blob: ec34badfdad84be92fc29b8cf372e56341da5326 [file] [log] [blame]
/*
* Copyright (c) 2014 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
* AUTHORS OR COPYRIGHT HOLDERS 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.
*/
#include "math64.h"
__attribute__((overloadable, always_inline, weak)) double
#if defined(COMPILING_POWR)
powr(double x, double y)
#elif defined(COMPILING_POWN)
pown(double x, int ny)
#elif defined(COMPILING_ROOTN)
rootn(double x, int ny)
#else
pow(double x, double y)
#endif
{
const double real_log2_tail = 5.76999904754328540596e-08;
const double real_log2_lead = 6.93147122859954833984e-01;
USE_TABLE(double2, p_powlog_tbl, POWLOG_TBL);
USE_TABLE(double2, p_log_F_inv_tbl, LOG_F_INV_TBL);
USE_TABLE(double2, p_two_to, TWO_TO_JBY64_EP);
#if defined(COMPILING_POWN)
double y = (double) ny;
#elif defined(COMPILING_ROOTN)
double dny = (double)ny;
double y = 1.0 / dny;
#endif
long ux = as_long(x);
long ax = ux & (~SIGNBIT_DP64);
int xpos = ax == ux;
long uy = as_long(y);
long ay = uy & (~SIGNBIT_DP64);
int ypos = ay == uy;
// Extended precision log
double v, vt;
{
int exp = (int)(ax >> 52) - 1023;
int mask_exp_1023 = exp == -1023;
double xexp = (double) exp;
long mantissa = ax & 0x000FFFFFFFFFFFFFL;
long temp_ux = as_long(as_double(0x3ff0000000000000L | mantissa) - 1.0);
exp = ((temp_ux & 0x7FF0000000000000L) >> 52) - 2045;
double xexp1 = (double) exp;
long mantissa1 = temp_ux & 0x000FFFFFFFFFFFFFL;
xexp = mask_exp_1023 ? xexp1 : xexp;
mantissa = mask_exp_1023 ? mantissa1 : mantissa;
long rax = (mantissa & 0x000ff00000000000) + ((mantissa & 0x0000080000000000) << 1);
int index = rax >> 44;
double F = as_double(rax | 0x3FE0000000000000L);
double Y = as_double(mantissa | 0x3FE0000000000000L);
double f = F - Y;
double2 tv = p_log_F_inv_tbl[index];
double log_h = tv.s0;
double log_t = tv.s1;
double f_inv = (log_h + log_t) * f;
double r1 = as_double(as_long(f_inv) & 0xfffffffff8000000L);
double r2 = fma(-F, r1, f) * (log_h + log_t);
double r = r1 + r2;
double poly = fma(r,
fma(r,
fma(r,
fma(r, 1.0/7.0, 1.0/6.0),
1.0/5.0),
1.0/4.0),
1.0/3.0);
poly = poly * r * r * r;
double hr1r1 = 0.5*r1*r1;
double poly0h = r1 + hr1r1;
double poly0t = r1 - poly0h + hr1r1;
poly = fma(r1, r2, fma(0.5*r2, r2, poly)) + r2 + poly0t;
tv = p_powlog_tbl[index];
log_h = tv.s0;
log_t = tv.s1;
double resT_t = fma(xexp, real_log2_tail, + log_t) - poly;
double resT = resT_t - poly0h;
double resH = fma(xexp, real_log2_lead, log_h);
double resT_h = poly0h;
double H = resT + resH;
double H_h = as_double(as_long(H) & 0xfffffffff8000000L);
double T = (resH - H + resT) + (resT_t - (resT + resT_h)) + (H - H_h);
H = H_h;
double y_head = as_double(uy & 0xfffffffff8000000L);
double y_tail = y - y_head;
#if defined(COMPILING_POWN)
int mask_2_24 = ay > 0x4170000000000000; // 2^24
int nyh = convert_int(y_head);
int nyt = ny - nyh;
double y_tail1 = (double)nyt;
y_tail = mask_2_24 ? y_tail1 : y_tail;
#endif
#if defined(COMPILING_ROOTN)
double fnyh = as_double(as_long(dny) & 0xfffffffffff00000);
double fnyt = (double)(ny - (int)fnyh);
y_tail = fma(-fnyt, y_head, fma(-fnyh, y_head, 1.0))/ dny;
#endif
double temp = fma(y_tail, H, fma(y_head, T, y_tail*T));
v = fma(y_head, H, temp);
vt = fma(y_head, H, -v) + temp;
}
// Now calculate exp of (v,vt)
double expv;
{
const double max_exp_arg = 709.782712893384;
const double min_exp_arg = -745.1332191019411;
const double sixtyfour_by_lnof2 = 92.33248261689366;
const double lnof2_by_64_head = 0.010830424260348081;
const double lnof2_by_64_tail = -4.359010638708991e-10;
double temp = v * sixtyfour_by_lnof2;
int n = (int)temp;
double dn = (double)n;
int j = n & 0x0000003f;
int m = n >> 6;
double2 tv = p_two_to[j];
double f1 = tv.s0;
double f2 = tv.s1;
double f = f1 + f2;
double r1 = fma(dn, -lnof2_by_64_head, v);
double r2 = dn * lnof2_by_64_tail;
double r = (r1 + r2) + vt;
double q = fma(r,
fma(r,
fma(r,
fma(r, 1.38889490863777199667e-03, 8.33336798434219616221e-03),
4.16666666662260795726e-02),
1.66666666665260878863e-01),
5.00000000000000008883e-01);
q = fma(r*r, q, r);
expv = fma(f, q, f2) + f1;
expv = ldexp(expv, m);
expv = v > max_exp_arg ? as_double(0x7FF0000000000000L) : expv;
expv = v < min_exp_arg ? 0.0 : expv;
}
// See whether y is an integer.
