[RFC PATCH] Implement dummy x87/MMX FPU mode switching

Uros Bizjak uros.bizjak@kss-loka.si
Wed Jun 15 07:44:00 GMT 2005


Hello!

> Attached patch implements dummy LCM mode switching to switch x87 FPU 
> between x87 and MMX mode. Currently, it just inserts dummy markers into 
> assembler dumps to show, where mode switching instructions would be

I forgot to say that before mode switching (as described in
http://gcc.gnu.org/ml/gcc-patches/2005-06/msg00569.html) is implemented, all
insn patterns should be reviewed regarding "unit" attribute setting. There is a
problem when attribute "type" is set to "multi". In this case, "unit" attribute
defaults to "integer" (which is a bit strange by itself). To overcome this
problem, "unit" attribute should be explicitly set to "i387" or "mmx" in every
pattern that has "type" attribute defined to "multi".

Uros.



More information about the Gcc-patches mailing list