| Message ID | 1366825269.37866.YahooMailNeo@web87402.mail.ir2.yahoo.com |
|---|---|
| State | New |
| Headers | show |
On 04/24/2013 11:41 AM, Graham Stott wrote: > All > > Currently using the match_scratch predicate on a destination operand will trigger the warning > > "warning: destination operand 0 allows non-lvalue", > > This happends because add_predicate_code() will set the pred->allows_non_lvalue when > it encounters a SCRATCH rtx code which subsequently triggers the above genrecog warning/ > > Graham > > gcc/ChangeLog > * gensupport.c:: (add_predicate_code) Also exclude SCRATCH from rtx codes which allow > non-lvalues. My question would be in what context does it make sense to use a SCRATCH as a destination? Do you have a multi-output insn where you need to allocate a reg for one of the outputs, but you never use that output value? Or is it something totally different? SCRATCH as an rtx code is painfully under-documented. Though I think treating it just like a REG in add_predicate_code probably makes sense. Approved. Graham, do you still have write access to the repo? jeff
Index: gcc/gensupport.c ========================================= --- gcc/gensupport.c (revision 198200) +++ gcc/gensupport.c (working copy) @@ -2732,7 +2732,8 @@ && code != MEM && code != CONCAT && code != PARALLEL - && code != STRICT_LOW_PART) + && code != STRICT_LOW_PART + && code != SCRATCH) pred->allows_non_lvalue = true; if (pred->num_codes == 1)