// inty = 0 means not an integer.
// inty = 1 means odd integer.
// inty = 2 means even integer.
#if defined(COMPILING_POWN) | defined(COMPILING_ROOTN)
int inty = 2 - (ny & 1);
#else
int inty;
{
int yexp = (int)(ay >> EXPSHIFTBITS_DP64) - EXPBIAS_DP64 + 1;
inty = yexp < 1 ? 0 : 2;
inty = yexp > 53 ? 2 : inty;
long mask = (1L << (53 - yexp)) - 1L;
int inty1 = (((ay & ~mask) >> (53 - yexp)) & 1L) == 1L ? 1 : 2;
inty1 = (ay & mask) != 0 ? 0 : inty1;
inty = !(yexp < 1) & !(yexp > 53) ? inty1 : inty;
}
#endif
expv *= inty == 1 & !xpos ? -1.0 : 1.0;
long ret = as_long(expv);
// Now all the edge cases
#if defined COMPILING_POWR
ret = ax < 0x3ff0000000000000L & uy == NINFBITPATT_DP64 ? PINFBITPATT_DP64 : ret;
ret = ax < 0x3ff0000000000000L & uy == PINFBITPATT_DP64 ? 0L : ret;
ret = ax == 0x3ff0000000000000L & ay < PINFBITPATT_DP64 ? 0x3ff0000000000000L : ret;
ret = ax == 0x3ff0000000000000L & ay == PINFBITPATT_DP64 ? QNANBITPATT_DP64 : ret;
ret = ax > 0x3ff0000000000000L & uy == NINFBITPATT_DP64 ? 0L : ret;
ret = ax > 0x3ff0000000000000L & uy == PINFBITPATT_DP64 ? PINFBITPATT_DP64 : ret;
ret = ux < PINFBITPATT_DP64 & ay == 0L ? 0x3ff0000000000000L : ret;
ret = ax == PINFBITPATT_DP64 & !ypos ? 0L : ret;
ret = ax == PINFBITPATT_DP64 & ypos ? PINFBITPATT_DP64 : ret;
ret = ax == PINFBITPATT_DP64 & uy == PINFBITPATT_DP64 ? PINFBITPATT_DP64 : ret;
ret = ax == PINFBITPATT_DP64 & ay == 0L ? QNANBITPATT_DP64 : ret;
ret = ax == 0L & !ypos ? PINFBITPATT_DP64 : ret;
ret = ax == 0L & ypos ? 0L : ret;
ret = ax == 0L & ay == 0L ? QNANBITPATT_DP64 : ret;
ret = ax != 0L & !xpos ? QNANBITPATT_DP64 : ret;
ret = ax > PINFBITPATT_DP64 ? ux : ret;
ret = ay > PINFBITPATT_DP64 ? uy : ret;
#elif defined COMPILING_POWN
long xinf = xpos ? PINFBITPATT_DP64 : NINFBITPATT_DP64;
ret = ax == 0L & !ypos & inty == 1 ? xinf : ret;
ret = ax == 0L & !ypos & inty == 2 ? PINFBITPATT_DP64 : ret;
ret = ax == 0L & ypos & inty == 2 ? 0L : ret;
long xzero = !xpos ? 0x8000000000000000L : 0L;
ret = ax == 0L & ypos & inty == 1 ? xzero : ret;
ret = ux == NINFBITPATT_DP64 & !ypos & inty == 1 ? 0x8000000000000000L : ret;
ret = ux == NINFBITPATT_DP64 & !ypos & inty != 1 ? 0L : ret;
ret = ux == NINFBITPATT_DP64 & ypos & inty == 1 ? NINFBITPATT_DP64 : ret;
ret = ux == NINFBITPATT_DP64 & ypos & inty != 1 ? PINFBITPATT_DP64 : ret;
