re PR fortran/28276 (EXPONENT() broken for real constants)

	* configure.in: Check for GMP 4.1 or newer.  Check for MPFR 2.2.0 
	or newer.
	* configure: Regenerated.
	* doc/install.texi: Document required versions of GMP and MPFR.
	* fortran/arith.c: Conditionally include arctangent2().
	(gfc_check_real_range): Use mpfr_subnormalize in preference to local
	hack.
	* fortran/trans-intrinsic.c (gfc_get_intrinsic_lib_fndecl): Append
	l for long double functions.
	* fortran/simplify.c: Wrap Copyright to new line.
	(gfc_simplify_atan2): Use mpfr_atan2 in preference to arctangent2().
        (gfc_simplify_log): Ditto.


	PR fortran/28276
	* fortran/simplify.c (gfc_simplify_exponent): Use mpfr_get_exp in
	preference to broken local hack.

	PR fortran/27021
	* fortran/simplify.c (gfc_simplify_nearest): Use mpfr_nexttoward and
	mpfr_subnormalize to handle numbers near zero in preference to broken
	 local hack.

	PR fortran/28276
	* testsuite/gfortran.dg/exponent_1.f90: New test.

	PR fortran/27021
	* testsuite/gfortran.dg/nearest_1.f90: New test.

From-SVN: r117257

ChangeLog

+2006-09-27  Steven G. Kargl  <kargl@gcc.gnu.org>
+
+	* configure.in: Check for GMP 4.1 or newer.  Check for MPFR 2.2.0 
+	or newer.
+	* configure: Regenerated.
+
 2006-09-27  Dave Brolley  <brolley@redhat.com>
 
 	* configure.in (RUNTEST): Look for 'runtest' in the source tree by using

configure.in

@@ -1097,17 +1097,23 @@ CFLAGS="$CFLAGS $gmpinc"
 # Check GMP actually works
 AC_MSG_CHECKING([for correct version of gmp.h])
 AC_TRY_COMPILE([#include "gmp.h"],[
-#if __GNU_MP_VERSION < 3
+#if __GNU_MP_VERSION < 4 || (__GNU_MP_VERSION == 4 && __GNU_MP_VERSION_MINOR < 1)
 choke me
 #endif
-], [AC_MSG_RESULT([yes])],
-  [AC_MSG_RESULT([no]); have_gmp=no])
+], [AC_MSG_RESULT([yes])], [AC_MSG_RESULT([no]); have_gmp=no])
 
 if test x"$have_gmp" = xyes; then
-  AC_MSG_CHECKING([for MPFR])
+  AC_MSG_CHECKING([for correct version of mpfr.h])
+  AC_TRY_COMPILE([#include "gmp.h"
+#include <mpfr.h>],[
+#if MPFR_VERSION_MAJOR < 2 || (MPFR_VERSION_MAJOR == 2 && MPFR_VERSION_MINOR < 2)
+  choke me
+#endif
+], [AC_MSG_RESULT([yes])], [AC_MSG_RESULT([buggy version of MPFR detected])])
 
   saved_LIBS="$LIBS"
   LIBS="$LIBS $gmplibs"
+  AC_MSG_CHECKING([for any version of mpfr.h])
   AC_TRY_LINK([#include <gmp.h>
 #include <mpfr.h>], [mpfr_t n; mpfr_init(n);],
     [AC_MSG_RESULT([yes])],  [AC_MSG_RESULT([no]); have_gmp=no])
@@ -1252,7 +1258,7 @@ if test -d ${srcdir}/gcc; then
         case ,${enable_languages},:${have_gmp}:${need_gmp} in
           *,${language},*:no:yes)
             # Specifically requested language; tell them.
-            AC_MSG_ERROR([GMP with MPFR support is required to build $language])
+            AC_MSG_ERROR([GMP 4.1 and MPFR 2.2 or newer versions required by $language])
             ;;
           *:no:yes)
             # Silently disable.

gcc/ChangeLog

+2006-09-27  Steven G. Kargl  <kargl@gcc.gnu.org>
+
+	* doc/install.texi: Document required versions of GMP and MPFR.
+
 2006-09-27  Paul Brook  <paul@codesourcery.com>
 
 	PR target/29230

gcc/doc/install.texi

@@ -290,17 +290,20 @@ Necessary (only on some platforms) to untar the source code.  Many
 systems' @command{tar} programs will also work, only try GNU
 @command{tar} if you have problems.
 
