This is the mail archive of the gcc-bugs@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

[Bug middle-end/38868] [4.4 Regression] r143152 breaks output routines in xplor-nih



------- Comment #39 from bonzini at gnu dot org  2009-01-19 11:04 -------
Looks like a scheduling bug:

-O1 -fforward-propagate has
        leal    -676(%ebp), %edi
        movl    $19, %ecx
        movl    $538976288, %eax
        rep stosl
        movw    $31096, -603(%ebp)
        movb    $122, -601(%ebp)

-O1 -fforward-propagate -fschedule-insns has
        leal    -676(%ebp), %edi
        movl    $19, %ecx
        movw    $31096, -603(%ebp)
        movl    $538976288, %eax
        rep stosl
        movb    $122, -601(%ebp)

and 676+19*4 = 600 so -603(%ebp) is 0x2020 in the bad code, 0x7978 in the good
code.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38868


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]