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Re: shifts and rotates by 1 on ix86
- To: Alan Modra <alan at linuxcare dot com dot au>
- Subject: Re: shifts and rotates by 1 on ix86
- From: Alexander Sokolov <robocop at netlink dot ru>
- Date: Wed, 10 May 2000 13:14:49 +0400 (MSD)
- cc: binutils <binutils at sourceware dot cygnus dot com>
On Wed, 10 May 2000, Alan Modra wrote:
> You can get the smaller opcode sequence by writing "shll %eax".
This should be documented in manual.
> The reason gas does not do this automatically is that on certain processors,
> eg. 486, the D1 E0 opcode sequence is slower than C1 E0 01.
Then why not to add directives like .386, .486 etc or a command line
option to specify the target cpu type?
--
Alexander Sokolov
System Administrator
Netlink Co. Ltd., Moscow
Tel/Fax: +7 095 2786139