Infinis, premiere tentative.

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@793 280ebfd0-de03-0410-8827-d642c229c3f4

33 files changed, 416 insertions, 156 deletions

diff --git a/add.c b/add.c
index 03d0cbbb3..5180e8a75 100644
--- a/add.c
+++ b/add.c
@@ -396,6 +396,31 @@ mpfr_add(a, b, c, rnd_mode)
     MPFR_SET_NAN(a); return;
   }
 
+  if (MPFR_IS_INF(b)) 
+    { 
+      if (MPFR_IS_INF(c)) 
+	{
+	  if (MPFR_SIGN(b) == MPFR_SIGN(c)) 
+	    { 
+	      MPFR_SET_INF(a); 
+	      if (MPFR_SIGN(a) != MPFR_SIGN(b)) { MPFR_CHANGE_SIGN(a); }
+	    }
+	  else
+	    MPFR_SET_NAN(a); 
+	}
+      else
+	{
+	  MPFR_SET_INF(a); 
+	  if (MPFR_SIGN(b) != MPFR_SIGN(a)) { MPFR_CHANGE_SIGN(a); }
+	}
+    }
+  else 
+    if (MPFR_IS_INF(c))
+      {
+	MPFR_SET_INF(a); 
+	if (MPFR_SIGN(c) != MPFR_SIGN(a)) { MPFR_CHANGE_SIGN(a); }
+      }
+
   if (!MPFR_NOTZERO(b)) { mpfr_set(a, c, rnd_mode); return; }
   if (!MPFR_NOTZERO(c)) { mpfr_set(a, b, rnd_mode); return; }
 
diff --git a/add_ulp.c b/add_ulp.c
index 57de75337..b9e30c206 100644
--- a/add_ulp.c
+++ b/add_ulp.c
@@ -34,6 +34,7 @@ mpfr_add_one_ulp(x)
 {
   int xn, sh; mp_limb_t *xp;
 
+  if (MPFR_IS_INF(x)) { return; }
   xn = 1 + (MPFR_PREC(x)-1)/BITS_PER_MP_LIMB;
   sh = xn*BITS_PER_MP_LIMB - MPFR_PREC(x);
   xp = MPFR_MANT(x);
@@ -50,6 +51,7 @@ int mpfr_sub_one_ulp(mpfr_ptr x)
 {
   int xn, sh; mp_limb_t *xp;
 
+  if (MPFR_IS_INF(x)) { return; }
   xn = 1 + (MPFR_PREC(x)-1)/BITS_PER_MP_LIMB;
   sh = xn*BITS_PER_MP_LIMB-MPFR_PREC(x);
   xp = MPFR_MANT(x);
diff --git a/agm.c b/agm.c
index 404089ba6..7c08a494f 100644
--- a/agm.c
+++ b/agm.c
@@ -51,6 +51,7 @@ mpfr_agm(r, a, b, rnd_mode)
   TMP_DECL(marker1);
   TMP_DECL(marker2);
 
+  /* TODO : CHECK FOR INFINITY. */
 
   /* If a or b is NaN, the result is NaN */
   if (MPFR_IS_NAN(op1) || MPFR_IS_NAN(op2)) 
@@ -60,8 +61,6 @@ mpfr_agm(r, a, b, rnd_mode)
   /* If a or b is negative, the result is NaN */
   if ((MPFR_SIGN(op1) < 0) || (MPFR_SIGN(op2) < 0))
     { MPFR_SET_NAN(r); return; }
-
-
   
   /* If a or b is 0, the result is 0 */
   if ((MPFR_NOTZERO(op1) && MPFR_NOTZERO(op2)) == 0)
diff --git a/cmp.c b/cmp.c
index 5e9258a04..a899d6184 100644
--- a/cmp.c
+++ b/cmp.c
@@ -55,6 +55,7 @@ mpfr_cmp3(b, c, s)
 
    if (!MPFR_NOTZERO(b)) {
      if (!MPFR_NOTZERO(c)) return 0; else return -(MPFR_SIGN(c));
+     /*TODO: bug ou feature ? s pas pris en compte... */
    }
    else if (!MPFR_NOTZERO(c)) return MPFR_SIGN(b);
 
@@ -62,6 +63,8 @@ mpfr_cmp3(b, c, s)
    if (s<0) return(MPFR_SIGN(b));
 
    /* now signs are equal */
+   if (MPFR_IS_INF(b)) 
+     return MPFR_SIGN(b) * !MPFR_IS_INF(c); 
 
    diff_exp = MPFR_EXP(b)-MPFR_EXP(c);
    s = (MPFR_SIGN(b) > 0) ? 1 : -1;
@@ -89,6 +92,8 @@ mpfr_cmp3(b, c, s)
    Assumes b>=c, which implies MPFR_EXP(b)>=MPFR_EXP(c).
    if b=c, returns prec(b).
 */
+/* TODO: semantique ? */
+
 int 
 #if __STDC__
 mpfr_cmp2 ( mpfr_srcptr b, mpfr_srcptr c )
diff --git a/cmp_ui.c b/cmp_ui.c
index 346cd6c6a..feb080a49 100644
--- a/cmp_ui.c
+++ b/cmp_ui.c
@@ -44,6 +44,7 @@ mpfr_cmp_ui_2exp (b, i, f)
 
   if (MPFR_SIGN(b) < 0) return -1;
   /* now b>=0 */
+  else if (MPFR_IS_INF(b)) return 1; 
   else if (!MPFR_NOTZERO(b)) return((i) ? -1 : 0);
   /* now b>0 */
   else if (i==0) return 1;
@@ -88,7 +89,8 @@ mpfr_cmp_si_2exp(b, i, f)
   int e, k, bn, si; mp_limb_t c, *bp;
 
   si = (i<0) ? -1 : 1; /* sign of i */
-  if (MPFR_SIGN(b) * i < 0) return MPFR_SIGN(b); /* both signs differ */
+  if (MPFR_SIGN(b) * i < 0 || MPFR_IS_INF(b)) return MPFR_SIGN(b); 
+  /* both signs differ */
   else if (!MPFR_NOTZERO(b) || (i==0)) { /* one is zero */
     if (i==0) return ((MPFR_NOTZERO(b)) ? MPFR_SIGN(b) : 0);
     else return si; /* b is zero */
diff --git a/configure b/configure
index 56e1738dd..60c9d9aa9 100755
--- a/configure
+++ b/configure
@@ -697,7 +697,6 @@ else
 fi
 
