[Bug target/26436] [3.4 only] Use of 'mov' may violate WAW dependency 'GR%, % in 1 - 127' (impliedf), specific resource number is 14

["wilson at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #15 from wilson at gcc dot gnu dot org  2006-03-02 00:06 -------
Created an attachment (id=10952)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=10952&action=view)
not recommended prototype patch to avoid assembler bug

I have a gcc-3.4.x patch that silences the assembler warnings for the testcase.
 However, I am not particularly happy about it.  It doesn't handle every
possible case.  Also, it doesn't attempt to verify that the predicate registers
are mutex.  It just emits a directive to disable the assembler warning.  In the
worst case, this could mask a gcc bug that would otherwise be found by the
assembler DV checks.  I haven't done any testing on this, other than running it
on the testcase.

I think it would be best if the problem was fixed in the assembler.  Meanwhile,
if you get suspicious assembler warnings, you can check the assembly code
yourself to see if there is a real problem, or if this is an assembler bug.  Or
if you are desperate, you can try using this patch.

I don't plan to do any further work on this.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26436