[PATCH] Minimum version of mpfr? (was Re: [PATCH] Fix up norm2 simplification (PR middle-end/88074)), take 2

[Jakub Jelinek]

On Thu, Feb 21, 2019 at 04:50:27PM -0500, David Malcolm wrote:
> gcc/fortran/ChangeLog:
>       PR middle-end/88074
>       * simplify.c (norm2_add_squared): Use mp_exp_t rather than
>       mpfr_exp_t.

I have discussed this with Richard on IRC earlier today, there is another
issue that mpfr_regular_p is only 3.0 and later.  And he prefers that
mp_exp_t over say
#if MPFR_VERSION < MPFR_VERSION_NUM(3,0,0)
typedef mp_exp_t mpfr_exp_t;
#endif

So, here is the full patch I'll bootstrap/regtest soon:

2019-02-22  David Malcolm  <dmalc...@redhat.com>
            Jakub Jelinek  <ja...@redhat.com>

        PR middle-end/88074
        * simplify.c (norm2_do_sqrt, gfc_simplify_norm2): Use
        mpfr_number_p && !mpfr_zero_p instead of mpfr_regular_p.
        (norm2_add_squared): Likewise.  Use mp_exp_t rather than mpfr_exp_t.

--- gcc/fortran/simplify.c.jj   2019-02-21 22:20:07.272388243 +0100
+++ gcc/fortran/simplify.c      2019-02-22 11:07:36.093374586 +0100
@@ -6061,8 +6061,8 @@ norm2_add_squared (gfc_expr *result, gfc
 
   gfc_set_model_kind (result->ts.kind);
   int index = gfc_validate_kind (BT_REAL, result->ts.kind, false);
-  mpfr_exp_t exp;
-  if (mpfr_regular_p (result->value.real))
+  mp_exp_t exp;
+  if (mpfr_number_p (result->value.real) && !mpfr_zero_p (result->value.real))
     {
       exp = mpfr_get_exp (result->value.real);
       /* If result is getting close to overflowing, scale down.  */
@@ -6076,7 +6076,7 @@ norm2_add_squared (gfc_expr *result, gfc
     }
 
   mpfr_init (tmp);
-  if (mpfr_regular_p (e->value.real))
+  if (mpfr_number_p (e->value.real) && !mpfr_zero_p (e->value.real))
     {
       exp = mpfr_get_exp (e->value.real);
       /* If e**2 would overflow or close to overflowing, scale down.  */
@@ -6117,7 +6117,9 @@ norm2_do_sqrt (gfc_expr *result, gfc_exp
   if (result != e)
     mpfr_set (result->value.real, e->value.real, GFC_RND_MODE);
   mpfr_sqrt (result->value.real, result->value.real, GFC_RND_MODE);
-  if (norm2_scale && mpfr_regular_p (result->value.real))
+  if (norm2_scale
+      && mpfr_number_p (result->value.real)
+      && !mpfr_zero_p (result->value.real))
     {
       mpfr_t tmp;
       mpfr_init (tmp);
@@ -6156,7 +6158,9 @@ gfc_simplify_norm2 (gfc_expr *e, gfc_exp
       result = simplify_transformation_to_scalar (result, e, NULL,
                                                  norm2_add_squared);
       mpfr_sqrt (result->value.real, result->value.real, GFC_RND_MODE);
-      if (norm2_scale && mpfr_regular_p (result->value.real))
+      if (norm2_scale
+         && mpfr_number_p (result->value.real)
+         && !mpfr_zero_p (result->value.real))
        {
          mpfr_t tmp;
          mpfr_init (tmp);

        Jakub