[Bug tree-optimization/55334] mgrid regression (ipa-cp disables vectorization)

["vincenzo.innocente at cern dot ch" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55334

--- Comment #10 from vincenzo Innocente <vincenzo.innocente at cern dot ch> 2012-11-16 13:46:13 UTC ---
actually looking into the generated code I do not see any trace of "runtime
check"
even in presence of "const"

c++ -O3 -ftree-vectorizer-verbose=1 -c alias.cc 

Analyzing loop at alias.cc:6


Vectorizing loop at alias.cc:6

6: create runtime check for data references *_7 and *_6
6: create runtime check for data references *_9 and *_6
6: created 2 versioning for alias checks.

6: LOOP VECTORIZED.
alias.cc:2: note: vectorized 1 loops in function.
pb-d-128-141-131-26:vectorize innocent$ otool -v -V -t alias.o
alias.o:
(__TEXT,__text) section
__Z3sumv:
0000000000000000    leaq    _mem+0x00001000(%rip),%rax
0000000000000007    leaq    _mem+0x00002000(%rip),%rdx
000000000000000e    nop
0000000000000010    movaps    (%rax),%xmm0
0000000000000013    addq    $0x10,%rax
0000000000000017    addps    0x00000ff0(%rax),%xmm0
000000000000001e    movaps    %xmm0,0xffffeff0(%rax)
0000000000000025    cmpq    %rdx,%rax
0000000000000028    jne    0x00000010
000000000000002a    repz/ret