re PR fortran/24519 (gfortran slow because of incomplete dependency checking)

2006-02-24  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/24519
	* dependency.c (gfc_is_same_range): Correct typo.
	(gfc_check_section_vs_section): Call gfc_is_same_range.

	PR fortran/25395
	* trans-common.c (add_equivalences): Add a new flag that is set when
	an equivalence is seen that prevents more from being reset until the
	start of a new traversal of the list, thus ensuring completion of
	all the equivalences.

2006-02-24  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/24519
	* gfortran.dg/dependency_3.f90: New test.
	* gfortran.fortran-torture/execute/vect-3.f90: Remove two of the
	XFAILs.

	PR fortran/25395
	* gfortran.dg/equiv_6.f90: New test.

From-SVN: r111416

3 files changed, 34 insertions, 10 deletions

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index d78819f..f000725 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,3 +1,15 @@
+2006-02-24  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/24519
+	* dependency.c (gfc_is_same_range): Correct typo.
+	(gfc_check_section_vs_section): Call gfc_is_same_range.
+
+	PR fortran/25395
+	* trans-common.c (add_equivalences): Add a new flag that is set when
+	an equivalence is seen that prevents more from being reset until the
+	start of a new traversal of the list, thus ensuring completion of
+	all the equivalences.
+
 2006-02-23  Erik Edelmann  <eedelman@gcc.gnu.org>
 
 	* module.c (read_module): Remove redundant code lines.
diff --git a/gcc/fortran/dependency.c b/gcc/fortran/dependency.c
index 62f3aa6..df6609b 100644
--- a/gcc/fortran/dependency.c
+++ b/gcc/fortran/dependency.c
@@ -159,7 +159,7 @@ gfc_is_same_range (gfc_array_ref * ar1, gfc_array_ref * ar2, int n, int def)
     e1 = ar1->as->lower[n];
 
   if (ar2->as && !e2)
-    e2 = ar2->as->upper[n];
+    e2 = ar2->as->lower[n];
 
   /* Check we have values for both.  */
   if (!(e1 && e2))
@@ -538,15 +538,19 @@ gfc_check_section_vs_section (gfc_ref * lref, gfc_ref * rref, int n)
   gfc_expr *r_start;
   gfc_expr *r_stride;
 
-  gfc_array_ref	l_ar;
-  gfc_array_ref	r_ar;
+  gfc_array_ref l_ar;
+  gfc_array_ref r_ar;
 
   mpz_t no_of_elements;
-  mpz_t	X1, X2;
+  mpz_t X1, X2;
   gfc_dependency dep;
 
   l_ar = lref->u.ar;
   r_ar = rref->u.ar;
+  
+  /* If they are the same range, return without more ado.  */
+  if (gfc_is_same_range (&l_ar, &r_ar, n, 0))
+    return GFC_DEP_EQUAL;
 
   l_start = l_ar.start[n];
   l_end = l_ar.end[n];
diff --git a/gcc/fortran/trans-common.c b/gcc/fortran/trans-common.c
index f819b34..5d72a50 100644
--- a/gcc/fortran/trans-common.c
+++ b/gcc/fortran/trans-common.c
@@ -755,15 +755,20 @@ find_equivalence (segment_info *n)
 }
 
 
-/* Add all symbols equivalenced within a segment.  We need to scan the
-   segment list multiple times to include indirect equivalences.  */
+  /* Add all symbols equivalenced within a segment.  We need to scan the
+   segment list multiple times to include indirect equivalences.  Since
+   a new segment_info can inserted at the beginning of the segment list,
+   depending on its offset, we have to force a final pass through the
+   loop by demanding that completion sees a pass with no matches; ie.
+   all symbols with equiv_built set and no new equivalences found.  */
 
 static void
 add_equivalences (bool *saw_equiv)
 {
   segment_info *f;
-  bool more;
+  bool seen_one, more;
 
+  seen_one = false;
   more = TRUE;
   while (more)
     {
@@ -773,9 +778,12 @@ add_equivalences (bool *saw_equiv)
 	  if (!f->sym->equiv_built)
 	    {
 	      f->sym->equiv_built = 1;
-	      more = find_equivalence (f);
-	      if (more)
-		*saw_equiv = true;
+	      seen_one = find_equivalence (f);
+	      if (seen_one)
+		{
+		  *saw_equiv = true;
+		  more = true;
+		}
 	    }
 	}
     }