separate integer and float registers
Chip Salzenberg
chip at ateng.uucp
Wed Sep 7 01:58:08 AEST 1988
[ this is becoming language-specific; followups are directed to comp.lang.c ]
According to alverson at decwrl.dec.com (Robert Alverson):
>One unfortunate aspect of separate fp and integer registers shows up
>with varargs parameter passing. Given that you want to pass parameters
>in registers in optimized code, it seems that any call to a varargs
>procedure must be detected, and any fp parameters passed in integer
>registers.
No. Fp variables may reside in a separate set of registers and be found
there by a varargs function. This approach requires compiler support for
noticing the actual type of each varargs parameter instead of just its
size; but that's why we have varargs (or stdarg) in the first place.
--
Chip Salzenberg <chip at ateng.uu.net> or <uunet!ateng!chip>
A T Engineering My employer may or may not agree with me.
The urgent leaves no time for the important.
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