Source reorganization. In short:

  * Added directories and moved related files into them:
      - src for the MPFR source files (to build the library).
      - doc for documentation files (except INSTALL, README...).
      - tools for various tools (scripts) and mbench.
      - tune for tuneup-related source files.
      - other for other source files (not distributed in tarballs).
    Existing directories:
      - tests for the source files of the test suite (make check).
      - examples for examples.
      - m4 for m4 files.
  * Renamed configure.in to configure.ac.
  * Added/updated Makefile.am files where needed.
  * Updated acinclude.m4 and configure.ac (AC_CONFIG_FILES line).
  * Updated the documentation (INSTALL, README, doc/README.dev and
    doc/mpfr.texi).
  * Updated NEWS and TODO.
  * Updated the scripts now in tools.

The following script was used:

#!/usr/bin/env zsh
svn mkdir doc other src tools tune
svn mv ${${(M)$(sed -n '/libmpfr_la_SOURCES/,/[^\]$/p' \
         Makefile.am):#*.[ch]}:#get_patches.c} mparam_h.in \
       round_raw_generic.c jyn_asympt.c src
svn mv mbench check_inits_clears coverage get_patches.sh mpfrlint \
  nightly-test update-patchv update-version tools
svn mv bidimensional_sample.c speed.c tuneup.c tune
svn mv *.{c,h} other
svn mv FAQ.html README.dev algorithm* faq.xsl fdl.texi mpfr.texi \
  update-faq doc
svn mv configure.in configure.ac
svn cp Makefile.am src/Makefile.am
svn rm replace_all
[Modifying some files, see above]
svn add doc/Makefile.am
svn add tune/Makefile.am

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@7087 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 250 insertions, 0 deletions

