[Bug target/18701] New: [4.0 regression] mmix-knuth-mmixware gcc.c-torture/execute failures: 20010224-1.c, 20020216-1.c, 20040218-1.c, 20040709-2.c

[Bug target/18701] New: [4.0 regression] mmix-knuth-mmixware gcc.c-torture/execute failures: 20010224-1.c, 20020216-1.c, 20040218-1.c, 20040709-2.c

[hp at gcc dot gnu dot org]

With LAST_UPDATED: "Sun Nov 28 09:51:57 UTC 2004" I get:
FAIL: gcc.c-torture/execute/20010224-1.c execution,  -O3 -fomit-frame-pointer
-funroll-loops
FAIL: gcc.c-torture/execute/20010224-1.c execution,  -O3 -fomit-frame-pointer
-funroll-all-loops -finline-functions
FAIL: gcc.c-torture/execute/20020216-1.c execution,  -O1
FAIL: gcc.c-torture/execute/20020216-1.c execution,  -O2
FAIL: gcc.c-torture/execute/20020216-1.c execution,  -O3 -fomit-frame-pointer
FAIL: gcc.c-torture/execute/20020216-1.c execution,  -O3 -g
FAIL: gcc.c-torture/execute/20020216-1.c execution,  -Os
FAIL: gcc.c-torture/execute/20040218-1.c execution,  -O1
FAIL: gcc.c-torture/execute/20040218-1.c execution,  -O2
FAIL: gcc.c-torture/execute/20040218-1.c execution,  -O3 -fomit-frame-pointer
FAIL: gcc.c-torture/execute/20040218-1.c execution,  -O3 -g
FAIL: gcc.c-torture/execute/20040218-1.c execution,  -Os
FAIL: gcc.c-torture/execute/20040709-2.c execution,  -Os

With the message in the .log for all being:
*** EXIT code 4242
(a call to abort)

Note that reporting these as one is not a presumption that
these regressions are all due to the same cause, though I will
split this PR only if I later find that's not the case.  The
specific number of MMIX regressions didn't seem to be of general
help, so I'm not doing that extra work anymore, I'm just
logging regressions.

Last known to work on: "Tue Nov 23 17:37:12 UTC 2004".
Known to fail on: "Thu Nov 25 02:57:33 UTC 2004"
with patches to fix PR target/18331, where named patches found 
not to cause this or any regression on an earlier checkout.

-- 
           Summary: [4.0 regression] mmix-knuth-mmixware gcc.c-
                    torture/execute failures: 20010224-1.c, 20020216-1.c,
                    20040218-1.c, 20040709-2.c
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: hp at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: mmix-knuth-mmixware


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18701

[Bug target/18701] [4.0 regression] mmix-knuth-mmixware gcc.c-torture/execute failures: 20010224-1.c, 20020216-1.c, 20040218-1.c, 20040709-2.c

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code
   Target Milestone|---                         |4.0.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18701

[Bug target/18701] [4.0 regression] mmix-knuth-mmixware gcc.c-torture/execute failures: 20010224-1.c, 20020216-1.c, 20040218-1.c, 20040709-2.c

[lerdsuwa at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P2                          |P3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18701

[Bug target/18701] [4.0 regression] mmix-knuth-mmixware gcc.c-torture/execute failures: 20010224-1.c, 20020216-1.c, 20040218-1.c, 20040709-2.c

[hp at gcc dot gnu dot org]

------- Additional Comments From hp at gcc dot gnu dot org  2004-12-19 18:02 -------
Looking at the 20040218-1.c failure.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-12-19 18:02:44
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18701

[Bug target/18701] [4.0 regression] mmix-knuth-mmixware gcc.c-torture/execute failures: 20010224-1.c, 20020216-1.c, 20040218-1.c, 20040709-2.c

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2004-12-20 00:54 -------
This is not assigned. 

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |NEW


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18701

[Bug target/18701] [4.0 regression] mmix-knuth-mmixware gcc.c-torture/execute failures: 20010224-1.c, 20020216-1.c, 20040218-1.c, 20040709-2.c

[hp at gcc dot gnu dot org]

------- Additional Comments From hp at gcc dot gnu dot org  2004-12-20 00:59 -------
Assign it to me, stupid bugzilla dammit!

