[Bug rtl-optimization/52528] New: combine bug (powerpc testcase)

[Bug rtl-optimization/52528] New: combine bug (powerpc testcase)

[cltang at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52528

             Bug #: 52528
           Summary: combine bug (powerpc testcase)
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: cltang@gcc.gnu.org
            Target: powerc-linux


The below testcase:
struct S {
  unsigned a : 30;
  unsigned b :  2;
};

int foo (int b)
{
  struct S s = {0};
  s.b = b;
  return bar (0x000b0010, 0x00040100ULL, *(unsigned long *)&s);
}

currently on trunk (target powerpc) compiles to:
foo:
        lis 6,0x4
        li 5,0
        ori 6,6,256
        li 7,0
        crxor 6,6,6
        b bar

Notice the incorrect code generated: no construction of the 1st arg (reg 3),
and
wrong code for the 3rd arg (reg 7)

I have diagnosed this as a problem in combine, and have a patch in testing.
Opening this issue for status tracking.

[Bug rtl-optimization/52528] combine bug (powerpc testcase)

[cltang at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52528

--- Comment #1 from Chung-Lin Tang <cltang at gcc dot gnu.org> 2012-03-10 14:57:34 UTC ---
Author: cltang
Date: Sat Mar 10 14:57:30 2012
New Revision: 185175

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=185175
Log:
2012-03-10  Chung-Lin Tang  <cltang@codesourcery.com>

    PR rtl-optimization/52528
    * combine.c (can_combine_p): Add setting of subst_low_luid
    before call to expand_field_assignment().

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/combine.c

[Bug rtl-optimization/52528] combine bug (powerpc testcase)

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52528

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

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

--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-03-12 14:14:14 UTC ---
Fixed.

[Bug rtl-optimization/52528] combine bug (powerpc testcase)

[cltang at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52528

--- Comment #3 from Chung-Lin Tang <cltang at gcc dot gnu.org> 2012-03-15 10:04:18 UTC ---
Author: cltang
Date: Thu Mar 15 10:04:12 2012
New Revision: 185425

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=185425
Log:
2012-03-15  Chung-Lin Tang  <cltang@codesourcery.com>

    Backport from mainline
    2012-03-10  Chung-Lin Tang  <cltang@codesourcery.com>

    PR rtl-optimization/52528
    * combine.c (can_combine_p): Add setting of subst_low_luid
    before call to expand_field_assignment().

Modified:
    branches/gcc-4_6-branch/gcc/ChangeLog
    branches/gcc-4_6-branch/gcc/combine.c

[Bug rtl-optimization/52528] combine bug (powerpc testcase)

[mikpe at it dot uu.se]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52528

--- Comment #4 from Mikael Pettersson <mikpe at it dot uu.se> 2012-04-15 14:55:13 UTC ---
This patch has now been applied to trunk aka 4.8 and to the 4.6 branch, but not
to the 4.7 branch.  Is the exclusion of 4.7 intentional?

[Bug rtl-optimization/52528] combine bug (powerpc testcase)

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52528

Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
   Last reconfirmed|                            |2012-04-23
                 CC|                            |ebotcazou at gcc dot
                   |                            |gnu.org
         Resolution|FIXED                       |
     Ever Confirmed|0                           |1

--- Comment #5 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2012-04-23 19:06:49 UTC ---
Of course not.  Please backport patches in order.

[Bug rtl-optimization/52528] combine bug (powerpc testcase)

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52528

--- Comment #6 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2012-05-26 13:55:51 UTC ---
Author: ebotcazou
Date: Sat May 26 13:55:46 2012
New Revision: 187915

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=187915
Log:
    Backport from mainline
    2012-03-10  Chung-Lin Tang  <cltang@codesourcery.com>

    PR rtl-optimization/52528
    * combine.c (can_combine_p): Add setting of subst_low_luid
    before call to expand_field_assignment().

Modified:
    branches/gcc-4_7-branch/gcc/ChangeLog
    branches/gcc-4_7-branch/gcc/combine.c

[Bug rtl-optimization/52528] combine bug (powerpc testcase)

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52528

Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:

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

--- Comment #7 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2012-05-26 13:57:00 UTC ---
.