 
-
 PACKAGE=mpfr
 
 VERSION=1.0
@@ -710,7 +709,7 @@ fi
 
 missing_dir=`cd $ac_aux_dir && pwd`
 echo $ac_n "checking for working aclocal""... $ac_c" 1>&6
-echo "configure:714: checking for working aclocal" >&5
+echo "configure:713: checking for working aclocal" >&5
 # Run test in a subshell; some versions of sh will print an error if
 # an executable is not found, even if stderr is redirected.
 # Redirect stdin to placate older versions of autoconf.  Sigh.
@@ -723,7 +722,7 @@ else
 fi
 
 echo $ac_n "checking for working autoconf""... $ac_c" 1>&6
-echo "configure:727: checking for working autoconf" >&5
+echo "configure:726: checking for working autoconf" >&5
 # Run test in a subshell; some versions of sh will print an error if
 # an executable is not found, even if stderr is redirected.
 # Redirect stdin to placate older versions of autoconf.  Sigh.
@@ -736,7 +735,7 @@ else
 fi
 
 echo $ac_n "checking for working automake""... $ac_c" 1>&6
-echo "configure:740: checking for working automake" >&5
+echo "configure:739: checking for working automake" >&5
 # Run test in a subshell; some versions of sh will print an error if
 # an executable is not found, even if stderr is redirected.
 # Redirect stdin to placate older versions of autoconf.  Sigh.
@@ -749,7 +748,7 @@ else
 fi
 
 echo $ac_n "checking for working autoheader""... $ac_c" 1>&6
-echo "configure:753: checking for working autoheader" >&5
+echo "configure:752: checking for working autoheader" >&5
 # Run test in a subshell; some versions of sh will print an error if
 # an executable is not found, even if stderr is redirected.
 # Redirect stdin to placate older versions of autoconf.  Sigh.
@@ -762,7 +761,7 @@ else
 fi
 
 echo $ac_n "checking for working makeinfo""... $ac_c" 1>&6
-echo "configure:766: checking for working makeinfo" >&5
+echo "configure:765: checking for working makeinfo" >&5
 # Run test in a subshell; some versions of sh will print an error if
 # an executable is not found, even if stderr is redirected.
 # Redirect stdin to placate older versions of autoconf.  Sigh.
@@ -807,7 +806,7 @@ fi
 # Extract the first word of "gcc", so it can be a program name with args.
 set dummy gcc; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:811: checking for $ac_word" >&5
+echo "configure:810: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_CC'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -837,7 +836,7 @@ if test -z "$CC"; then
   # Extract the first word of "cc", so it can be a program name with args.
 set dummy cc; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:841: checking for $ac_word" >&5
+echo "configure:840: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_CC'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -888,7 +887,7 @@ fi
       # Extract the first word of "cl", so it can be a program name with args.
 set dummy cl; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:892: checking for $ac_word" >&5
+echo "configure:891: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_CC'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -920,7 +919,7 @@ fi
 fi
 
 echo $ac_n "checking whether the C compiler ($CC $CFLAGS $LDFLAGS) works""... $ac_c" 1>&6
-echo "configure:924: checking whether the C compiler ($CC $CFLAGS $LDFLAGS) works" >&5
+echo "configure:923: checking whether the C compiler ($CC $CFLAGS $LDFLAGS) works" >&5
 
 ac_ext=c
 # CFLAGS is not in ac_cpp because -g, -O, etc. are not valid cpp options.
@@ -931,12 +930,12 @@ cross_compiling=$ac_cv_prog_cc_cross
 
 cat > conftest.$ac_ext << EOF
 
-#line 935 "configure"
+#line 934 "configure"
 #include "confdefs.h"
 
 main(){return(0);}
 EOF
-if { (eval echo configure:940: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:939: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   ac_cv_prog_cc_works=yes
   # If we can't run a trivial program, we are probably using a cross compiler.
   if (./conftest; exit) 2>/dev/null; then
@@ -962,12 +961,12 @@ if test $ac_cv_prog_cc_works = no; then
   { echo "configure: error: installation or configuration problem: C compiler cannot create executables." 1>&2; exit 1; }
 fi
 echo $ac_n "checking whether the C compiler ($CC $CFLAGS $LDFLAGS) is a cross-compiler""... $ac_c" 1>&6
-echo "configure:966: checking whether the C compiler ($CC $CFLAGS $LDFLAGS) is a cross-compiler" >&5
+echo "configure:965: checking whether the C compiler ($CC $CFLAGS $LDFLAGS) is a cross-compiler" >&5
 echo "$ac_t""$ac_cv_prog_cc_cross" 1>&6
 cross_compiling=$ac_cv_prog_cc_cross
 
 echo $ac_n "checking whether we are using GNU C""... $ac_c" 1>&6
-echo "configure:971: checking whether we are using GNU C" >&5
+echo "configure:970: checking whether we are using GNU C" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_gcc'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -976,7 +975,7 @@ else
   yes;
 #endif
 EOF
-if { ac_try='${CC-cc} -E conftest.c'; { (eval echo configure:980: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; } | egrep yes >/dev/null 2>&1; then
+if { ac_try='${CC-cc} -E conftest.c'; { (eval echo configure:979: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }; } | egrep yes >/dev/null 2>&1; then
   ac_cv_prog_gcc=yes
 else
   ac_cv_prog_gcc=no
@@ -995,7 +994,7 @@ ac_test_CFLAGS="${CFLAGS+set}"
 ac_save_CFLAGS="$CFLAGS"
 CFLAGS=
 echo $ac_n "checking whether ${CC-cc} accepts -g""... $ac_c" 1>&6
-echo "configure:999: checking whether ${CC-cc} accepts -g" >&5
+echo "configure:998: checking whether ${CC-cc} accepts -g" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_cc_g'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1029,7 +1028,7 @@ fi
 # Extract the first word of "ranlib", so it can be a program name with args.
 set dummy ranlib; ac_word=$2
 echo $ac_n "checking for $ac_word""... $ac_c" 1>&6
-echo "configure:1033: checking for $ac_word" >&5
+echo "configure:1032: checking for $ac_word" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_RANLIB'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -1058,13 +1057,13 @@ fi
 
 
 	echo $ac_n "checking OS type""... $ac_c" 1>&6
-echo "configure:1062: checking OS type" >&5
+echo "configure:1061: checking OS type" >&5
 	OS_TYPE=`uname -a | awk '{print $ 1}' `
 	echo "$ac_t""$OS_TYPE" 1>&6
 
 
 	echo $ac_n "checking Mach type""... $ac_c" 1>&6
-echo "configure:1068: checking Mach type" >&5
+echo "configure:1067: checking Mach type" >&5
 	MACHTYPE=`uname -m`
 	echo "$ac_t""$MACHTYPE" 1>&6
 
@@ -1073,7 +1072,7 @@ MISCFLAGS='$<'
 case $OS_TYPE in 
 	HP-UX*)
 		echo $ac_n "checking for main in -lM""... $ac_c" 1>&6
-echo "configure:1077: checking for main in -lM" >&5
+echo "configure:1076: checking for main in -lM" >&5
 ac_lib_var=`echo M'_'main | sed 'y%./+-%__p_%'`
 if eval "test \"`echo '$''{'ac_cv_lib_$ac_lib_var'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
@@ -1081,14 +1080,14 @@ else
   ac_save_LIBS="$LIBS"
 LIBS="-lM  $LIBS"
 cat > conftest.$ac_ext <<EOF
-#line 1085 "configure"
+#line 1084 "configure"
 #include "confdefs.h"
 
 int main() {
 main()
 ; return 0; }
 EOF
-if { (eval echo configure:1092: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:1091: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   rm -rf conftest*
   eval "ac_cv_lib_$ac_lib_var=yes"
 else
@@ -1118,7 +1117,7 @@ fi
 	SunOS*)
 		MISCFLAGS="trunc.c" 
 		echo $ac_n "checking for main in -lm""... $ac_c" 1>&6
-echo "configure:1122: checking for main in -lm" >&5
+echo "configure:1121: checking for main in -lm" >&5
 ac_lib_var=`echo m'_'main | sed 'y%./+-%__p_%'`
 if eval "test \"`echo '$''{'ac_cv_lib_$ac_lib_var'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
@@ -1126,14 +1125,14 @@ else
   ac_save_LIBS="$LIBS"
 LIBS="-lm  $LIBS"
 cat > conftest.$ac_ext <<EOF
-#line 1130 "configure"
+#line 1129 "configure"
 #include "confdefs.h"
 
