note_stores vs. PRE_DEC, POST_INC and so on

[Ian Lance Taylor]

Rask Ingemann Lambertsen <rask@sygehus.dk> writes:

>    The comment for note_stores() (in rtlanal.c) says:
> 
> /* Call FUN on each register or MEM that is stored into or clobbered by X.
>    (X would be the pattern of an insn).
> 
>    But this doesn't happen when a register is modified by e.g. a PRE_DEC
> expression. Is this an oversight or intentional? If intentional, the comment
> should say so and perhaps also why.

The note_stores interface doesn't really provide a way to handle
PRE_DEC or other such expressions.  We could change that by redefining
the interface, but we would need to audit all the calls to
note_stores.  That would be a good idea in any case since it is
certainly possible, even likely, that some of them should be handle
autoincrement expressions but aren't.

Ian