_t mantissa;
uint32_t exponenta;
bool negative;
return build_custom_float(
value, format, &negative, &mantissa, &exponenta) &&
setup_custom_float(
format, negative, mantissa, exponenta, result);
}
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