[Bug target/50063] New: [avr]: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[Bug target/50063] New: [avr]: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

             Bug #: 50063
           Summary: [avr]: wrong code for gcc.dg/torture/pta-ptrarith-3.c
    Classification: Unclassified
           Product: gcc
           Version: 4.6.1
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: gjl@gcc.gnu.org
                CC: eric.weddington@atmel.com
            Target: avr


Testcase gcc.dg/torture/pta-ptrarith-3.c
  
http://gcc.gnu.org/viewcvs/trunk/gcc/testsuite/gcc.dg/torture/pta-ptrarith-3.c?revision=145490&view=markup
produces wrong code for current trunk and avr-gcc 4.6.1

struct X 
{
  int *p;
  int *q;
  int *r;
};

int __attribute__((noinline))
foo (int i, int j, int k, int off)
{
  struct X x;
  int **p, *q;
  x.p = &i;
  x.q = &j;
  x.r = &k;
  p = &x.q;
  p += off;
  /* *p points to { i, j, k } */
  q = *p;
  return *q;
}

With -Os -mmcu=atmega88 4.6.1 output is (wrong):

foo:
    push r28     ;  42    *pushqi/1    [length = 1]
    push r29     ;  43    *pushqi/1    [length = 1]
    in r28,__SP_L__     ;  44    *movhi_sp/2    [length = 2]
    in r29,__SP_H__
    sbiw r28,12     ;  45    *addhi3/3    [length = 1]
    in __tmp_reg__,__SREG__     ;  46    *movhi_sp/1    [length = 5]
    cli
    out __SP_H__,r29
    out __SREG__,__tmp_reg__
    out __SP_L__,r28
/* prologue: function */
/* frame size = 12 */
/* stack size = 14 */
.L__stack_usage = 14
    std Y+8,r25     ;  2    *movhi/3    [length = 2]
    std Y+7,r24
    std Y+10,r23     ;  3    *movhi/3    [length = 2]
    std Y+9,r22
    std Y+12,r21     ;  4    *movhi/3    [length = 2]
    std Y+11,r20
    lsl r18     ;  55    *ashlhi3_const/2    [length = 2]
    rol r19
    add r18,r28     ;  16    *addhi3/1    [length = 2]
    adc r19,r29
    movw r26,r18     ;  41    *movhi/1    [length = 1]
    adiw r26,3     ;  18    *movhi/2    [length = 4]
    ld r30,X+
    ld r31,X
    sbiw r26,3+1
    ld r24,Z     ;  35    *movqi/4    [length = 1]
    ldd r25,Z+1     ;  36    *movqi/4    [length = 1]
/* epilogue start */
    adiw r28,12     ;  49    *addhi3/2    [length = 1]
    in __tmp_reg__,__SREG__     ;  50    *movhi_sp/1    [length = 5]
    cli
    out __SP_H__,r29
    out __SREG__,__tmp_reg__
    out __SP_L__,r28
    pop r29     ;  51    popqi    [length = 1]
    pop r28     ;  52    popqi    [length = 1]
    ret     ;  53    return_from_epilogue    [length = 1]



With 4.5.2 and same options, the test case runs on exit:


foo:
    push r29     ;  42    *pushhi/1    [length = 2]
    push r28
    in r28,__SP_L__     ;  43    *movhi_sp/2    [length = 2]
    in r29,__SP_H__
    sbiw r28,12     ;  44    *addhi3/3    [length = 1]
    in __tmp_reg__,__SREG__     ;  45    *movhi_sp/1    [length = 5]
    cli
    out __SP_H__,r29
    out __SREG__,__tmp_reg__
    out __SP_L__,r28
/* prologue: function */
/* frame size = 12 */
/* stack size = 14 */
.L__stack_usage = 14
    std Y+8,r25     ;  2    *movhi/3    [length = 2]
    std Y+7,r24
    std Y+10,r23     ;  3    *movhi/3    [length = 2]
    std Y+9,r22
    std Y+12,r21     ;  4    *movhi/3    [length = 2]
    std Y+11,r20
    movw r24,r28     ;  38    *movhi/1    [length = 1]
    adiw r24,7     ;  9    *addhi3/2    [length = 1]
    std Y+2,r25     ;  10    *movhi/3    [length = 2]
    std Y+1,r24
    movw r24,r28     ;  39    *movhi/1    [length = 1]
    adiw r24,9     ;  11    *addhi3/2    [length = 1]
    std Y+4,r25     ;  12    *movhi/3    [length = 2]
    std Y+3,r24
    movw r24,r28     ;  40    *movhi/1    [length = 1]
    adiw r24,11     ;  13    *addhi3/2    [length = 1]
    std Y+6,r25     ;  14    *movhi/3    [length = 2]
    std Y+5,r24
    lsl r18     ;  53    *ashlhi3_const/2    [length = 2]
    rol r19
    add r18,r28     ;  16    *addhi3/1    [length = 2]
    adc r19,r29
    movw r26,r18     ;  41    *movhi/1    [length = 1]
    adiw r26,3     ;  18    *movhi/2    [length = 4]
    ld r30,X+
    ld r31,X
    sbiw r26,3+1
    ld r24,Z     ;  35    *movqi/4    [length = 1]
    ldd r25,Z+1     ;  36    *movqi/4    [length = 1]
/* epilogue start */
    adiw r28,12     ;  48    *addhi3/2    [length = 1]
    in __tmp_reg__,__SREG__     ;  49    *movhi_sp/1    [length = 5]
    cli
    out __SP_H__,r29
    out __SREG__,__tmp_reg__
    out __SP_L__,r28
    pop r28     ;  50    pophi    [length = 2]
    pop r29
    ret     ;  51    return_from_epilogue    [length = 1]

[Bug target/50063] [avr]: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

Georg-Johann Lay <gjl at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011-08-12
   Target Milestone|---                         |4.6.2
     Ever Confirmed|0                           |1

--- Comment #1 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2011-08-12 20:33:32 UTC ---
Setting status to NEW, see gcc-testresults:

4.7.0 20110810 (experimental)
   http://gcc.gnu.org/ml/gcc-testresults/2011-08/msg01258.html

4.6.2 20110805 (prerelease)
   http://gcc.gnu.org/ml/gcc-testresults/2011-08/msg00698.html

[Bug target/50063] [avr]: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

--- Comment #2 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2011-08-13 17:04:10 UTC ---
Created attachment 25004
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25004
asm-no-dse.s

Compiler output with -Os -mmcu=atmega8 -fno-dse

[Bug target/50063] [avr]: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

--- Comment #3 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2011-08-13 17:05:39 UTC ---
Created attachment 25005
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25005
asm-dse.s

Compiler output with -Os -mmcu=atmega8 (-fdse by default)

[Bug rtl-optimization/50063] [avr]: DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

Georg-Johann Lay <gjl at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|target                      |rtl-optimization
            Summary|[avr]: wrong code for       |[avr]: DSE: wrong code for
                   |gcc.dg/torture/pta-ptrarith |gcc.dg/torture/pta-ptrarith
                   |-3.c                        |-3.c

--- Comment #4 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2011-08-13 17:09:49 UTC ---
This is not a target issue.

RTL Dead Store Elimination (DSE), activated by -fdse, deletes insns that are
not dead.

[Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[avr]: DSE: wrong code for  |[4.6/4.7 Regression] DSE:
                   |gcc.dg/torture/pta-ptrarith |wrong code for
                   |-3.c                        |gcc.dg/torture/pta-ptrarith
                   |                            |-3.c

--- Comment #5 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-08-14 09:52:28 UTC ---
Sounds like some of the latent RTL alias issues we have with regarding to
find_base_value and friends (see some i?86 bugreport I fail to remember right
now).

[Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

--- Comment #6 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2011-08-15 08:07:29 UTC ---
(In reply to comment #5)
> Sounds like some of the latent RTL alias issues we have with regarding to
> find_base_value and friends (see some i?86 bugreport I fail to remember right
> now).

You mean PR49330?

[Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

--- Comment #7 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-08-15 11:05:08 UTC ---
(In reply to comment #6)
> (In reply to comment #5)
> > Sounds like some of the latent RTL alias issues we have with regarding to
> > find_base_value and friends (see some i?86 bugreport I fail to remember right
> > now).
> 
> You mean PR49330?

