41 * [-pi/2 , +pi/2], and let n = k mod 4.
42 * 2. Let S=S(y1+y2), C=C(y1+y2). Depending on n, we have
43 *
44 * n sin(x) cos(x) tan(x)
45 * ----------------------------------------------------------
46 * 0 S C S/C
47 * 1 C -S -C/S
48 * 2 -S -C S/C
49 * 3 -C S -C/S
50 * ----------------------------------------------------------
51 *
52 * Special cases:
53 * Let trig be any of sin, cos, or tan.
54 * trig(+-INF) is NaN, with signals;
55 * trig(NaN) is that NaN;
56 *
57 * Accuracy:
58 * computer TRIG(x) returns trig(x) nearly rounded.
59 */
60
61 #pragma weak tanl = __tanl
62
63 #include "libm.h"
64 #include "longdouble.h"
65
66 long double
67 tanl(long double x) {
68 long double y[2], z = 0.0L;
69 int n, ix;
70
71 ix = *(int *) &x; /* High word of x */
72 ix &= 0x7fffffff;
73 if (ix <= 0x3ffe9220) /* |x| ~< pi/4 */
74 return (__k_tanl(x, z, 0));
75 else if (ix >= 0x7fff0000) /* trig(Inf or NaN) is NaN */
76 return (x - x);
77 else { /* argument reduction needed */
78 n = __rem_pio2l(x, y);
79 return (__k_tanl(y[0], y[1], (n & 1)));
80 }
81 }
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41 * [-pi/2 , +pi/2], and let n = k mod 4.
42 * 2. Let S=S(y1+y2), C=C(y1+y2). Depending on n, we have
43 *
44 * n sin(x) cos(x) tan(x)
45 * ----------------------------------------------------------
46 * 0 S C S/C
47 * 1 C -S -C/S
48 * 2 -S -C S/C
49 * 3 -C S -C/S
50 * ----------------------------------------------------------
51 *
52 * Special cases:
53 * Let trig be any of sin, cos, or tan.
54 * trig(+-INF) is NaN, with signals;
55 * trig(NaN) is that NaN;
56 *
57 * Accuracy:
58 * computer TRIG(x) returns trig(x) nearly rounded.
59 */
60
61 #pragma weak __tanl = tanl
62
63 #include "libm.h"
64 #include "longdouble.h"
65
66 long double
67 tanl(long double x) {
68 long double y[2], z = 0.0L;
69 int n, ix;
70
71 ix = *(int *) &x; /* High word of x */
72 ix &= 0x7fffffff;
73 if (ix <= 0x3ffe9220) /* |x| ~< pi/4 */
74 return (__k_tanl(x, z, 0));
75 else if (ix >= 0x7fff0000) /* trig(Inf or NaN) is NaN */
76 return (x - x);
77 else { /* argument reduction needed */
78 n = __rem_pio2l(x, y);
79 return (__k_tanl(y[0], y[1], (n & 1)));
80 }
81 }
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