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_hypot.c b/libm/upstream-freebsd/lib/msun/src/e_hypot.c
new file mode 100644
index 0000000..2398e98
--- /dev/null
+++ b/libm/upstream-freebsd/lib/msun/src/e_hypot.c
@@ -0,0 +1,131 @@
+
+/* @(#)e_hypot.c 1.3 95/01/18 */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunSoft, 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("$FreeBSD$");
+
+/* __ieee754_hypot(x,y)
+ *
+ * Method :
+ * If (assume round-to-nearest) z=x*x+y*y
+ * has error less than sqrt(2)/2 ulp, than
+ * sqrt(z) has error less than 1 ulp (exercise).
+ *
+ * So, compute sqrt(x*x+y*y) with some care as
+ * follows to get the error below 1 ulp:
+ *
+ * Assume x>y>0;
+ * (if possible, set rounding to round-to-nearest)
+ * 1. if x > 2y use
+ * x1*x1+(y*y+(x2*(x+x1))) for x*x+y*y
+ * where x1 = x with lower 32 bits cleared, x2 = x-x1; else
+ * 2. if x <= 2y use
+ * t1*y1+((x-y)*(x-y)+(t1*y2+t2*y))
+ * where t1 = 2x with lower 32 bits cleared, t2 = 2x-t1,
+ * y1= y with lower 32 bits chopped, y2 = y-y1.
+ *
+ * NOTE: scaling may be necessary if some argument is too
+ * large or too tiny
+ *
+ * Special cases:
+ * hypot(x,y) is INF if x or y is +INF or -INF; else
+ * hypot(x,y) is NAN if x or y is NAN.
+ *
+ * Accuracy:
+ * hypot(x,y) returns sqrt(x^2+y^2) with error less
+ * than 1 ulps (units in the last place)
+ */
+
+#include <float.h>
+
+#include "math.h"
+#include "math_private.h"
+
+double
+__ieee754_hypot(double x, double y)
+{
+ double a,b,t1,t2,y1,y2,w;
+ int32_t j,k,ha,hb;
+
+ GET_HIGH_WORD(ha,x);
+ ha &= 0x7fffffff;
+ GET_HIGH_WORD(hb,y);
+ hb &= 0x7fffffff;
+ if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;}
+ a = fabs(a);
+ b = fabs(b);
+ if((ha-hb)>0x3c00000) {return a+b;} /* x/y > 2**60 */
+ k=0;
+ if(ha > 0x5f300000) { /* a>2**500 */
+ if(ha >= 0x7ff00000) { /* Inf or NaN */
+ u_int32_t low;
+ /* Use original arg order iff result is NaN; quieten sNaNs. */
+ w = fabs(x+0.0)-fabs(y+0.0);
+ GET_LOW_WORD(low,a);
+ if(((ha&0xfffff)|low)==0) w = a;
+ GET_LOW_WORD(low,b);
+ if(((hb^0x7ff00000)|low)==0) w = b;
+ return w;
+ }
+ /* scale a and b by 2**-600 */
+ ha -= 0x25800000; hb -= 0x25800000; k += 600;
+ SET_HIGH_WORD(a,ha);
+ SET_HIGH_WORD(b,hb);
+ }
+ if(hb < 0x20b00000) { /* b < 2**-500 */
+ if(hb <= 0x000fffff) { /* subnormal b or 0 */
+ u_int32_t low;
+ GET_LOW_WORD(low,b);
+ if((hb|low)==0) return a;
+ t1=0;
+ SET_HIGH_WORD(t1,0x7fd00000); /* t1=2^1022 */
+ b *= t1;
+ a *= t1;
+ k -= 1022;
+ } else { /* scale a and b by 2^600 */
+ ha += 0x25800000; /* a *= 2^600 */
+ hb += 0x25800000; /* b *= 2^600 */
+ k -= 600;
+ SET_HIGH_WORD(a,ha);
+ SET_HIGH_WORD(b,hb);
+ }
+ }
+ /* medium size a and b */
+ w = a-b;
+ if (w>b) {
+ t1 = 0;
+ SET_HIGH_WORD(t1,ha);
+ t2 = a-t1;
+ w = sqrt(t1*t1-(b*(-b)-t2*(a+t1)));
+ } else {
+ a = a+a;
+ y1 = 0;
+ SET_HIGH_WORD(y1,hb);
+ y2 = b - y1;
+ t1 = 0;
+ SET_HIGH_WORD(t1,ha+0x00100000);
+ t2 = a - t1;
+ w = sqrt(t1*y1-(w*(-w)-(t1*y2+t2*b)));
+ }
+ if(k!=0) {
+ u_int32_t high;
+ t1 = 1.0;
+ GET_HIGH_WORD(high,t1);
+ SET_HIGH_WORD(t1,high+(k<<20));
+ return t1*w;
+ } else return w;
+}
+
+#if LDBL_MANT_DIG == 53
+__weak_reference(hypot, hypotl);
+#endif