other/7114: ICE building strcoll.op from glibc-2.2.5

Alan Modra amodra@bigpond.net.au
Mon Jul 15 16:54:00 GMT 2002


On Mon, Jul 15, 2002 at 12:43:02PM -0700, Geoff Keating wrote:
> > Date: Mon, 15 Jul 2002 18:56:03 +0930
> > From: Alan Modra <amodra@bigpond.net.au>
> 
> > This patch cures the testcase.  The !using_store_multiple code tests
> > whether regs are live before saving.  We need to do something similar
> > for using_store_multiple, in case all regs need not be saved.
> 
> Those registers are actually saved, whether they need to be or not,
> correct?
> 
> So the RTL generated is an accurate representation of the instruction,
> and the bug must be elsewhere.

The testcase saves r30 and r31, but both are marked unused (don't
appear in regs_ever_live).  Later rtl analysis decides that the
save instruction can be eliminated, thus the ICE.  The real bug is
that r30 is not marked used when current_function_needs_context.
This is also the reason for PR5967.

The code that I copied from the !using_store_multiple case just
papers over this bug.  So the above patch merely makes -mmultiple
and -mno-multiple consistently wrong.

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre



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