Yes.

[Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[steven at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

Steven Bosscher <steven at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |steven at gcc dot gnu.org

--- Comment #8 from Steven Bosscher <steven at gcc dot gnu.org> 2011-09-11 15:25:10 UTC ---

Already wrong in the .expand dump:
;; MEM[(volatile unsigned int *)&var][arg_1(D)] ={v} v_2;

(insn 9 8 10 (set (reg:DI 63)
        (sign_extend:DI (reg/v:SI 60 [ argD.1604 ]))) t.c:6 -1
     (nil))

(insn 10 9 11 (set (reg/f:DI 64)
        (symbol_ref:DI ("var") <var_decl 0x7f4b8054f140 var>)) t.c:6 -1
     (nil))

(insn 11 10 0 (set (mem/s:SI (plus:DI (mult:DI (reg:DI 63)
                    (const_int 4 [0x4]))
                (reg/f:DI 64)) [2 varD.1603 S4 A32])
        (reg/v:SI 59 [ vD.1607 ])) t.c:6 -1
     (nil))

It seems to me that the MEM in insn 11 should be mem/s/v.

[Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[steven at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

--- Comment #9 from Steven Bosscher <steven at gcc dot gnu.org> 2011-09-11 15:46:22 UTC ---
(In reply to comment #8)
> Already wrong in the .expand dump:

This comment somehow ended up in the wrong PR. It should be in bug 50078.

[Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.6.2                       |4.6.3

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-10-26 17:13:44 UTC ---
GCC 4.6.2 is being released.

[Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

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

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

--- Comment #11 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-10-27 09:59:55 UTC ---
Candidate for downgrading again if only avr-* is affected.

[Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #12 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-12-19 18:34:16 UTC ---
I believe this is just because of very weird target avr stuff, either it is a
target bug that can be fixed up in the backend somehow, or perhaps would need
some middle-end help, but still it is avr specific.
Doesn't seem to have anything to do with PR49330.

The problem seems to be that the prologue here looks like:
(insn/f 43 7 44 2 (set (mem/c:QI (post_dec:HI (reg/f:HI 32 __SP_L__)) [5 S1
A8])
        (reg:QI 28 r28)) pr50063.c:9 -1
     (nil))
(insn/f 44 43 45 2 (set (mem/c:QI (post_dec:HI (reg/f:HI 32 __SP_L__)) [5 S1
A8])
        (reg:QI 29 r29)) pr50063.c:9 -1
     (expr_list:REG_DEAD (reg:QI 29 r29)
        (nil)))
(insn 45 44 46 2 (set (reg/f:HI 28 r28)
        (reg/f:HI 32 __SP_L__)) pr50063.c:9 -1
     (nil))
(insn/f 46 45 47 2 (set (reg/f:HI 28 r28)
        (plus:HI (reg/f:HI 28 r28)
            (const_int -12 [0xfffffffffffffff4]))) pr50063.c:9 -1
     (expr_list:REG_CFA_ADJUST_CFA (set (reg/f:HI 28 r28)
            (plus:HI (reg/f:HI 32 __SP_L__)
                (const_int -12 [0xfffffffffffffff4])))
        (nil)))
(insn 47 46 48 2 (set (reg/f:HI 32 __SP_L__)
        (reg/f:HI 28 r28)) pr50063.c:9 -1
     (nil))

where reg 28 is frame pointer and reg 32 is stack pointer.  When
canon_true_dependence is called by DSE, one of the mem addresses is r28 plus
CONST_INT, the other is a VALUE, which is in the end a VALUE of r28 plus some
offset.  But r28 (frame pointer) and r32 (stack pointer) have the same VALUE in
this case, and because of the initialization of sp from fp r32 is actually
before r28 in that VALUE's locs list.  So, find_base_term for that VALUE
returns (address r32), while find_base_term for r28 plus CONST_INT doesn't use
cselib values at all and thus returns (address r28) and base_alias_check just
fails.  The question is why avr does this, and if it really has to do that, it
should make sure somehow that for the alias analysis either REG_BASE_VALUE of
r28 is the same as REG_BASE_VALUE of r32.  E.g. it could define FIND_BASE_TERM
and do something for r28/r32 if they are known to be the same.
init_alias_analysis ignores prologue and epilogue insns after reload, which is
probably why record_set isn't called here on the r32 = r28 set.

[Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

--- Comment #13 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2011-12-19 18:56:49 UTC ---
(In reply to comment #12)
> I believe this is just because of very weird target avr stuff, either it is a
> target bug that can be fixed up in the backend somehow, or perhaps would need
> some middle-end help, but still it is avr specific.

The insns describe exactly what the machine is doing:

insn 43/44: Save FP (r28/29) to Stack. This in done in two QI pushes and not in
one HI. SP push is post-decrement and with a HI push the resulting address
would be wrong. AVR is 8-bit machine with 16-bit PMODE.

insn 45: Initialize FP with SP

insn 46: Set up a frame (12 bytes here). AVR's SP cannot be changed directly,
not even atomically so changing SP is quite expensive and IRQs must be turned
off. Therefore, prologue generation works out two methods of setting up
frame/changing SP and picks the most efficient:

* For big offsets it is:
    FP = SP;
    FP -= const;
    SP = FP

* For small offsets SP is adjusted by dummy pushes/pops, for example:
    SP -= 2 as of: push(dummy); push(dummy);
    FP = SP

Similar applies to epilogue generation.

This example exercises the first approach. The 3rd step is (SP = FP):

insn 47: Write back SP

If the generic analysis ignores prologue/epilogue but optimizers optimize
against prologue/epilogue using that incorrect information based on lazy
analysis, then the problem is in generic code.

[Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P2                          |P4

--- Comment #14 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-12-19 19:12:56 UTC ---
Well, it is certainly desirable not to process the prologue insns during
init_alias_analysis.  The fact that stack pointer has the same value as frame
pointer after the prologue is not usual and something the generic code isn't
prepared for (usually either frame pointer is eliminated (of course then the
register can be used for something else) or frame pointer is initialized from
stack pointer and then decremented (or incremented) still inside of the
prologue).
So you need to tell the alias analysis about that, as the prologue isn't
scanned, it is the backend responsibility to tell that.

[Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

--- Comment #15 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2011-12-19 23:24:13 UTC ---
(In reply to comment #14)
> Well, it is certainly desirable not to process the prologue insns during
> init_alias_analysis.  The fact that stack pointer has the same value as frame
> pointer after the prologue is not usual and something the generic code isn't
> prepared for.

So bottom line is that GCC is not ready for AVR?

> So you need to tell the alias analysis about that, as the prologue isn't
> scanned, it is the backend responsibility to tell that.

Ya, I skimmed the hooks once again... What hook needs to be
implemented/adjusted by AVR backend to ship that information if prologue and
elimination information is not enough already...?

[Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

--- Comment #16 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-12-20 00:22:19 UTC ---
Well, you or whomever wants to fix this bug needs to propose some solution.
I'm not familiar with avr, so I don't know if avr is doing something like this
(starting function with r32 == r28) always, or always for functions that
require frame pointer, conditionally only for some CPUs, ...
If it is always that way, you might want to consider just in some backend
initialization that is run after init_alias_target call change
this_target_rtl->x_static_reg_base_value[STACK_POINTER_REGNUM]
to this_target_rtl->x_static_reg_base_value[FRAME_POINTER_REGNUM] (or vice
versa), so that the RTL alias analysis doesn't disambiguate r28 from r32 based
MEM accesses.  Or a target hook somewhere in init_alias_analysis, or
#define FIND_BASE_TERM(X) avr_find_base_term (X)
where that function would return under the conditions where body starts with
r32 == r28 would if (REG_P (x) && REGNO (x) == STACK_POINTER_REGNUM) return
find_base_term (frame_pointer_rtx); else return NULL_RTX;

[Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

--- Comment #17 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-12-20 06:54:00 UTC ---
FIND_BASE_TERM is actually supposed just an alternate rtx expression, not its
find_base_term value, so something like (perhaps with more conditions, when r28
is never equal to r32 in the body or r32 isn't initialized from r28, it doesn't
need to be done):
if (reload_completed && frame_pointer_needed && REG_P (x) && REGNO (x) ==
STACK_POINTER_REGNUM) return frame_pointer_rtx;
return NULL_RTX;

[Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

Georg-Johann Lay <gjl at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |denisc at gcc dot gnu.org

--- Comment #18 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2011-12-22 00:03:08 UTC ---
>From what you wrote the internals documentation need to be fixed, i.e. there
should be a disclaimer in expand_prologue documentation that SP=FP is an
illegal configuration that breaks GCC.

