Re: Question about Register Class Allocation

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Question about Register Class Allocation
\ Balaji V. Iyer (29 Jan 2008)
. \ Ian Lance Taylor (30 Jan 2008)

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Subject:	Re: Question about Register Class Allocation
Group:	Gcc
From:	Ian Lance Taylor
Date:	30 Jan 2008

"Balaji V. Iyer" <bviyer> writes:

> I saw that regclass() function determines which class of register
> the registers in the current units should be assigned to. The question I
> have is: Will this decision change in any other parts of the compiler?
> or is this this the final place where they fix the register class? So,
> if I add my own priority-based register-class assigner, can I just
> replace this function and add my own?

regclass sets preferences. Those preferences will not change later.
The register allocator will honor those preferences if possible.
However, it is not required to honor them. It is only required to
honor the constraints in the MD file.

Ian