[Bug middle-end/61894] New: Fail to fold read from constant vector initializer

[Bug middle-end/61894] New: Fail to fold read from constant vector initializer

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61894

            Bug ID: 61894
           Summary: Fail to fold read from constant vector initializer
           Product: gcc
           Version: 4.9.1
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rguenth at gcc dot gnu.org

The following is not handled by fold_const_aggregate_ref and siblings.


/* { dg-do run } */
/* { dg-options "-O" } */

extern void abort (void);

/* We should fold all reads from xconstant and eliminate it, removing
   the reference to blah which cannot be resolved at link time.  */
extern int blah;

typedef int v4si __attribute__((vector_size(16)));

static const struct {
    int *y;
    const v4si x[2] __attribute__((aligned(32)));
} xconstant = { &blah, { { 0, 1, 2, 3 }, { 2, 3, 4, 5 } } };

int main()
{
  if (sizeof (int) != 4)
    return 0;
  if (*(int *)&xconstant.x[0][0] != 0)
    abort ();
  if (*(int *)&xconstant.x[0][1] != 1)
  if (*(int *)&xconstant.x[0][2] != 2)
    abort ();
  if (*(int *)&xconstant.x[0][3] != 3)
    abort ();
  if (*(int *)&xconstant.x[1][0] != 2)
    abort ();
  if (*(int *)&xconstant.x[1][1] != 3)
    abort ();
  if (*(int *)&xconstant.x[1][2] != 4)
    abort ();
  if (*(int *)&xconstant.x[1][3] != 5)
    abort ();
  return 0;
}

[Bug middle-end/61894] Fail to fold read from constant vector initializer

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61894

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Because fold_ctor_reference doesn't handle VECTOR_CST.

[Bug middle-end/61894] Fail to fold read from constant vector initializer

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61894

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2014-07-24
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Mine.

[Bug middle-end/61894] Fail to fold read from constant vector initializer

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61894

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Fri Jul 25 07:44:57 2014
New Revision: 213045

URL: https://gcc.gnu.org/viewcvs?rev=213045&root=gcc&view=rev
Log:
2014-07-25  Richard Biener  <rguenther@suse.de>

    PR middle-end/61762
    PR middle-end/61894
    * fold-const.c (native_encode_int): Add and handle offset
    parameter to do partial encodings of expr.
    (native_encode_fixed): Likewise.
    (native_encode_real): Likewise.
    (native_encode_complex): Likewise.
    (native_encode_vector): Likewise.
    (native_encode_string): Likewise.
    (native_encode_expr): Likewise.
    * fold-const.c (native_encode_expr): Add offset parameter
    defaulting to -1.
    * gimple-fold.c (fold_string_cst_ctor_reference): Remove.
    (fold_ctor_reference): Handle all reads from tcc_constant
    ctors.

    * gcc.dg/pr61762.c: New testcase.
    * gcc.dg/fold-cstring.c: Likewise.
    * gcc.dg/fold-cvect.c: Likewise.

Added:
    trunk/gcc/testsuite/gcc.dg/fold-cstring.c
    trunk/gcc/testsuite/gcc.dg/fold-cvect.c
    trunk/gcc/testsuite/gcc.dg/pr61762.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/fold-const.c
    trunk/gcc/fold-const.h
    trunk/gcc/gimple-fold.c
    trunk/gcc/testsuite/ChangeLog

[Bug middle-end/61894] Fail to fold read from constant vector initializer

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61894

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed on trunk.