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-rw-r--r--src/math/acosl.c57
1 files changed, 28 insertions, 29 deletions
diff --git a/src/math/acosl.c b/src/math/acosl.c
index 9e7b7fb3..c03bdf02 100644
--- a/src/math/acosl.c
+++ b/src/math/acosl.c
@@ -23,46 +23,45 @@ long double acosl(long double x)
}
#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
#include "__invtrigl.h"
+#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, w, s, c, df;
- int16_t expsign, expt;
- u.e = x;
- expsign = u.xbits.expsign;
- expt = expsign & 0x7fff;
+ union ldshape u = {x};
+ long double z, s, c, f;
+ uint16_t e = u.i.se & 0x7fff;
+
/* |x| >= 1 or nan */
- if (expt >= 0x3fff) {
- if (expt == 0x3fff &&
- ((u.bits.manh & ~LDBL_NBIT) | u.bits.manl) == 0) {
- if (expsign > 0)
- return 0; /* acos(1) = 0 */
- return 2*pio2_hi + 0x1p-120f; /* acos(-1)= pi */
- }
- return 0/(x-x); /* acos(|x|>1) is NaN */
+ if (e >= 0x3fff) {
+ if (x == 1)
+ return 0;
+ if (x == -1)
+ return 2*pio2_hi + 0x1p-120f;
+ return 0/(x-x);
}
/* |x| < 0.5 */
- if (expt < 0x3fff - 1) {
- if (expt < 0x3fff - 65)
- return pio2_hi + 0x1p-120f; /* x < 0x1p-65: acosl(x)=pi/2 */
- return pio2_hi - (x - (pio2_lo - x * __invtrigl_R(x*x)));
+ 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 (expsign < 0) {
- z = (1.0 + x) * 0.5;
+ if (u.i.se >> 15) {
+ z = (1 + x)*0.5;
s = sqrtl(z);
- w = __invtrigl_R(z) * s - pio2_lo;
- return 2*(pio2_hi - (s + w));
+ return 2*(pio2_hi - (__invtrigl_R(z)*s - pio2_lo + s));
}
/* x > 0.5 */
- z = (1.0 - x) * 0.5;
+ z = (1 - x)*0.5;
s = sqrtl(z);
- u.e = s;
- u.bits.manl = 0;
- df = u.e;
- c = (z - df * df) / (s + df);
- w = __invtrigl_R(z) * s + c;
- return 2*(df + w);
+ u.f = s;
+ CLEARBOTTOM(u);
+ f = u.f;
+ c = (z - f*f)/(s + f);
+ return 2*(__invtrigl_R(z)*s + c + f);
}
#endif