Register Rematerialization In New Register Allocator

[Michael Matz]

Hi,

On Thu, 24 Jul 2003, Mukta Punjani, Noida wrote:

> 1. For constructing remat computation sequence for pseudos -
>    o df.h - struct ref(corresponding to each def) to be modified to hold the
> remat insn sequence (in terms of the insn uids) for the def making up the
> insn chain.

Hmm, so you not just want to remember the actual expression, but really
the whole construction sequence, which possibly consists of more than
one insn, yes?  Why?  IOW why is the expression itself not enough?  I
would guess, that if for instance the 'pattern' would contain something
like:
  (plus:SI (plus:SI (mult:SI (reg:SI x) (reg:SI y)) (reg:SI z)) (const 4))
the necessary insn sequence to actually calculate this expression can be
generated on the fly.

> More comments/suggestions awaited.

Other than the above this plan looks like a natural and good extension to
the current method, indeed.


Ciao,
Michael.