http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51799
Ira Rosen <irar at il dot ibm.com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
CC| |irar at il dot ibm.com
AssignedTo|unassigned at gcc dot |irar at gcc dot gnu.org
|gnu.org |
--- Comment #4 from Ira Rosen <irar at il dot ibm.com> 2012-01-12 10:48:11 UTC
---
This is actually the same problem as in pr 51301, and the fix of 51301 looks
incomplete: we want an over-promoted sequence to end with type demotion
operation, so we need to check that properly:
Index: tree-vect-patterns.c
===================================================================
--- tree-vect-patterns.c (revision 182840)
+++ tree-vect-patterns.c (working copy)
@@ -1186,13 +1186,15 @@
{
use_lhs = gimple_assign_lhs (use_stmt);
use_type = TREE_TYPE (use_lhs);
- /* Support only type promotion or signedess change. Check that USE_TYPE
- is not bigger than the original type. */
+ /* Support only type demotion or signedess change. */
if (!INTEGRAL_TYPE_P (use_type)
- || TYPE_PRECISION (new_type) > TYPE_PRECISION (use_type)
- || TYPE_PRECISION (type) < TYPE_PRECISION (use_type))
+ || TYPE_PRECISION (type) <= TYPE_PRECISION (use_type))
return NULL;
+ /* Check that NEW_TYPE is not bigger than the conversion result. */
+ if (TYPE_PRECISION (new_type) > TYPE_PRECISION (use_type))
+ return NULL;
+
if (TYPE_UNSIGNED (new_type) != TYPE_UNSIGNED (use_type)
|| TYPE_PRECISION (new_type) != TYPE_PRECISION (use_type))
{
I am going to test this patch.
