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RE: Deep CSE bug!
- From: Roger Sayle <roger at eyesopen dot com>
- To: Dave Korn <dk at artimi dot com>
- Cc: gcc at gcc dot gnu dot org
- Date: Fri, 18 Jun 2004 08:28:46 -0600 (MDT)
- Subject: RE: Deep CSE bug!
My apologies for the appalling grammar! When I typed it in this end my
message was in English, but ping reports 40% packet loss between me and
my mail server, and I'm getting 30 second delays between typing a
character and it appearing in pine!
On Fri, 18 Jun 2004, Roger Sayle wrote:
> that it is the REG_EQUAL note states that at the point this instruction
> is executed "bar" will have the same value as "baz". The REG_EQUAL note
> is used to record the equivalence when (set (foo) (baz)) is either not
> not recognized/available as a backend, or has a higher cost than the
> original. In normal use, "baz" will be more grounded (contain more
> constants) than "bar". In the RTL optimizers, it should always be
> valid to reasonable the SET_SRC on an instruction with its REG_EQUAL
> note (except when the REG_EQUAL notes contains an expression list).