 int main() {
 main()
 ; return 0; }
 EOF
-if { (eval echo configure:1137: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:1136: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   rm -rf conftest*
   eval "ac_cv_lib_$ac_lib_var=yes"
 else
@@ -1163,7 +1162,7 @@ fi
 		;;
 	Linux*)
 		echo $ac_n "checking for main in -lm""... $ac_c" 1>&6
-echo "configure:1167: checking for main in -lm" >&5
+echo "configure:1166: checking for main in -lm" >&5
 ac_lib_var=`echo m'_'main | sed 'y%./+-%__p_%'`
 if eval "test \"`echo '$''{'ac_cv_lib_$ac_lib_var'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
@@ -1171,14 +1170,14 @@ else
   ac_save_LIBS="$LIBS"
 LIBS="-lm  $LIBS"
 cat > conftest.$ac_ext <<EOF
-#line 1175 "configure"
+#line 1174 "configure"
 #include "confdefs.h"
 
 int main() {
 main()
 ; return 0; }
 EOF
-if { (eval echo configure:1182: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:1181: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   rm -rf conftest*
   eval "ac_cv_lib_$ac_lib_var=yes"
 else
@@ -1217,7 +1216,7 @@ EOF
 		fi;;
 	IRIX64)
 		echo $ac_n "checking for main in -lm""... $ac_c" 1>&6
-echo "configure:1221: checking for main in -lm" >&5
+echo "configure:1220: checking for main in -lm" >&5
 ac_lib_var=`echo m'_'main | sed 'y%./+-%__p_%'`
 if eval "test \"`echo '$''{'ac_cv_lib_$ac_lib_var'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
@@ -1225,14 +1224,14 @@ else
   ac_save_LIBS="$LIBS"
 LIBS="-lm  $LIBS"
 cat > conftest.$ac_ext <<EOF
-#line 1229 "configure"
+#line 1228 "configure"
 #include "confdefs.h"
 
 int main() {
 main()
 ; return 0; }
 EOF
-if { (eval echo configure:1236: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:1235: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   rm -rf conftest*
   eval "ac_cv_lib_$ac_lib_var=yes"
 else
@@ -1267,7 +1266,7 @@ fi
 		fi;;
 	OSF*)
 		echo $ac_n "checking for main in -lm""... $ac_c" 1>&6
-echo "configure:1271: checking for main in -lm" >&5
+echo "configure:1270: checking for main in -lm" >&5
 ac_lib_var=`echo m'_'main | sed 'y%./+-%__p_%'`
 if eval "test \"`echo '$''{'ac_cv_lib_$ac_lib_var'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
@@ -1275,14 +1274,14 @@ else
   ac_save_LIBS="$LIBS"
 LIBS="-lm  $LIBS"
 cat > conftest.$ac_ext <<EOF
-#line 1279 "configure"
+#line 1278 "configure"
 #include "confdefs.h"
 
 int main() {
 main()
 ; return 0; }
 EOF
-if { (eval echo configure:1286: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:1285: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   rm -rf conftest*
   eval "ac_cv_lib_$ac_lib_var=yes"
 else
@@ -1324,7 +1323,7 @@ EOF
 		;;
 	*)	
 		echo $ac_n "checking for main in -lm""... $ac_c" 1>&6
-echo "configure:1328: checking for main in -lm" >&5
+echo "configure:1327: checking for main in -lm" >&5
 ac_lib_var=`echo m'_'main | sed 'y%./+-%__p_%'`
 if eval "test \"`echo '$''{'ac_cv_lib_$ac_lib_var'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
@@ -1332,14 +1331,14 @@ else
   ac_save_LIBS="$LIBS"
 LIBS="-lm  $LIBS"
 cat > conftest.$ac_ext <<EOF
-#line 1336 "configure"
+#line 1335 "configure"
 #include "confdefs.h"
 
 int main() {
 main()
 ; return 0; }
 EOF
-if { (eval echo configure:1343: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:1342: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   rm -rf conftest*
   eval "ac_cv_lib_$ac_lib_var=yes"
 else
@@ -1371,7 +1370,7 @@ esac
 	
 
 echo $ac_n "checking how to run the C preprocessor""... $ac_c" 1>&6
-echo "configure:1375: checking how to run the C preprocessor" >&5
+echo "configure:1374: checking how to run the C preprocessor" >&5
 # On Suns, sometimes $CPP names a directory.
 if test -n "$CPP" && test -d "$CPP"; then
   CPP=
@@ -1386,13 +1385,13 @@ else
   # On the NeXT, cc -E runs the code through the compiler's parser,
   # not just through cpp.
   cat > conftest.$ac_ext <<EOF
-#line 1390 "configure"
+#line 1389 "configure"
 #include "confdefs.h"
 #include <assert.h>
 Syntax Error
 EOF
 ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
-{ (eval echo configure:1396: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
+{ (eval echo configure:1395: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
 ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
 if test -z "$ac_err"; then
   :
@@ -1403,13 +1402,13 @@ else
   rm -rf conftest*
   CPP="${CC-cc} -E -traditional-cpp"
   cat > conftest.$ac_ext <<EOF
-#line 1407 "configure"
+#line 1406 "configure"
 #include "confdefs.h"
 #include <assert.h>
 Syntax Error
 EOF
 ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
-{ (eval echo configure:1413: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
+{ (eval echo configure:1412: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
 ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
 if test -z "$ac_err"; then
   :
@@ -1420,13 +1419,13 @@ else
   rm -rf conftest*
   CPP="${CC-cc} -nologo -E"
   cat > conftest.$ac_ext <<EOF
-#line 1424 "configure"
+#line 1423 "configure"
 #include "confdefs.h"
 #include <assert.h>
 Syntax Error
 EOF
 ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
-{ (eval echo configure:1430: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
+{ (eval echo configure:1429: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
 ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
 if test -z "$ac_err"; then
   :
@@ -1455,17 +1454,17 @@ if  test "$with_gmp_include"
 then  
   ac_safe=`echo "$with_gmp_include/gmp-impl.h" | sed 'y%./+-%__p_%'`
 echo $ac_n "checking for $with_gmp_include/gmp-impl.h""... $ac_c" 1>&6
-echo "configure:1459: checking for $with_gmp_include/gmp-impl.h" >&5
+echo "configure:1458: checking for $with_gmp_include/gmp-impl.h" >&5
 if eval "test \"`echo '$''{'ac_cv_header_$ac_safe'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 1464 "configure"
+#line 1463 "configure"
 #include "confdefs.h"
 #include <$with_gmp_include/gmp-impl.h>
 EOF
 ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
-{ (eval echo configure:1469: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
+{ (eval echo configure:1468: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
 ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
 if test -z "$ac_err"; then
   rm -rf conftest*
@@ -1490,17 +1489,17 @@ fi
 else
   ac_safe=`echo "gmp-impl.h" | sed 'y%./+-%__p_%'`
 echo $ac_n "checking for gmp-impl.h""... $ac_c" 1>&6
-echo "configure:1494: checking for gmp-impl.h" >&5
+echo "configure:1493: checking for gmp-impl.h" >&5
 if eval "test \"`echo '$''{'ac_cv_header_$ac_safe'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 1499 "configure"
+#line 1498 "configure"
 #include "confdefs.h"
 #include <gmp-impl.h>
 EOF
 ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
-{ (eval echo configure:1504: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
+{ (eval echo configure:1503: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
 ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
 if test -z "$ac_err"; then
   rm -rf conftest*
@@ -1531,7 +1530,7 @@ fi
 if ` test "$with_gmp_lib" `
 then  
   echo $ac_n "checking gmp library""... $ac_c" 1>&6
-echo "configure:1535: checking gmp library" >&5
+echo "configure:1534: checking gmp library" >&5
 	if  test -r "$with_gmp_lib/libgmp.a"
 	then
 	  LDADD="$LDADD $with_gmp_lib/libgmp.a"
@@ -1541,7 +1540,7 @@ echo "configure:1535: checking gmp library" >&5
   echo "$ac_t""yes" 1>&6
 else
   echo $ac_n "checking for main in -lgmp""... $ac_c" 1>&6
-echo "configure:1545: checking for main in -lgmp" >&5
+echo "configure:1544: checking for main in -lgmp" >&5
 ac_lib_var=`echo gmp'_'main | sed 'y%./+-%__p_%'`
 if eval "test \"`echo '$''{'ac_cv_lib_$ac_lib_var'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
@@ -1549,14 +1548,14 @@ else
   ac_save_LIBS="$LIBS"
 LIBS="-lgmp  $LIBS"
 cat > conftest.$ac_ext <<EOF
-#line 1553 "configure"
+#line 1552 "configure"
 #include "confdefs.h"
 
