[Bug middle-end/54315] unnecessary copy of return value for union

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54315

--- Comment #5 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2012-10-20 21:00:26 UTC ---
Author: ebotcazou
Date: Sat Oct 20 21:00:23 2012
New Revision: 192641

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=192641
Log:
    PR rtl-optimization/54315
    * calls.c (expand_call): Don't deal specifically with BLKmode values
    returned in naked registers.
    * expr.h (copy_blkmode_from_reg): Adjust prototype.
    * expr.c (copy_blkmode_from_reg): Rename first parameter into TARGET and
    make it required.  Assert that SRCREG hasn't BLKmode.  Add a couple of 
    short-circuits for common cases and be prepared for sub-word registers.
    (expand_assignment): Call copy_blkmode_from_reg for BLKmode values
    returned in naked registers.
    (store_expr): Likewise.
    (store_field): Likewise.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/calls.c
    trunk/gcc/expr.c
    trunk/gcc/expr.h