}
#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
#include "__invtrigl.h"
-
-static const long double
-pi = 3.14159265358979323846264338327950280e+00L;
+#if LDBL_MANT_DIG == 64
+#define CLEARBOTTOM(u) (u.i.m &= -1ULL << 32)
+#elif LDBL_MANT_DIG == 113
+#define CLEARBOTTOM(u) (u.i.lo = 0)
+#endif
long double acosl(long double x)
{
- union IEEEl2bits u;
- long double z, p, q, r, w, s, c, df;
- int16_t expsign, expt;
- u.e = x;
- expsign = u.xbits.expsign;
- expt = expsign & 0x7fff;
- if (expt >= BIAS) { /* |x| >= 1 */
- if (expt == BIAS &&
- ((u.bits.manh & ~LDBL_NBIT) | u.bits.manl) == 0) {
- if (expsign > 0)
- return 0.0; /* acos(1) = 0 */
- else
- return pi + 2.0 * pio2_lo; /* acos(-1)= pi */
- }
- return (x - x) / (x - x); /* acos(|x|>1) is NaN */
+ union ldshape u = {x};
+ long double z, s, c, f;
+ uint16_t e = u.i.se & 0x7fff;
+
+ /* |x| >= 1 or nan */
+ if (e >= 0x3fff) {
+ if (x == 1)
+ return 0;
+ if (x == -1)
+ return 2*pio2_hi + 0x1p-120f;
+ return 0/(x-x);
}
- if (expt < BIAS - 1) { /* |x| < 0.5 */
- if (expt < ACOS_CONST)
- return pio2_hi + pio2_lo; /* x tiny: acosl=pi/2 */
- z = x * x;
- p = P(z);
- q = Q(z);
- r = p / q;
- return pio2_hi - (x - (pio2_lo - x * r));
- } else if (expsign < 0) { /* x < -0.5 */
- z = (1.0 + x) * 0.5;
- p = P(z);
- q = Q(z);
- s = sqrtl(z);
- r = p / q;
- w = r * s - pio2_lo;
- return pi - 2.0 * (s + w);
- } else { /* x > 0.5 */
- z = (1.0 - x) * 0.5;
+ /* |x| < 0.5 */
+ if (e < 0x3fff - 1) {
+ if (e < 0x3fff - LDBL_MANT_DIG - 1)
+ return pio2_hi + 0x1p-120f;
+ return pio2_hi - (__invtrigl_R(x*x)*x - pio2_lo + x);
+ }
+ /* x < -0.5 */
+ if (u.i.se >> 15) {
+ z = (1 + x)*0.5;
s = sqrtl(z);
- u.e = s;
- u.bits.manl = 0;
- df = u.e;
- c = (z - df * df) / (s + df);
- p = P(z);
- q = Q(z);
- r = p / q;
- w = r * s + c;
- return 2.0 * (df + w);
+ return 2*(pio2_hi - (__invtrigl_R(z)*s - pio2_lo + s));
}
+ /* x > 0.5 */
+ z = (1 - x)*0.5;
+ s = sqrtl(z);
+ u.f = s;
+ CLEARBOTTOM(u);
+ f = u.f;
+ c = (z - f*f)/(s + f);
+ return 2*(__invtrigl_R(z)*s + c + f);
}
#endif