[Bug middle-end/57370] New: [4.9 Regression] compile time hog in reassoc

[Bug middle-end/57370] New: [4.9 Regression] compile time hog in reassoc

[Joost.VandeVondele at mat dot ethz.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57370

            Bug ID: 57370
           Summary: [4.9 Regression] compile time hog in reassoc
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: Joost.VandeVondele at mat dot ethz.ch

Between rev 199047 and 199075 the attached testcase started using an excessive
amount of time (up from about 4s with 4.7.2). The important option seems to be
-ffast-math (16s without this option).

Reproduce with:

time gfortran -c -g -O2 -ffast-math bug.f90

The stack looks like:

#0  0x0000000000af4b79 in reassociate_bb(basic_block_def*) ()
#1  0x0000000000af4ae8 in reassociate_bb(basic_block_def*) ()
#2  0x0000000000af4ae8 in reassociate_bb(basic_block_def*) ()
#3  0x0000000000af4ae8 in reassociate_bb(basic_block_def*) ()
#4  0x0000000000af4ae8 in reassociate_bb(basic_block_def*) ()
#5  0x0000000000af6701 in execute_reassoc() ()
#6  0x0000000000906550 in execute_one_pass(opt_pass*) ()

[Bug middle-end/57370] [4.9 Regression] compile time hog in reassoc

[Joost.VandeVondele at mat dot ethz.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57370

Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |Joost.VandeVondele at mat dot ethz
                   |                            |.ch

--- Comment #1 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> ---
Created attachment 30162
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30162&action=edit
testcase

[Bug middle-end/57370] [4.9 Regression] compile time hog in reassoc

[Joost.VandeVondele at mat dot ethz.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57370

Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |eraman at google dot com

--- Comment #2 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> ---
I assume it is caused by

http://gcc.gnu.org/viewcvs/gcc?view=revision&revision=199048

[Bug middle-end/57370] [4.9 Regression] compile time hog in reassoc

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57370

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.9.0

[Bug middle-end/57370] [4.9 Regression] compile time hog in reassoc

[Joost.VandeVondele at mat dot ethz.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57370

--- Comment #3 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> ---
I actually suspect the compilation is in an infinite loop. Still running after
15min.

[Bug middle-end/57370] [4.9 Regression] compile time hog in reassoc

[Joost.VandeVondele at mat dot ethz.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57370

--- Comment #4 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> ---
I killed the compilation after 15h...

[Bug middle-end/57370] [4.9 Regression] compiler hangs in reassoc

[Joost.VandeVondele at mat dot ethz.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57370

Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.9 Regression] compile    |[4.9 Regression] compiler
                   |time hog in reassoc         |hangs in reassoc

--- Comment #5 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> ---
This is actually hanging and not just taking a long time. 

I've also create PR57393 which is an ICE that happened during an attempt to
reduce the testcase of this PR. This might or might not be related.

[Bug middle-end/57370] [4.9 Regression] compiler hangs in reassoc

[Joost.VandeVondele at mat dot ethz.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57370

--- Comment #6 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> ---
Reduced testcase, which appears 'minimal' to trigger a hanging compilation at 

gfortran -c -O2 -ffast-math bug.f90

> cat bug.f90
  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

[Bug middle-end/57370] [4.9 Regression] compiler hangs in reassoc

[Joost.VandeVondele at mat dot ethz.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57370

--- Comment #7 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> ---
Since the bug is still 'unconfirmed', I'm wondering if this can not be
reproduced, or if I can provide some more information (more than the small
testcase in comment #6 and the revision that caused it in comment #2) ?

[Bug tree-optimization/57370] [4.9 Regression] compiler hangs in reassoc

[glisse at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57370

Marc Glisse <glisse at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-06-13
          Component|middle-end                  |tree-optimization
     Ever confirmed|0                           |1

--- Comment #8 from Marc Glisse <glisse at gcc dot gnu.org> ---
Confirmed.

[Bug tree-optimization/57370] [4.9 Regression] compiler hangs in reassoc

[Joost.VandeVondele at mat dot ethz.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57370

Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                URL|                            |http://gcc.gnu.org/ml/gcc-p
                   |                            |atches/2013-07/msg01584.htm
                   |                            |l

--- Comment #9 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> ---
fixed with the patch in :
http://gcc.gnu.org/ml/gcc-patches/2013-07/msg01584.html

[Bug tree-optimization/57370] [4.9 Regression] compiler hangs in reassoc

[eraman at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57370

--- Comment #10 from eraman at gcc dot gnu.org ---
Author: eraman
Date: Wed Sep  4 17:48:15 2013
New Revision: 202262

URL: http://gcc.gnu.org/viewcvs?rev=202262&root=gcc&view=rev
Log:
2013-09-04  Easwaran Raman  <eraman@google.com>

    PR middle-end/57370
    PR tree-optimization/58011
    * tree-ssa-reassoc.c (get_stmt_uid_with_default): New function,
    (build_and_add_sum): Use it.
    (appears_later_in_bb): Simplify code.

gcc/testsuite/ChangeLog:
2013-09-04  Easwaran Raman  <eraman@google.com>

    PR middle-end/57370
    PR tree-optimization/58011
    * gfortran.dg/reassoc_12.f90: New testcase.
    * gcc.dg/tree-ssa/reassoc-31.c: New testcase.


Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/reassoc-31.c
    trunk/gcc/testsuite/gfortran.dg/reassoc_12.f90
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-reassoc.c

[Bug tree-optimization/57370] [4.9 Regression] compiler hangs in reassoc

[Joost.VandeVondele at mat dot ethz.ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57370

Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> changed:

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

--- Comment #11 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> ---
Fixed. 

Easwaran please reopen if you have a specific reason for not closing this PR
(usually developers close the PRs for which they commit patches).