diff --git a/src/pow_si.c b/src/pow_si.c
new file mode 100644
index 000000000..32c405acb
--- /dev/null
+++ b/src/pow_si.c
@@ -0,0 +1,250 @@
+/* mpfr_pow_si -- power function x^y with y a signed int
+
+Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
+Contributed by the Arenaire 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. */
+
+#define MPFR_NEED_LONGLONG_H
+#include "mpfr-impl.h"
+
+/* The computation of y = pow_si(x,n) is done by
+ *    y = pow_ui(x,n)       if n >= 0
+ *    y = 1 / pow_ui(x,-n)  if n < 0
+ */
+
+int
+mpfr_pow_si (mpfr_ptr y, mpfr_srcptr x, long int n, mpfr_rnd_t rnd)
+{
+  MPFR_LOG_FUNC (("x[%#R]=%R n=%ld rnd=%d", x, x, n, rnd),
+                 ("y[%#R]=%R", y, y));
+
+  if (n >= 0)
+    return mpfr_pow_ui (y, x, n, rnd);
+  else
+    {
+      if (MPFR_UNLIKELY (MPFR_IS_SINGULAR (x)))
+        {
+          if (MPFR_IS_NAN (x))
+            {
+              MPFR_SET_NAN (y);
+              MPFR_RET_NAN;
+            }
+          else if (MPFR_IS_INF (x))
+            {
+              MPFR_SET_ZERO (y);
+              if (MPFR_IS_POS (x) || ((unsigned) n & 1) == 0)
+                MPFR_SET_POS (y);
+              else
+                MPFR_SET_NEG (y);
+              MPFR_RET (0);
+            }
+          else /* x is zero */
+            {
+              MPFR_ASSERTD (MPFR_IS_ZERO (x));
+              MPFR_SET_INF(y);
+              if (MPFR_IS_POS (x) || ((unsigned) n & 1) == 0)
+                MPFR_SET_POS (y);
+              else
+                MPFR_SET_NEG (y);
+              MPFR_RET(0);
+            }
+        }
+
+      /* detect exact powers: x^(-n) is exact iff x is a power of 2 */
+      if (mpfr_cmp_si_2exp (x, MPFR_SIGN(x), MPFR_EXP(x) - 1) == 0)
+        {
+          mpfr_exp_t expx = MPFR_EXP (x) - 1, expy;
+          MPFR_ASSERTD (n < 0);
+          /* Warning: n * expx may overflow!
+           *
+           * Some systems (apparently alpha-freebsd) abort with
+           * LONG_MIN / 1, and LONG_MIN / -1 is undefined.
+           * http://www.freebsd.org/cgi/query-pr.cgi?pr=72024
+           *
+           * Proof of the overflow checking. The expressions below are
+           * assumed to be on the rational numbers, but the word "overflow"
+           * still has its own meaning in the C context. / still denotes
+           * the integer (truncated) division, and // denotes the exact
+           * division.
+           * - First, (__gmpfr_emin - 1) / n and (__gmpfr_emax - 1) / n
+           *   cannot overflow due to the constraints on the exponents of
+           *   MPFR numbers.
+           * - If n = -1, then n * expx = - expx, which is representable
+           *   because of the constraints on the exponents of MPFR numbers.
+           * - If expx = 0, then n * expx = 0, which is representable.
+           * - If n < -1 and expx > 0:
+           *   + If expx > (__gmpfr_emin - 1) / n, then
+           *           expx >= (__gmpfr_emin - 1) / n + 1
+           *                > (__gmpfr_emin - 1) // n,
+           *     and
+           *           n * expx < __gmpfr_emin - 1,
+           *     i.e.
+           *           n * expx <= __gmpfr_emin - 2.
+           *     This corresponds to an underflow, with a null result in
+           *     the rounding-to-nearest mode.
+           *   + If expx <= (__gmpfr_emin - 1) / n, then n * expx cannot
+           *     overflow since 0 < expx <= (__gmpfr_emin - 1) / n and
+           *           0 > n * expx >= n * ((__gmpfr_emin - 1) / n)
+           *                        >= __gmpfr_emin - 1.
+           * - If n < -1 and expx < 0:
+           *   + If expx < (__gmpfr_emax - 1) / n, then
+           *           expx <= (__gmpfr_emax - 1) / n - 1
+           *                < (__gmpfr_emax - 1) // n,
+           *     and
+           *           n * expx > __gmpfr_emax - 1,
+           *     i.e.
+           *           n * expx >= __gmpfr_emax.
+           *     This corresponds to an overflow (2^(n * expx) has an
+           *     exponent > __gmpfr_emax).
+           *   + If expx >= (__gmpfr_emax - 1) / n, then n * expx cannot
+           *     overflow since 0 > expx >= (__gmpfr_emax - 1) / n and
+           *           0 < n * expx <= n * ((__gmpfr_emax - 1) / n)
+           *                        <= __gmpfr_emax - 1.
+           * Note: one could use expx bounds based on MPFR_EXP_MIN and
+           * MPFR_EXP_MAX instead of __gmpfr_emin and __gmpfr_emax. The
+           * current bounds do not lead to noticeably slower code and
+           * allow us to avoid a bug in Sun's compiler for Solaris/x86
+           * (when optimizations are enabled); known affected versions:
+           *   cc: Sun C 5.8 2005/10/13
+           *   cc: Sun C 5.8 Patch 121016-02 2006/03/31
+           *   cc: Sun C 5.8 Patch 121016-04 2006/10/18
+           */
+          expy =
+            n != -1 && expx > 0 && expx > (__gmpfr_emin - 1) / n ?
