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/* $Id: extF80_sincos.c $ */
/** @file
* SoftFloat - VBox Extension - extF80_sin, extF80_cos, extF80_sincos, extF80_atan2.
*/
/*
* Copyright (C) 2022 Oracle and/or its affiliates.
*
* This file is part of VirtualBox base platform packages, as
* available from https://www.virtualbox.org.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, in version 3 of the
* License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <https://www.gnu.org/licenses>.
*
* SPDX-License-Identifier: GPL-3.0-only
*/
/*********************************************************************************************************************************
* Header Files *
*********************************************************************************************************************************/
#include <stdbool.h>
#include <stdint.h>
#include "platform.h"
#include "internals.h"
#include "specialize.h"
#include "softfloat.h"
#include <iprt/types.h>
#include <iprt/x86.h>
#include "extF80_sincos.h"
static void cordic_sincos( float128_t z, float128_t *pv1, float128_t *pv2 SOFTFLOAT_STATE_DECL_COMMA )
{
float128_t v1 = { { 0, 0 } }; /* MSC thinks it can be used uninitialized */
float128_t v2 = { { 0, 0 } }; /* MSC thinks it can be used uninitialized */
/** @todo TBD: CORDIC kernel should be easily implemented in assembly * */
float128_t x1 = ui32_to_f128(1, pState);
float128_t x2 = ui32_to_f128(0, pState);
float128_t zz = ui32_to_f128(0, pState);
float128_t p2m = ui32_to_f128(1, pState);
float128_t two = ui32_to_f128(2, pState);
for (unsigned k = 0; k < RT_ELEMENTS(g_ar128FsincosCORDICConsts); k++)
{
float128_t atg = *(float128_t *)&g_ar128FsincosCORDICConsts[k];
float128_t scale = *(float128_t *)&g_ar128FsincosCORDICConsts2[k];
float128_t px1 = f128_mul(x1, p2m, pState);
float128_t px2 = f128_mul(x2, p2m, pState);
if (f128_le(zz, z, pState))
{
x1 = f128_sub(x1, px2, pState);
x2 = f128_add(x2, px1, pState);
zz = f128_add(zz, atg, pState);
}
else
{
x1 = f128_add(x1, px2, pState);
x2 = f128_sub(x2, px1, pState);
zz = f128_sub(zz, atg, pState);
}
p2m = f128_div(p2m, two, pState);
v1 = f128_mul(x1, scale, pState);
v2 = f128_mul(x2, scale, pState);
}
*pv1 = v1;
*pv2 = v2;
}
static float128_t cordic_atan2( float128_t y, float128_t x SOFTFLOAT_STATE_DECL_COMMA )
{
float128_t v1 = { { 0, 0 } }; /* MSC thinks it can be used uninitialized */
float128_t v2 = { { 0, 0 } }; /* MSC thinks it can be used uninitialized */
/** @todo TBD: CORDIC kernel should be easily implemented in assembly * */
float128_t x1 = x, x2 = y;
float128_t z = ui32_to_f128(0, pState);
float128_t zero = ui32_to_f128(0, pState);
float128_t p2m = ui32_to_f128(1, pState);
float128_t two = ui32_to_f128(2, pState);
for (unsigned k = 0; k < RT_ELEMENTS(g_ar128FsincosCORDICConsts); k++)
{
float128_t atg = *(float128_t *)&g_ar128FsincosCORDICConsts[k];
float128_t scale = *(float128_t *)&g_ar128FsincosCORDICConsts2[k];
float128_t px1 = f128_mul(x1, p2m, pState);
float128_t px2 = f128_mul(x2, p2m, pState);
if (f128_le(x2, zero, pState))
{
x1 = f128_sub(x1, px2, pState);
x2 = f128_add(x2, px1, pState);
z = f128_sub(z, atg, pState);
}
else
{
x1 = f128_add(x1, px2, pState);
x2 = f128_sub(x2, px1, pState);
z = f128_add(z, atg, pState);
}
p2m = f128_div(p2m, two, pState);
v1 = f128_mul(x1, scale, pState);
v2 = f128_mul(x2, scale, pState);
}
return z;
}
extFloat80_t extF80_sin( extFloat80_t x SOFTFLOAT_STATE_DECL_COMMA )
{
int32_t fSign = 0;
extFloat80_t f80zero = ui32_to_extF80(0, pState);
if (extF80_le(x, f80zero, pState))
{
x = extF80_sub(f80zero, x, pState);
fSign = 1;
}
extFloat80_t f80pi2 = f128_to_extF80(*(float128_t *)&g_r128pi2, pState);
/** @todo TBD: Partial remainder should be calculated using float128 value of pi2 to increase precision **/
