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Re: Suggestion for a fix to Bug middle-end/20177

From: kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner)
To: MUSTAFA at il dot ibm dot com
Cc: gcc at gcc dot gnu dot org
Date: Wed, 16 Mar 05 10:27:59 EST
Subject: Re: Suggestion for a fix to Bug middle-end/20177

    REG_NOTE (NONNEG)
    REG_NOTE (NO_CONFLICT)
    REG_NOTE (UNUSED)
       mustn't be copied
       describe a fact about other instructions so this
       may change if copied.

Tricky.  Often UNUSED means that we're allocating a psuedo for some temporary
which we know isn't used. 

    REG_NOTE (CC_SETTER)
    REG_NOTE (CC_USER)
      I suppose that using CC0 is possible only in branch instructions (correct
    me if I am wrong)

It can also be used in "scc" insns.

Follow-Ups:
- Re: Suggestion for a fix to Bug middle-end/20177
  - From: Mostafa Hagog

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