[Bug target/32437] [4.3 Regression] MIPS: FAIL in gcc.dg/cleanup-[8|9|10|11].c

["ian at airs dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #23 from ian at airs dot com  2007-06-30 17:57 -------
The patch in comment #19 of PR 32437 looks clearly correct.  That
patch should not be reverted, at least not by itself.  I'm not clear
on whether that was the patch that was reverted, but, if it was, I
don't think it should have been.  We are not in a time critical
situation here.  Let's take the time to figure out the right fix even
if Richard doesn't have time to work on it.

This is DCE, not DSE.  In DSE we can not eliminate frame related
instructions, because the stores into the frame are used by code which
dataflow doesn't see: the exception unwinder.  That does not apply to
DCE.  In DCE, we should be able to eliminate changes to the stack
pointer when the stack pointer is not used, even though those changes
are frame related.

So I think this patch should be unreverted, and I don't think you should add a
test for frame relatedness.  Then we should fix PR 32475.  Further comments
over there.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32437