uint16_t fCxFlags = 0;
extFloat80_t rem = extF80_partialRem(x, f80pi2, pState->roundingMode, &fCxFlags, pState);
int32_t const quo = X86_FSW_CX_TO_QUOTIENT(fCxFlags);
float128_t z = extF80_to_f128(rem, pState);
float128_t f128zero = ui32_to_f128(0, pState);
float128_t v1, v2;
cordic_sincos(z, &v1, &v2, pState);
float128_t v;
switch(quo % 4)
{
#ifdef _MSC_VER /* stupid MSC thinks v might be used uninitialized otherwise: */
default:
#endif
case 0:
v = v2;
break;
case 1:
v = v1;
break;
case 2:
v = f128_sub(f128zero, v2, pState);
break;
case 3:
v = f128_sub(f128zero, v1, pState);
break;
}
if (fSign)
v = f128_sub(f128zero, v, pState);
return f128_to_extF80(v, pState);
}
extFloat80_t extF80_cos( extFloat80_t x SOFTFLOAT_STATE_DECL_COMMA )
{
extFloat80_t f80zero = ui32_to_extF80(0, pState);
if (extF80_le(x, f80zero, pState))
x = extF80_sub(f80zero, x, pState);
extFloat80_t f80pi2 = f128_to_extF80(*(float128_t *)&g_r128pi2, pState);
/** TBD: Partial remainder should be calculated using float128 value of pi2 to increase precision **/
uint16_t fCxFlags = 0;
extFloat80_t rem = extF80_partialRem(x, f80pi2, pState->roundingMode, &fCxFlags, pState);
int32_t const quo = X86_FSW_CX_TO_QUOTIENT(fCxFlags);
float128_t z = extF80_to_f128(rem, pState);
float128_t f128zero = ui32_to_f128(0, pState);
float128_t v1, v2;
cordic_sincos(z, &v1, &v2, pState);
float128_t v;
switch(quo % 4)
{
#ifdef _MSC_VER /* stupid MSC thinks v might be used uninitialized otherwise: */
default:
#endif
case 0:
v = v1;
break;
case 1:
v = f128_sub(f128zero, v2, pState);;
break;
case 2:
v = f128_sub(f128zero, v1, pState);
break;
case 3:
v = v2;
break;
}
return f128_to_extF80(v, pState);
}
void extF80_sincos( extFloat80_t x, extFloat80_t* pSin, extFloat80_t* pCos SOFTFLOAT_STATE_DECL_COMMA )
{
uint16_t fCxFlags = 0;
int32_t quo;
extFloat80_t rem, f80pi2, f80zero;
int32_t fSign = 0;
f80zero = ui32_to_extF80(0, pState);
if (extF80_le(x, f80zero, pState))
{
x = extF80_sub(f80zero, x, pState);
fSign = 1;
}
f80pi2 = f128_to_extF80(*(float128_t const *)&g_r128pi2, pState);
/** @todo TBD: Partial remainder should be calculated using float128 value of pi2 to increase precision **/
rem = extF80_partialRem(x, f80pi2, pState->roundingMode, &fCxFlags, pState);
quo = X86_FSW_CX_TO_QUOTIENT(fCxFlags);
float128_t z = extF80_to_f128(rem, pState);
float128_t f128zero = ui32_to_f128(0, pState);
float128_t v1, v2;
cordic_sincos(z, &v1, &v2, pState);
float128_t vCos, vSin;
switch(quo % 4)
{
#ifdef _MSC_VER /* stupid MSC thinks vCos & cSin might be used uninitialized otherwise: */
default:
#endif
case 0:
vCos = v1;
vSin = v2;
break;
case 1:
vCos = f128_sub(f128zero, v2, pState);
vSin = v1;
break;
case 2:
vCos = f128_sub(f128zero, v1, pState);
vSin = f128_sub(f128zero, v2, pState);
break;
case 3:
vCos = v2;
vSin = f128_sub(f128zero, v1, pState);
break;
}
if (fSign)
vSin = f128_sub(f128zero, vSin, pState);
*pCos = f128_to_extF80(vCos, pState);
*pSin = f128_to_extF80(vSin, pState);
}
extFloat80_t extF80_atan2( extFloat80_t f80y, extFloat80_t f80x SOFTFLOAT_STATE_DECL_COMMA )
{
float128_t v;
int32_t fSignX = 0, fSignY = 0;
float128_t f128zero = ui32_to_f128(0, pState);
float128_t y = extF80_to_f128(f80y, pState);
float128_t x = extF80_to_f128(f80x, pState);
if (f128_le(x, f128zero, pState))
{
x = f128_sub(f128zero, x, pState);
fSignX = 1;
}
if (f128_le(y, f128zero, pState))
{
y = f128_sub(f128zero, y, pState);
fSignY = 1;
}
v = cordic_atan2(y, x, pState);
if (fSignX)
{
if (fSignY)
v = f128_sub(v, *(float128_t const *)&g_r128pi, pState);
else
v = f128_sub(*(float128_t const *)&g_r128pi, v, pState);
}
else
{
if (fSignY)
v = f128_sub(f128zero, v, pState);
}
return f128_to_extF80(v, pState);
}
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