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Diffstat (limited to 'Build/source/libs/mpfr/mpfr-3.1.2/src/cache.c')
-rw-r--r--Build/source/libs/mpfr/mpfr-3.1.2/src/cache.c145
1 files changed, 145 insertions, 0 deletions
diff --git a/Build/source/libs/mpfr/mpfr-3.1.2/src/cache.c b/Build/source/libs/mpfr/mpfr-3.1.2/src/cache.c
new file mode 100644
index 00000000000..359ac424228
--- /dev/null
+++ b/Build/source/libs/mpfr/mpfr-3.1.2/src/cache.c
@@ -0,0 +1,145 @@
+/* mpfr_cache -- cache interface for multiple-precision constants in MPFR.
+
+Copyright 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
+Contributed by the AriC and Caramel projects, INRIA.
+
+This file is part of the GNU MPFR Library.
+
+The GNU MPFR Library is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 3 of the License, or (at your
+option) any later version.
+
+The GNU MPFR Library is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see
+http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
+51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+#include "mpfr-impl.h"
+
+#if 0 /* this function is not used/documented/tested so far, it could be
+ useful if some user wants to add a new constant to mpfr, and
+ implement a cache mechanism for that constant */
+void
+mpfr_init_cache (mpfr_cache_t cache, int (*func)(mpfr_ptr, mpfr_rnd_t))
+{
+ MPFR_PREC (cache->x) = 0; /* Invalid prec to detect that the cache is not
+ valid. Maybe add a flag? */
+ cache->func = func;
+}
+#endif
+
+void
+mpfr_clear_cache (mpfr_cache_t cache)
+{
+ if (MPFR_PREC (cache->x) != 0)
+ mpfr_clear (cache->x);
+ MPFR_PREC (cache->x) = 0;
+}
+
+int
+mpfr_cache (mpfr_ptr dest, mpfr_cache_t cache, mpfr_rnd_t rnd)
+{
+ mpfr_prec_t prec = MPFR_PREC (dest);
+ mpfr_prec_t pold = MPFR_PREC (cache->x);
+ int inexact, sign;
+ MPFR_SAVE_EXPO_DECL (expo);
+
+ MPFR_SAVE_EXPO_MARK (expo);
+
+ if (MPFR_UNLIKELY (prec > pold))
+ {
+ /* No previous result in the cache or the precision of the
+ previous result is not sufficient. */
+
+ if (MPFR_UNLIKELY (pold == 0)) /* No previous result. */
+ mpfr_init2 (cache->x, prec);
+
+ /* Update the cache. */
+ pold = prec;
+ /* no need to keep the previous value */
+ mpfr_set_prec (cache->x, pold);
+ cache->inexact = (*cache->func) (cache->x, MPFR_RNDN);
+ }
+
+ /* now pold >= prec is the precision of cache->x */
+
+ /* First, check if the cache has the exact value (unlikely).
+ Else the exact value is between (assuming x=cache->x > 0):
+ x and x+ulp(x) if cache->inexact < 0,
+ x-ulp(x) and x if cache->inexact > 0,
+ and abs(x-exact) <= ulp(x)/2. */
+
+ /* we assume all cached constants are positive */
+ MPFR_ASSERTN (MPFR_IS_POS (cache->x)); /* TODO... */
+ sign = MPFR_SIGN (cache->x);
+ MPFR_SET_EXP (dest, MPFR_GET_EXP (cache->x));
+ MPFR_SET_SIGN (dest, sign);
+
+ /* round cache->x from precision pold down to precision prec */
+ MPFR_RNDRAW_GEN (inexact, dest,
+ MPFR_MANT (cache->x), pold, rnd, sign,
+ if (MPFR_UNLIKELY (cache->inexact == 0))
+ {
+ if ((_sp[0] & _ulp) == 0)
+ {
+ inexact = -sign;
+ goto trunc_doit;
+ }
+ else
+ goto addoneulp;
+ }
+ else if (cache->inexact < 0)
+ goto addoneulp;
+ else /* cache->inexact > 0 */
+ {
+ inexact = -sign;
+ goto trunc_doit;
+ },
+ if (MPFR_UNLIKELY (++MPFR_EXP (dest) > __gmpfr_emax))
+ mpfr_overflow (dest, rnd, sign);
+ );
+
+ if (MPFR_LIKELY (cache->inexact != 0))
+ {
+ switch (rnd)
+ {
+ case MPFR_RNDZ:
+ case MPFR_RNDD:
+ if (MPFR_UNLIKELY (inexact == 0))
+ {
+ inexact = cache->inexact;
+ if (inexact > 0)
+ {
+ mpfr_nextbelow (dest);
+ inexact = -inexact;
+ }
+ }
+ break;
+ case MPFR_RNDU:
+ case MPFR_RNDA:
+ if (MPFR_UNLIKELY (inexact == 0))
+ {
+ inexact = cache->inexact;
+ if (inexact < 0)
+ {
+ mpfr_nextabove (dest);
+ inexact = -inexact;
+ }
+ }
+ break;
+ default: /* MPFR_RNDN */
+ if (MPFR_UNLIKELY(inexact == 0))
+ inexact = cache->inexact;
+ break;
+ }
+ }
+
+ MPFR_SAVE_EXPO_FREE (expo);
+ return mpfr_check_range (dest, inexact, rnd);
+}