 int main() {
 main()
 ; return 0; }
 EOF
-if { (eval echo configure:1560: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:1559: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   rm -rf conftest*
   eval "ac_cv_lib_$ac_lib_var=yes"
 else
diff --git a/div.c b/div.c
index 5aec7622d..eaf6afbbc 100644
--- a/div.c
+++ b/div.c
@@ -54,23 +54,51 @@ mpfr_div (r, u, v, rnd_mode)
   TMP_DECL (marker);
 
   if (MPFR_IS_NAN(u) || MPFR_IS_NAN(v)) { MPFR_SET_NAN(r); return; }
-  
+  if (MPFR_IS_INF(u)) 
+    { 
+      if (MPFR_IS_INF(v)) 
+	{
+	  MPFR_SET_NAN(r); return; 
+	}
+      else
+	{ 
+	  MPFR_SET_INF(r); 
+	  if (MPFR_SIGN(r) != MPFR_SIGN(u) * MPFR_SIGN(v)) 
+	    { MPFR_CHANGE_SIGN(r); }
+	  return; 
+	}
+    }
+  else
+    { 
+      if (MPFR_IS_INF(v)) 
+	{
+	  MPFR_SET_ZERO(r); 
+	  if (MPFR_SIGN(r) != MPFR_SIGN(u) * MPFR_SIGN(v)) 
+	    { MPFR_CHANGE_SIGN(r); }
+	  return; 
+	}
+    }
+
   usize = (MPFR_PREC(u) - 1)/BITS_PER_MP_LIMB + 1; 
   vsize = (MPFR_PREC(v) - 1)/BITS_PER_MP_LIMB + 1; 
   sign_quotient = ((MPFR_SIGN(u) * MPFR_SIGN(v) > 0) ? 1 : -1); 
   prec = MPFR_PREC(r);
 
-  if (!MPFR_NOTZERO(u)) { MPFR_SET_ZERO(r); return; }
 
   if (!MPFR_NOTZERO(v))
-    vsize = 1 / v->_mp_d[vsize - 1];    /* Gestion des infinis ? */
-  
-  if (!MPFR_NOTZERO(v))
     {
-      r->_mp_exp = 0;
-      MPN_ZERO(r->_mp_d, r->_mp_size); 
-      return;
+      if (!MPFR_NOTZERO(u)) 
+	{ MPFR_SET_NAN(r); return; }
+      else
+	{
+	  MPFR_SET_INF(r); 
+	  if (MPFR_SIGN(r) != MPFR_SIGN(v) * MPFR_SIGN(u)) 
+	    MPFR_CHANGE_SIGN(r); 
+	  return;
+	}
     }
+  
+  if (!MPFR_NOTZERO(u)) { MPFR_SET_ZERO(r); return; }
 
   up = u->_mp_d;
   vp = v->_mp_d;
diff --git a/div_ui.c b/div_ui.c
index ea46da4ae..a093e749e 100644
--- a/div_ui.c
+++ b/div_ui.c
@@ -50,7 +50,25 @@ mpfr_div_ui(y, x, u, rnd_mode)
   TMP_DECL(marker);
 
   if (MPFR_IS_NAN(x)) { MPFR_SET_NAN(y); return 1; }
-  if (u==0) { fprintf(stderr, "division by zero\n"); exit(1); }
+
+  if (MPFR_IS_INF(x)) 
+    { 
+      MPFR_SET_INF(y); 
+      if (MPFR_SIGN(y) * MPFR_SIGN(x) * u < 0)
+	MPFR_CHANGE_SIGN(y); 
+      return 0; 
+      /*    TODO: semantique de la division par un zero entier ? signe ? */
+    }
+
+  if (u==0) 
+    {
+      if (MPFR_IS_ZERO(x)) { MPFR_SET_NAN(y) ; return 1; }
+      else
+	{ 
+	  MPFR_SET_INF(y); MPFR_SET_SAME_SIGN(y, x); return 0; 
+	  /* TODO: semantique de la division dans ce cas-la aussi ? */
+	}
+    }
 
   TMP_MARK(marker);
   xn = (MPFR_PREC(x)-1)/BITS_PER_MP_LIMB + 1;
diff --git a/dump.c b/dump.c
index d51eb5f73..6fdff81ff 100644
--- a/dump.c
+++ b/dump.c
@@ -42,6 +42,17 @@ mpfr_dump (u, rnd_mode)
   mp_exp_t exp;
   char *str;
 
+  if (MPFR_IS_INF(u)) 
+    {
+      if (MPFR_SIGN(u) == 1) printf("Inf\n"); else printf("-Inf\n"); 
+      return; 
+    }
+  if (MPFR_IS_NAN(u)) 
+    {
+      printf("NaN\n"); 
+      return; 
+    }
+
   str = mpfr_get_str (NULL, &exp, 10, 0, u, rnd_mode);
   if (str[0] == '-')
     printf ("-0.%se%ld\n", str + 1, exp);
diff --git a/eq.c b/eq.c
index e38b4a709..f7eceb02a 100644
--- a/eq.c
+++ b/eq.c
@@ -47,8 +47,10 @@ mpfr_eq (u, v, n_bits)
   usize = (MPFR_PREC(u)-1)/BITS_PER_MP_LIMB + 1;
   vsize = (MPFR_PREC(v)-1)/BITS_PER_MP_LIMB + 1;
 
+  usign = MPFR_SIGN(u); 
+
   /* 1. Are the signs different?  */
-  if (MPFR_SIGN(u) ==  MPFR_SIGN(v))
+  if (usign ==  MPFR_SIGN(v))
     {
       /* U and V are both non-negative or both negative.  */
       if (!MPFR_NOTZERO(u))
@@ -61,12 +63,15 @@ mpfr_eq (u, v, n_bits)
   else
     {
       /* Either U or V is negative, but not both.  */
-      return 0;
+      if (MPFR_NOTZERO(u) || MPFR_NOTZERO(v)) 
+	return 0;
+      else return 1; /* particular case -0 = +0 */
     }
 
   /* U and V have the same sign and are both non-zero.  */
-
-  usign = MPFR_SIGN(u); 
+  if (MPFR_IS_INF(u)) 
+    return (MPFR_IS_INF(v) && (usign == MPFR_SIGN(v))); 
+  else if (MPFR_IS_INF(v)) return 0; 
 
