OpenLibm/ld128/e_rem_pio2l.h
Ed Schouten 845b329cb9 Remove __always_inline, just like we do for ld80.
__always_inline is a (Free)BSD specific definition from cdefs.h.
Compilers like Clang don't care about these keywords anyway, as they
simply do whatever they like.

It looks like we already removed this keyword from ld80/e_rem_pio2l.h as
well. Apply exactly the same change to the ld128 version as well.
2015-10-26 10:28:11 +01:00

145 lines
4.2 KiB
C

/* From: @(#)e_rem_pio2.c 1.4 95/01/18 */
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
* Copyright (c) 2008 Steven G. Kargl, David Schultz, Bruce D. Evans.
*
* Developed at SunSoft, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*
* Optimized by Bruce D. Evans.
*/
#include "cdefs-compat.h"
//__FBSDID("$FreeBSD: src/lib/msun/ld128/e_rem_pio2l.h,v 1.2 2011/05/30 19:41:28 kargl Exp $");
/* ld128 version of __ieee754_rem_pio2l(x,y)
*
* return the remainder of x rem pi/2 in y[0]+y[1]
* use __kernel_rem_pio2()
*/
#include <float.h>
#include <openlibm_math.h>
#include "math_private.h"
#include "fpmath.h"
#define BIAS (LDBL_MAX_EXP - 1)
/*
* XXX need to verify that nonzero integer multiples of pi/2 within the
* range get no closer to a long double than 2**-140, or that
* ilogb(x) + ilogb(min_delta) < 45 - -140.
*/
/*
* invpio2: 113 bits of 2/pi
* pio2_1: first 68 bits of pi/2
* pio2_1t: pi/2 - pio2_1
* pio2_2: second 68 bits of pi/2
* pio2_2t: pi/2 - (pio2_1+pio2_2)
* pio2_3: third 68 bits of pi/2
* pio2_3t: pi/2 - (pio2_1+pio2_2+pio2_3)
*/
static const double
zero = 0.00000000000000000000e+00, /* 0x00000000, 0x00000000 */
two24 = 1.67772160000000000000e+07; /* 0x41700000, 0x00000000 */
static const long double
invpio2 = 6.3661977236758134307553505349005747e-01L, /* 0x145f306dc9c882a53f84eafa3ea6a.0p-113 */
pio2_1 = 1.5707963267948966192292994253909555e+00L, /* 0x1921fb54442d18469800000000000.0p-112 */
pio2_1t = 2.0222662487959507323996846200947577e-21L, /* 0x13198a2e03707344a4093822299f3.0p-181 */
pio2_2 = 2.0222662487959507323994779168837751e-21L, /* 0x13198a2e03707344a400000000000.0p-181 */
pio2_2t = 2.0670321098263988236496903051604844e-43L, /* 0x127044533e63a0105df531d89cd91.0p-254 */
pio2_3 = 2.0670321098263988236499468110329591e-43L, /* 0x127044533e63a0105e00000000000.0p-254 */
pio2_3t = -2.5650587247459238361625433492959285e-65L; /* -0x159c4ec64ddaeb5f78671cbfb2210.0p-327 */
//VBS
//static inline __always_inline int
//__ieee754_rem_pio2l(long double x, long double *y)
static inline int
__ieee754_rem_pio2l(long double x, long double *y)
{
union IEEEl2bits u,u1;
long double z,w,t,r,fn;
double tx[5],ty[3];
int64_t n;
int e0,ex,i,j,nx;
int16_t expsign;
u.e = x;
expsign = u.xbits.expsign;
ex = expsign & 0x7fff;
if (ex < BIAS + 45 || ex == BIAS + 45 &&
u.bits.manh < 0x921fb54442d1LL) {
/* |x| ~< 2^45*(pi/2), medium size */
/* Use a specialized rint() to get fn. Assume round-to-nearest. */
fn = x*invpio2+0x1.8p112;
fn = fn-0x1.8p112;
#ifdef HAVE_EFFICIENT_I64RINT
n = i64rint(fn);
#else
n = fn;
#endif
r = x-fn*pio2_1;
w = fn*pio2_1t; /* 1st round good to 180 bit */
{
union IEEEl2bits u2;
int ex1;
j = ex;
y[0] = r-w;
u2.e = y[0];
ex1 = u2.xbits.expsign & 0x7fff;
i = j-ex1;
if(i>51) { /* 2nd iteration needed, good to 248 */
t = r;
w = fn*pio2_2;
r = t-w;
w = fn*pio2_2t-((t-r)-w);
y[0] = r-w;
u2.e = y[0];
ex1 = u2.xbits.expsign & 0x7fff;
i = j-ex1;
if(i>119) { /* 3rd iteration need, 316 bits acc */
t = r; /* will cover all possible cases */
w = fn*pio2_3;
r = t-w;
w = fn*pio2_3t-((t-r)-w);
y[0] = r-w;
}
}
}
y[1] = (r-y[0])-w;
return n;
}
/*
* all other (large) arguments
*/
if(ex==0x7fff) { /* x is inf or NaN */
y[0]=y[1]=x-x; return 0;
}
/* set z = scalbn(|x|,ilogb(x)-23) */
u1.e = x;
e0 = ex - BIAS - 23; /* e0 = ilogb(|x|)-23; */
u1.xbits.expsign = ex - e0;
z = u1.e;
for(i=0;i<4;i++) {
tx[i] = (double)((int32_t)(z));
z = (z-tx[i])*two24;
}
tx[4] = z;
nx = 5;
while(tx[nx-1]==zero) nx--; /* skip zero term */
n = __kernel_rem_pio2(tx,ty,e0,nx,3);
t = (long double)ty[2] + ty[1];
r = t + ty[0];
w = ty[0] - (r - t);
if(expsign<0) {y[0] = -r; y[1] = -w; return -n;}
y[0] = r; y[1] = w; return n;
}