Ticket #118 (closed defect: fixed)

Opened 13 months ago

Last modified 12 months ago

sparselu: divison by zero in checkmat()

Reported by: Nathan Weeks <weeks@…> Owned by:
Priority: minor Milestone: version 1.2
Component: sparselu Version: version 1.1
Keywords: Cc:
Application Version: omp-tasks Blocked By:
Blocking: Sensitive: no
Needs experiment: no
Experimental observations:
$ idbc -dbx bin/sparselu.intel.single-omp-tasks
Intel(R) Debugger for applications running on Intel(R) 64, Version 12.0, Build [1.3842.2.154]
------------------
object file name: bin/sparselu.intel.single-omp-tasks
Reading symbolic information from /home/weeks/bots/bin/sparselu.intel.single-omp-tasks...done
(idb) run -n 10x10 -c
Structure for matrix serial @ 0x0x63e580
xxx x x x
xxx
xxxx
  xxx
x  xxx
    xxx
x    xxxx
      xxx
x     xxxx
        xx
Structure for matrix serial @ 0x0x63e580
xxx x x x
xxx x x x
xxxxx x x
  xxx x x
xxxxxxx x
    xxx x
xxxxxxxxx
      xxx
xxxxxxxxxx
        xx
Structure for matrix benchmark @ 0x0x888b70
xxx x x x
xxx
xxxx
  xxx
x  xxx
    xxx
x    xxxx
      xxx
x     xxxx
        xx
Computing SparseLU Factorization (10x10 matrix with 100x100 blocks)  completed!
Structure for matrix benchmark @ 0x0x888b70
xxx x x x
xxx x x x
xxxxx x x
  xxx x x
xxxxxxx x
    xxx x
xxxxxxxxx
      xxx
xxxxxxxxxx
        xx
Thread received signal FPE
stopped at [int checkmat(float*, float*):44 0x0000000000402ce0]
     44          r_err = r_err / M[i*bots_arg_size_1+j];
(idb) printf "%f", M[i*bots_arg_size_1+j]
0.000000
(idb) print i
84
(idb) print j
11

Description

There is a division-by-zero exception in checkmat() in the omp-tasks versions
of sparselu when check mode ("-c") is used. This can be triggered using the
following compilers:

1. Intel 12.0 with the "-fp-trap=common" option specified at compile time
2. PGI 11.0 compiler with the "-Ktrap=fp" option specified at compile time

Change History

Changed 12 months ago by ALEX DURAN <aduran@…>

  • status changed from new to closed
  • resolution set to fixed

(In [0602f9a0c1d71b3705f2bcb71f51c0c658b7d61e]) Check for zero-values in SparseLU checkmat (closes #118)

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