On Thu, Sep 5, 2013 at 9:23 PM, Easwaran Raman <era...@google.com> wrote:
> On Tue, Aug 27, 2013 at 3:35 AM, Richard Biener
> <richard.guent...@gmail.com> wrote:
>> On Thu, Aug 1, 2013 at 1:34 AM, Easwaran Raman <era...@google.com> wrote:
>>> I have a new patch that supersedes this. The new patch also fixes PR
>>> tree-optimization/57393 and PR tree-optimization/58011. Bootstraps and
>>> no test regression on x86_64/linux. Ok for trunk?
>>>
>>> 2013-07-31 Easwaran Raman <era...@google.com>
>>>
>>> PR middle-end/57370
>>> * tree-ssa-reassoc.c (build_and_add_sum): Fix UID assignment and reset
>>> of debug statements that cause inconsistent IR.
>>
>> Missing ChangeLog entry for the insert_stmt_after hunk which I do not like
>> at all. The other hunks are ok, but we need to work harder to preserve
>> debug stmts - simply removing all is not going to fly.
>>
>> Richard.
>
> I looked into the problem related to the debug stmts in this failing
> test case in detail. Initially, the code sequence looks
>
>
> s$n_13 = MEM[(struct S *)&s];
> # DEBUG s$n => s$n_13
> _2 = (double) s$n_13;
> _4 = _2 * a_3(D);
> _6 = (double) i_5(D);
> _7 = _4 * _6;
> _9 = (double) j_8(D);
> _10 = _7 * _9;
> bar (_10);
> # DEBUG D#2 => (double) k_12(D)
> # DEBUG D#1 => _7 * D#2
> # DEBUG t$n => (int) D#1
>
> After reassociation
>
> s$n_13 = MEM[(struct S *)&s];
> # DEBUG s$n => s$n_13
> _2 = (double) s$n_13;
> _6 = (double) i_5(D);
> # DEBUG D#3 => _4 * _6
> _9 = (double) j_8(D);
> _4 = _9 * _2;
> _7 = _4 * a_3(D);
> _10 = _7 * _6;
> bar (_10);
> # DEBUG D#2 => (double) k_12(D)
> # DEBUG D#1 => D#3 * D#2
> # DEBUG t$n => (int) D#1
>
> In the above, # DEBUG D#3 => _4 * _6 appears above the statement that
> defines _4. But even if I move the def of D#3 below the statement
> defining _4, it is not sufficient. Before reassociation, t$n refers to
> the expression (s$n_13 * a_3(D) * i_5(D) * k_12(D)), but after
> reassociation it would refer to ( j_8(D) * s$n_13 * i_5(D) *
> k_12(D)). It seems the correct fix is to discard the debug temps whose
> RHS contains a variable that is involved in reassociation and then
> reconstruct it. Is that the expected fix here?
The value of the DEBUG expression changes because the value
that _4 computes changes - that is a no-no that may not happen.
We cannot re-use _4 (without previously releasing it and allocating
it newly) with a new value. releasing _4 should have fixed up the
debug stmts.
So - can you verify whether we are indeed just replacing the
RHS of _4 = _2 * a_3(D) to _9 * _2 without changing the SSA name of
that expression?
Another reason why re-using the same LHS for another value is
wrong is that annotated information like points-to sets, alignment
and soon value-range information will be wrong.
Thanks,
Richard.
> - Easwaran
>
>>>
>>> testsuite/ChangeLog:
>>> 2013-07-31 Easwaran Raman <era...@google.com>
>>>
>>> PR middle-end/57370
>>> PR tree-optimization/57393
>>> PR tree-optimization/58011
>>> * gfortran.dg/reassoc_12.f90: New testcase.
>>> * gcc.dg/tree-ssa/reassoc-31.c: New testcase.
>>> * gcc.dg/tree-ssa/reassoc-31.c: New testcase.
>>>
>>>
>>> On Fri, Jul 12, 2013 at 7:57 AM, Easwaran Raman <era...@google.com> wrote:
>>>> Ping.
>>>>
>>>> On Thu, Jun 27, 2013 at 10:15 AM, Easwaran Raman <era...@google.com> wrote:
>>>>> A newly generated statement in build_and_add_sum function of
>>>>> tree-ssa-reassoc.c has to be assigned the UID of its adjacent
>>>>> statement. In one instance, it was assigned the wrong uid (of an
>>>>> earlier phi statement) which messed up the IR and caused the test
>>>>> program to hang. Bootstraps and no test regressions on x86_64/linux.
>>>>> Ok for trunk?
>>>>>
>>>>> Thanks,
>>>>> Easwaran
>>>>>
>>>>>
>>>>> 2013-06-27 Easwaran Raman <era...@google.com>
>>>>>
>>>>> PR middle-end/57370
>>>>> * tree-ssa-reassoc.c (build_and_add_sum): Do not use the UID of a
>>>>> phi
>>>>> node for a non-phi gimple statement.
>>>>>
>>>>> testsuite/ChangeLog:
>>>>> 2013-06-27 Easwaran Raman <era...@google.com>
>>>>>
>>>>> PR middle-end/57370
>>>>> * gfortran.dg/reassoc_12.f90: New testcase.
