Question about insn predicates and constraints

[Andreas Schwab]

Richard Sandiford <rdsandiford@googlemail.com> writes:

> Worse than redundant really.  If the register operand is a spilled pseudo,
> "o" allows reload to replace the operand with a stack memory reference,
> which would lead to an ICE after reload.  (Reload only checks constraints
> in that situation, not predicates.)

What kind of ICE would that be?  Perhaps recog complaining that the insn
no longer matches?  (Since the insn body happily handles a MEM that
would not be the problem.)

> Which is just a way of saying that there were even more reasons for
> making the change you wanted to make...

What I really want to find out is the motivation for the original
changes in revision 11511.  There are similar problems left in vax.md,
btw.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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