   /* 2. Are the exponents different?  */
   if (uexp > vexp)
diff --git a/exp.c b/exp.c
index 7cd8164b1..9be1202ba 100644
--- a/exp.c
+++ b/exp.c
@@ -47,6 +47,15 @@ mpfr_exp(y, x, rnd_mode)
   mpfr_t r, s, t;
 
   if (MPFR_IS_NAN(x)) { MPFR_SET_NAN(y); return 1; }
+  if (MPFR_IS_INF(x)) 
+    { 
+      if (MPFR_SIGN(x) > 0) 
+	{ MPFR_SET_INF(y); if (MPFR_SIGN(y) == -1) { MPFR_CHANGE_SIGN(y); } }
+      else 
+	{ MPFR_SET_ZERO(y);  if (MPFR_SIGN(y) == -1) { MPFR_CHANGE_SIGN(y); } }
+      /*    TODO: conflits entre infinis et zeros ? */
+    }
+      
   if (!MPFR_NOTZERO(x)) { mpfr_set_ui(y, 1, GMP_RNDN); return 0; }
 
   expx = MPFR_EXP(x);
diff --git a/exp2.c b/exp2.c
index 9e8e090be..74ad9ac86 100644
--- a/exp2.c
+++ b/exp2.c
@@ -106,6 +106,14 @@ mpfr_exp2(y, x, rnd_mode)
   TMP_DECL(marker);
 
   if (MPFR_IS_NAN(x)) { MPFR_SET_NAN(y); return 1; }
+  if (MPFR_IS_INF(x)) 
+    { 
+      if (MPFR_SIGN(x) > 0) 
+	{ MPFR_SET_INF(y); if (MPFR_SIGN(y) == -1) { MPFR_CHANGE_SIGN(y); } }
+      else 
+	{ MPFR_SET_ZERO(y);  if (MPFR_SIGN(y) == -1) { MPFR_CHANGE_SIGN(y); } }
+      /*    TODO: conflits entre infinis et zeros ? */
+	    }
   if (!MPFR_NOTZERO(x)) { mpfr_set_ui(y, 1, GMP_RNDN); return 0; }
 
   expx = MPFR_EXP(x);
diff --git a/exp3.c b/exp3.c
index 741a6a268..6de20291d 100644
--- a/exp3.c
+++ b/exp3.c
@@ -174,6 +174,14 @@ mp_rnd_t rnd_mode;
   int logn;
   /* commencons par 0 */
   if (MPFR_IS_NAN(x)) { MPFR_SET_NAN(y); return 1; }
+  if (MPFR_IS_INF(x)) 
+    { 
+      if (MPFR_SIGN(x) > 0) 
+	{ MPFR_SET_INF(y); if (MPFR_SIGN(y) == -1) { MPFR_CHANGE_SIGN(y); } }
+      else 
+	{ MPFR_SET_ZERO(y);  if (MPFR_SIGN(y) == -1) { MPFR_CHANGE_SIGN(y); } }
+      /* TODO: conflits entre infinis et zeros ? */
+    }
   if (!MPFR_NOTZERO(x)) { 
     mpfr_set_ui(y, 1, GMP_RNDN); 
     return 0;
diff --git a/extract.c b/extract.c
index 451917308..4d70095f3 100644
--- a/extract.c
+++ b/extract.c
@@ -23,6 +23,8 @@ int  i;
   int size;
   int j;
 
+  /* TODO: gestion de l'infini. */
+  
   if (MPFR_ABSSIZE(p) < two_i){
     int j;
     y->_mp_alloc=two_i_2 ;	
diff --git a/generic.c b/generic.c
index 5c7475764..75a90b1d5 100644
--- a/generic.c
+++ b/generic.c
@@ -23,6 +23,8 @@ MA 02111-1307, USA. */
 #  error You should specify a name 
 #endif
 
+/* TODO: Reflechir a un traitement generique des infinis ? */
+
 #ifdef B
 #  ifndef A
 #    error B cannot be used without A
diff --git a/get_str.c b/get_str.c
index dfebc04ba..8c6797abe 100644
--- a/get_str.c
+++ b/get_str.c
@@ -58,9 +58,17 @@ char *mpfr_get_str(str, expptr, base, n, op, rnd_mode)
 	    base);
     exit(1);
   }
-
+  
   neg = (MPFR_SIGN(op)<0) ? 1 : 0;
 
+  if (MPFR_IS_INF(op)) { 
+    if (str==NULL) str = (*_mp_allocate_func)(neg + 4);
+    str0 = str; 
+    if (neg) { *str++ = '-'; }
+    *str++ = 'I'; *str++ = 'n'; *str++ = 'f'; *str='\0'; 
+    return str0; 
+  }
+
   if (!MPFR_NOTZERO(op)) {
     if (str==NULL) str = (*_mp_allocate_func)(neg + n + 1);
     str0 = str;
diff --git a/log.c b/log.c
index 6f0195e99..c32b95e72 100644
--- a/log.c
+++ b/log.c
@@ -62,9 +62,19 @@ mpfr_log(r, a, rnd_mode)
   double ref;
   TMP_DECL(marker);
 
-  /* If a is NaN or a is negative or null, the result is NaN */
-  if (MPFR_IS_NAN(a) || (MPFR_NOTZERO(a)==0) || (MPFR_SIGN(a)<0))
+  /* If a is NaN, the result is NaN */
+  if (MPFR_IS_NAN(a))
     { MPFR_SET_NAN(r); return 1; }
+  
+  if (MPFR_IS_ZERO(a)) 
+    {
+      MPFR_SET_INF(r); if (MPFR_SIGN(r) != -1) { MPFR_CHANGE_SIGN(r); }
+    }
+
+  if (MPFR_IS_INF(a))
+    {
+      MPFR_SET_INF(r); if (MPFR_SIGN(r) != 1) { MPFR_CHANGE_SIGN(r); }
+    }
 
   /* If a is 1, the result is 0 */
   if (mpfr_cmp_ui_2exp(a,1,0)==0){
diff --git a/mpfr.h b/mpfr.h
index 03dc3b12c..4e7f2cef7 100644
--- a/mpfr.h
+++ b/mpfr.h
@@ -88,17 +88,23 @@ typedef __gmp_const __mpfr_struct *mpfr_srcptr;
 
 /* bit 31 of _mp_size is used for sign,
    bit 30 of _mp_size is used for Nan flag,
+   bit 29 of _mp_size is used for Inf flag,
    remaining bits are used to store the number of allocated limbs */
 #define MPFR_IS_NAN(x) (((x)->_mp_size >> 30)&1)
 #define MPFR_SET_NAN(x) ((x)->_mp_size |= (1<<30))
+#define MPFR_IS_INF(x) (((x)->_mp_size >> 29)&1)
+#define MPFR_SET_INF(x) ((x)->_mp_size |= (1<<29))
+#define MPFR_IS_FP(x) ((((x) -> _mp_size >> 29) & 3) == 0)
+#define MPFR_SET_IS_FP(x) ((x) -> _mp_size &= 2684354559UL); /* 1001111...1 */
 #define MPFR_ABSSIZE(x) ((x)->_mp_size & ((1<<30)-1))
 #define MPFR_SIZE(x) ((x)->_mp_size)
 #define MPFR_EXP(x) ((x)->_mp_exp)
 #define MPFR_MANT(x) ((x)->_mp_d)
 #define MPFR_SIGN(x) (((x)->_mp_size >> 31) ? -1 : 1)
-#define MPFR_ISNONNEG(x) (MPFR_SIGN(x)>=0)
-#define MPFR_ISNEG(x) (MPFR_SIGN(x)==-1)
+#define MPFR_ISNONNEG(x) (MPFR_NOTZERO((x)) && MPFR_SIGN(x)>=0)
+#define MPFR_ISNEG(x) (MPFR_NOTZERO((x)) && MPFR_SIGN(x)==-1)
 #define MPFR_CHANGE_SIGN(x) (MPFR_SIZE(x) = MPFR_SIZE(x) ^ (((mp_size_t)1)<<31))
+#define MPFR_SET_SAME_SIGN(x, y) if (MPFR_SIGN((x)) != MPFR_SIGN((y))) { MPFR_CHANGE_SIGN((x)); }
 #define MPFR_PREC(x) ((x)->_mp_prec)
 #define MPFR_NOTZERO(x) (MPFR_MANT(x)[(MPFR_PREC(x)-1)/BITS_PER_MP_LIMB])
 #define MPFR_SET_ZERO(x) (MPFR_MANT(x)[(MPFR_PREC(x)-1)/BITS_PER_MP_LIMB] = 0)
diff --git a/mpz_set_fr.c b/mpz_set_fr.c
index 7c01399af..34b03a6fd 100644
--- a/mpz_set_fr.c
+++ b/mpz_set_fr.c
@@ -37,6 +37,8 @@ mpz_set_fr (z, f)
 {
   int fn, sh;
 