-@item GNU Multiple Precision Library (GMP) version 4.0 (or later)
+@item GNU Multiple Precision Library (GMP) version 4.1 (or later)
 
-Necessary to build the Fortran frontend.  If you don't have it
+Necessary to build the Fortran frontend.  If you do not have it
 installed in your library search path, you will have to configure with
 the @option{--with-gmp} or @option{--with-gmp-dir} configure option.
 
-@item MPFR Library
+@item MPFR Library version 2.2 (or later)
 
 Necessary to build the Fortran frontend.  It can be downloaded from
-@uref{http://www.mpfr.org/}.  It is also included in the current GMP
-release (4.1.3) when configured with @option{--enable-mpfr}.
+@uref{http://www.mpfr.org/}.  The version of MPFR that is bundled with
+GMP 4.1.x contains numerous bugs.  Although gfortran will appear
+to function with the buggy verions of MPFR, there are few gfortran bugs
+that will not be fixed to use this version.  It is strongly
+recommended to upgrade to at least MPFR version 2.2.
 
 The @option{--with-mpfr} or @option{--with-mpfr-dir} configure option should
 be used if your MPFR Library is not installed in your library search path.

gcc/fortran/ChangeLog

+2006-09-27  Steven G. Kargl  <kargl@gcc.gnu.org>
+
+	* arith.c: Conditionally include arctangent2().
+	(gfc_check_real_range): Use mpfr_subnormalize in preference to local
+	hack.
+	* trans-intrinsic.c (gfc_get_intrinsic_lib_fndecl): Append
+	l for long double functions.
+	* simplify.c: Wrap Copyright to new line.
+	(gfc_simplify_atan2): Use mpfr_atan2 in preference to arctangent2().
+        (gfc_simplify_log): Ditto.
+
+
+	PR fortran/28276
+	* simplify.c (gfc_simplify_exponent): Use mpfr_get_exp in
+	preference to broken local hack.
+
+	PR fortran/27021
+	* simplify.c (gfc_simplify_nearest): Use mpfr_nexttoward and
+	mpfr_subnormalize to handle numbers near zero in preference to broken
+	 local hack.
+
 2006-09-26  Jakub Jelinek  <jakub@redhat.com>
 
 	PR fortran/29097

gcc/fortran/arith.c

@@ -75,6 +75,7 @@ gfc_set_model (mpfr_t x)
   mpfr_set_default_prec (mpfr_get_prec (x));
 }
 
+#if !defined(MPFR_VERSION_MAJOR)
 /* Calculate atan2 (y, x)
 
 atan2(y, x) = atan(y/x)				if x > 0,
@@ -124,7 +125,7 @@ arctangent2 (mpfr_t y, mpfr_t x, mpfr_t result)
 
   mpfr_clear (t);
 }
-
+#endif
 
 /* Given an arithmetic error code, return a pointer to a string that
    explains the error.  */
@@ -407,6 +408,7 @@ gfc_check_real_range (mpfr_t p, int kind)
     }
   else if (mpfr_cmp (q, gfc_real_kinds[i].tiny) < 0)
     {
+#if !defined(MPFR_VERSION_MAJOR)
       /* MPFR operates on a number with a given precision and enormous
 	exponential range.  To represent subnormal numbers, the exponent is
 	allowed to become smaller than emin, but always retains the full
@@ -428,14 +430,31 @@ gfc_check_real_range (mpfr_t p, int kind)
       sprintf (s, "0.%sE%d", bin, (int) e);
       mpfr_set_str (q, s, gfc_real_kinds[i].radix, GMP_RNDN);
 
+      gfc_free (s);
+      gfc_free (bin);
+#else
+      mp_exp_t emin, emax;
+
+      /* Save current values of emin and emax.  */
+      emin = mpfr_get_emin ();
+      emax = mpfr_get_emax ();
+
+      /* Set emin and emax for the current model number.  */
+      mpfr_set_emin ((mp_exp_t) gfc_real_kinds[i].min_exponent - 1);
+      mpfr_set_emax ((mp_exp_t) gfc_real_kinds[i].max_exponent - 1);
+      mpfr_subnormalize (q, 0, GFC_RND_MODE);
+
+      /* Reset emin and emax.  */
+      mpfr_set_emin (emin);
+      mpfr_set_emax (emax);
+#endif
+
+      /* Copy sign if needed.  */
       if (mpfr_sgn (p) < 0)
 	mpfr_neg (p, q, GMP_RNDN);
       else
 	mpfr_set (p, q, GMP_RNDN);
 
