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[Bug libfortran/77473] New: New PRNG causes regressions on DragonFly BSD
- From: "rimvydas.jas at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Sun, 04 Sep 2016 14:23:52 +0000
- Subject: [Bug libfortran/77473] New: New PRNG causes regressions on DragonFly BSD
- Auto-submitted: auto-generated
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77473
Bug ID: 77473
Summary: New PRNG causes regressions on DragonFly BSD
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libfortran
Assignee: unassigned at gcc dot gnu.org
Reporter: rimvydas.jas at gmail dot com
Target Milestone: ---
Created attachment 39550
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=39550&action=edit
changes to tests
Native configuration is x86_64-unknown-dragonfly4.7
r239356 Replace KISS PRNG with xorshift1024* using per-thread state
caused all execution failures for:
FAIL: gfortran.dg/random_7.f90 -O0 execution test
FAIL: gfortran.fortran-torture/execute/random_1.f90 execution, -O0
r239611 Always initialize PRNG using random data from the OS
added:
FAIL: gfortran.dg/random_4.f90 -O0 execution test
Adding prints for seed and check arrays before comparison shows that they
differ:
./random_4.x
seed 42 42 42 42 42 42
42 42 42 42 42 42
42 42 42 42 42 42 42
42 42 42 42 42 42 42
42 42 42 42 42 42
0
check -2110421118 -1194805269 1415242221 54534463 1225148040 821055102
-1530405947 -1820502322 2146652427 -147906310 -1761641582 -1622508139
2006260459 151764285 -1191598697 -239551325 -1064082961 2093503284
1165045647 -1200385605 -867398903 -830236747 846618033 706688103
1954790377 859476278 -1696051309 -1413451556 -1779817981 1071423788
1556108935 1966576166 0
If -pthread is explicitly used for those tests (attachment) only failure left
is gfortran.dg/graphite/pr68279.f90 pr71348
(execute/random_1.f90 still fails in testsuite - doesn't take -pthread flag)
Should libgfortran.so always bring in libpthread.so or new PRNG could be
changed to have deterministic behavior with or without -pthread on DragonFly?