| Index: fusl/src/math/atan2.c
|
| diff --git a/fusl/src/math/atan2.c b/fusl/src/math/atan2.c
|
| index 5a1903c6240821b70e6993f3769563c5eb1ba18f..11427d76b482c77f61785c577ab1b1a2716c94e1 100644
|
| --- a/fusl/src/math/atan2.c
|
| +++ b/fusl/src/math/atan2.c
|
| @@ -39,69 +39,81 @@
|
|
|
| #include "libm.h"
|
|
|
| -static const double
|
| -pi = 3.1415926535897931160E+00, /* 0x400921FB, 0x54442D18 */
|
| -pi_lo = 1.2246467991473531772E-16; /* 0x3CA1A626, 0x33145C07 */
|
| +static const double pi = 3.1415926535897931160E+00, /* 0x400921FB, 0x54442D18 */
|
| + pi_lo = 1.2246467991473531772E-16; /* 0x3CA1A626, 0x33145C07 */
|
|
|
| -double atan2(double y, double x)
|
| -{
|
| - double z;
|
| - uint32_t m,lx,ly,ix,iy;
|
| +double atan2(double y, double x) {
|
| + double z;
|
| + uint32_t m, lx, ly, ix, iy;
|
|
|
| - if (isnan(x) || isnan(y))
|
| - return x+y;
|
| - EXTRACT_WORDS(ix, lx, x);
|
| - EXTRACT_WORDS(iy, ly, y);
|
| - if ((ix-0x3ff00000 | lx) == 0) /* x = 1.0 */
|
| - return atan(y);
|
| - m = ((iy>>31)&1) | ((ix>>30)&2); /* 2*sign(x)+sign(y) */
|
| - ix = ix & 0x7fffffff;
|
| - iy = iy & 0x7fffffff;
|
| + if (isnan(x) || isnan(y))
|
| + return x + y;
|
| + EXTRACT_WORDS(ix, lx, x);
|
| + EXTRACT_WORDS(iy, ly, y);
|
| + if ((ix - 0x3ff00000 | lx) == 0) /* x = 1.0 */
|
| + return atan(y);
|
| + m = ((iy >> 31) & 1) | ((ix >> 30) & 2); /* 2*sign(x)+sign(y) */
|
| + ix = ix & 0x7fffffff;
|
| + iy = iy & 0x7fffffff;
|
|
|
| - /* when y = 0 */
|
| - if ((iy|ly) == 0) {
|
| - switch(m) {
|
| - case 0:
|
| - case 1: return y; /* atan(+-0,+anything)=+-0 */
|
| - case 2: return pi; /* atan(+0,-anything) = pi */
|
| - case 3: return -pi; /* atan(-0,-anything) =-pi */
|
| - }
|
| - }
|
| - /* when x = 0 */
|
| - if ((ix|lx) == 0)
|
| - return m&1 ? -pi/2 : pi/2;
|
| - /* when x is INF */
|
| - if (ix == 0x7ff00000) {
|
| - if (iy == 0x7ff00000) {
|
| - switch(m) {
|
| - case 0: return pi/4; /* atan(+INF,+INF) */
|
| - case 1: return -pi/4; /* atan(-INF,+INF) */
|
| - case 2: return 3*pi/4; /* atan(+INF,-INF) */
|
| - case 3: return -3*pi/4; /* atan(-INF,-INF) */
|
| - }
|
| - } else {
|
| - switch(m) {
|
| - case 0: return 0.0; /* atan(+...,+INF) */
|
| - case 1: return -0.0; /* atan(-...,+INF) */
|
| - case 2: return pi; /* atan(+...,-INF) */
|
| - case 3: return -pi; /* atan(-...,-INF) */
|
| - }
|
| - }
|
| - }
|
| - /* |y/x| > 0x1p64 */
|
| - if (ix+(64<<20) < iy || iy == 0x7ff00000)
|
| - return m&1 ? -pi/2 : pi/2;
|
| + /* when y = 0 */
|
| + if ((iy | ly) == 0) {
|
| + switch (m) {
|
| + case 0:
|
| + case 1:
|
| + return y; /* atan(+-0,+anything)=+-0 */
|
| + case 2:
|
| + return pi; /* atan(+0,-anything) = pi */
|
| + case 3:
|
| + return -pi; /* atan(-0,-anything) =-pi */
|
| + }
|
| + }
|
| + /* when x = 0 */
|
| + if ((ix | lx) == 0)
|
| + return m & 1 ? -pi / 2 : pi / 2;
|
| + /* when x is INF */
|
| + if (ix == 0x7ff00000) {
|
| + if (iy == 0x7ff00000) {
|
| + switch (m) {
|
| + case 0:
|
| + return pi / 4; /* atan(+INF,+INF) */
|
| + case 1:
|
| + return -pi / 4; /* atan(-INF,+INF) */
|
| + case 2:
|
| + return 3 * pi / 4; /* atan(+INF,-INF) */
|
| + case 3:
|
| + return -3 * pi / 4; /* atan(-INF,-INF) */
|
| + }
|
| + } else {
|
| + switch (m) {
|
| + case 0:
|
| + return 0.0; /* atan(+...,+INF) */
|
| + case 1:
|
| + return -0.0; /* atan(-...,+INF) */
|
| + case 2:
|
| + return pi; /* atan(+...,-INF) */
|
| + case 3:
|
| + return -pi; /* atan(-...,-INF) */
|
| + }
|
| + }
|
| + }
|
| + /* |y/x| > 0x1p64 */
|
| + if (ix + (64 << 20) < iy || iy == 0x7ff00000)
|
| + return m & 1 ? -pi / 2 : pi / 2;
|
|
|
| - /* z = atan(|y/x|) without spurious underflow */
|
| - if ((m&2) && iy+(64<<20) < ix) /* |y/x| < 0x1p-64, x<0 */
|
| - z = 0;
|
| - else
|
| - z = atan(fabs(y/x));
|
| - switch (m) {
|
| - case 0: return z; /* atan(+,+) */
|
| - case 1: return -z; /* atan(-,+) */
|
| - case 2: return pi - (z-pi_lo); /* atan(+,-) */
|
| - default: /* case 3 */
|
| - return (z-pi_lo) - pi; /* atan(-,-) */
|
| - }
|
| + /* z = atan(|y/x|) without spurious underflow */
|
| + if ((m & 2) && iy + (64 << 20) < ix) /* |y/x| < 0x1p-64, x<0 */
|
| + z = 0;
|
| + else
|
| + z = atan(fabs(y / x));
|
| + switch (m) {
|
| + case 0:
|
| + return z; /* atan(+,+) */
|
| + case 1:
|
| + return -z; /* atan(-,+) */
|
| + case 2:
|
| + return pi - (z - pi_lo); /* atan(+,-) */
|
| + default: /* case 3 */
|
| + return (z - pi_lo) - pi; /* atan(-,-) */
|
| + }
|
| }
|
|
|