float tanf(float x)
{
double y;
uint32_t ix;
unsigned n, sign;
GET_FLOAT_WORD(ix, x);
sign = ix >> 31;
ix &= 0x7fffffff;
if (ix <= 0x3f490fda) { /* |x| ~<= pi/4 */
if (ix < 0x39800000) { /* |x| < 2**-12 */
/* raise inexact if x!=0 and underflow if subnormal */
FORCE_EVAL(ix < 0x00800000 ? x/0x1p120f : x+0x1p120f);
return x;
}
return __tandf(x, 0);
}
if (ix <= 0x407b53d1) { /* |x| ~<= 5*pi/4 */
if (ix <= 0x4016cbe3) /* |x| ~<= 3pi/4 */
return __tandf((sign ? x+t1pio2 : x-t1pio2), 1);
else
return __tandf((sign ? x+t2pio2 : x-t2pio2), 0);
}
if (ix <= 0x40e231d5) { /* |x| ~<= 9*pi/4 */
if (ix <= 0x40afeddf) /* |x| ~<= 7*pi/4 */
return __tandf((sign ? x+t3pio2 : x-t3pio2), 1);
else
return __tandf((sign ? x+t4pio2 : x-t4pio2), 0);
}
/* tan(Inf or NaN) is NaN */
if (ix >= 0x7f800000)
return x - x;
/* argument reduction */
n = __rem_pio2f(x, &y);
return __tandf(y, n&1);
}
float tanf(float x)
{
double y;
int32_t n, hx, ix;
GET_FLOAT_WORD(hx, x);
ix = hx & 0x7fffffff;
if (ix <= 0x3f490fda) { /* |x| ~<= pi/4 */
if (ix < 0x39800000) /* |x| < 2**-12 */
/* return x and raise inexact if x != 0 */
if ((int)x == 0)
return x;
return __tandf(x, 1);
}
if (ix <= 0x407b53d1) { /* |x| ~<= 5*pi/4 */
if (ix <= 0x4016cbe3) /* |x| ~<= 3pi/4 */
return __tandf((hx > 0 ? x-t1pio2 : x+t1pio2), -1);
else
return __tandf((hx > 0 ? x-t2pio2 : x+t2pio2), 1);
}
if (ix <= 0x40e231d5) { /* |x| ~<= 9*pi/4 */
if (ix <= 0x40afeddf) /* |x| ~<= 7*pi/4 */
return __tandf((hx > 0 ? x-t3pio2 : x+t3pio2), -1);
else
return __tandf((hx > 0 ? x-t4pio2 : x+t4pio2), 1);
}
/* tan(Inf or NaN) is NaN */
if (ix >= 0x7f800000)
return x - x;
/* general argument reduction needed */
n = __rem_pio2f(x, &y);
/* integer parameter: n even: 1; n odd: -1 */
return __tandf(y, 1-((n&1)<<1));
}
