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move __BYTE_ORDER definition to alltypes.h
[musl]
/
src
/
math
/
atan2.c
diff --git
a/src/math/atan2.c
b/src/math/atan2.c
index
825a38f
..
5a1903c
100644
(file)
--- a/
src/math/atan2.c
+++ b/
src/math/atan2.c
@@
-39,75
+39,63
@@
#include "libm.h"
#include "libm.h"
-// FIXME
-static const volatile double
-tiny = 1.0e-300;
static const double
static const double
-pi_o_4 = 7.8539816339744827900E-01, /* 0x3FE921FB, 0x54442D18 */
-pi_o_2 = 1.5707963267948965580E+00, /* 0x3FF921FB, 0x54442D18 */
-pi = 3.1415926535897931160E+00; /* 0x400921FB, 0x54442D18 */
-static const volatile double
+pi = 3.1415926535897931160E+00, /* 0x400921FB, 0x54442D18 */
pi_lo = 1.2246467991473531772E-16; /* 0x3CA1A626, 0x33145C07 */
double atan2(double y, double x)
{
double z;
pi_lo = 1.2246467991473531772E-16; /* 0x3CA1A626, 0x33145C07 */
double atan2(double y, double x)
{
double z;
- int32_t k,m,hx,hy,ix,iy;
- uint32_t lx,ly;
+ uint32_t m,lx,ly,ix,iy;
- EXTRACT_WORDS(hx, lx, x);
- ix = hx & 0x7fffffff;
- EXTRACT_WORDS(hy, ly, y);
- iy = hy & 0x7fffffff;
- if ((ix|((lx|-lx)>>31)) > 0x7ff00000 ||
- (iy|((ly|-ly)>>31)) > 0x7ff00000) /* x or y is NaN */
+ if (isnan(x) || isnan(y))
return x+y;
return x+y;
- if ((hx-0x3ff00000 | lx) == 0) /* x = 1.0 */
+ EXTRACT_WORDS(ix, lx, x);
+ EXTRACT_WORDS(iy, ly, y);
+ if ((ix-0x3ff00000 | lx) == 0) /* x = 1.0 */
return atan(y);
return atan(y);
- m = ((hy>>31)&1) | ((hx>>30)&2); /* 2*sign(x)+sign(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:
/* when y = 0 */
if ((iy|ly) == 0) {
switch(m) {
case 0:
- case 1: return y;
/* atan(+-0,+anything)=+-0 */
- case 2: return pi
+tiny
; /* atan(+0,-anything) = pi */
- case 3: return -pi
-tiny
; /* atan(-0,-anything) =-pi */
+ 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)
}
}
/* when x = 0 */
if ((ix|lx) == 0)
- return
hy < 0 ? -pi_o_2-tiny : pi_o_2+tiny
;
+ return
m&1 ? -pi/2 : pi/2
;
/* when x is INF */
if (ix == 0x7ff00000) {
if (iy == 0x7ff00000) {
switch(m) {
/* when x is INF */
if (ix == 0x7ff00000) {
if (iy == 0x7ff00000) {
switch(m) {
- case 0: return pi
_o_4+tiny;
/* atan(+INF,+INF) */
- case 1: return -pi
_o_4-tiny;
/* atan(-INF,+INF) */
- case 2: return 3
.0*pi_o_4+tiny
; /* atan(+INF,-INF) */
- case 3: return -3
.0*pi_o_4-tiny
; /* atan(-INF,-INF) */
+ 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) {
}
} else {
switch(m) {
- case 0: return 0.0;
/* atan(+...,+INF) */
- case 1: return -0.0;
/* atan(-...,+INF) */
- case 2: return pi
+tiny;
/* atan(+...,-INF) */
- case 3: return -pi
-tiny;
/* atan(-...,-INF) */
+ 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) */
}
}
}
}
}
}
- /*
when y is INF
*/
- if (iy == 0x7ff00000)
- return
hy < 0 ? -pi_o_2-tiny : pi_o_2+tiny
;
+ /*
|y/x| > 0x1p64
*/
+ if (i
x+(64<<20) < iy || i
y == 0x7ff00000)
+ return
m&1 ? -pi/2 : pi/2
;
- /* compute y/x */
- k = (iy-ix)>>20;
- if (k > 60) { /* |y/x| > 2**60 */
- z = pi_o_2+0.5*pi_lo;
- m &= 1;
- } else if (hx < 0 && k < -60) /* 0 > |y|/x > -2**-60 */
- z = 0.0;
- else /* safe to do y/x */
+ /* 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(+,+) */
z = atan(fabs(y/x));
switch (m) {
case 0: return z; /* atan(+,+) */