* mpfr: Update to 2001-11-16. Patch TMP handling of agm.c and sqrt.c,

        separate .c files for floor and ceil.

1 files changed, 150 insertions, 0 deletions

diff --git a/mpfr/tanh.c b/mpfr/tanh.c
new file mode 100644
index 000000000..4f0baa5ec
--- /dev/null
+++ b/mpfr/tanh.c
@@ -0,0 +1,150 @@
+/* mpfr_tanh -- hyperbolic tangent
+
+Copyright (C) 2001 Free Software Foundation.
+
+This file is part of the MPFR Library.
+
+The 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 2.1 of the License, or (at your
+option) any later version.
+
+The 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 MPFR Library; see the file COPYING.LIB.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+MA 02111-1307, USA. */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+#include "mpfr.h"
+#include "mpfr-impl.h"
+
+ /* The computation of cosh is done by
+
+    tanh= [e^(x)^2-1]/+[e^(x)^2+1]
+ */
+
+int
+#if __STDC__
+mpfr_tanh (mpfr_ptr y, mpfr_srcptr xt , mp_rnd_t rnd_mode) 
+#else
+mpfr_tanh (y, xt, rnd_mode)
+     mpfr_ptr y;
+     mpfr_srcptr xt;
+     mp_rnd_t rnd_mode;
+#endif
+{
+
+    /****** Declaration ******/
+    mpfr_t x;
+    mp_prec_t Nxt = MPFR_PREC(xt);
+    int flag_neg=0, inexact=0;
+    
+    /* Special value checking */
+
+    if (MPFR_IS_NAN(xt)) 
+      {
+        MPFR_SET_NAN(y); 
+        return 1; 
+      }
+    MPFR_CLEAR_NAN(y);
+
+    if (MPFR_IS_INF(xt))
+      {
+        if(MPFR_SIGN(xt) > 0)
+          return mpfr_set_si(y,1,rnd_mode); /* tanh(inf) = 1 */
+        else
+          return mpfr_set_si(y,-1,rnd_mode); /* tanh(-inf) = -1 */
+      }
+    MPFR_CLEAR_INF(y);
+
+    /* tanh(0) = 0 */
+    if(!MPFR_NOTZERO(xt))
+      {              
+        MPFR_SET_ZERO(y);
+        MPFR_SET_SAME_SIGN(y,xt);
+        return 0;
+      }
+    
+    mpfr_init2(x,Nxt);
+    mpfr_set(x,xt,GMP_RNDN);
+
+    if(MPFR_SIGN(x)<0)
+      {
+        MPFR_CHANGE_SIGN(x);
+        flag_neg=1;
+      }
+
+    /* General case */
+    {
+      /* Declaration of the intermediary variable */
+      mpfr_t t, te, ta,tb;       
+      int d;
+
+      /* Declaration of the size variable */
+      mp_prec_t Nx = Nxt;   /* Precision of input variable */
+      mp_prec_t Ny = MPFR_PREC(y);   /* Precision of input variable */
+
+      mp_prec_t Nt;   /* Precision of the intermediary variable */
+      long int err;  /* Precision of error */
+      
+      /* compute the precision of intermediary variable */
+      Nt=MAX(Nx,Ny);
+      /* the optimal number of bits : see algorithms.ps */
+      Nt = Nt+_mpfr_ceil_log2(9)+_mpfr_ceil_log2(Nt);
+
+      /* initialise of intermediary	variable */
+      mpfr_init(t); 
+      mpfr_init(te);             
+      mpfr_init(ta);             
+      mpfr_init(tb);                    
+
+
+      /* First computation of cosh */
+      do {
+
+	/* reactualisation of the precision */
+	mpfr_set_prec(t,Nt);
+	mpfr_set_prec(te,Nt);             
+	mpfr_set_prec(ta,Nt);             
+	mpfr_set_prec(tb,Nt);             
+
+        /* compute tanh */
+        mpfr_mul_2exp(te,x,1,GMP_RNDN); /* 2x */
+        mpfr_exp(te,te,GMP_RNDN);       /* exp(2x) */
+        mpfr_add_ui(ta,te,1,GMP_RNDD);  /* exp(2x) + 1*/
+        mpfr_sub_ui(tb,te,1,GMP_RNDU);  /* exp(2x) - 1*/
+        mpfr_div(t,tb,ta,GMP_RNDN);     /* (exp(2x)-1)/(exp(2x)+1)*/
+
+
+        /* calculation of the error*/
+        d = MPFR_EXP(te)-MPFR_EXP(t);
+	
+	/* estimation of the error */
+        /*err = Nt-(_mpfr_ceil_log2(7+pow(2,d+1)));*/
+        err = Nt-(MAX(d+1,3)+1);
+
+	/* actualisation of the precision */
+        Nt += 10; 
+
+      } while ((err <0)||!mpfr_can_round(t,err,GMP_RNDN,rnd_mode,Ny));
+ 
+      if (flag_neg==1)
+          MPFR_CHANGE_SIGN(t);
+ 
+      inexact = mpfr_set(y,t,rnd_mode);
+      mpfr_clear(t);
+      mpfr_clear(te);
+      mpfr_clear(ta);
+      mpfr_clear(tb);
+    }
+    mpfr_clear(x);
+    return inexact;
+
+}
+