-      gfc_free (s);
-      gfc_free (bin);
-
       retval = ARITH_OK;
     }
   else

gcc/fortran/simplify.c

 /* Simplify intrinsic functions at compile-time.
-   Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software
-   Foundation, Inc.
+   Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006
+   Free Software Foundation, Inc.
    Contributed by Andy Vaught & Katherine Holcomb
 
 This file is part of GCC.
@@ -607,7 +607,11 @@ gfc_simplify_atan2 (gfc_expr * y, gfc_expr * x)
       return &gfc_bad_expr;
     }
 
+#if !defined(MPFR_VERSION_MAJOR)
   arctangent2 (y->value.real, x->value.real, result->value.real);
+#else
+  mpfr_atan2 (result->value.real, y->value.real, x->value.real, GFC_RND_MODE);
+#endif
 
   return range_check (result, "ATAN2");
 }
@@ -1054,9 +1058,12 @@ gfc_expr *
 gfc_simplify_exponent (gfc_expr * x)
 {
   int i;
-  mpfr_t tmp;
   gfc_expr *result;
 
+#if !defined(MPFR_VERSION_MAJOR)
+  mpfr_t tmp;
+#endif
+
   if (x->expr_type != EXPR_CONSTANT)
     return NULL;
 
@@ -1071,6 +1078,9 @@ gfc_simplify_exponent (gfc_expr * x)
       return result;
     }
 
+#if !defined(MPFR_VERSION_MAJOR)
+  /* PR fortran/28276 suffers from a buggy MPFR, and this block of code
+     does not function correctly.  */
   mpfr_init (tmp);
 
   mpfr_abs (tmp, x->value.real, GFC_RND_MODE);
@@ -1085,6 +1095,11 @@ gfc_simplify_exponent (gfc_expr * x)
     mpz_add_ui (result->value.integer,result->value.integer, 1);
 
   mpfr_clear (tmp);
+#else
+  /* Requires MPFR 2.2.0 or newer.  */
+  i = (int) mpfr_get_exp (x->value.real);
+  mpz_set_si (result->value.integer, i);
+#endif
 
   return range_check (result, "EXPONENT");
 }
@@ -2146,8 +2161,13 @@ gfc_simplify_log (gfc_expr * x)
       mpfr_init (xr);
       mpfr_init (xi);
 
-      arctangent2 (x->value.complex.i, x->value.complex.r,
-	           result->value.complex.i);
+#if !defined(MPFR_VERSION_MAJOR)
+      arctangent2 (x->value.complex.i, x->value.complex.r, result->value.complex.i);
+#else
+      mpfr_atan2 (result->value.complex.i, x->value.complex.i, x->value.complex.r,
+		  GFC_RND_MODE);
+#endif
+
 
       mpfr_mul (xr, x->value.complex.r, x->value.complex.r, GFC_RND_MODE);
       mpfr_mul (xi, x->value.complex.i, x->value.complex.i, GFC_RND_MODE);
@@ -2474,27 +2494,28 @@ gfc_simplify_nearest (gfc_expr * x, gfc_expr * s)
 {
   gfc_expr *result;
   mpfr_t tmp;
-  int direction, sgn;
+  int sgn;
+#if !defined(MPFR_VERSION_MAJOR)
+  int direction;
+#else
+  mp_exp_t emin, emax;
+#endif
 
   if (x->expr_type != EXPR_CONSTANT || s->expr_type != EXPR_CONSTANT)
     return NULL;
 
-  gfc_set_model_kind (x->ts.kind);
-  result = gfc_copy_expr (x);
-
-  direction = mpfr_sgn (s->value.real);
-
-  if (direction == 0)
+  if (mpfr_sgn (s->value.real) == 0)
     {
-      gfc_error ("Second argument of NEAREST at %L may not be zero",
-		 &s->where);
-      gfc_free (result);
+      gfc_error ("Second argument of NEAREST at %L shall not be zero", &s->where);
       return &gfc_bad_expr;
     }
 
-  /* TODO: Use mpfr_nextabove and mpfr_nextbelow once we move to a
-     newer version of mpfr.  */
+  gfc_set_model_kind (x->ts.kind);
+  result = gfc_copy_expr (x);
+
+#if !defined(MPFR_VERSION_MAJOR)
 
