[Bug middle-end/36326] New: gimplification of aggregate copies introduces extra aggregate copy

[Bug middle-end/36326] New: gimplification of aggregate copies introduces extra aggregate copy

[rguenth at gcc dot gnu dot org]

union X { int i; double x; };

int foo (union X *p)
{
  union X x = *p;
  return x.x;
}

produces

  union X x.0;

  x.0 = *p;
  x = x.0;

this is not optimized at any point.  Using a struct instead usually SRA
is able to remove the extra copy.


-- 
           Summary: gimplification of aggregate copies introduces extra
                    aggregate copy
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rguenth at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36326

[Bug middle-end/36326] gimplification of aggregate copies introduces extra aggregate copy

[rguenth at gcc dot gnu dot org]

------- Comment #1 from rguenth at gcc dot gnu dot org  2008-05-25 16:47 -------
Caused by the fix for PR17526.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
OtherBugsDependingO|                            |17526
              nThis|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36326

[Bug middle-end/36326] gimplification of aggregate copies introduces extra aggregate copy

[rguenth at gcc dot gnu dot org]

------- Comment #2 from rguenth at gcc dot gnu dot org  2008-05-25 17:18 -------
Which was just a workaround.  It needs proper fixing so that

Index: tree-gimple.c
===================================================================
--- tree-gimple.c       (revision 135859)
+++ tree-gimple.c       (working copy)
@@ -116,10 +116,7 @@ is_gimple_mem_rhs (tree t)
      a renamed variable.  Also force a temporary if the type doesn't need
      to be stored in memory, since it's cheap and prevents erroneous
      tailcalls (PR 17526).  */
-  if (is_gimple_reg_type (TREE_TYPE (t))
-      || (TYPE_MODE (TREE_TYPE (t)) != BLKmode
-         && (TREE_CODE (t) != CALL_EXPR
-              || ! aggregate_value_p (t, t))))
+  if (is_gimple_reg_type (TREE_TYPE (t)))
     return is_gimple_val (t);
   else
     return is_gimple_formal_tmp_rhs (t);

doesn't regress.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36326

[Bug middle-end/36326] gimplification of aggregate copies introduces extra aggregate copy

[matz at gcc dot gnu dot org]

------- Comment #3 from matz at gcc dot gnu dot org  2008-05-27 14:28 -------
Subject: Bug 36326

Author: matz
Date: Tue May 27 14:28:02 2008
New Revision: 136033

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=136033
Log:
PR middle-end/36326
* tree-gimple.c (is_gimple_mem_rhs): Remove work-around for
non-BLKmode types.
* tree-tailcall.c (find_tail_calls): Don't mark calls storing
into memory as tail calls.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/tree-gimple.c
    trunk/gcc/tree-tailcall.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36326

[Bug middle-end/36326] gimplification of aggregate copies introduces extra aggregate copy

[pinskia at gcc dot gnu dot org]

------- Comment #4 from pinskia at gcc dot gnu dot org  2008-05-28 08:05 -------
Fixed.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36326

[Bug middle-end/36326] gimplification of aggregate copies introduces extra aggregate copy

[rguenth at gcc dot gnu dot org]

------- Comment #5 from rguenth at gcc dot gnu dot org  2008-12-03 15:11 -------
Subject: Bug 36326

Author: rguenth
Date: Wed Dec  3 15:10:03 2008
New Revision: 142396

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=142396
Log:
2008-12-03  Richard Guenther  <rguenther@suse.de>

        PR middle-end/36326
        * gimplify.c (is_gimple_mem_or_call_rhs): Remove work-around for
        non-BLKmode types.

        * gcc.dg/tree-ssa/pr36326.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/pr36326.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/gimplify.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36326