X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fmath%2Facosl.c;h=c03bdf0235ccffd08ca26b603531a9defe11070a;hb=c5f4b2dfea320356f69445dc1adf8f73596a3c36;hp=170520fe9c3e794acacd388d5be87324a2331938;hpb=eca1c35e5be967478c8fe9381c6f4652b6645d5e;p=musl

diff --git a/src/math/acosl.c b/src/math/acosl.c
index 170520fe..c03bdf02 100644
--- a/src/math/acosl.c
+++ b/src/math/acosl.c
@@ -23,57 +23,45 @@ long double acosl(long double x)
 }
 #elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
 #include "__invtrigl.h"
-
-static const long double
-one = 1.00000000000000000000e+00,
-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 = (one + 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 = (one - 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