+            MPFR_EMIN_MIN - 2 /* Underflow */ :
+            n != -1 && expx < 0 && expx < (__gmpfr_emax - 1) / n ?
+            MPFR_EMAX_MAX /* Overflow */ : n * expx;
+          return mpfr_set_si_2exp (y, n % 2 ? MPFR_INT_SIGN (x) : 1,
+                                   expy, rnd);
+        }
+
+      /* General case */
+      {
+        /* Declaration of the intermediary variable */
+        mpfr_t t;
+        /* Declaration of the size variable */
+        mpfr_prec_t Ny;                              /* target precision */
+        mpfr_prec_t Nt;                              /* working precision */
+        mpfr_rnd_t rnd1;
+        int size_n;
+        int inexact;
+        unsigned long abs_n;
+        MPFR_SAVE_EXPO_DECL (expo);
+        MPFR_ZIV_DECL (loop);
+
+        abs_n = - (unsigned long) n;
+        count_leading_zeros (size_n, (mp_limb_t) abs_n);
+        size_n = GMP_NUMB_BITS - size_n;
+
+        /* initial working precision */
+        Ny = MPFR_PREC (y);
+        Nt = Ny + size_n + 3 + MPFR_INT_CEIL_LOG2 (Ny);
+
+        MPFR_SAVE_EXPO_MARK (expo);
+
+        /* initialise of intermediary   variable */
+        mpfr_init2 (t, Nt);
+
+        /* We will compute rnd(rnd1(1/x) ^ |n|), where rnd1 is the rounding
+           toward sign(x), to avoid spurious overflow or underflow, as in
+           mpfr_pow_z. */
+        rnd1 = MPFR_EXP (x) < 1 ? MPFR_RNDZ :
+          (MPFR_SIGN (x) > 0 ? MPFR_RNDU : MPFR_RNDD);
+
+        MPFR_ZIV_INIT (loop, Nt);
+        for (;;)
+          {
+            MPFR_BLOCK_DECL (flags);
+
+            /* compute (1/x)^|n| */
+            MPFR_BLOCK (flags, mpfr_ui_div (t, 1, x, rnd1));
+            MPFR_ASSERTD (! MPFR_UNDERFLOW (flags));
+            /* t = (1/x)*(1+theta) where |theta| <= 2^(-Nt) */
+            if (MPFR_UNLIKELY (MPFR_OVERFLOW (flags)))
+              goto overflow;
+            MPFR_BLOCK (flags, mpfr_pow_ui (t, t, abs_n, rnd));
+            /* t = (1/x)^|n|*(1+theta')^(|n|+1) where |theta'| <= 2^(-Nt).
+               If (|n|+1)*2^(-Nt) <= 1/2, which is satisfied as soon as
+               Nt >= bits(n)+2, then we can use Lemma \ref{lemma_graillat}
+               from algorithms.tex, which yields x^n*(1+theta) with
+               |theta| <= 2(|n|+1)*2^(-Nt), thus the error is bounded by
+               2(|n|+1) ulps <= 2^(bits(n)+2) ulps. */
+            if (MPFR_UNLIKELY (MPFR_OVERFLOW (flags)))
+              {
+              overflow:
+                MPFR_ZIV_FREE (loop);
+                mpfr_clear (t);
+                MPFR_SAVE_EXPO_FREE (expo);
+                MPFR_LOG_MSG (("overflow\n", 0));
+                return mpfr_overflow (y, rnd, abs_n & 1 ?
+                                      MPFR_SIGN (x) : MPFR_SIGN_POS);
+              }
+            if (MPFR_UNLIKELY (MPFR_UNDERFLOW (flags)))
+              {
+                MPFR_ZIV_FREE (loop);
+                mpfr_clear (t);
+                MPFR_LOG_MSG (("underflow\n", 0));
+                if (rnd == MPFR_RNDN)
+                  {
+                    mpfr_t y2, nn;
+
+                    /* We cannot decide now whether the result should be
+                       rounded toward zero or away from zero. So, like
+                       in mpfr_pow_pos_z, let's use the general case of
+                       mpfr_pow in precision 2. */
+                    MPFR_ASSERTD (mpfr_cmp_si_2exp (x, MPFR_SIGN (x),
+                                                    MPFR_EXP (x) - 1) != 0);
+                    mpfr_init2 (y2, 2);
+                    mpfr_init2 (nn, sizeof (long) * CHAR_BIT);
+                    inexact = mpfr_set_si (nn, n, MPFR_RNDN);
+                    MPFR_ASSERTN (inexact == 0);
+                    inexact = mpfr_pow_general (y2, x, nn, rnd, 1,
+                                                (mpfr_save_expo_t *) NULL);
+                    mpfr_clear (nn);
+                    mpfr_set (y, y2, MPFR_RNDN);
+                    mpfr_clear (y2);
+                    MPFR_SAVE_EXPO_UPDATE_FLAGS (expo, MPFR_FLAGS_UNDERFLOW);
+                    goto end;
+                  }
+                else
+                  {
+                    MPFR_SAVE_EXPO_FREE (expo);
+                    return mpfr_underflow (y, rnd, abs_n & 1 ?
+                                           MPFR_SIGN (x) : MPFR_SIGN_POS);
+                  }
+              }
+            /* error estimate -- see pow function in algorithms.ps */
+            if (MPFR_LIKELY (MPFR_CAN_ROUND (t, Nt - size_n - 2, Ny, rnd)))
+              break;
+
+            /* actualisation of the precision */
+            MPFR_ZIV_NEXT (loop, Nt);
+            mpfr_set_prec (t, Nt);
+          }
+        MPFR_ZIV_FREE (loop);
+
+        inexact = mpfr_set (y, t, rnd);
+        mpfr_clear (t);
+
+      end:
+        MPFR_SAVE_EXPO_FREE (expo);
+        return mpfr_check_range (y, inexact, rnd);
+      }
+    }
+}