Upgrade libm.
This brings us up to date with FreeBSD HEAD, fixes various bugs, unifies
the set of functions we support on ARM, MIPS, and x86, fixes "long double",
adds ISO C99 support, and adds basic unit tests.
It turns out that our "long double" functions have always been broken
for non-normal numbers. This patch fixes that by not using the upstream
implementations and just forwarding to the regular "double" implementation
instead (since "long double" on Android is just "double" anyway, which is
what BSD doesn't support).
All the tests pass on ARM, MIPS, and x86, plus glibc on x86-64.
Bug: 3169850
Bug: 8012787
Bug: https://code.google.com/p/android/issues/detail?id=6697
Change-Id: If0c343030959c24bfc50d4d21c9530052c581837
diff --git a/libm/upstream-freebsd/lib/msun/src/e_atan2f.c b/libm/upstream-freebsd/lib/msun/src/e_atan2f.c
new file mode 100644
index 0000000..fc77bff
--- /dev/null
+++ b/libm/upstream-freebsd/lib/msun/src/e_atan2f.c
@@ -0,0 +1,96 @@
+/* e_atan2f.c -- float version of e_atan2.c.
+ * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
+ */
+
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "math.h"
+#include "math_private.h"
+
+static volatile float
+tiny = 1.0e-30;
+static const float
+zero = 0.0,
+pi_o_4 = 7.8539818525e-01, /* 0x3f490fdb */
+pi_o_2 = 1.5707963705e+00, /* 0x3fc90fdb */
+pi = 3.1415927410e+00; /* 0x40490fdb */
+static volatile float
+pi_lo = -8.7422776573e-08; /* 0xb3bbbd2e */
+
+float
+__ieee754_atan2f(float y, float x)
+{
+ float z;
+ int32_t k,m,hx,hy,ix,iy;
+
+ GET_FLOAT_WORD(hx,x);
+ ix = hx&0x7fffffff;
+ GET_FLOAT_WORD(hy,y);
+ iy = hy&0x7fffffff;
+ if((ix>0x7f800000)||
+ (iy>0x7f800000)) /* x or y is NaN */
+ return x+y;
+ if(hx==0x3f800000) return atanf(y); /* x=1.0 */
+ m = ((hy>>31)&1)|((hx>>30)&2); /* 2*sign(x)+sign(y) */
+
+ /* when y = 0 */
+ if(iy==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 */
+ }
+ }
+ /* when x = 0 */
+ if(ix==0) return (hy<0)? -pi_o_2-tiny: pi_o_2+tiny;
+
+ /* when x is INF */
+ if(ix==0x7f800000) {
+ if(iy==0x7f800000) {
+ 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 (float)3.0*pi_o_4+tiny;/*atan(+INF,-INF)*/
+ case 3: return (float)-3.0*pi_o_4-tiny;/*atan(-INF,-INF)*/
+ }
+ } else {
+ switch(m) {
+ case 0: return zero ; /* atan(+...,+INF) */
+ case 1: return -zero ; /* atan(-...,+INF) */
+ case 2: return pi+tiny ; /* atan(+...,-INF) */
+ case 3: return -pi-tiny ; /* atan(-...,-INF) */
+ }
+ }
+ }
+ /* when y is INF */
+ if(iy==0x7f800000) return (hy<0)? -pi_o_2-tiny: pi_o_2+tiny;
+
+ /* compute y/x */
+ k = (iy-ix)>>23;
+ if(k > 26) { /* |y/x| > 2**26 */
+ z=pi_o_2+(float)0.5*pi_lo;
+ m&=1;
+ }
+ else if(k<-26&&hx<0) z=0.0; /* 0 > |y|/x > -2**-26 */
+ else z=atanf(fabsf(y/x)); /* safe to do 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(-,-) */
+ }
+}