[Bug middle-end/52584] New: Fails to constant fold vector upper/lower half BIT_FIELD_REFs

[Bug middle-end/52584] New: Fails to constant fold vector upper/lower half BIT_FIELD_REFs

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52584

             Bug #: 52584
           Summary: Fails to constant fold vector upper/lower half
                    BIT_FIELD_REFs
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: rguenth@gcc.gnu.org
        ReportedBy: rguenth@gcc.gnu.org
            Target: x86_64-*-*


int main()
{
    int a = 1;
    typedef int v4si __attribute__ ((vector_size (8 * sizeof(int))));
    v4si x;
    v4si y;
    y = x + a;
    foo(y);
    return 0;
}

shows a missed optimization in how we fold BIT_FIELD_REFs that select
the upper/lower part of a vector:

<bb 2>:
  D.1719_9 = BIT_FIELD_REF <x_4(D), 128, 0>;
  D.1721_10 = BIT_FIELD_REF <{ 1, 1, 1, 1, 1, 1, 1, 1 }, 128, 0>;
  D.1722_11 = D.1719_9 + D.1721_10;
  D.1723_12 = BIT_FIELD_REF <x_4(D), 128, 128>;
  D.1725_13 = BIT_FIELD_REF <{ 1, 1, 1, 1, 1, 1, 1, 1 }, 128, 128>;
  D.1726_14 = D.1723_12 + D.1725_13;
  y_5 = {D.1722_11, D.1726_14};
  foo (y_5);
  return 0;

we should have constant-folded D.1721_10 and D.1725_13.

[Bug middle-end/52584] Fails to constant fold vector upper/lower half BIT_FIELD_REFs

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52584

--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-03-14 14:55:16 UTC ---
Author: rguenth
Date: Wed Mar 14 14:55:11 2012
New Revision: 185385

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=185385
Log:
2012-03-14  Richard Guenther  <rguenther@suse.de>

    PR middle-end/52584
    * tree-vect-generic.c (type_for_widest_vector_mode): Take
    element type instead of mode, use build_vector_type_for_mode
    instead of the langhook, build a vector of proper signedness.
    (expand_vector_operations_1): Adjust.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/tree-vect-generic.c

[Bug middle-end/52584] Fails to constant fold vector upper/lower half BIT_FIELD_REFs

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52584

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2012-03-16
     Ever Confirmed|0                           |1

[Bug middle-end/52584] Fails to constant fold vector upper/lower half BIT_FIELD_REFs

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52584

--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-03-16 14:49:11 UTC ---
Author: rguenth
Date: Fri Mar 16 14:49:05 2012
New Revision: 185468

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=185468
Log:
2012-03-16  Richard Guenther  <rguenther@suse.de>

    PR middle-end/52584
    * fold-const.c (fold_ternary_loc): Fold vector typed BIT_FIELD_REFs
    of vector constants and constructors.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/fold-const.c

[Bug middle-end/52584] Fails to constant fold vector upper/lower half BIT_FIELD_REFs

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52584

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

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

--- Comment #3 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-03-16 16:54:43 UTC ---
Fixed.

[Bug middle-end/52584] Fails to constant fold vector upper/lower half BIT_FIELD_REFs

[davem at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52584

--- Comment #4 from davem at gcc dot gnu.org 2012-05-19 06:19:16 UTC ---
Author: davem
Date: Sat May 19 06:19:10 2012
New Revision: 187675

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=187675
Log:
Fix VIS3 vector shift wrong code generation on sparc.

    Backport r185385 from mainline.
    2012-03-14  Richard Guenther  <rguenther@suse.de>

    PR middle-end/52584
    * tree-vect-generic.c (type_for_widest_vector_mode): Take
    element type instead of mode, use build_vector_type_for_mode
    instead of the langhook, build a vector of proper signedness.
    (expand_vector_operations_1): Adjust.

Modified:
    branches/gcc-4_7-branch/gcc/ChangeLog
    branches/gcc-4_7-branch/gcc/tree-vect-generic.c