ret = ux == PINFBITPATT_DP64 & !ypos ? 0L : ret;
ret = ux == PINFBITPATT_DP64 & ypos ? PINFBITPATT_DP64 : ret;
ret = ax > PINFBITPATT_DP64 ? ux : ret;
ret = ny == 0 ? 0x3ff0000000000000L : ret;
#elif defined COMPILING_ROOTN
ret = !xpos & inty == 2 ? QNANBITPATT_DP64 : ret;
long xinf = xpos ? PINFBITPATT_DP64 : NINFBITPATT_DP64;
ret = ax == 0L & !ypos & inty == 1 ? xinf : ret;
ret = ax == 0L & !ypos & inty == 2 ? PINFBITPATT_DP64 : ret;
ret = ax == 0L & ypos & inty == 2 ? 0L : ret;
long xzero = xpos ? 0L : 0x8000000000000000L;
ret = ax == 0L & ypos & inty == 1 ? xzero : ret;
ret = ux == NINFBITPATT_DP64 & ypos & inty == 1 ? NINFBITPATT_DP64 : ret;
ret = ux == NINFBITPATT_DP64 & !ypos & inty == 1 ? 0x8000000000000000L : ret;
ret = ux == PINFBITPATT_DP64 & !ypos ? 0L : ret;
ret = ux == PINFBITPATT_DP64 & ypos ? PINFBITPATT_DP64 : ret;
ret = ax > PINFBITPATT_DP64 ? ux : ret;
ret = ny == 0 ? QNANBITPATT_DP64 : ret;
#else
ret = !xpos & inty == 0 ? QNANBITPATT_DP64 : ret;
ret = ax < 0x3ff0000000000000L & uy == NINFBITPATT_DP64 ? PINFBITPATT_DP64 : ret;
ret = ax > 0x3ff0000000000000L & uy == NINFBITPATT_DP64 ? 0L : ret;
ret = ax < 0x3ff0000000000000L & uy == PINFBITPATT_DP64 ? 0L : ret;
ret = ax > 0x3ff0000000000000L & uy == PINFBITPATT_DP64 ? PINFBITPATT_DP64 : ret;
long xinf = xpos ? PINFBITPATT_DP64 : NINFBITPATT_DP64;
ret = ax == 0L & !ypos & inty == 1 ? xinf : ret;
ret = ax == 0L & !ypos & inty != 1 ? PINFBITPATT_DP64 : ret;
long xzero = xpos ? 0L : 0x8000000000000000L;
ret = ax == 0L & ypos & inty == 1 ? xzero : ret;
ret = ax == 0L & ypos & inty != 1 ? 0L : ret;
ret = ax == 0L & uy == NINFBITPATT_DP64 ? PINFBITPATT_DP64 : ret;
ret = ux == 0xbff0000000000000L & ay == PINFBITPATT_DP64 ? 0x3ff0000000000000L : ret;
ret = ux == NINFBITPATT_DP64 & !ypos & inty == 1 ? 0x8000000000000000L : ret;
ret = ux == NINFBITPATT_DP64 & !ypos & inty != 1 ? 0L : ret;
ret = ux == NINFBITPATT_DP64 & ypos & inty == 1 ? NINFBITPATT_DP64 : ret;
ret = ux == NINFBITPATT_DP64 & ypos & inty != 1 ? PINFBITPATT_DP64 : ret;
ret = ux == PINFBITPATT_DP64 & !ypos ? 0L : ret;
ret = ux == PINFBITPATT_DP64 & ypos ? PINFBITPATT_DP64 : ret;
ret = ax > PINFBITPATT_DP64 ? ux : ret;
ret = ay > PINFBITPATT_DP64 ? uy : ret;
ret = ay == 0L ? 0x3ff0000000000000L : ret;
ret = ux == 0x3ff0000000000000L ? 0x3ff0000000000000L : ret;
#endif
return as_double(ret);
}