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Re: insns for register-move between general and floating


Greg McGary <greg@mcgary.org> writes:

> I'm working on a port that has instructions to move bits between
> 64-bit floating-point and 64-bit general-purpose regs.  I say "bits"
> because there's no conversion between float and int: the bit pattern
> is unaltered.  Therefore, it's possible to use scratch FPRs for
> spilling GPRs & vice-versa, and float<->int conversions need not go
> through memory.
>
> Among all the knobs to turn regarding register classes, reload
> classes, and modes+constraints on movM, floatMN2, fixMN2 patterns,
> I need some advice on how to do this properly.

The Alpha port supports the "itof" and "ftoi" instructions, which do
exactly that. So you might want to look there.

-- 
	Falk


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