+  /* TODO: semantique de INF, NAN dans ce contexte ; lever une FPE ? */
+
   fn = 1 + (MPFR_PREC(f)-1)/BITS_PER_MP_LIMB;
 
   /* check whether allocated space for z is enough */
diff --git a/mul.c b/mul.c
index 6c899f645..dd693b3bb 100644
--- a/mul.c
+++ b/mul.c
@@ -47,6 +47,22 @@ mpfr_mul(a, b, c, rnd_mode)
 
   /* deal with NaN and zero */
   if (MPFR_IS_NAN(b) || MPFR_IS_NAN(c)) { MPFR_SET_NAN(a); return; }
+  if (MPFR_IS_INF(b)) 
+    {
+      if (!MPFR_NOTZERO(c)) { MPFR_SET_NAN(a); return; }
+      else 
+	{ 
+	  if (MPFR_SIGN(a) != MPFR_SIGN(b) * MPFR_SIGN(c)) MPFR_CHANGE_SIGN(a);
+	}
+    }
+  else if (MPFR_IS_INF(c)) 
+    {
+      if (!MPFR_NOTZERO(b)) { MPFR_SET_NAN(a); return; }
+      else 
+	{ 
+	  if (MPFR_SIGN(a) != MPFR_SIGN(b) * MPFR_SIGN(c)) MPFR_CHANGE_SIGN(a);
+	}
+    }
   if (!MPFR_NOTZERO(b) || !MPFR_NOTZERO(c)) { MPFR_SET_ZERO(a); return; }
 
   sign_product = MPFR_SIGN(b) * MPFR_SIGN(c);
diff --git a/mul_ui.c b/mul_ui.c
index 503e27a43..b2a22bdf6 100644
--- a/mul_ui.c
+++ b/mul_ui.c
@@ -40,6 +40,17 @@ mpfr_mul_ui(y, x, u, rnd_mode)
   unsigned long xsize, ysize, cnt, dif, ex, sh; 
   TMP_DECL(marker);
 
+  if (MPFR_IS_INF(x)) 
+    {
+      if (u) 
+	{ 
+	  MPFR_SET_INF(y); 
+	  if (MPFR_SIGN(y) != MPFR_SIGN(x) * u) { MPFR_CHANGE_SIGN(y); }
+	  return; 
+	}
+      else { MPFR_SET_NAN(y); return; }
+    }
+
   TMP_MARK(marker);
   my = MPFR_MANT(y); ex = MPFR_EXP(x);  
   ysize = (MPFR_PREC(y)-1)/BITS_PER_MP_LIMB + 1;
diff --git a/out_str.c b/out_str.c
index 04ea9d724..468a850dd 100644
--- a/out_str.c
+++ b/out_str.c
@@ -42,8 +42,14 @@ mpfr_out_str (stream, base, n_digits, op, rnd_mode)
 
   if (MPFR_IS_NAN(op)) { fprintf(stream, "NaN"); return 3; }
   if (!MPFR_NOTZERO(op)) { fprintf(stream, "0"); return 1; }
+  if (MPFR_IS_INF(op)) 
+    { 
+      if (MPFR_SIGN(op) == 1) { fprintf(stream, "Inf"); return 3; }
+      else { fprintf(stream, "-Inf"); return 4; }
+    }
 
   s = mpfr_get_str(NULL, &e, base, n_digits, op, rnd_mode);
+  /*	  TODO: maintenir le code pour les infinis dans get_str ?  */
   s0 = s;
   /* for op=3.1416 we have s = "31416" and e = 1 */
   
diff --git a/pow.c b/pow.c
index 7b1b74336..cb7204e0f 100644
--- a/pow.c
+++ b/pow.c
@@ -38,7 +38,16 @@ mpfr_pow_ui (x, y, n, rnd)
 #endif
 {
   long int i; double err;
-  
+
+  if (MPFR_IS_INF(y)) 
+    {
+      if (n == 0) { MPFR_SET_NAN(x); return; }
+      else if ((MPFR_SIGN(y) < 0 && (MPFR_SIGN(x) > 0 || n % 2 == 0)) ||
+	       MPFR_SIGN(y) > 0 && (MPFR_SIGN(x) < 0 && n % 2 == 1))
+	MPFR_CHANGE_SIGN(x); 
+      MPFR_SET_INF(x); return; 
+    }
+
   if (n==0) { mpfr_set_ui(x, 1, rnd); return 0; }
   mpfr_set(x, y, rnd); err = 1.0;
   for (i=0;(1<<i)<=n;i++);
@@ -51,6 +60,10 @@ mpfr_pow_ui (x, y, n, rnd)
 }
 
 /* sets x to y^n, and returns ceil(log2(max ulp error)) */
+
+/* TODO: gerer l'infini en cas de debordement ? Fait mecaniquement si fait 
+   dans mul ? */
+
 int
 #if __STDC__
 mpfr_ui_pow_ui (mpfr_ptr x, unsigned long int y, unsigned long int n,
diff --git a/print_raw.c b/print_raw.c
index 77821a61c..cfb596244 100644
--- a/print_raw.c
+++ b/print_raw.c
@@ -40,6 +40,8 @@ mpfr_get_str_raw(digit_ptr, x)
   ex = MPFR_EXP(x); 
   p = MPFR_PREC(x); 
 
+  /* TODO: utilite de gerer l'infini a ce niveau ? */
+
   if (MPFR_SIGN(x) < 0) { *digit_ptr = '-'; digit_ptr++; }
   sprintf(digit_ptr, "0."); digit_ptr += 2; 
 
