Revisiting GCC's minimum MPFR version

Revisiting GCC's minimum MPFR version

[Kaveh R. GHAZI]

As requested by Richard G here:
http://gcc.gnu.org/ml/gcc-patches/2007-05/msg00945.html

I'm re-visiting during stage3 the minimum MPFR version required by GCC.
At the time of the above post, mpfr-2.3.0 had not yet been released, but
it was this past August, and one can obtain it here:
http://www.mpfr.org/mpfr-current

The current situation is that GCC requires only mpfr-2.2.0, however it
recommends mpfr-2.2.1 in the documentation and configure checks.  (If
configure find 2.2.0, it will say something like "buggy but acceptable"
and continue bootstrapping).

Also, there is some functionality for builtin bessel, remquo and gamma
functions that is only active when mpfr-2.3.0 is available.  The testcase
gcc.dg/torture/builtin-math-4.c for these mpfr-2.3.0 functions is XFAILed
at the moment.


Our options include:

1.  Do nothing.  Things work, don't break it.  Revisit again in stage1.

2.  Continue accepting 2.2.0, but update the recommended version from
    2.2.1 to 2.3.0.  This would entail updating the configure warning,
    the docs and the removing the XFAIL from the testcase.  This
    option would cause no change in hard bootstrap requirements.

3.  In addtion to #2, hard fail for anything less than mpfr-2.3.0.


I have no strong opinion on which way to go.

		Thoughts?
		--Kaveh
--
Kaveh R. Ghazi			ghazi@caip.rutgers.edu

Re: Revisiting GCC's minimum MPFR version

[Richard Guenther]

On Dec 9, 2007 11:05 PM, Kaveh R. GHAZI <ghazi@caip.rutgers.edu> wrote:
> As requested by Richard G here:
> http://gcc.gnu.org/ml/gcc-patches/2007-05/msg00945.html
>
> I'm re-visiting during stage3 the minimum MPFR version required by GCC.
> At the time of the above post, mpfr-2.3.0 had not yet been released, but
> it was this past August, and one can obtain it here:
> http://www.mpfr.org/mpfr-current
>
> The current situation is that GCC requires only mpfr-2.2.0, however it
> recommends mpfr-2.2.1 in the documentation and configure checks.  (If
> configure find 2.2.0, it will say something like "buggy but acceptable"
> and continue bootstrapping).
>
> Also, there is some functionality for builtin bessel, remquo and gamma
> functions that is only active when mpfr-2.3.0 is available.  The testcase
> gcc.dg/torture/builtin-math-4.c for these mpfr-2.3.0 functions is XFAILed
> at the moment.
>
>
> Our options include:
>
> 1.  Do nothing.  Things work, don't break it.  Revisit again in stage1.
>
> 2.  Continue accepting 2.2.0, but update the recommended version from
>     2.2.1 to 2.3.0.  This would entail updating the configure warning,
>     the docs and the removing the XFAIL from the testcase.  This
>     option would cause no change in hard bootstrap requirements.
>
> 3.  In addtion to #2, hard fail for anything less than mpfr-2.3.0.
>
>
> I have no strong opinion on which way to go.

I would update the recommended version to 2.3.0 and fail for anything less
than 2.2.1.

Richard.

Re: Revisiting GCC's minimum MPFR version

[Mark Mitchell]

Richard Guenther wrote:

> I would update the recommended version to 2.3.0 and fail for anything less
> than 2.2.1.

I agree.  Not optimizing bessel functions as builtins doesn't bother me
too much, but we might as well move past the buggy version.

Thanks,

-- 
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713

Re: Revisiting GCC's minimum MPFR version

[Gabriel Dos Reis]

"Richard Guenther" <richard.guenther@gmail.com> writes:

| I would update the recommended version to 2.3.0 and fail for anything less
| than 2.2.1.

Yes, that makes sense to me.  
I don't think we should require 2.3.0.


-- Gaby

PATCH: Update MPFR versions (was Re: Revisiting GCC's minimum MPFR version)

[Kaveh R. GHAZI]

On Sun, 9 Dec 2007, Mark Mitchell wrote:

> Richard Guenther wrote:
>
> > I would update the recommended version to 2.3.0 and fail for anything less
> > than 2.2.1.
>
> I agree.  Not optimizing bessel functions as builtins doesn't bother me
> too much, but we might as well move past the buggy version.
>
> Thanks,
> Mark Mitchell


Ok, here's my patch.  Since we may have some developers still using 2.2.0,
I'll wait say a week after approval before installing to give them time to
upgrade.

I have limited ability to test patches at the moment.  The sparc-solaris
infrastructure at rutgers.edu which I had access to fried and will not be
fixed or replaced any time soon.  So I haven't tested this patch beyond
top level a configure run.  However I see several XPASSes for
builtin-math-4.c from people which indicates to me that the testcase does
in fact pass with mpfr-2.3.0.  The only other change is the one liner to
the docs.

http://gcc.gnu.org/ml/gcc-testresults/2007-12/msg00458.html
http://gcc.gnu.org/ml/gcc-testresults/2007-12/msg00382.html
http://gcc.gnu.org/ml/gcc-testresults/2007-12/msg00374.html

In the mean time I'm in search of a new place to play with gcc.  If
further testing is required, I'll do more rigorous checks before
installing when I move my stuff to a new home.


