double jvm_fplib_acos(double x) {
double z,p,q,r,w,s,c,df;
int hx,ix;
hx = __JHI(x);
ix = hx&0x7fffffff;
if(ix>=0x3ff00000) { /* |x| >= 1 */
if(((ix-0x3ff00000)|__JLO(x))==0) { /* |x|==1 */
if(hx>0) return 0.0; /* acos(1) = 0 */
else return ac_pi+2.0*ac_pio2_lo; /* acos(-1)= pi */
}
return jvm_ddiv(jvm_dsub(x, x), jvm_dsub(x, x)); /* acos(|x|>1) is NaN */
}
if(ix<0x3fe00000) { /* |x| < 0.5 */
if(ix<=0x3c600000) return ac_pio2_hi+ac_pio2_lo;/*if|x|<2**-57*/
z = jvm_dmul(x, x);
p = jvm_dmul(z, jvm_dadd(ac_pS0, jvm_dmul(z, jvm_dadd(ac_pS1, jvm_dmul(z, jvm_dadd(ac_pS2, jvm_dmul(z, jvm_dadd(ac_pS3, jvm_dmul(z, jvm_dadd(ac_pS4, jvm_dmul(z, ac_pS5)))))))))));
q = jvm_dadd(ac_one, jvm_dmul(z, jvm_dadd(ac_qS1, jvm_dmul(z, jvm_dadd(ac_qS2, jvm_dmul(z, jvm_dadd(ac_qS3, jvm_dmul(z, ac_qS4))))))));
r = jvm_ddiv(p, q);
return jvm_dsub(ac_pio2_hi, jvm_dsub(x, jvm_dsub(ac_pio2_lo, jvm_dmul(x, r))));
} else if (hx<0) { /* x < -0.5 */
z = jvm_dmul(jvm_dadd(ac_one, x), 0.5);
p = jvm_dmul(z, jvm_dadd(ac_pS0, jvm_dmul(z, jvm_dadd(ac_pS1, jvm_dmul(z, jvm_dadd(ac_pS2, jvm_dmul(z, jvm_dadd(ac_pS3, jvm_dmul(z, jvm_dadd(ac_pS4, jvm_dmul(z, ac_pS5)))))))))));
q = jvm_dadd(ac_one, jvm_dmul(z, jvm_dadd(ac_qS1, jvm_dmul(z, jvm_dadd(ac_qS2, jvm_dmul(z, jvm_dadd(ac_qS3, jvm_dmul(z, ac_qS4))))))));
s = ieee754_sqrt(z);
r = jvm_ddiv(p, q);
w = jvm_dsub(jvm_dmul(r, s), ac_pio2_lo);
return jvm_dsub(ac_pi, jvm_dmul(2.0, jvm_dadd(s, w)));
} else { /* x > 0.5 */
z = jvm_dmul(jvm_dsub(ac_one, x), 0.5);
s = ieee754_sqrt(z);
df = s;
__JLO(df) = 0;
c = jvm_ddiv(jvm_dsub(z, jvm_dmul(df, df)), jvm_dadd(s, df));
p = jvm_dmul(z, jvm_dadd(ac_pS0, jvm_dmul(z, jvm_dadd(ac_pS1, jvm_dmul(z, jvm_dadd(ac_pS2, jvm_dmul(z, jvm_dadd(ac_pS3, jvm_dmul(z, jvm_dadd(ac_pS4, jvm_dmul(z, ac_pS5)))))))))));
q = jvm_dadd(ac_one, jvm_dmul(z, jvm_dadd(ac_qS1, jvm_dmul(z, jvm_dadd(ac_qS2, jvm_dmul(z, jvm_dadd(ac_qS3, jvm_dmul(z, ac_qS4))))))));
r = jvm_ddiv(p, q);
w = jvm_dadd(jvm_dmul(r, s), c);
return jvm_dmul(2.0, jvm_dadd(df, w));
}
}
JVM_SOFTFP_LINKAGE jdouble jvm_sqrt(jdouble x) {
return ieee754_sqrt(x);
}
