[Bug target/53272] New: wrong condition-codes for strict-low-part destination and small-integer source

[Bug target/53272] New: wrong condition-codes for strict-low-part destination and small-integer source

[hp at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53272

             Bug #: 53272
           Summary: wrong condition-codes for strict-low-part destination
                    and small-integer source
    Classification: Unclassified
           Product: gcc
           Version: 4.4.7
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: hp@gcc.gnu.org
              Host: x86_64-unknown-linux-gnu
            Target: crisv32-*


Bug spotted on the 4.7 branch, exposed by the test-case as far back as the 4.4
branch r186831.  Test-case to be attached, need a PR number.

[Bug target/53272] wrong condition-codes for strict-low-part destination and small-integer source

[hp at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53272

Hans-Peter Nilsson <hp at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-05-08
         AssignedTo|unassigned at gcc dot       |hp at gcc dot gnu.org
                   |gnu.org                     |
     Ever Confirmed|0                           |1

--- Comment #1 from Hans-Peter Nilsson <hp at gcc dot gnu.org> 2012-05-08 00:11:03 UTC ---
Created attachment 27337
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27337
testcase to be compiled with -O2

The effect of the bug is to eliminate the NULL-pointer check for rtc->ops->f
and always call it, which is not a good idea when it is NULL.  Test-case
derived from a Linux driver.

Unfortunately, presence of a main function makes the bug hide by slightly
changing the generated code, so I have to put the framework in a separate file
to make a runnable test-case. This is a secondary bug, for which I will clone a
PR from this PR: with the marker-asms and attributes noclone, noinline, there
should be no need for that.  It seems static branch predictions change.

[Bug target/53272] wrong condition-codes for strict-low-part destination and small-integer source

[hp at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53272

--- Comment #2 from Hans-Peter Nilsson <hp at gcc dot gnu.org> 2012-05-08 15:20:56 UTC ---
Author: hp
Date: Tue May  8 15:20:52 2012
New Revision: 187283

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=187283
Log:
    PR target/53272
    * config/cris/cris.c (cris_normal_notice_update_cc): For TARGET_V32,
    when a constant source operand matches an "I" constraint, the "no
    CC0 change" applies to a register-destination only, not a
    strict_low_part-destination.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/cris/cris.c

[Bug target/53272] wrong condition-codes for strict-low-part destination and small-integer source

[hp at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53272

--- Comment #4 from Hans-Peter Nilsson <hp at gcc dot gnu.org> 2012-05-08 15:27:08 UTC ---
Author: hp
Date: Tue May  8 15:27:03 2012
New Revision: 187285

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=187285
Log:
    PR target/53272
    * config/cris/cris.c (cris_normal_notice_update_cc): For TARGET_V32,
    when a constant source operand matches an "I" constraint, the "no
    CC0 change" applies to a register-destination only, not a
    strict_low_part-destination.

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

[Bug target/53272] wrong condition-codes for strict-low-part destination and small-integer source

[hp at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53272

--- Comment #3 from Hans-Peter Nilsson <hp at gcc dot gnu.org> 2012-05-08 15:21:55 UTC ---
Author: hp
Date: Tue May  8 15:21:50 2012
New Revision: 187284

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=187284
Log:
    PR target/53272
    * gcc.dg/torture/pr53272-1.c, gcc.dg/torture/pr53272-2.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/torture/pr53272-1.c
    trunk/gcc/testsuite/gcc.dg/torture/pr53272-2.c
Modified:
    trunk/gcc/testsuite/ChangeLog

[Bug target/53272] wrong condition-codes for strict-low-part destination and small-integer source

[hp at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53272

--- Comment #5 from Hans-Peter Nilsson <hp at gcc dot gnu.org> 2012-05-08 15:28:02 UTC ---
Author: hp
Date: Tue May  8 15:27:58 2012
New Revision: 187286

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=187286
Log:
    PR target/53272
    * gcc.dg/torture/pr53272-1.c, gcc.dg/torture/pr53272-2.c: New test.

Added:
    branches/gcc-4_7-branch/gcc/testsuite/gcc.dg/torture/pr53272-1.c
    branches/gcc-4_7-branch/gcc/testsuite/gcc.dg/torture/pr53272-2.c
Modified:
    branches/gcc-4_7-branch/gcc/testsuite/ChangeLog

[Bug target/53272] wrong condition-codes for strict-low-part destination and small-integer source

[hp at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53272

Hans-Peter Nilsson <hp at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.7.2

--- Comment #6 from Hans-Peter Nilsson <hp at gcc dot gnu.org> 2012-05-08 15:35:20 UTC ---
target-bug fixed, no further backports intended.

[Bug target/53272] wrong condition-codes for strict-low-part destination and small-integer source

[hp at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53272

Hans-Peter Nilsson <hp at gcc dot gnu.org> changed:

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

--- Comment #7 from Hans-Peter Nilsson <hp at gcc dot gnu.org> 2012-05-08 15:37:20 UTC ---
oops, have to actually change to "resolved, fixed" too.