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |hp at gcc dot gnu dot org
                   |dot org                     |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18701

[Bug target/18701] [4.0 regression] mmix-knuth-mmixware gcc.c-torture/execute failures: 20010224-1.c, 20020216-1.c, 20040218-1.c, 20040709-2.c

[hp at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2004-12-19 18:02:44         |2004-12-20 00:59:11
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18701

[Bug target/18701] [4.0 regression] mmix-knuth-mmixware gcc.c-torture/execute failures: 20010224-1.c, 20020216-1.c, 20040218-1.c, 20040709-2.c

[hp at bitrange dot com]

------- Additional Comments From hp at bitrange dot com  2004-12-20 01:00 -------
Subject: Re:  [4.0 regression] mmix-knuth-mmixware
 gcc.c-torture/execute failures: 20010224-1.c, 20020216-1.c, 20040218-1.c,
 20040709-2.c

On Sun, 20 Dec 2004, steven at gcc dot gnu dot org wrote:
> ------- Additional Comments From steven at gcc dot gnu dot org  2004-12-20 00:54 -------
> This is not assigned.

Likely because of a bug in bugzilla: I pressed the
verify-and-assign-to-me button.  Then again...

brgds, H-P


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18701

[Bug target/18701] [4.0 regression] mmix-knuth-mmixware gcc.c-torture/execute failures: 20010224-1.c, 20020216-1.c, 20040218-1.c, 20040709-2.c

[hp at gcc dot gnu dot org]

------- Additional Comments From hp at gcc dot gnu dot org  2004-12-20 01:55 -------
Combine changes:

(insn 13 12 15 0 (set (reg:HI 273)
        (mem:HI (plus:DI (reg/v/f:DI 269 [ y ])
                (const_int 2 [0x2])) [3 S2 A16])) 1 {movhi} (nil)
    (expr_list:REG_DEAD (reg/v/f:DI 269 [ y ])
        (nil)))
(insn 15 13 16 0 (set (reg:DI 275)
        (plus:DI (reg:DI 272)
            (subreg:DI (reg:HI 273) 0))) 7 {adddi3} (insn_list:REG_DEP_TRUE 12
(insn_list:REG_DEP_TRUE 13 (nil)))
    (expr_list:REG_DEAD (reg:DI 272)
        (expr_list:REG_DEAD (reg:HI 273)
            (nil))))

into:

(insn 15 13 16 0 (set (reg:DI 275)
        (plus:DI (reg:DI 272)
            (subreg:DI (mem:HI (plus:DI (reg/v/f:DI 269 [ y ])
                        (const_int 2 [0x2])) [3 S2 A16]) 0))) 7 {adddi3}
(insn_list:REG_DEP_TRUE 12 (nil))
    (expr_list:REG_DEAD (reg/v/f:DI 269 [ y ])
        (expr_list:REG_DEAD (reg:DI 272)
            (nil))))

which is already wrong because the address isn't valid in DImode
(STRICT_ALIGNMENT).  Likely a paradoxical subregs issue; they're allowed
if !INSN_SCHEDULING.



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18701

[Bug target/18701] [4.0 regression] mmix-knuth-mmixware gcc.c-torture/execute failures: 20010224-1.c, 20020216-1.c, 20040218-1.c, 20040709-2.c

[hp at gcc dot gnu dot org]

------- Additional Comments From hp at gcc dot gnu dot org  2004-12-20 03:40 -------
On the assumption that the above transformation is valid [because when we see
the (subreg:DI (mem:HI ...)) we should think of it as a (reg:DI ...)], we later
get (though I have no clue why there's SImode here):
Breakpoint 8, try_combine (i3=0xf6efe398, i2=0xf6efe370, i1=0x0,
new_direct_jump_p=0xfefffa28)
    at /home/hp/combined/combined/gcc/combine.c:1629
i1 = (nil)
i2 = (insn 16 15 17 0 (set (subreg:DI (reg:HI 276) 0)
        (plus:DI (reg:DI 272)
            (subreg:DI (mem:HI (plus:DI (reg/v/f:DI 269 [ y ])
                        (const_int 2 [0x2])) [3 S2 A16]) 0))) 7 {adddi3}
(insn_list:REG_DEP_TRUE 12 (nil))
    (expr_list:REG_DEAD (reg:DI 272)
        (expr_list:REG_DEAD (reg/v/f:DI 269 [ y ])
            (nil))))
i3 = (insn 17 16 18 0 (set (reg:SI 277)
        (subreg:SI (reg:HI 276) 0)) 2 {movsi} (insn_list:REG_DEP_TRUE 16 (nil))
    (expr_list:REG_DEAD (reg:HI 276)
        (nil)))

