[Bug target/23322] [4.1/4.2/4.3 regression] performance regression: global regalloc doesn't split live ranges

[hubicka at gcc dot gnu dot org]

------- Comment #17 from hubicka at gcc dot gnu dot org  2008-02-05 16:18 
-------
The simplified testcase is dealt with the call crossed frequency patch.  I now
get:
.L2:
        faddl   (%edx,%eax,8)
        addl    $1, %eax
        cmpl    $2000, %eax
        jne     .L2
        fstpl   -24(%ebp)
        call    foo
        fldl    -24(%ebp)
        leave
        ret

With full testcase:
[EMAIL PROTECTED]:/aux/hubicka/trunk-write/buidl2/gcc$
/aux/hubicka/gcc-install/bin/g++ -O2 tt.cc --static
[EMAIL PROTECTED]:/aux/hubicka/trunk-write/buidl2/gcc$ time ./a.out

real    0m4.102s
user    0m4.092s
sys     0m0.008s

[EMAIL PROTECTED]:/aux/hubicka/trunk-write/buidl2/gcc$ g++-3.3 -O2 tt.cc 
--static
[EMAIL PROTECTED]:/aux/hubicka/trunk-write/buidl2/gcc$ time ./a.out

real    0m3.714s
user    0m3.708s
sys     0m0.000s

I don't have 2.95.3.  But we probably need to analyze what happent relatively
to 3.3 and 3.4 too


-- 

hubicka at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2005-08-11 14:56:31         |2008-02-05 16:18:23
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23322