.hi .lo notations

Hiroshi Yamauchi yamauchi at google.com
Mon Dec 7 16:05:14 PST 2009

 Hi guys,

-XX:+PrintAssembly and the alloc_class chunk0 both made sense to me.



On Mon, Dec 7, 2009 at 9:10 AM, Tom Rodriguez <Thomas.Rodriguez at sun.com> wrote:
> 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,
> 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

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