Piotr Caban : msvcrt: Import atan2 from musl.
Alexandre Julliard
julliard at winehq.org
Thu Aug 6 16:33:46 CDT 2020
Module: wine
Branch: master
Commit: d9456a8cea2f9c8e7e65e2c706eb8d1a7a9c1966
URL: https://source.winehq.org/git/wine.git/?a=commit;h=d9456a8cea2f9c8e7e65e2c706eb8d1a7a9c1966
Author: Piotr Caban <piotr at codeweavers.com>
Date: Thu Aug 6 16:59:25 2020 +0200
msvcrt: Import atan2 from musl.
Signed-off-by: Piotr Caban <piotr at codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard at winehq.org>
---
dlls/msvcrt/math.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 67 insertions(+), 4 deletions(-)
diff --git a/dlls/msvcrt/math.c b/dlls/msvcrt/math.c
index 73277a6a7b..85565d2bf3 100644
--- a/dlls/msvcrt/math.c
+++ b/dlls/msvcrt/math.c
@@ -798,12 +798,75 @@ double CDECL MSVCRT_atan( double x )
/*********************************************************************
* MSVCRT_atan2 (MSVCRT.@)
+ *
+ * Copied from musl: src/math/atan2.c
*/
-double CDECL MSVCRT_atan2( double x, double y )
+double CDECL MSVCRT_atan2( double y, double x )
{
- double ret = atan2(x, y);
- if (isnan(x)) return math_error(_DOMAIN, "atan2", x, y, ret);
- return ret;
+ static const double pi = 3.1415926535897931160E+00,
+ pi_lo = 1.2246467991473531772E-16;
+
+ double z;
+ unsigned int m, lx, ly, ix, iy;
+
+ if (isnan(x) || isnan(y))
+ return x+y;
+ ix = *(ULONGLONG*)&x >> 32;
+ lx = *(ULONGLONG*)&x;
+ iy = *(ULONGLONG*)&y >> 32;
+ ly = *(ULONGLONG*)&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;
+
+ /* 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(-,-) */
+ }
}
/*********************************************************************
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