From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <8b329015bd7b449ab8a5147291d081de@caldo.demon.co.uk> To: 9fans@cse.psu.edu Subject: Re: [9fans] 8a/8l bug From: Charles Forsyth In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Thu, 18 Dec 2003 00:25:13 +0000 Topicbox-Message-UUID: a880f84a-eacc-11e9-9e20-41e7f4b1d025 a linker option seems wrong, since it's not a global attribute, but the correctness of the substitution depends on the surrounding context. it's usually perfectly all right to replace ADDL $1, ... by INCL for instance. one way might be to add a pseudo-op (similar to NOSCHED) that could be used by either assembler or compiler to constrain instruction selection. that's possibly a nuisance to use and implement. another method is to have the linker check whether the shorter instruction is actually equivalent in context to the longer one it must otherwise use, since that's really the problem here (eg, either the flag bits are set the same way or subsequent instructions don't need them)