with svn version 133159 the following bugs show up in the tree vectorizer if
you do not bootstrap the compiler:
FAIL: gcc.dg/vect/vect-strided-store-u16-i4.c scan-tree-dump-times vect
"vectorized 1 loops" 2
FAIL: gcc.dg/vect/vect-vfa-03.c scan-tree-dump-times vect "vectorized 1 loops"
1
XPASS: gcc.dg/vect/vect-vfa-03.c scan-tree-dump-times vect "vectorized 1 loops"
0
FAIL: gcc.dg/vect/slp-21.c scan-tree-dump-times vect "vectorized 4 loops" 1
FAIL: gcc.dg/vect/slp-21.c scan-tree-dump-times vect "vectorizing stmts using
SLP" 2
and the bugs go away when you bootstrap. I have made modifications to
register allocator, and these downstream changes cause the compiler to be
enough different so that the bugs become hard failures.
however the bugs are easily reproducible by
--enable-languages=c --with-cpu=default-32 --disable-multilib
--disable-bootstrap
with this version of the compiler. I have not played around with this in other
revisions. I know that this combo will reproduce the issue. Since this is
most likely a storage leak or an uninitialized variable, it is important to
recreate the environment exactly.
Kenny
--
Summary: heisenbug in tree vectorizer
Product: gcc
Version: 4.4.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: zadeck at naturalbridge dot com
GCC build triplet: powerpc-unknown-linux-gnu 32 bit compiler
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35642
