.hi .lo notations

Tom Rodriguez Thomas.Rodriguez at Sun.COM
Mon Dec 7 09:10:44 PST 2009

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
alloc_class chunk0( ECX,   EBX,   EBP,   EDI,   EAX,   EDX,   ESI, ESP,


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

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