@@ -72,6 +74,9 @@ mpfr_print_raw(x)
   char *str; 
 
   if (MPFR_IS_NAN(x)) printf("NaN");
+  else if (MPFR_IS_INF(x)) {
+    if (MPFR_SIGN(x) == 1) { printf("Inf"); } else printf("-Inf"); 
+  }
   else if (!MPFR_NOTZERO(x)) printf("0");
   else {
      /* 3 char for sign + 0 + binary point
diff --git a/reldiff.c b/reldiff.c
index 4c018a133..dd5b7fb56 100644
--- a/reldiff.c
+++ b/reldiff.c
@@ -37,10 +37,22 @@ mpfr_reldiff(a, b, c, rnd_mode)
 #endif
 {
   if (MPFR_IS_NAN(b) || MPFR_IS_NAN(c)) { MPFR_SET_NAN(a); return; }
+  if (MPFR_IS_INF(b)) 
+    { 
+      if (MPFR_IS_INF(c) && (MPFR_SIGN(c) == MPFR_SIGN(b)))
+	{ MPFR_SET_ZERO(a); return; }
+      else { MPFR_SET_NAN(a); return; }
+    }
+
+  if (MPFR_IS_INF(c)) 
+    {
+      MPFR_SET_INF(a); 
+      if (MPFR_SIGN(a) == MPFR_SIGN(c)) { MPFR_CHANGE_SIGN(a); }
+    }
 
   if (!MPFR_NOTZERO(b)) /* reldiff = abs(c)/c = sign(c) */
+    /*    TODO: faire preciser la SEMANTIQUE DE CE FOUTOIR. */
     mpfr_set_ui(a, MPFR_SIGN(c), rnd_mode);
-
   else {
     mpfr_sub(a, b, c, rnd_mode);
     mpfr_abs(a, a, rnd_mode); /* for compatibility with MPF */
diff --git a/round.c b/round.c
index 9e6f6e9d3..6e4e81226 100644
--- a/round.c
+++ b/round.c
@@ -184,6 +184,7 @@ mpfr_round(x, rnd_mode, prec)
   mp_limb_t *tmp; int carry, signx; mp_prec_t nw;
   TMP_DECL(marker);
 
+  if (MPFR_IS_INF(x) || MPFR_IS_NAN(x)) return; 
   nw = prec / BITS_PER_MP_LIMB; 
   if (prec & (BITS_PER_MP_LIMB - 1)) nw++;
   signx = MPFR_SIGN(x);
diff --git a/set.c b/set.c
index 7f869b087..42c317ff6 100644
--- a/set.c
+++ b/set.c
@@ -38,6 +38,12 @@ mpfr_set4(a, b, rnd_mode, signb)
   int carry, an, preca = MPFR_PREC(a), sh; mp_limb_t *ap = MPFR_MANT(a);
 
   if (MPFR_IS_NAN(b)) { MPFR_SET_NAN(a); return; }
+  if (MPFR_IS_INF(b)) 
+    { 
+      MPFR_SET_INF(a); 
+      if (MPFR_SIGN(a) * signb < 0) MPFR_CHANGE_SIGN(a); 
+      return; 
+    }
 
   carry = mpfr_round_raw(ap, MPFR_MANT(b), MPFR_PREC(b), (signb<0), preca, rnd_mode);
   MPFR_EXP(a) = MPFR_EXP(b);
diff --git a/set_d.c b/set_d.c
index 15851d12b..d4353be1d 100644
--- a/set_d.c
+++ b/set_d.c
@@ -31,6 +31,8 @@ extern int isnan(double);
 #include "mpfr.h"
 
 #define NaN sqrt(-1) /* ensures a machine-independent NaN */
+#define Infp 1/0.
+#define Infm -1/0.
 
 /* Included from gmp-2.0.2, patched to support denorms */
 
@@ -247,6 +249,12 @@ mpfr_set_d(r, d, rnd_mode)
 
   if (d == 0) { MPFR_SET_ZERO(r); return; }
   else if (isnan(d)) { MPFR_SET_NAN(r); return; }
+  else if (isinf(d)) 
+    { 
+      MPFR_SET_INF(r); 
+      if ((d > 0 && (MPFR_SIGN(r) == -1)) || (d < 0 && (MPFR_SIGN(r) == 1)))
+	MPFR_CHANGE_SIGN(r); 
+    }
 
   signd = (d < 0) ? -1 : 1;
   d = ABS (d);
@@ -290,6 +298,12 @@ mpfr_get_d2(src, e)
     printf("recognized NaN\n");
 #endif
     return NaN; }
+  if (MPFR_IS_INF(src)) { 
+#ifdef DEBUG
+    printf("Found Inf.\n");
+#endif
+    return (MPFR_SIGN(src) == 1 ? Infp : Infm); 
+  }
   if (MPFR_NOTZERO(src)==0) return 0.0;
   size = 1+(MPFR_PREC(src)-1)/BITS_PER_MP_LIMB;
   qp = MPFR_MANT(src);
diff --git a/set_str_raw.c b/set_str_raw.c
index eb2d2ed1f..caf09192f 100644
--- a/set_str_raw.c
+++ b/set_str_raw.c
@@ -55,7 +55,18 @@ mpfr_set_str_raw(x, str)
 
   if (*str == '-') { negative = 1; str++; }
   else if (*str == '+') str++;
-
+  
+  if (*str == 'I') 
+    { 
+      MPFR_SET_INF(x); if (MPFR_ISNEG(x) != negative) { MPFR_CHANGE_SIGN(x); }
+      return; 
+    }
+     
+  if (*str == 'N')
+    {
+      MPFR_SET_NAN(x); return; 
+    }
+ 
   while (*str == '0') { str++; } 
 
   while (*str == '0' || *str == '1')
diff --git a/sin_cos.c b/sin_cos.c
index 548da131c..99206b3df 100644
--- a/sin_cos.c
+++ b/sin_cos.c
@@ -66,7 +66,7 @@ mp_rnd_t rnd_mode;
   int logn;
   int tmp_factor;
   int tmpi;
-  if (MPFR_IS_NAN(x)) { MPFR_SET_NAN(sinus);  MPFR_SET_NAN(cosinus); return 1; }
+  if (MPFR_IS_NAN(x) || MPFR_IS_INF(x)) { MPFR_SET_NAN(sinus);  MPFR_SET_NAN(cosinus); return 1; }
   if (!MPFR_NOTZERO(x)) { 
     mpfr_set_ui(sinus, 0, GMP_RNDN); 
     mpfr_set_ui(cosinus, 1, GMP_RNDN); 
diff --git a/sqrt.c b/sqrt.c
index 7e083e1a0..6eb4efc37 100644
--- a/sqrt.c
+++ b/sqrt.c
@@ -50,7 +50,12 @@ mpfr_sqrt (r, u, rnd_mode)
   TMP_DECL (marker); TMP_DECL(marker0); 
 
   if (MPFR_IS_NAN(u) || MPFR_SIGN(u) == -1) { MPFR_SET_NAN(r); return 0; }
-  
+  if (MPFR_IS_INF(u)) 
+    { 
+      MPFR_SET_INF(r); 
+      if (MPFR_SIGN(r) != 1) { MPFR_CHANGE_SIGN(r); }
+    }
+
   prec = MPFR_PREC(r);
 
   if (!MPFR_NOTZERO(u))
diff --git a/sub.c b/sub.c
index 28416d6e6..9b718896f 100644
--- a/sub.c
+++ b/sub.c
@@ -515,6 +515,31 @@ mpfr_sub(a, b, c, rnd_mode)
 
   if (MPFR_IS_NAN(b) || MPFR_IS_NAN(c)) { MPFR_SET_NAN(a); return; }
 
+  if (MPFR_IS_INF(b)) 
+    { 
+      if (MPFR_IS_INF(c)) 
+	{
+	  if (MPFR_SIGN(b) != MPFR_SIGN(c)) 
+	    { 
+	      MPFR_SET_INF(a); 
+	      if (MPFR_SIGN(a) != MPFR_SIGN(b)) { MPFR_CHANGE_SIGN(a); }
+	    }
+	  else
+	    MPFR_SET_NAN(a); 
+	}
+      else
+	{
+	  MPFR_SET_INF(a); 
+	  if (MPFR_SIGN(b) != MPFR_SIGN(a)) { MPFR_CHANGE_SIGN(a); }
+	}
+    }
+  else 
+    if (MPFR_IS_INF(c))
+      {
+	MPFR_SET_INF(a); 
+	if (MPFR_SIGN(c) == MPFR_SIGN(a)) { MPFR_CHANGE_SIGN(a); }
+      }
+
   if (!MPFR_NOTZERO(b)) { mpfr_neg(a, c, rnd_mode); return; }
   if (!MPFR_NOTZERO(c)) { mpfr_set(a, b, rnd_mode); return; }
 
