Line number notes revamp?

[Richard Henderson]

On Wed, Sep 12, 2001 at 04:46:43PM +0200, Jan Hubicka wrote:
> I think for line numbers we should use same - have REG_LINENUM note
> that has value pointing to the linenum record - eighter represented
> in RTL as (linenum line column string) or separately.

I think having a dedicated field in the INSN rtx will use less space.

We could have a magic value (0?) that means "no assigned line number",
which means that no line number entry is emitted for this insn, which
means it appears at whatever line number is assigned to some preceeding
insn.

> (we may want to attach multiple lines to single insn in combining).

Why?  How would you represent this in the debug format?

> later we may add linenum_emit_insn instruction familly to handle this in cases
> we want to emit new instruction with line number information atached.

Possibly.  But there are lots of insns that we emit (particularly spill
code) for which no line number is necessarily appropriate.


r~