[Bug target/26726] -fivopts producing out of bounds array refs

[ubizjak at gmail dot com]

------- Comment #16 from ubizjak at gmail dot com  2007-10-26 10:06 -------
(In reply to comment #14)

> > This is now a target specific problem, on i?86 and x86_64 we are left with an
> > offset of -4B and so referencing &a[5] in the exit condition.
> > 
> This is PR target/24669.

Hm, the testcase in PR 24669 was fixed by adjusting x86 costs, but we still
generate offset of -4 bytes here. There are also some relevant comments in PR
27707 (dupe?).

This issue with -4 offset is annoying because code size of offsetted load insn
is huge:

   f:   c7 40 fc 01 00 00 00    movl   $0x1,-0x4(%eax)

BTW: The issue in Comment #15 is now fixed in the testsuite.


-- 

ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
OtherBugsDependingO|                            |27707
              nThis|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26726