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_fmodl.c b/libm/upstream-freebsd/lib/msun/src/e_fmodl.c
new file mode 100644
index 0000000..e315f76
--- /dev/null
+++ b/libm/upstream-freebsd/lib/msun/src/e_fmodl.c
@@ -0,0 +1,149 @@
+/* @(#)e_fmod.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("$FreeBSD$");
+
+#include <float.h>
+#include <stdint.h>
+
+#include "fpmath.h"
+#include "math.h"
+#include "math_private.h"
+
+#define BIAS (LDBL_MAX_EXP - 1)
+
+#if LDBL_MANL_SIZE > 32
+typedef uint64_t manl_t;
+#else
+typedef uint32_t manl_t;
+#endif
+
+#if LDBL_MANH_SIZE > 32
+typedef uint64_t manh_t;
+#else
+typedef uint32_t manh_t;
+#endif
+
+/*
+ * These macros add and remove an explicit integer bit in front of the
+ * fractional mantissa, if the architecture doesn't have such a bit by
+ * default already.
+ */
+#ifdef LDBL_IMPLICIT_NBIT
+#define SET_NBIT(hx) ((hx) | (1ULL << LDBL_MANH_SIZE))
+#define HFRAC_BITS LDBL_MANH_SIZE
+#else
+#define SET_NBIT(hx) (hx)
+#define HFRAC_BITS (LDBL_MANH_SIZE - 1)
+#endif
+
+#define MANL_SHIFT (LDBL_MANL_SIZE - 1)
+
+static const long double one = 1.0, Zero[] = {0.0, -0.0,};
+
+/*
+ * fmodl(x,y)
+ * Return x mod y in exact arithmetic
+ * Method: shift and subtract
+ *
+ * Assumptions:
+ * - The low part of the mantissa fits in a manl_t exactly.
+ * - The high part of the mantissa fits in an int64_t with enough room
+ * for an explicit integer bit in front of the fractional bits.
+ */
+long double
+fmodl(long double x, long double y)
+{
+ union IEEEl2bits ux, uy;
+ int64_t hx,hz; /* We need a carry bit even if LDBL_MANH_SIZE is 32. */
+ manh_t hy;
+ manl_t lx,ly,lz;
+ int ix,iy,n,sx;
+
+ ux.e = x;
+ uy.e = y;
+ sx = ux.bits.sign;
+
+ /* purge off exception values */
+ if((uy.bits.exp|uy.bits.manh|uy.bits.manl)==0 || /* y=0 */
+ (ux.bits.exp == BIAS + LDBL_MAX_EXP) || /* or x not finite */
+ (uy.bits.exp == BIAS + LDBL_MAX_EXP &&
+ ((uy.bits.manh&~LDBL_NBIT)|uy.bits.manl)!=0)) /* or y is NaN */
+ return (x*y)/(x*y);
+ if(ux.bits.exp<=uy.bits.exp) {
+ if((ux.bits.exp<uy.bits.exp) ||
+ (ux.bits.manh<=uy.bits.manh &&
+ (ux.bits.manh<uy.bits.manh ||
+ ux.bits.manl<uy.bits.manl))) {
+ return x; /* |x|<|y| return x or x-y */
+ }
+ if(ux.bits.manh==uy.bits.manh && ux.bits.manl==uy.bits.manl) {
+ return Zero[sx]; /* |x|=|y| return x*0*/
+ }
+ }
+
+ /* determine ix = ilogb(x) */
+ if(ux.bits.exp == 0) { /* subnormal x */
+ ux.e *= 0x1.0p512;
+ ix = ux.bits.exp - (BIAS + 512);
+ } else {
+ ix = ux.bits.exp - BIAS;
+ }
+
+ /* determine iy = ilogb(y) */
+ if(uy.bits.exp == 0) { /* subnormal y */
+ uy.e *= 0x1.0p512;
+ iy = uy.bits.exp - (BIAS + 512);
+ } else {
+ iy = uy.bits.exp - BIAS;
+ }
+
+ /* set up {hx,lx}, {hy,ly} and align y to x */
+ hx = SET_NBIT(ux.bits.manh);
+ hy = SET_NBIT(uy.bits.manh);
+ lx = ux.bits.manl;
+ ly = uy.bits.manl;
+
+ /* fix point fmod */
+ n = ix - iy;
+
+ while(n--) {
+ hz=hx-hy;lz=lx-ly; if(lx<ly) hz -= 1;
+ if(hz<0){hx = hx+hx+(lx>>MANL_SHIFT); lx = lx+lx;}
+ else {
+ if ((hz|lz)==0) /* return sign(x)*0 */
+ return Zero[sx];
+ hx = hz+hz+(lz>>MANL_SHIFT); lx = lz+lz;
+ }
+ }
+ hz=hx-hy;lz=lx-ly; if(lx<ly) hz -= 1;
+ if(hz>=0) {hx=hz;lx=lz;}
+
+ /* convert back to floating value and restore the sign */
+ if((hx|lx)==0) /* return sign(x)*0 */
+ return Zero[sx];
+ while(hx<(1ULL<<HFRAC_BITS)) { /* normalize x */
+ hx = hx+hx+(lx>>MANL_SHIFT); lx = lx+lx;
+ iy -= 1;
+ }
+ ux.bits.manh = hx; /* The mantissa is truncated here if needed. */
+ ux.bits.manl = lx;
+ if (iy < LDBL_MIN_EXP) {
+ ux.bits.exp = iy + (BIAS + 512);
+ ux.e *= 0x1p-512;
+ } else {
+ ux.bits.exp = iy + BIAS;
+ }
+ x = ux.e * one; /* create necessary signal */
+ return x; /* exact output */
+}