Ok for mainline?

		Thanks,
		--Kaveh


2007-12-10  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>

	* configure.ac: Change required MPFR from 2.2.0 -> 2.2.1.
	Change recommended MPFR from 2.2.1 > 2.3.0.
	* configure: Regenerate.

gcc:
	* doc/install.texi: Change recommended MPFR from 2.2.1 > 2.3.0.

testsuite:
	* gcc.dg/torture/builtin-math-4.c: Remove XFAIL.

diff -rup orig/egcc-SVN20071209/configure.ac egcc-SVN20071209/configure.ac
--- orig/egcc-SVN20071209/configure.ac	Mon Oct  8 23:02:51 2007
+++ egcc-SVN20071209/configure.ac	Mon Dec 10 14:34:45 2007
@@ -1220,11 +1220,11 @@ if test -d ${srcdir}/gcc && test "x$have
   if test x"$have_gmp" = xyes; then
     saved_LIBS="$LIBS"
     LIBS="$LIBS $gmplibs"
-    dnl MPFR 2.2.0 is acceptable but buggy, MPFR 2.2.1 is better.
+    dnl MPFR 2.2.1 is acceptable, but MPFR 2.3.0 is better.
     AC_MSG_CHECKING([for correct version of mpfr.h])
     AC_TRY_LINK([#include <gmp.h>
     #include <mpfr.h>],[
-    #if MPFR_VERSION < MPFR_VERSION_NUM(2,2,0)
+    #if MPFR_VERSION < MPFR_VERSION_NUM(2,2,1)
     choke me
     #endif
     mpfr_t n;
@@ -1237,7 +1237,7 @@ if test -d ${srcdir}/gcc && test "x$have
     mpfr_subnormalize (x, t, GMP_RNDN);
     ], [AC_TRY_LINK([#include <gmp.h>
     #include <mpfr.h>],[
-    #if MPFR_VERSION < MPFR_VERSION_NUM(2,2,1)
+    #if MPFR_VERSION < MPFR_VERSION_NUM(2,3,0)
     choke me
     #endif
     mpfr_t n; mpfr_init(n);
@@ -1248,7 +1248,7 @@ if test -d ${srcdir}/gcc && test "x$have
   CFLAGS="$saved_CFLAGS"

   if test x$have_gmp != xyes; then
-    AC_MSG_ERROR([Building GCC requires GMP 4.1+ and MPFR 2.2.1+.
+    AC_MSG_ERROR([Building GCC requires GMP 4.1+ and MPFR 2.3.0+.
 Try the --with-gmp and/or --with-mpfr options to specify their locations.
 Copies of these libraries' source code can be found at their respective
 hosting sites as well as at ftp://gcc.gnu.org/pub/gcc/infrastructure/.
diff -rup orig/egcc-SVN20071209/gcc/doc/install.texi egcc-SVN20071209/gcc/doc/install.texi
--- orig/egcc-SVN20071209/gcc/doc/install.texi	Fri Dec  7 23:02:22 2007
+++ egcc-SVN20071209/gcc/doc/install.texi	Mon Dec 10 14:34:45 2007
@@ -302,7 +302,7 @@ library search path, you will have to co
 @option{--with-gmp} configure option.  See also
 @option{--with-gmp-lib} and @option{--with-gmp-include}.

-@item MPFR Library version 2.2.1 (or later)
+@item MPFR Library version 2.3.0 (or later)

 Necessary to build GCC.  It can be downloaded from
 @uref{http://www.mpfr.org/}.  The version of MPFR that is bundled with
diff -rup orig/egcc-SVN20071209/gcc/testsuite/gcc.dg/torture/builtin-math-4.c egcc-SVN20071209/gcc/testsuite/gcc.dg/torture/builtin-math-4.c
--- orig/egcc-SVN20071209/gcc/testsuite/gcc.dg/torture/builtin-math-4.c	Fri May 25 23:02:37 2007
+++ egcc-SVN20071209/gcc/testsuite/gcc.dg/torture/builtin-math-4.c	Mon Dec 10 14:34:45 2007
@@ -7,8 +7,6 @@
    Origin: Kaveh R. Ghazi,  April 23, 2007.  */

 /* { dg-do link } */
-/* Expect failures at least until mpfr-2.3.0 is released. */
-/* { dg-xfail-if "This test requires mpfr-2.3.0" { *-*-* } { "*" } { "" } } */

 /* All references to link_error should go away at compile-time.  */
 extern void link_error(int);

Re: PATCH: Update MPFR versions (was Re: Revisiting GCC's minimum MPFR version)

[Mark Mitchell]

Kaveh R. GHAZI wrote:

>>> I would update the recommended version to 2.3.0 and fail for anything less
>>> than 2.2.1.

> Ok, here's my patch.  Since we may have some developers still using 2.2.0,
> I'll wait say a week after approval before installing to give them time to
> upgrade.

> Ok for mainline?

OK, under the guidelines you suggest above.

Thanks,

-- 
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713