Piotr Caban : msvcrt: Import atan2f from musl.
Alexandre Julliard
julliard at winehq.org
Thu Aug 6 16:33:46 CDT 2020
Module: wine
Branch: master
Commit: 5eaa4c56b1232bf3c9a469b3c8d2314ebf5bb7e9
URL: https://source.winehq.org/git/wine.git/?a=commit;h=5eaa4c56b1232bf3c9a469b3c8d2314ebf5bb7e9
Author: Piotr Caban <piotr at codeweavers.com>
Date: Thu Aug 6 16:59:21 2020 +0200
msvcrt: Import atan2f from musl.
Signed-off-by: Piotr Caban <piotr at codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard at winehq.org>
---
dlls/msvcrt/math.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 65 insertions(+), 4 deletions(-)
diff --git a/dlls/msvcrt/math.c b/dlls/msvcrt/math.c
index 723c341c65..73277a6a7b 100644
--- a/dlls/msvcrt/math.c
+++ b/dlls/msvcrt/math.c
@@ -340,12 +340,73 @@ float CDECL MSVCRT_atanf( float x )
/*********************************************************************
* MSVCRT_atan2f (MSVCRT.@)
+ *
+ * Copied from musl: src/math/atan2f.c
*/
-float CDECL MSVCRT_atan2f( float x, float y )
+float CDECL MSVCRT_atan2f( float y, float x )
{
- float ret = atan2f(x, y);
- if (isnan(x)) return math_error(_DOMAIN, "atan2f", x, y, ret);
- return ret;
+ static const float pi = 3.1415927410e+00,
+ pi_lo = -8.7422776573e-08;
+
+ float z;
+ unsigned int m, ix, iy;
+
+ if (MSVCRT__isnanf(x) || MSVCRT__isnanf(y))
+ return x + y;
+ ix = *(unsigned int*)&x;
+ iy = *(unsigned int*)&y;
+ if (ix == 0x3f800000) /* x=1.0 */
+ return atanf(y);
+ m = ((iy >> 31) & 1) | ((ix >> 30) & 2); /* 2*sign(x)+sign(y) */
+ ix &= 0x7fffffff;
+ iy &= 0x7fffffff;
+
+ /* when y = 0 */
+ if (iy == 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 == 0)
+ return m & 1 ? -pi / 2 : pi / 2;
+ /* when x is INF */
+ if (ix == 0x7f800000) {
+ if (iy == 0x7f800000) {
+ 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 0.0f; /* atan(+...,+INF) */
+ case 1: return -0.0f; /* atan(-...,+INF) */
+ case 2: return pi; /* atan(+...,-INF) */
+ case 3: return -pi; /* atan(-...,-INF) */
+ }
+ }
+ }
+ /* |y/x| > 0x1p26 */
+ if (ix + (26 << 23) < iy || iy == 0x7f800000)
+ return m & 1 ? -pi / 2 : pi / 2;
+
+ /* z = atan(|y/x|) with correct underflow */
+ if ((m & 2) && iy + (26 << 23) < ix) /*|y/x| < 0x1p-26, x < 0 */
+ z = 0.0;
+ else
+ z = atanf(fabsf(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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