>>>>>
>>>>>
>>>>> Index: gcc/testsuite/gfortran.dg/reassoc_12.f90
>>>>> ===================================================================
>>>>> --- gcc/testsuite/gfortran.dg/reassoc_12.f90 (revision 0)
>>>>> +++ gcc/testsuite/gfortran.dg/reassoc_12.f90 (revision 0)
>>>>> @@ -0,0 +1,74 @@
>>>>> +! { dg-do compile }
>>>>> +! { dg-options "-O2 -ffast-math" }
>>>>> +! PR middle-end/57370
>>>>> +
>>>>> + SUBROUTINE xb88_lr_adiabatic_lda_calc(e_ndrho_ndrho_ndrho, &
>>>>> + grad_deriv,npoints, sx)
>>>>> + IMPLICIT REAL*8 (t)
>>>>> + INTEGER, PARAMETER :: dp=8
>>>>> + REAL(kind=dp), DIMENSION(1:npoints) :: e_ndrho_ndrho_ndrho, &
>>>>> + e_ndrho_ndrho_rho
>>>>> + DO ii=1,npoints
>>>>> + IF( grad_deriv >= 2 .OR. grad_deriv == -2 ) THEN
>>>>> + t1425 = t233 * t557
>>>>> + t1429 = beta * t225
>>>>> + t1622 = t327 * t1621
>>>>> + t1626 = t327 * t1625
>>>>> + t1632 = t327 * t1631
>>>>> + t1685 = t105 * t1684
>>>>> + t2057 = t1636 + t8 * (t2635 + t3288)
>>>>> + END IF
>>>>> + IF( grad_deriv >= 3 .OR. grad_deriv == -3 ) THEN
>>>>> + t5469 = t5440 - t5443 - t5446 - t5449 - &
>>>>> + t5451 - t5454 - t5456 + t5459 - &
>>>>> + t5462 + t5466 - t5468
>>>>> + t5478 = 0.240e2_dp * t1616 * t973 * t645 * t1425
>>>>> + t5489 = 0.1600000000e2_dp * t1429 * t1658
>>>>> + t5531 = 0.160e2_dp * t112 * t1626
>>>>> + t5533 = 0.160e2_dp * t112 * t1632
>>>>> + t5537 = 0.160e2_dp * t112 * t1622
>>>>> + t5541 = t5472 - t5478 - t5523 + t5525 + &
>>>>> + t5531 + t5533 + t5535 + t5537 + &
>>>>> + t5540
>>>>> + t5565 = t112 * t1685
>>>>> + t5575 = t5545 - t5548 + t5551 + t5553 - &
>>>>> + t5558 + t5560 - t5562 + t5564 - &
>>>>> + 0.80e1_dp * t5565 + t5568 + t5572 + &
>>>>> + t5574
>>>>> + t5611 = t5579 - t5585 + t5590 - t5595 + &
>>>>> + t5597 - t5602 + t5604 + t5607 + &
>>>>> + t5610
>>>>> + t5613 = t5469 + t5541 + t5575 + t5611
>>>>> + t6223 = t6189 - &
>>>>> + 0.3333333336e0_dp * t83 * t84 * t5613 + &
>>>>> + t6222
>>>>> + t6227 = - t8 * (t5305 + t6223)
>>>>> + e_ndrho_ndrho_rho(ii) = e_ndrho_ndrho_rho(ii) + &
>>>>> + t6227 * sx
>>>>> + t6352 = t5440 - t5443 - t5446 - t5449 - &
>>>>> + t5451 - t5454 + &
>>>>> + 0.40e1_dp * t102 * t327 * t2057 * t557 - &
>>>>> + t5456 + t5459 - t5462 + t5466 - &
>>>>> + t5468
>>>>> + t6363 = t5480 - t5489 + &
>>>>> + 0.9600000000e2_dp * t1054 * t640 * t3679
>>>>> + t6367 = t5472 - t5474 - t5478 - t5523 + &
>>>>> + t5525 + t5531 + t5533 + t5535 + &
>>>>> + t5537 - 0.20e1_dp * t102 * t105 * t6363 + &
>>>>> + t5540
>>>>> + t6370 = t5545 - t5548 + t5551 + t5553 - &
>>>>> + t5558 + t5560 - t5562 + t5564 - &
>>>>> + 0.40e1_dp * t5565 + &
>>>>> + t5568 + t5572 + t5574
>>>>> + t6373 = t5579 - t5585 + t5590 - t5595 + &
>>>>> + t5597 - t5602 + t5604 + t5607 + &
>>>>> + t5610
>>>>> + t6375 = t6352 + t6367 + t6370 + t6373
>>>>> + t6380 = - 0.3333333336e0_dp * t83 * t84 * t6375 + t5701
>>>>> + t6669 = -t4704 - t8 * (t6344 + t6380 + t6665)
>>>>> + e_ndrho_ndrho_ndrho(ii) = e_ndrho_ndrho_ndrho(ii) + &
>>>>> + t6669 * sx
>>>>> + END IF
>>>>> + END DO
>>>>> + END SUBROUTINE xb88_lr_adiabatic_lda_calc
>>>>> +
>>>>> Index: gcc/tree-ssa-reassoc.c
>>>>> ===================================================================
>>>>> --- gcc/tree-ssa-reassoc.c (revision 200429)
>>>>> +++ gcc/tree-ssa-reassoc.c (working copy)
>>>>> @@ -1207,7 +1207,7 @@ build_and_add_sum (tree type, tree op1, tree op2,
>>>>> if (gimple_code (op1def) == GIMPLE_PHI)
>>>>> {
>>>>> gsi = gsi_after_labels (gimple_bb (op1def));
>>>>> - gimple_set_uid (sum, gimple_uid (op1def));
>>>>> + gimple_set_uid (sum, gimple_uid (gsi_stmt (gsi)));
>>>>> gsi_insert_before (&gsi, sum, GSI_NEW_STMT);
>>>>> }
>>>>> else
