------- Comment #7 from spark at gcc dot gnu dot org 2007-03-13 16:15 -------
tree-nrv code doesn't see:
<bb 2>:
<retval>.type = 0;
because it only looks at GIMPLE_MODIFY with the operand 0 as the return value.
In this case, there's GIMPLE_MODIFY of the component of the return value
hence not all modification to the return value.
The following patch seems to get around the problem:
Index: tree-nrv.c
===================================================================
--- tree-nrv.c (revision 122871)
+++ tree-nrv.c (working copy)
@@ -163,6 +163,12 @@ tree_nrv (void)
result_type))
return 0;
}
+ else if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT
+ && TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 0)) ==
COMPONENT_REF
+ && TREE_OPERAND (GIMPLE_STMT_OPERAND (stmt, 0), 0) ==
result)
+ /* If there's any MODIFY of component of RESULT,
+ then bail out. */
+ return 0;
}
}
I'm not sure this is sufficient - can there be any other
gimple statement combination that modifies only part of RESULT ?
--
spark at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |spark at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30590
