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)); }