Kevin D. Kissell wrote: > > Nigel Stephens wrote: > > > Thiemo Seufer wrote: > > > >GNU as has "move" as builtin macro which is expanded differently for > > > >32 and 64 bit mode. This simplifies the task of writing code for both > > > >models. Unfortunately the expansion was broken for a while and > > > >generated always the 64 bit version if the toolchain was 64bit > > > >_capable_. IIRC this was fixed in the early 2.14 timeframe. > > > > > > Wouldn't it be safer, as Kevin suggests, for the "move" macro to > > > generate "or $rd,$0,$rs", since that will work correctly in either mode? > > > > For CPUs with two adders the instruction scheduling is a bit better. > > For CPUs with two adders, only one of which can do ORs, you mean. Yes. > Isn't that a pretty small population of MIPS CPUs? Sure, but there's little reason to deny this optimization. > > Ther are also many other macros which are expanded in dependence of > > the 32/64 bit address/register size, a different "move" macro > > expansion won't help much if the assembler invocation was wrong. > > Perhaps, but it strikes me as being only prudent to remove unnecessarily > fragile artifacts like this. It was an assembler bug. Thiemo