causing gcc to end up in combine_simplify_rtx
with x = (subreg:SI (subreg:HI (plus:DI (reg:DI 272)
            (subreg:DI (mem:HI (plus:DI (reg/v/f:DI 269 [ y ])
                        (const_int 2 [0x2])) [3 S2 A16]) 0)) 6) 0)
and now the subreg-will-be-a-reg-not-a-mem-access-in-the-outer-mode assumption
is made false, because x is transformed into
(plus:DI (reg:DI 272)
    (subreg:DI (mem:SI (plus:DI (reg/v/f:DI 269 [ y ])
                (const_int 6 [0x6])) [3 S4 A16]) 0))
where the mem is now an invalid address (accessing SImode at !SImode boundary)
though as the result is not a SEGV but an unexpected result, the test-case
will abort rather than the simulator simulate a SIGSEGV (or SIGBUS).

The solution should be along the lines to avoid generating the first paradoxical
subreg.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18701

[Bug target/18701] [4.0 regression] mmix-knuth-mmixware gcc.c-torture/execute failures: 20010224-1.c, 20020216-1.c, 20040218-1.c, 20040709-2.c

[hp at gcc dot gnu dot org]

------- Additional Comments From hp at gcc dot gnu dot org  2004-12-23 18:46 -------
<URL:http://gcc.gnu.org/ml/gcc-patches/2004-12/msg01628.html>

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |patch


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18701

[Bug target/18701] [4.0 regression] mmix-knuth-mmixware gcc.c-torture/execute failures: 20010224-1.c, 20020216-1.c, 20040218-1.c, 20040709-2.c

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-12-31 16:24 -------
Subject: Bug 18701

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	hp@gcc.gnu.org	2004-12-31 16:24:48

Modified files:
	gcc            : ChangeLog combine.c 

Log message:
	PR target/18701
	* combine.c (gen_lowpart_for_combine): When stripping SUBREG of
	MEM, adjust imode and isize.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.6987&r2=2.6988
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/combine.c.diff?cvsroot=gcc&r1=1.463&r2=1.464



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18701

[Bug target/18701] [4.0 regression] mmix-knuth-mmixware gcc.c-torture/execute failures: 20010224-1.c, 20020216-1.c, 20040218-1.c, 20040709-2.c

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-12-31 16:28 -------
Subject: Bug 18701

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	hp@gcc.gnu.org	2004-12-31 16:28:34

Modified files:
	gcc            : ChangeLog combine.c 

Log message:
	PR target/18701
	* combine.c (combine_simplify_rtx): Do not allow paradoxical
	subregs of MEM.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.6988&r2=2.6989
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/combine.c.diff?cvsroot=gcc&r1=1.464&r2=1.465



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18701

[Bug target/18701] [4.0 regression] mmix-knuth-mmixware gcc.c-torture/execute failures: 20010224-1.c, 20020216-1.c, 20040218-1.c, 20040709-2.c

[hp at gcc dot gnu dot org]

------- Additional Comments From hp at gcc dot gnu dot org  2004-12-31 16:33 -------
<URL:http://gcc.gnu.org/ml/gcc-patches/2004-12/msg02151.html>

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18701

[Bug target/18701] [4.0 regression] mmix-knuth-mmixware gcc.c-torture/execute failures: 20010224-1.c, 20020216-1.c, 20040218-1.c, 20040709-2.c

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-01-21 02:14 -------
Subject: Bug 18701

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	hp@gcc.gnu.org	2005-01-21 02:14:27

Modified files:
	gcc            : ChangeLog combine.c 

Log message:
	PR target/18701
	* combine.c (combine_simplify_rtx): Revert change of 2004-12-31.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.7214&r2=2.7215
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/combine.c.diff?cvsroot=gcc&r1=1.469&r2=1.470



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18701