Re: how to build a non-lwl gcc

[James E Wilson <wilson at specifixinc dot com>]

eagle_zhou@ali.com.tw wrote:
> I am developing program on mips flatform,
> but my mips platform do not support lwl/lwr/.. instruction.

All MIPS processors have lwl/lwr instruction.

MIPS clones built without benefit of a MIPS license never have lwl/lwr, 
because they are covered by a patent.  So presumably you are trying to 
generate code for an unlicensed MIPS clone.

Currently, we have no support for mips clones in the mips port.  I tried 
submitting a binutils patch for the mips port for a mips clone once, and 
it was rejected on the grounds that it wasn't actually a mips part. 
There was some concern about legal issues here.  We shouldn't claim 
something is a mips part when it isn't, as that may infringe on MIPS 
(the company) trademarks.  Anyways, we can work around this problem by 
creating a new configuration tuple, and then including mips files as 
necessary into the new port.  I never got around to trying this.

It is easy enough to hack up the MIPS port to do what you want though. 
If you disable the bitfield patterns, extv, extzv, insv, and if you 
disable the builtin memcpy patterns, then that should be good enough. 
You can probably do better with memcpy, e.g. you can probably just 
disable the bits that emit lwl/etc sequences, and still make use of the 
rest of the code.
--
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com