diff --git a/zeta.c b/zeta.c
index c0157e734..ccafec63c 100644
--- a/zeta.c
+++ b/zeta.c
@@ -36,81 +36,67 @@ mpfr_zeta(result, op, rnd_mode)
      mp_rnd_t rnd_mode;
 #endif
 {
-	mpfr_t s,s2,x,y,u,b,v,nn,z,z2; 
-	int i,n,succes; 
-
-	/* first version */
-	if (mpfr_get_d(op) != 2.0 || rnd_mode != GMP_RNDN 
-	|| MPFR_PREC(result) != 53) {
-	   fprintf(stderr, "not yet implemented\n"); exit(1);
-	}
-
-mpfr_set_default_prec(67);
-mpfr_init(x);
-mpfr_init(y);
-mpfr_init(s);
-mpfr_init(s2);
-mpfr_init(u);
-mpfr_init(b);
-mpfr_init(v);
-mpfr_init(nn);
-mpfr_init(z);
-mpfr_init(z2);
-mpfr_set_ui(u,1,GMP_RNDN);
-mpfr_set_ui(s,0,GMP_RNDN);
-/*s=Somme des 1/i^2 (i=100...2)*/
-n=100;
-for (i=n; i>1; i--)
-{
-mpfr_set_ui(x,i*i,GMP_RNDN);
-mpfr_div(y,u,x,GMP_RNDN);
-mpfr_add(s,s,y,GMP_RNDN);
-};
-/*mpfr_print_raw(s);printf("\n");
-t=mpfr_out_str(stdout,10,0,s,GMP_RNDN);printf("\n");*/
-/*Application d'Euler-Maclaurin, jusqu'au terme 1/n^7 - n=100)*/
-mpfr_set_ui(nn,n,GMP_RNDN);
-mpfr_div(z,u,nn,GMP_RNDN);
-mpfr_set(s2,z,GMP_RNDN);
-mpfr_mul(z2,z,z,GMP_RNDN);
-mpfr_div_2exp(v,z2,1,GMP_RNDN);
-mpfr_sub(s2,s2,v,GMP_RNDN);
-mpfr_set_ui(b,6,GMP_RNDN);
-mpfr_mul(z,z,z2,GMP_RNDN);
-mpfr_div(v,z,b,GMP_RNDN);
-mpfr_add(s2,s2,v,GMP_RNDN);
-mpfr_set_si(b,-30,GMP_RNDN);
-mpfr_mul(z,z,z2,GMP_RNDN);
-mpfr_div(v,z,b,GMP_RNDN);
-mpfr_add(s2,s2,v,GMP_RNDN);
-mpfr_set_si(b,42,GMP_RNDN);
-mpfr_mul(z,z,z2,GMP_RNDN);
-mpfr_div(v,z,b,GMP_RNDN);
-mpfr_add(s2,s2,v,GMP_RNDN);
-/*mpfr_print_raw(s2);printf("\n");
-t=mpfr_out_str(stdout,10,0,s2,GMP_RNDN);printf("\n");*/
-mpfr_add(s,s,s2,GMP_RNDN);
-/*mpfr_print_raw(s);printf("\n");
-t=mpfr_out_str(stdout,10,0,s,GMP_RNDN);printf("\n");*/
-mpfr_add(s,s,u,GMP_RNDN);
-/*mpfr_print_raw(s);printf("\n");
-t=mpfr_out_str(stdout,10,0,s,GMP_RNDN);printf("\n");*/
-/*Peut-on arrondir ? La reponse est oui*/
-succes=mpfr_can_round(s,57,GMP_RNDN,GMP_RNDN,53);
-if (succes) mpfr_set(result,s,GMP_RNDN);
-else {
-  fprintf(stderr, "can't round in mpfr_zeta\n"); exit(1);
-}
+  mpfr_t s,s2,x,y,u,b,v,nn,z,z2; 
+  int i,n,succes; 
+
+  /* first version */
+  if (mpfr_get_d(op) != 2.0 || rnd_mode != GMP_RNDN 
+      || MPFR_PREC(result) != 53) {
+    fprintf(stderr, "not yet implemented\n"); exit(1);
+  }
+
+  mpfr_set_default_prec(67);
+
+  mpfr_init(x); mpfr_init(y); mpfr_init(s); mpfr_init(s2);
+  mpfr_init(u); mpfr_init(b); mpfr_init(v); mpfr_init(nn);
+  mpfr_init(z); mpfr_init(z2);
+
+  mpfr_set_ui(u,1,GMP_RNDN);
+  mpfr_set_ui(s,0,GMP_RNDN);
+
+  /* s=Somme des 1/i^2 (i=100...2) */
+  n=100;
+  for (i=n; i>1; i--)
+    {
+      mpfr_div_ui(y,u,i*i,GMP_RNDN);
+      mpfr_add(s,s,y,GMP_RNDN);
+    }
+
+  /* Application d'Euler-Maclaurin, jusqu'au terme 1/n^7 - n=100) */
+  /*   mpfr_set_ui(nn,n,GMP_RNDN); */
+  mpfr_div_ui(z,u,n,GMP_RNDN);
+  mpfr_mul(z2,z,z,GMP_RNDN);
+  mpfr_div_2exp(v,z2,1,GMP_RNDN);
+
+  mpfr_set(s2,z,GMP_RNDN);
+  mpfr_sub(s2,s2,v,GMP_RNDN);
+
+  mpfr_mul(z,z,z2,GMP_RNDN);
+  mpfr_div_ui(v,z,6,GMP_RNDN);
+  mpfr_add(s2,s2,v,GMP_RNDN);
+
+  mpfr_mul(z,z,z2,GMP_RNDN);
+  mpfr_div_ui(v,z,30,GMP_RNDN);
+  mpfr_sub(s2,s2,v,GMP_RNDN);
+
+  mpfr_mul(z,z,z2,GMP_RNDN);
+  mpfr_div_ui(v,z,42,GMP_RNDN);
+  mpfr_add(s2,s2,v,GMP_RNDN);
+
+  mpfr_add(s,s,s2,GMP_RNDN);
+  mpfr_add(s,s,u,GMP_RNDN);
+
+  /*Peut-on arrondir ? La reponse est oui*/
+  succes=mpfr_can_round(s, 57, GMP_RNDN,GMP_RNDN, 53);
+
+  if (succes) mpfr_set(result,s,GMP_RNDN);
+  else {
+    fprintf(stderr, "can't round in mpfr_zeta\n"); exit(1);
+  }
+
+  mpfr_clear(x); mpfr_clear(y); mpfr_clear(s); mpfr_clear(s2);
+  mpfr_clear(u); mpfr_clear(b); mpfr_clear(v); mpfr_clear(nn);
+  mpfr_clear(z); mpfr_clear(z2);
 
-mpfr_clear(x);
-mpfr_clear(y);
-mpfr_clear(s);
-mpfr_clear(s2);
-mpfr_clear(u);
-mpfr_clear(b);
-mpfr_clear(v);
-mpfr_clear(nn);
-mpfr_clear(z);
-mpfr_clear(z2);
-return 1; /* result is inexact */
+  return 1; /* result is inexact */
 }