+  direction = mpfr_sgn (s->value.real);
   sgn = mpfr_sgn (x->value.real);
 
   if (sgn == 0)
@@ -2539,6 +2560,28 @@ gfc_simplify_nearest (gfc_expr * x, gfc_expr * s)
       if (sgn < 0)
 	mpfr_neg (result->value.real, result->value.real, GFC_RND_MODE);
     }
+#else
+
+  /* Save current values of emin and emax.  */
+  emin = mpfr_get_emin ();
+  emax = mpfr_get_emax ();
+
+  /* Set emin and emax for the current model number.  */
+  sgn = gfc_validate_kind (BT_REAL, x->ts.kind, 0);
+  mpfr_set_emin ((mp_exp_t) gfc_real_kinds[sgn].min_exponent - 1);
+  mpfr_set_emax ((mp_exp_t) gfc_real_kinds[sgn].max_exponent - 1);
+
+  sgn = mpfr_sgn (s->value.real); 
+  mpfr_init (tmp);
+  mpfr_set_inf (tmp, sgn);
+  mpfr_nexttoward (result->value.real, tmp);
+  mpfr_subnormalize (result->value.real, 0, GFC_RND_MODE);
+ 
+  mpfr_set_emin (emin);
+  mpfr_set_emax (emax);
+ 
+  mpfr_clear(tmp);
+#endif
 
   return range_check (result, "NEAREST");
 }

gcc/fortran/trans-intrinsic.c

@@ -590,12 +590,18 @@ gfc_get_intrinsic_lib_fndecl (gfc_intrinsic_map_t * m, gfc_expr * expr)
 
   if (m->libm_name)
     {
-      gcc_assert (ts->kind == 4 || ts->kind == 8 || ts->kind == 10
-                 || ts->kind == 16);
-      snprintf (name, sizeof (name), "%s%s%s",
-		ts->type == BT_COMPLEX ? "c" : "",
-		m->name,
-		ts->kind == 4 ? "f" : "");
+      if (ts->kind == 4)
+	snprintf (name, sizeof (name), "%s%s%s",
+		ts->type == BT_COMPLEX ? "c" : "", m->name, "f");
+      else if (ts->kind == 8)
+	snprintf (name, sizeof (name), "%s%s",
+		ts->type == BT_COMPLEX ? "c" : "", m->name);
+      else
+	{
+	  gcc_assert (ts->kind == 10 || ts->kind == 16);
+	  snprintf (name, sizeof (name), "%s%s%s",
+		ts->type == BT_COMPLEX ? "c" : "", m->name, "l");
+	}
     }
   else
     {

gcc/testsuite/ChangeLog

+2006-09-27  Steven G. Kargl  <kargls@gcc.gnu.org>
+
+	PR fortran/28276
+	* gfortran.dg/exponent_1.f90: New test.
+
+	PR fortran/27021
+	* gfortran.dg/nearest_1.f90: New test.
+
 2006-09-26  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/25261

gcc/testsuite/gfortran.dg/exponent_1.f90

+! { dg-do run }
+! PR fortran/28276
+! Original code submitted by Harald Anlauf
+! Converted to Dejagnu for the testsuite by Steven G. Kargl
+!
+program gfcbug36
+  implicit none
+  real, parameter :: one = 1.0
+  real :: a = one
+
+  if (fraction(a) /= 0.5) call abort
+  if (fraction(one) /= 0.5) call abort
+  if (fraction(1.0) /= 0.5) call abort
+
+  if (exponent(a) /= 1.0) call abort
+  if (exponent(one) /= 1.0) call abort
+  if (exponent (1.0) /= 1.0) call abort
+
+  if (scale(fraction(a),   exponent(a))   / a   /= 1.) call abort
+  if (scale(fraction(one), exponent(one)) / one /= 1.) call abort
+  if (scale(fraction(1.0), exponent(1.0)) / 1.0 /= 1.) call abort
+
+end program gfcbug36

gcc/testsuite/gfortran.dg/nearest_1.f90

+! { dg-do run }
+! PR fortran/27021
+! Original code submitted by Dominique d'Humieres
+! Converted to Dejagnu for the testsuite by Steven G. Kargl
+program chop
+  real o, t, td, tu, x, y
+  o = 1.
+  t = tiny(o)
+  td = nearest(t,-1.0)
+  x = td/2.0
+  y = nearest(tiny(o),-1.0)/2.0
+  if (abs(x - y) /= 0.) call abort
+end program chop
+