.hi .lo notations

[Tom Rodriguez]

I've considered adding support for $$second in the adlc so that we can replace all these .lo/.hi things with the real register but it never moved to the top of the list.  hi/lo isn't really even a good description of the notion since that's a platform dependent thing.  Basically foo.lo is foo and foo.hi is the next following register in the alloc_class chunk0.

// For the Intel integer registers, the equivalent Long pairs are
// EDX:EAX, EBX:ECX, and EDI:EBP.
alloc_class chunk0( ECX,   EBX,   EBP,   EDI,   EAX,   EDX,   ESI, ESP,

tom

On Dec 4, 2009, at 6:04 PM, Hiroshi Yamauchi wrote:

> Hi,
> 
> In PrintOptoAssembly output, I see .hi and .lo notations used for
> handling 64 bit long values on 32 bit Linux x86. For example, EAX.hi
> or EBP.lo.
> 
> I heard that they are aliases to other registers. If so, what are the
> exact rules about the aliases?
> 
> Thanks,
> Hiroshi