[Bug tree-optimization/32810] New: Not folding of const element for goto

[Bug tree-optimization/32810] New: Not folding of const element for goto

[pinskia at gcc dot gnu dot org]

Testcase:
void a(int*);  void b(int*);  void c(int*);  void d(int*);
void func2(int* val) {
  const void *const labels[] = { &&a, &&b, &&c, &&d };
  goto *labels[2];
  a: a(val);
  b: b(val);
  c: c(val);
  d: d(val);
}

Right now we get (for PPC-darwin):

;; goto labels[2]
(insn 6 5 7 t5.c:10 (set (reg:SI 121)
        (high:SI (label_ref:SI 0))) -1 (nil))

(insn 7 6 8 t5.c:10 (set (reg:SI 120)
        (lo_sum:SI (reg:SI 121)
            (label_ref:SI 0))) -1 (expr_list:REG_EQUAL (label_ref:SI 0)
        (nil)))

(jump_insn 8 7 9 t5.c:10 (set (pc)
        (reg:SI 120)) -1 (nil))


See how we get the "correct" proping of array element.


-- 
           Summary: Not folding of const element for goto
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: missed-optimization, TREE
          Severity: enhancement
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pinskia at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32810

[Bug tree-optimization/32810] Not folding of const element for goto

[rguenth at gcc dot gnu dot org]

------- Comment #1 from rguenth at gcc dot gnu dot org  2007-07-19 18:08 -------
Confirmed.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rguenth at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2007-07-19 18:08:04
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32810

[Bug tree-optimization/32810] Not folding of const element for goto

[rguenth at gcc dot gnu dot org]

------- Comment #2 from rguenth at gcc dot gnu dot org  2008-03-26 23:37 -------
Useless conversions get in the way here.  I have a patch.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |rguenth at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2007-07-19 18:08:04         |2008-03-26 23:37:19
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32810

[Bug tree-optimization/32810] Not folding of const element for goto

[rguenth at gcc dot gnu dot org]

------- Comment #4 from rguenth at gcc dot gnu dot org  2008-03-27 16:33 -------
Subject: Bug 32810

Author: rguenth
Date: Thu Mar 27 16:32:28 2008
New Revision: 133645

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=133645
Log:
2008-03-27  Richard Guenther  <rguenther@suse.de>

        PR tree-optimization/32810
        * tree-ssa-ccp.c (get_symbol_constant_value): Strip useless
        conversions from DECL_INITIAL.
        (fold_const_aggregate_ref): Likewise from constructor elements.

        * gcc.dg/tree-ssa/ssa-ccp-18.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-18.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-ccp.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32810

[Bug tree-optimization/32810] Not folding of const element for goto

[rguenth at gcc dot gnu dot org]

------- Comment #3 from rguenth at gcc dot gnu dot org  2008-03-27 16:32 -------
Fixed.


-- 

rguenth at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32810