tree-ssa-loop-prefetch.c: Add debug for dropped prefetches.

2010-05-11  Christian Borntraeger  <borntraeger@de.ibm.com>

        * tree-ssa-loop-prefetch.c: Add debug for dropped prefetches.

From-SVN: r159256

gcc/ChangeLog

+2010-05-11  Christian Borntraeger  <borntraeger@de.ibm.com>
+
+        * tree-ssa-loop-prefetch.c: Add debug for dropped prefetches.
+
 2010-05-11  Jakub Jelinek  <jakub@redhat.com>
 
 	* gcc.c (execute): For -### don't quote arguments that

gcc/tree-ssa-loop-prefetch.c

@@ -860,11 +860,20 @@ should_issue_prefetch_p (struct mem_ref *ref)
   /* For now do not issue prefetches for only first few of the
      iterations.  */
   if (ref->prefetch_before != PREFETCH_ALL)
-    return false;
+    {
+      if (dump_file && (dump_flags & TDF_DETAILS))
+        fprintf (dump_file, "Ignoring %p due to prefetch_before\n",
+		 (void *) ref);
+      return false;
+    }
 
   /* Do not prefetch nontemporal stores.  */
   if (ref->storent_p)
-    return false;
+    {
+      if (dump_file && (dump_flags & TDF_DETAILS))
+        fprintf (dump_file, "Ignoring nontemporal store %p\n", (void *) ref);
+      return false;
+    }
 
   return true;
 }