Moreover there is:

> FIND_BASE_TERM (x): It is always safe for this macro to not be defined.

Which is obviously wrong.

I don't know enough of alias internals,  but I get more and more the impression
that implementing FIND_BASE_TERM is just working around problem in generic code
and instead of backend hacking around it the generic code should be made
robust.

At the moment I tend to deactivate malicous pass(es) in the backend until they
use robust approach and don't value performance higher than correctness.

[Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

--- Comment #19 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2012-02-20 13:41:39 UTC ---
FYI, after updating to SVN 184386 (2012-02-20) I see 14 new FAILs in the avr
test suite; all of which can be cured with -fno-dse:

FAIL: gcc.c-torture/execute/20020215-1.c execution,  -O1 
FAIL: gcc.c-torture/execute/20020215-1.c execution,  -Os 

FAIL: gcc.c-torture/execute/930126-1.c execution,  -O1 

FAIL: gcc.c-torture/execute/991118-1.c execution,  -O1 
FAIL: gcc.c-torture/execute/991118-1.c execution,  -Os 

FAIL: gcc.c-torture/execute/bf64-1.c execution,  -O1 
FAIL: gcc.c-torture/execute/bf64-1.c execution,  -Os 

FAIL: gcc.c-torture/execute/pr51877.c execution,  -O1 
FAIL: gcc.c-torture/execute/pr51877.c execution,  -O2 
FAIL: gcc.c-torture/execute/pr51877.c execution,  -O3 -fomit-frame-pointer 
FAIL: gcc.c-torture/execute/pr51877.c execution,  -O3 -g 
FAIL: gcc.c-torture/execute/pr51877.c execution,  -Os 
plugin -flto-partition=none 
FAIL: gcc.c-torture/execute/pr51877.c execution,  -O2 -flto
-fno-use-linker-plugin -flto-partition=none 
FAIL: gcc.c-torture/execute/pr51877.c execution,  -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects

[Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

--- Comment #20 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-02-20 13:52:50 UTC ---
Please just fix up your backend, e.g. by turning that sp = hfp move (insn 47
above) into an UNSPEC move.

[Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

--- Comment #21 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2012-02-22 09:25:48 UTC ---
Author: gjl
Date: Wed Feb 22 09:25:35 2012
New Revision: 184461

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=184461
Log:
    PR rtl-optimization/50063
    * config/avr/avr.md (movhi_sp_r): Handle -1 (unknown IRQ state)
    and 2 (8-bit SP) in operand 2.
    * config/avr/avr.c (avr_prologue_setup_frame): Adjust prologue
    setup to use movhi_sp_r instead of vanilla move to write SP.
    Adjust REG_CFA notes to superseed unspec.
    (expand_epilogue): Adjust epilogue setup to use movhi_sp_r instead
    of vanilla move.
    As function body might contain CLI or SEI: Use irq_state 0 (IRQ
    known to be off) only with TARGET_NO_INTERRUPTS. Never use
    irq_state 1 (IRQ known to be on) here.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/avr/avr.c
    trunk/gcc/config/avr/avr.md

[Bug rtl-optimization/50063] [4.6/4.7 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.6.3                       |4.6.4

--- Comment #22 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-03-01 14:38:50 UTC ---
GCC 4.6.3 is being released.

[Bug rtl-optimization/50063] [4.6/4.7/4.8 Regression] DSE: wrong code for gcc.dg/torture/pta-ptrarith-3.c

[gjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50063

Georg-Johann Lay <gjl at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
      Known to work|                            |4.7.0
         Resolution|                            |FIXED
   Target Milestone|4.6.4                       |4.7.0
      Known to fail|4.7.0                       |4.6.3

--- Comment #23 from Georg-Johann Lay <gjl at gcc dot gnu.org> 2012-03-22 16:10:43 UTC ---
Bumping milestone to 4.7.0 where the issue is fixed.